name: Linux
on: [push]
permissions:
  contents: read
jobs:
  gcc:
    runs-on: ubuntu-22.04
    strategy:
      matrix:
        cfgopt:
          - ""
          - "CFLAGS=-DTCL_UTF_MAX=3"
          - "CFLAGS=-DTCL_NO_DEPRECATED=1"
          - "--disable-shared"

name: Build Binaries
on: [push]
permissions:
  contents: read
jobs:
  linux:
    name: Linux
    runs-on: ubuntu-20.04
    defaults:
      run:
        shell: bash
    steps:
      - name: Checkout
        uses: actions/checkout@v3
      - name: Prepare

config.status
config.status.lineno
html
manifest.uuid
_FOSSIL_
*/tclConfig.sh
*/tclsh*
*/tcltest
*/versions.vc
*/version.vc
*/libtcl.vfs
*/libtcl*.zip
*/tclUuid.h
libtommath/bn.ilg
libtommath/bn.ind

.PP
The \fIwideSeekProc\fR field contains the address of a function called by the
generic layer to move the access point at which subsequent input or output
operations will be applied. \fIWideSeekProc\fR must match the following
prototype:
.PP
.CS
typedef long long \fBTcl_DriverWideSeekProc\fR(
        void *\fIinstanceData\fR,
        long long \fIoffset\fR,
        int \fIseekMode\fR,
        int *\fIerrorCodePtr\fR);
.CE
.PP
The \fIinstanceData\fR argument is the same as the value given to
\fBTcl_CreateChannel\fR when this channel was created.  \fIOffset\fR and
\fIseekMode\fR have the same meaning as for the \fBTcl_Seek\fR

'\"
'\" Copyright (c) 1996-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH Tcl_CreateObjCommand 3 8.0 Tcl "Tcl Library Procedures"
.so man.macros
.BS
.SH NAME
Tcl_CreateObjCommand, Tcl_CreateObjCommand2, Tcl_DeleteCommand, Tcl_DeleteCommandFromToken, Tcl_GetCommandInfo, Tcl_GetCommandInfoFromToken, Tcl_SetCommandInfo, Tcl_SetCommandInfoFromToken, Tcl_GetCommandName, Tcl_GetCommandFullName, Tcl_GetCommandFromObj \- implement new commands in C
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
Tcl_Command
\fBTcl_CreateObjCommand\fR(\fIinterp, cmdName, proc, clientData, deleteProc\fR)
.sp
Tcl_Command
\fBTcl_CreateObjCommand2\fR(\fIinterp, cmdName, proc2, clientData, deleteProc\fR)
.sp
int
\fBTcl_DeleteCommand\fR(\fIinterp, cmdName\fR)
.sp
int
\fBTcl_DeleteCommandFromToken\fR(\fIinterp, token\fR)
.sp
int

.AP Tcl_Interp *interp in
Interpreter in which to create a new command or that contains a command.
.AP "const char" *cmdName in
Name of command.
.AP Tcl_ObjCmdProc *proc in
Implementation of the new command: \fIproc\fR will be called whenever
\fIcmdName\fR is invoked as a command.
.AP Tcl_ObjCmdProc2 *proc2 in
Implementation of the new command: \fIproc2\fR will be called whenever
\fIcmdName\fR is invoked as a command.
.AP void *clientData in
Arbitrary one-word value to pass to \fIproc\fR and \fIdeleteProc\fR.
.AP Tcl_CmdDeleteProc *deleteProc in
Procedure to call before \fIcmdName\fR is deleted from the interpreter;
allows for command-specific cleanup. If NULL, then no procedure is
called before the command is deleted.
.AP Tcl_Command token in

.CS
typedef void \fBTcl_CmdDeleteProc\fR(
        void *\fIclientData\fR);
.CE
.PP
The \fIclientData\fR argument will be the same as the \fIclientData\fR
argument passed to \fBTcl_CreateObjCommand\fR.
.PP
\fBTcl_CreateObjCommand2\fR does the same as \fBTcl_CreateObjCommand\fR,
except its \fIproc2\fR argument is of type \fBTcl_ObjCmdProc2\fR.
.PP
.CS
typedef int \fBTcl_ObjCmdProc2\fR(
        void *\fIclientData\fR,
        Tcl_Interp *\fIinterp\fR,
        size_t \fIobjc\fR,
        Tcl_Obj *const \fIobjv\fR[]);
.CE
.PP
\fBTcl_DeleteCommand\fR deletes a command from a command interpreter.
Once the call completes, attempts to invoke \fIcmdName\fR in
\fIinterp\fR will result in errors.
If \fIcmdName\fR is not bound as a command in \fIinterp\fR then
\fBTcl_DeleteCommand\fR does nothing and returns -1;  otherwise
it returns 0.

    Tcl_ObjCmdProc *\fIobjProc\fR;
    void *\fIobjClientData\fR;
    Tcl_CmdProc *\fIproc\fR;
    void *\fIclientData\fR;
    Tcl_CmdDeleteProc *\fIdeleteProc\fR;
    void *\fIdeleteData\fR;
    Tcl_Namespace *\fInamespacePtr\fR;
    Tcl_ObjCmdProc2 *\fIobjProc2\fR;
    void *\fIobjClientData2\fR;
} \fBTcl_CmdInfo\fR;
.CE
.PP
The \fIisNativeObjectProc\fR field has the value 2 if
\fBTcl_CreateObjCommand2\fR was called to register the command;
it has the value 1 if \fBTcl_CreateObjCommand\fR was called to
register the command; it is 0 if only \fBTcl_CreateCommand\fR was called.
It allows a program to determine whether it is faster to
call \fIobjProc2\fR, \fIobjProc\fR or \fIproc\fR:
\fIobjProc2\fR/\fIobjProc\fR is normally faster
if \fIisNativeObjectProc\fR has the value 2;
\fIobjProc\fR/\fIobjProc\fR is normally faster
if \fIisNativeObjectProc\fR has the value 1.
The fields \fIobjProc\fR and \fIobjClientData\fR
have the same meaning as the \fIproc\fR and \fIclientData\fR
arguments to \fBTcl_CreateObjCommand\fR;
they hold information about the value-based command procedure
that the Tcl interpreter calls to implement the command.
The fields \fIproc\fR and \fIclientData\fR

'\"
'\" Copyright (c) 1989-1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2002 Kevin B. Kenny <kennykb@acm.org>.  All rights reserved.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH Tcl_CreateTrace 3 "" Tcl "Tcl Library Procedures"
.so man.macros
.BS
.SH NAME
Tcl_CreateTrace, Tcl_CreateObjTrace, Tcl_CreateObjTrace2, Tcl_DeleteTrace \- arrange for command execution to be traced
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
Tcl_Trace
\fBTcl_CreateTrace\fR(\fIinterp, level, proc, clientData\fR)
.sp
Tcl_Trace
\fBTcl_CreateObjTrace\fR(\fIinterp, level, flags, objProc, clientData, deleteProc\fR)
.sp
Tcl_Trace
\fBTcl_CreateObjTrace2\fR(\fIinterp, level, flags, objProc2, clientData, deleteProc\fR)
.sp
\fBTcl_DeleteTrace\fR(\fIinterp, trace\fR)
.SH ARGUMENTS
.AS Tcl_CmdObjTraceDeleteProc *deleteProc
.AP Tcl_Interp *interp in
Interpreter containing command to be traced or untraced.
.AP int level in
Only commands at or below this nesting level will be traced unless
0 is specified.  1 means
top-level commands only, 2 means top-level commands or those that are
invoked as immediate consequences of executing top-level commands
(procedure bodies, bracketed commands, etc.) and so on.
A value of 0 means that commands at any level are traced.
.AP int flags in
Flags governing the trace execution.  See below for details.
.AP Tcl_CmdObjTraceProc *objProc in
Procedure to call for each command that is executed.  See below for
details of the calling sequence.
.AP Tcl_CmdObjTraceProc2 *objProc2 in
Procedure to call for each command that is executed.  See below for
details of the calling sequence.
.AP Tcl_CmdTraceProc *proc in
Procedure to call for each command that is executed.  See below for
details on the calling sequence.
.AP void *clientData in
Arbitrary one-word value to pass to \fIobjProc\fR, \fIobjProc2\fR or \fIproc\fR.
.AP Tcl_CmdObjTraceDeleteProc *deleteProc in
Procedure to call when the trace is deleted.  See below for details of
the calling sequence.  A NULL pointer is permissible and results in no
callback when the trace is deleted.
.AP Tcl_Trace trace in
Token for trace to be removed (return value from previous call
to \fBTcl_CreateTrace\fR).

A Tcl value containing the script to execute.
.AP int flags in
ORed combination of flag bits that specify additional options.
\fBTCL_EVAL_GLOBAL\fR and \fBTCL_EVAL_DIRECT\fR are currently supported.
.AP "const char" *fileName in
Name of a file containing a Tcl script.
.AP size_t objc in
The number of values in the array pointed to by \fIobjv\fR;
this is also the number of words in the command.
.AP Tcl_Obj **objv in
Points to an array of pointers to values; each value holds the
value of a single word in the command to execute.
.AP int numBytes in
The number of bytes in \fIscript\fR, not including any
null terminating character.  If \-1, then all characters up to the

Tcl_GetVersion \- get the version of the library at runtime
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
\fBTcl_GetVersion\fR(\fImajor, minor, patchLevel, type\fR)
.SH ARGUMENTS

.AP int *major out
Major version number of the Tcl library.
.AP int *minor out
Minor version number of the Tcl library.
.AP int *patchLevel out
The patch level of the Tcl library (or alpha or beta number).
.AP int *type out
The type of release, also indicates the type of patch level. Can be
one of \fBTCL_ALPHA_RELEASE\fR, \fBTCL_BETA_RELEASE\fR, or
\fBTCL_FINAL_RELEASE\fR.
.BE

.SH DESCRIPTION
.PP

.\"
.\" Copyright (c) 2008 Kevin B. Kenny.
.\" Copyright (c) 2018 Nathan Coulter.
.\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH NRE 3 8.6 Tcl "Tcl Library Procedures"
.so man.macros
.BS
.SH NAME
Tcl_NRCreateCommand, Tcl_NRCreateCommand2, Tcl_NRCallObjProc, Tcl_NRCallObjProc2, Tcl_NREvalObj, Tcl_NREvalObjv, Tcl_NRCmdSwap, Tcl_NRExprObj, Tcl_NRAddCallback \- Non-Recursive (stackless) evaluation of Tcl scripts.
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
Tcl_Command
\fBTcl_NRCreateCommand\fR(\fIinterp, cmdName, proc, nreProc, clientData,
                    deleteProc\fR)
.sp
Tcl_Command
\fBTcl_NRCreateCommand2\fR(\fIinterp, cmdName, proc2, nreProc2, clientData,
                    deleteProc\fR)
.sp
int
\fBTcl_NRCallObjProc\fR(\fIinterp, nreProc, clientData, objc, objv\fR)
.sp
int
\fBTcl_NRCallObjProc2\fR(\fIinterp, nreProc2, clientData, objc, objv\fR)
.sp
int
\fBTcl_NREvalObj\fR(\fIinterp, objPtr, flags\fR)
.sp
int
\fBTcl_NREvalObjv\fR(\fIinterp, objc, objv, flags\fR)
.sp
int

.AP "const char" *cmdName in
Name of the command to create.
.AP Tcl_ObjCmdProc *proc in
Called in order to evaluate a command.  Is often just a small wrapper that uses
\fBTcl_NRCallObjProc\fR to call \fInreProc\fR using a new trampoline.  Behaves
in the same way as the \fIproc\fR argument to \fBTcl_CreateObjCommand\fR(3)
(\fIq.v.\fR).
.AP Tcl_ObjCmdProc2 *proc2 in
Called in order to evaluate a command.  Is often just a small wrapper that uses
\fBTcl_NRCallObjProc2\fR to call \fInreProc2\fR using a new trampoline.  Behaves
in the same way as the \fIproc2\fR argument to \fBTcl_CreateObjCommand2\fR(3)
(\fIq.v.\fR).
.AP Tcl_ObjCmdProc *nreProc in
Called instead of \fIproc\fR when a trampoline is already in use.
.AP Tcl_ObjCmdProc2 *nreProc2 in
Called instead of \fIproc2\fR when a trampoline is already in use.
.AP void *clientData in
Arbitrary one-word value passed to \fIproc\fR, \fInreProc\fR, \fIdeleteProc\fR
and \fIobjProc\fR.
.AP Tcl_CmdDeleteProc *deleteProc in/out
Called before \fIcmdName\fR is deleted from the interpreter, allowing for
command-specific cleanup. May be NULL.
.AP size_t objc in

resolves \fIcmdName\fR, which may contain namespace qualifiers, relative to the
current namespace, creates a command by that name, and returns a token for the
command which may be used in subsequent calls to \fBTcl_GetCommandName\fR.
Except for a few cases noted below any existing command by the same name is
first deleted.  If \fIinterp\fR is in the process of being deleted
\fBTcl_NRCreateCommand\fR does not create any command, does not delete any
command, and returns NULL.
.PP
\fBTcl_NRCreateCommand2\fR, is an alternative to \fBTcl_NRCreateCommand\fR
in the same way as \fBTcl_CreateObjCommand2\fR.
.PP
\fBTcl_NREvalObj\fR pushes a function that is like \fBTcl_EvalObjEx\fR but
consumes no space on the C stack.
.PP
\fBTcl_NREvalObjv\fR pushes a function that is like \fBTcl_EvalObjv\fR but
consumes no space on the C stack.
.PP

It should have arguments and result that match the type
\fBTcl_VarTraceProc\fR:
.PP
.CS
typedef char *\fBTcl_VarTraceProc\fR(
        void *\fIclientData\fR,
        Tcl_Interp *\fIinterp\fR,
        const char *\fIname1\fR,
        const char *\fIname2\fR,
        int \fIflags\fR);
.CE
.PP
The \fIclientData\fR and \fIinterp\fR parameters will
have the same values as those passed to \fBTcl_TraceVar\fR when the
trace was created.
\fIclientData\fR typically points to an application-specific

declare 672 {
    Tcl_Obj *Tcl_GetRange(Tcl_Obj *objPtr, size_t first, size_t last)
}
declare 673 {
    int Tcl_GetUniChar(Tcl_Obj *objPtr, size_t index)
}

declare 676 {
    Tcl_Command Tcl_CreateObjCommand2(Tcl_Interp *interp,
	    const char *cmdName,
	    Tcl_ObjCmdProc2 *proc2, void *clientData,
	    Tcl_CmdDeleteProc *deleteProc)
}
declare 677 {
    Tcl_Trace Tcl_CreateObjTrace2(Tcl_Interp *interp, int level, int flags,
	    Tcl_CmdObjTraceProc2 *objProc2, void *clientData,
	    Tcl_CmdObjTraceDeleteProc *delProc)
}
declare 678 {
    Tcl_Command Tcl_NRCreateCommand2(Tcl_Interp *interp,
	    const char *cmdName, Tcl_ObjCmdProc2 *proc,
	    Tcl_ObjCmdProc2 *nreProc2, void *clientData,
	    Tcl_CmdDeleteProc *deleteProc)
}
declare 679 {
    int Tcl_NRCallObjProc2(Tcl_Interp *interp, Tcl_ObjCmdProc2 *objProc2,
	    void *clientData, size_t objc, Tcl_Obj *const objv[])
}

# ----- BASELINE -- FOR -- 8.7.0 ----- #

##############################################################################

# Define the platform specific public Tcl interface. These functions are only
# available on the designated platform.

	int argc, const char *argv[]);
typedef void (Tcl_CmdTraceProc) (void *clientData, Tcl_Interp *interp,
	int level, char *command, Tcl_CmdProc *proc,
	void *cmdClientData, int argc, const char *argv[]);
typedef int (Tcl_CmdObjTraceProc) (void *clientData, Tcl_Interp *interp,
	int level, const char *command, Tcl_Command commandInfo, int objc,
	struct Tcl_Obj *const *objv);
typedef int (Tcl_CmdObjTraceProc2) (void *clientData, Tcl_Interp *interp,
	int level, const char *command, Tcl_Command commandInfo, size_t objc,
	struct Tcl_Obj *const objv[]);
typedef void (Tcl_CmdObjTraceDeleteProc) (void *clientData);
typedef void (Tcl_DupInternalRepProc) (struct Tcl_Obj *srcPtr,
	struct Tcl_Obj *dupPtr);
typedef int (Tcl_EncodingConvertProc) (void *clientData, const char *src,
	int srcLen, int flags, Tcl_EncodingState *statePtr, char *dst,
	int dstLen, int *srcReadPtr, int *dstWrotePtr, int *dstCharsPtr);
#define Tcl_EncodingFreeProc Tcl_FreeProc

typedef void (Tcl_FreeProc) (void *blockPtr);
typedef void (Tcl_IdleProc) (void *clientData);
typedef void (Tcl_InterpDeleteProc) (void *clientData,
	Tcl_Interp *interp);
typedef void (Tcl_NamespaceDeleteProc) (void *clientData);
typedef int (Tcl_ObjCmdProc) (void *clientData, Tcl_Interp *interp,
	int objc, struct Tcl_Obj *const *objv);
typedef int (Tcl_ObjCmdProc2) (void *clientData, Tcl_Interp *interp,
	size_t objc, struct Tcl_Obj *const *objv);
typedef int (Tcl_LibraryInitProc) (Tcl_Interp *interp);
typedef int (Tcl_LibraryUnloadProc) (Tcl_Interp *interp, int flags);
typedef void (Tcl_PanicProc) (const char *format, ...);
typedef void (Tcl_TcpAcceptProc) (void *callbackData, Tcl_Channel chan,
	char *address, int port);
typedef void (Tcl_TimerProc) (void *clientData);
typedef int (Tcl_SetFromAnyProc) (Tcl_Interp *interp, struct Tcl_Obj *objPtr);

    void *deleteData;	/* Value to pass to deleteProc (usually the
				 * same as clientData). */
    Tcl_Namespace *namespacePtr;/* Points to the namespace that contains this
				 * command. Note that Tcl_SetCmdInfo will not
				 * change a command's namespace; use
				 * TclRenameCommand or Tcl_Eval (of 'rename')
				 * to do that. */
    Tcl_ObjCmdProc2 *objProc2;	/* Not used in Tcl 8.7. */
    void *objClientData2;	/* Not used in Tcl 8.7. */
} Tcl_CmdInfo;

/*
 *----------------------------------------------------------------------------
 * The structure defined below is used to hold dynamic strings. The only
 * fields that clients should use are string and length, accessible via the
 * macros Tcl_DStringValue and Tcl_DStringLength.

 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
buildInfoObjCmd2(
    void *clientData,
    Tcl_Interp *interp,		/* Current interpreter. */
    size_t objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    if (objc - 1 > 1) {
	Tcl_WrongNumArgs(interp, 1, objv, "?option?");
	return TCL_ERROR;
    }
    if (objc == 2) {
	int len;
	const char *arg = TclGetStringFromObj(objv[1], &len);
	if (len == 7 && !strcmp(arg, "version")) {

	}
	Tcl_AppendResult(interp, "0", NULL);
	return TCL_OK;
    }
    Tcl_AppendResult(interp, (char *)clientData, NULL);
    return TCL_OK;
}

static int
buildInfoObjCmd(
    void *clientData,
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    return buildInfoObjCmd2(clientData, interp, (size_t)objc, objv);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateInterp --
 *
 *	Create a new TCL command interpreter.

     * Register Tcl's version number.
     * TIP #268: Full patchlevel instead of just major.minor
     * TIP #599: Extended build information "+<UUID>.<tag1>.<tag2>...."
     */

    Tcl_PkgProvideEx(interp, "Tcl", TCL_PATCH_LEVEL, &tclStubs);
    Tcl_PkgProvideEx(interp, "tcl", TCL_PATCH_LEVEL, &tclStubs);
    Tcl_CmdInfo info2;
    Tcl_Command buildInfoCmd = Tcl_CreateObjCommand(interp, "::tcl::build-info",
	    buildInfoObjCmd, (void *)version, NULL);
    Tcl_GetCommandInfoFromToken(buildInfoCmd, &info2);
    info2.objProc2 = buildInfoObjCmd2;
    info2.objClientData2 = (void *)version;
    Tcl_SetCommandInfoFromToken(buildInfoCmd, &info2);

    if (TclTommath_Init(interp) != TCL_OK) {
	Tcl_Panic("%s", Tcl_GetStringResult(interp));
    }

    if (TclOOInit(interp) != TCL_OK) {
	Tcl_Panic("%s", Tcl_GetStringResult(interp));

 *	the name of a command by Tcl_EvalObj or Tcl_Eval, the object-based
 *	Tcl_ObjCmdProc proc will be called. When the command is deleted from
 *	the table, deleteProc will be called. See the manual entry for details
 *	on the calling sequence.
 *
 *----------------------------------------------------------------------
 */

typedef struct {
    Tcl_ObjCmdProc2 *proc;
    void *clientData; /* Arbitrary value to pass to proc function. */
    Tcl_CmdDeleteProc *deleteProc;
    void *deleteData; /* Arbitrary value to pass to deleteProc function. */
    Tcl_ObjCmdProc2 *nreProc;
} CmdWrapperInfo;


static int cmdWrapperProc(void *clientData,
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj * const *objv)
{
    CmdWrapperInfo *info = (CmdWrapperInfo *)clientData;
    if (objc < 0) {
	objc = -1;
    }
    return info->proc(info->clientData, interp, (size_t)objc, objv);
}

static void cmdWrapperDeleteProc(void *clientData) {
    CmdWrapperInfo *info = (CmdWrapperInfo *)clientData;

    clientData = info->deleteData;
    Tcl_CmdDeleteProc *deleteProc = info->deleteProc;
    Tcl_Free(info);
    if (deleteProc != NULL) {
	deleteProc(clientData);
    }
}

Tcl_Command
Tcl_CreateObjCommand2(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the
				 * specified namespace; otherwise it is put in
				 * the global namespace. */
    Tcl_ObjCmdProc2 *proc,	/* Object-based function to associate with
				 * name. */
    void *clientData,	/* Arbitrary value to pass to object
				 * function. */
    Tcl_CmdDeleteProc *deleteProc
				/* If not NULL, gives a function to call when
				 * this command is deleted. */
)
{
    CmdWrapperInfo *info = (CmdWrapperInfo *)Tcl_Alloc(sizeof(CmdWrapperInfo));
    info->proc = proc;
    info->clientData = clientData;
    info->deleteProc = deleteProc;
    info->deleteData = clientData;

    return Tcl_CreateObjCommand(interp, cmdName,
	    (proc ? cmdWrapperProc : NULL),
	    info, cmdWrapperDeleteProc);
}

Tcl_Command
Tcl_CreateObjCommand(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the

 *	returned. If the command doesn't exist then 0 is returned.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
invokeObj2Command(
    void *clientData,	/* Points to command's Command structure. */
    Tcl_Interp *interp,		/* Current interpreter. */
    size_t objc,		/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    int result;
    Command *cmdPtr = (Command *) clientData;

    if (objc > INT_MAX) {
	objc = TCL_INDEX_NONE;
    }
    if (cmdPtr->objProc != NULL) {
	result = cmdPtr->objProc(cmdPtr->objClientData, interp, objc, objv);
    } else {
	result = Tcl_NRCallObjProc(interp, cmdPtr->nreProc,
		cmdPtr->objClientData, objc, objv);
    }
    return result;
}

static int cmdWrapper2Proc(void *clientData,
    Tcl_Interp *interp,
    size_t objc,
    Tcl_Obj *const objv[])
{
    Command *cmdPtr = (Command *)clientData;
    return cmdPtr->objProc(cmdPtr->objClientData, interp, objc, objv);
}

int
Tcl_SetCommandInfoFromToken(
    Tcl_Command cmd,
    const Tcl_CmdInfo *infoPtr)
{
    Command *cmdPtr;		/* Internal representation of the command */

    } else {
	if (infoPtr->objProc != cmdPtr->objProc) {
	    cmdPtr->nreProc = NULL;
	    cmdPtr->objProc = infoPtr->objProc;
	}
	cmdPtr->objClientData = infoPtr->objClientData;
    }
    if (cmdPtr->deleteProc == cmdWrapperDeleteProc) {
	CmdWrapperInfo *info = (CmdWrapperInfo *)cmdPtr->deleteData;
	if (infoPtr->objProc2 == NULL) {
	    info->proc = invokeObj2Command;
	    info->clientData = cmdPtr;
	    info->nreProc = NULL;
	} else {
	    if (infoPtr->objProc2 != info->proc) {
		info->nreProc = NULL;
		info->proc = infoPtr->objProc2;
	    }
	    info->clientData = infoPtr->objClientData2;
	}
	info->deleteProc = infoPtr->deleteProc;
	info->deleteData = infoPtr->deleteData;
    } else {
	if ((infoPtr->objProc2 != NULL) && (infoPtr->objProc2 != cmdWrapper2Proc)) {
	    CmdWrapperInfo *info = (CmdWrapperInfo *)Tcl_Alloc(sizeof(CmdWrapperInfo));
	    info->proc = infoPtr->objProc2;
	    info->clientData = infoPtr->objClientData2;
	    info->nreProc = NULL;
	    info->deleteProc = infoPtr->deleteProc;
	    info->deleteData = infoPtr->deleteData;
	    cmdPtr->deleteProc = cmdWrapperDeleteProc;
	    cmdPtr->deleteData = info;
	} else {
	    cmdPtr->deleteProc = infoPtr->deleteProc;
	    cmdPtr->deleteData = infoPtr->deleteData;
	}
    }
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandInfo --

    if (cmd == NULL) {
	return 0;
    }

    /*
     * Set isNativeObjectProc 1 if objProc was registered by a call to
     * Tcl_CreateObjCommand. Set isNativeObjectProc 2 if objProc was
     * registered by a call to Tcl_CreateObjCommand2. Otherwise set it to 0.
     */

    cmdPtr = (Command *) cmd;
    infoPtr->isNativeObjectProc =
	    (cmdPtr->objProc != TclInvokeStringCommand);
    infoPtr->objProc = cmdPtr->objProc;
    infoPtr->objClientData = cmdPtr->objClientData;
    infoPtr->proc = cmdPtr->proc;
    infoPtr->clientData = cmdPtr->clientData;
    if (cmdPtr->deleteProc == cmdWrapperDeleteProc) {
	CmdWrapperInfo *info = (CmdWrapperInfo *)cmdPtr->deleteData;
	infoPtr->deleteProc = info->deleteProc;
	infoPtr->deleteData = info->deleteData;
	infoPtr->objProc2 = info->proc;
	infoPtr->objClientData2 = info->clientData;
	if (cmdPtr->objProc == cmdWrapperProc) {
	    infoPtr->isNativeObjectProc = 2;
	}
    } else {
	infoPtr->deleteProc = cmdPtr->deleteProc;
	infoPtr->deleteData = cmdPtr->deleteData;
	infoPtr->objProc2 = cmdWrapper2Proc;
	infoPtr->objClientData2 = cmdPtr;
    }
    infoPtr->namespacePtr = (Tcl_Namespace *) cmdPtr->nsPtr;
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandName --

    NRE_callback *rootPtr = TOP_CB(interp);

    TclNRAddCallback(interp, Dispatch, objProc, clientData,
	    INT2PTR(objc), objv);
    return TclNRRunCallbacks(interp, TCL_OK, rootPtr);
}

int wrapperNRObjProc(
    void *clientData,
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{
    CmdWrapperInfo *info = (CmdWrapperInfo *)clientData;
    clientData = info->clientData;
    Tcl_ObjCmdProc2 *proc = info->proc;
    Tcl_Free(info);
    if (objc < 0) {
	objc = -1;
    }
    return proc(clientData, interp, (size_t)objc, objv);
}

int
Tcl_NRCallObjProc2(
    Tcl_Interp *interp,
    Tcl_ObjCmdProc2 *objProc,
    void *clientData,
    size_t objc,
    Tcl_Obj *const objv[])
{
    if (objc > INT_MAX) {
	Tcl_WrongNumArgs(interp, 1, objv, "?args?");
	return TCL_ERROR;
    }

    NRE_callback *rootPtr = TOP_CB(interp);
    CmdWrapperInfo *info = (CmdWrapperInfo *)Tcl_Alloc(sizeof(CmdWrapperInfo));
    info->clientData = clientData;
    info->proc = objProc;

    TclNRAddCallback(interp, Dispatch, wrapperNRObjProc, info,
	    INT2PTR(objc), objv);
    return TclNRRunCallbacks(interp, TCL_OK, rootPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_NRCreateCommand --
 *
 *	Define a new NRE-enabled object-based command in a command table.
 *

 *	the name of a command by Tcl_EvalObj or Tcl_Eval, the object-based
 *	Tcl_ObjCmdProc proc will be called. When the command is deleted from
 *	the table, deleteProc will be called. See the manual entry for details
 *	on the calling sequence.
 *
 *----------------------------------------------------------------------
 */

static int cmdWrapperNreProc(
    void *clientData,
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{
    CmdWrapperInfo *info = (CmdWrapperInfo *)clientData;
    if (objc < 0) {
	objc = -1;
    }
    return info->nreProc(info->clientData, interp, (size_t)objc, objv);
}

Tcl_Command
Tcl_NRCreateCommand2(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the
				 * specified namespace; otherwise it is put in
				 * the global namespace. */
    Tcl_ObjCmdProc2 *proc,	/* Object-based function to associate with
				 * name, provides direct access for direct
				 * calls. */
    Tcl_ObjCmdProc2 *nreProc,	/* Object-based function to associate with
				 * name, provides NR implementation */
    void *clientData,	/* Arbitrary value to pass to object
				 * function. */
    Tcl_CmdDeleteProc *deleteProc)
				/* If not NULL, gives a function to call when
				 * this command is deleted. */
{
    CmdWrapperInfo *info = (CmdWrapperInfo *)Tcl_Alloc(sizeof(CmdWrapperInfo));
    info->proc = proc;
    info->clientData = clientData;
    info->nreProc = nreProc;
    info->deleteProc = deleteProc;
    info->deleteData = clientData;
    return Tcl_NRCreateCommand(interp, cmdName,
	    (proc ? cmdWrapperProc : NULL),
	    (nreProc ? cmdWrapperNreProc : NULL),
	    info, cmdWrapperDeleteProc);
}

Tcl_Command
Tcl_NRCreateCommand(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the

     */

    objc -= 2;
    objv += 2;

    /* Final sanity check. Do not exceed limits on max list length. */

    if (elementCount && (size_t)objc > LIST_MAX/elementCount) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"max length of a Tcl list (%" TCL_Z_MODIFIER "u elements) exceeded", LIST_MAX));
	Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
	return TCL_ERROR;
    }
    totalElems = objc * elementCount;

    /*
     * Get an empty list object that is allocated large enough to hold each
     * init value elementCount times.
     */

    listPtr = Tcl_NewListObj(totalElems, NULL);
    if (totalElems) {
	ListRep listRep;
	ListObjGetRep(listPtr, &listRep);
	dataArray = ListRepElementsBase(&listRep);
	listRep.storePtr->numUsed = totalElems;
	if (listRep.spanPtr) {
	    /* Future proofing in case Tcl_NewListObj returns a span */
	    listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
	    listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
	}


    }

    /*
     * Set the elements. Note that we handle the common degenerate case of a
     * single value being repeated separately to permit the compiler as much
     * room as possible to optimize a loop that might be run a very large
     * number of times.

    if (!elemc) {
	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }

    if (Tcl_IsShared(objv[1])
	|| ListObjRepIsShared(objv[1])) { /* Bug 1675044 */
	Tcl_Obj *resultObj, **dataArray;
	ListRep listRep;

	resultObj = Tcl_NewListObj(elemc, NULL);

	/* Modify the internal rep in-place */
	ListObjGetRep(resultObj, &listRep);
	listRep.storePtr->numUsed = elemc;
	dataArray = ListRepElementsBase(&listRep);
	if (listRep.spanPtr) {
	    /* Future proofing */
	    listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
	    listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
	}

	for (i=0,j=elemc-1 ; i<elemc ; i++,j--) {
	    dataArray[j] = elemv[i];
	    Tcl_IncrRefCount(elemv[i]);
	}

	Tcl_SetObjResult(interp, resultObj);

    }

    /*
     * Now store the sorted elements in the result list.
     */

    if (sortInfo.resultCode == TCL_OK) {
	ListRep listRep;
	Tcl_Obj **newArray, *objPtr;

	resultPtr = Tcl_NewListObj(sortInfo.numElements * groupSize, NULL);
	ListObjGetRep(resultPtr, &listRep);
	newArray = ListRepElementsBase(&listRep);
	if (group) {
	    for (i=0; elementPtr!=NULL ; elementPtr=elementPtr->nextPtr) {
		idx = elementPtr->payload.index;
		for (j = 0; j < groupSize; j++) {
		    if (indices) {
			TclNewIndexObj(objPtr, idx + j - groupOffset);
			newArray[i++] = objPtr;

	} else {
	    for (i=0; elementPtr != NULL ; elementPtr = elementPtr->nextPtr) {
		objPtr = elementPtr->payload.objPtr;
		newArray[i++] = objPtr;
		Tcl_IncrRefCount(objPtr);
	    }
	}
	listRep.storePtr->numUsed = i;
	if (listRep.spanPtr) {
	    listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
	    listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
	}
	Tcl_SetObjResult(interp, resultPtr);
    }

  done:
    if (sortMode == SORTMODE_COMMAND) {
	TclDecrRefCount(sortInfo.compareCmdPtr);
	TclDecrRefCount(listObj);

		    Tcl_DStringValue(&buffer), &isNew);
	    if (isNew) {
		/*
		 * First time we've encountered this match clause, so it must
		 * point to here.
		 */

		Tcl_SetHashValue(hPtr, INT2PTR(CurrentOffset(envPtr) - jumpLocation));
	    }
	    Tcl_DStringFree(&buffer);
	} else {
	    /*
	     * This is a default clause, so patch up the fallthrough from the
	     * INST_JUMP_TABLE instruction to here.
	     */

    objArrayBytes = envPtr->mallocedLiteralArray ? 0 :
	    envPtr->literalArrayNext * sizeof(Tcl_Obj *);
    exceptArrayBytes = envPtr->exceptArrayNext * sizeof(ExceptionRange);
    cmdLocBytes = GetCmdLocEncodingSize(envPtr);

    /*
     * Compute the total number of bytes needed for this bytecode.
     *
     * Note that code bytes need not be aligned but since later elements are we
     * need to pad anyway, either directly after ByteCode or after codeBytes,
     * and it's easier and more consistent to do the former.
     */

    structureSize = TCL_ALIGN(sizeof(ByteCode));  /* align code bytes */
    structureSize += TCL_ALIGN(codeBytes);	  /* align object array */
    structureSize += TCL_ALIGN(objArrayBytes);	  /* align exc range arr */
    structureSize += TCL_ALIGN(exceptArrayBytes); /* align AuxData array */
    structureSize += cmdLocBytes;

    if (envPtr->iPtr->varFramePtr != NULL) {
	namespacePtr = envPtr->iPtr->varFramePtr->nsPtr;

    codePtr->numCodeBytes = codeBytes;
    codePtr->numLitObjects = numLitObjects;
    codePtr->numExceptRanges = envPtr->exceptArrayNext;
    codePtr->numCmdLocBytes = cmdLocBytes;
    codePtr->maxExceptDepth = envPtr->maxExceptDepth;
    codePtr->maxStackDepth = envPtr->maxStackDepth;

    p += TCL_ALIGN(sizeof(ByteCode));	/* align code bytes */
    codePtr->codeStart = p;
    memcpy(p, envPtr->codeStart, codeBytes);
    p += TCL_ALIGN(codeBytes);		/* align object array */

    if (envPtr->mallocedLiteralArray) {
	codePtr->objArrayPtr = envPtr->literalArrayPtr;
	codePtr->flags |= TCL_BYTECODE_FREE_LITERALS;

 */

static int
QueryConfigObjCmd(
    void *clientData,
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const *objv)
{
    QCCD *cdPtr = (QCCD *)clientData;
    Tcl_Obj *pkgName = cdPtr->pkg;
    Tcl_Obj *pDB, *pkgDict, *val, *listPtr;
    size_t m, n = 0;
    static const char *const subcmdStrings[] = {
	"get", "list", NULL

/* 671 */
EXTERN const char *	Tcl_UtfAtIndex(const char *src, size_t index);
/* 672 */
EXTERN Tcl_Obj *	Tcl_GetRange(Tcl_Obj *objPtr, size_t first,
				size_t last);
/* 673 */
EXTERN int		Tcl_GetUniChar(Tcl_Obj *objPtr, size_t index);
/* Slot 674 is reserved */
/* Slot 675 is reserved */
/* 676 */
EXTERN Tcl_Command	Tcl_CreateObjCommand2(Tcl_Interp *interp,
				const char *cmdName, Tcl_ObjCmdProc2 *proc2,
				void *clientData,
				Tcl_CmdDeleteProc *deleteProc);
/* 677 */
EXTERN Tcl_Trace	Tcl_CreateObjTrace2(Tcl_Interp *interp, int level,
				int flags, Tcl_CmdObjTraceProc2 *objProc2,
				void *clientData,
				Tcl_CmdObjTraceDeleteProc *delProc);
/* 678 */
EXTERN Tcl_Command	Tcl_NRCreateCommand2(Tcl_Interp *interp,
				const char *cmdName, Tcl_ObjCmdProc2 *proc,
				Tcl_ObjCmdProc2 *nreProc2, void *clientData,
				Tcl_CmdDeleteProc *deleteProc);
/* 679 */
EXTERN int		Tcl_NRCallObjProc2(Tcl_Interp *interp,
				Tcl_ObjCmdProc2 *objProc2, void *clientData,
				size_t objc, Tcl_Obj *const objv[]);

typedef struct {
    const struct TclPlatStubs *tclPlatStubs;
    const struct TclIntStubs *tclIntStubs;
    const struct TclIntPlatStubs *tclIntPlatStubs;
} TclStubHooks;

    int (*tcl_ParseArgsObjv) (Tcl_Interp *interp, const Tcl_ArgvInfo *argTable, size_t *objcPtr, Tcl_Obj *const *objv, Tcl_Obj ***remObjv); /* 667 */
    size_t (*tcl_UniCharLen) (const int *uniStr); /* 668 */
    size_t (*tcl_NumUtfChars) (const char *src, size_t length); /* 669 */
    size_t (*tcl_GetCharLength) (Tcl_Obj *objPtr); /* 670 */
    const char * (*tcl_UtfAtIndex) (const char *src, size_t index); /* 671 */
    Tcl_Obj * (*tcl_GetRange) (Tcl_Obj *objPtr, size_t first, size_t last); /* 672 */
    int (*tcl_GetUniChar) (Tcl_Obj *objPtr, size_t index); /* 673 */
    void (*reserved674)(void);
    void (*reserved675)(void);
    Tcl_Command (*tcl_CreateObjCommand2) (Tcl_Interp *interp, const char *cmdName, Tcl_ObjCmdProc2 *proc2, void *clientData, Tcl_CmdDeleteProc *deleteProc); /* 676 */
    Tcl_Trace (*tcl_CreateObjTrace2) (Tcl_Interp *interp, int level, int flags, Tcl_CmdObjTraceProc2 *objProc2, void *clientData, Tcl_CmdObjTraceDeleteProc *delProc); /* 677 */
    Tcl_Command (*tcl_NRCreateCommand2) (Tcl_Interp *interp, const char *cmdName, Tcl_ObjCmdProc2 *proc, Tcl_ObjCmdProc2 *nreProc2, void *clientData, Tcl_CmdDeleteProc *deleteProc); /* 678 */
    int (*tcl_NRCallObjProc2) (Tcl_Interp *interp, Tcl_ObjCmdProc2 *objProc2, void *clientData, size_t objc, Tcl_Obj *const objv[]); /* 679 */
} TclStubs;

extern const TclStubs *tclStubsPtr;

#ifdef __cplusplus
}
#endif

	(tclStubsPtr->tcl_GetCharLength) /* 670 */
#define Tcl_UtfAtIndex \
	(tclStubsPtr->tcl_UtfAtIndex) /* 671 */
#define Tcl_GetRange \
	(tclStubsPtr->tcl_GetRange) /* 672 */
#define Tcl_GetUniChar \
	(tclStubsPtr->tcl_GetUniChar) /* 673 */
/* Slot 674 is reserved */
/* Slot 675 is reserved */
#define Tcl_CreateObjCommand2 \
	(tclStubsPtr->tcl_CreateObjCommand2) /* 676 */
#define Tcl_CreateObjTrace2 \
	(tclStubsPtr->tcl_CreateObjTrace2) /* 677 */
#define Tcl_NRCreateCommand2 \
	(tclStubsPtr->tcl_NRCreateCommand2) /* 678 */
#define Tcl_NRCallObjProc2 \
	(tclStubsPtr->tcl_NRCallObjProc2) /* 679 */

#endif /* defined(USE_TCL_STUBS) */

/* !END!: Do not edit above this line. */

#ifdef _WIN32
#   undef Tcl_CreateFileHandler

	    codePtr->numSrcBytes?
		    codePtr->structureSize/(float)codePtr->numSrcBytes :
#endif
	    0.0);

#ifdef TCL_COMPILE_STATS
    Tcl_AppendPrintfToObj(bufferObj,
	    "  Code %" TCL_Z_MODIFIER "u = header %" TCL_Z_MODIFIER "u+inst %" TCL_Z_MODIFIER "u+litObj %"
	    TCL_Z_MODIFIER "u+exc %" TCL_Z_MODIFIER "u+aux %" TCL_Z_MODIFIER "u+cmdMap %" TCL_Z_MODIFIER "u\n",
	    codePtr->structureSize,
	    offsetof(ByteCode, localCachePtr),
	    codePtr->numCodeBytes,
	    codePtr->numLitObjects * sizeof(Tcl_Obj *),
	    codePtr->numExceptRanges*sizeof(ExceptionRange),
	    BA_AuxData_Size(codePtr->auxData) * sizeof(AuxData),
	    codePtr->numCmdLocBytes);
#endif /* TCL_COMPILE_STATS */

 * Helpers for NR - non-recursive calls to TEBC
 * Minimal data required to fully reconstruct the execution state.
 */

typedef struct {
    ByteCode *codePtr;		/* Constant until the BC returns */
				/* -----------------------------------------*/
    Tcl_Obj **catchTop;		/* These fields are used on return TO this */
    Tcl_Obj *auxObjList;	/* this level: they record the state when a */
    CmdFrame cmdFrame;		/* new codePtr was received for NR */
                                /* execution. */
    Tcl_Obj *stack[1];		/* Start of the actual combined catch and obj
				 * stacks; the struct will be expanded as
				 * necessary */
} TEBCdata;

#define TEBC_YIELD() \
    do {						\
	esPtr->tosPtr = tosPtr;				\

#define OBJ_AT_TOS	*tosPtr

#define OBJ_UNDER_TOS	*(tosPtr-1)

#define OBJ_AT_DEPTH(n)	*(tosPtr-(n))

#define CURR_DEPTH	((size_t)(tosPtr - initTosPtr))

#define STACK_BASE(esPtr) ((esPtr)->stackWords - 1)

/*
 * Macros used to trace instruction execution. The macros TRACE,
 * TRACE_WITH_OBJ, and O2S are only used inside TclNRExecuteByteCode. O2S is
 * only used in TRACE* calls to get a string from an object.
 */

#ifdef TCL_COMPILE_DEBUG
#   define TRACE(a) \
    while (traceInstructions) {					\
	fprintf(stdout, "%2" TCL_Z_MODIFIER "u: %2" TCL_Z_MODIFIER "u (%" TCL_Z_MODIFIER "u) %s ", iPtr->numLevels,	\
		CURR_DEPTH,				\
		(size_t)(pc - codePtr->codeStart),		\
		GetOpcodeName(pc));				\
	printf a;						\
	break;							\
    }
#   define TRACE_APPEND(a) \
    while (traceInstructions) {		\
	printf a;			\
	break;				\
    }
#   define TRACE_ERROR(interp) \
    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
#   define TRACE_WITH_OBJ(a, objPtr) \
    while (traceInstructions) {					\
	fprintf(stdout, "%2" TCL_Z_MODIFIER "u: %2" TCL_Z_MODIFIER "u (%" TCL_Z_MODIFIER "u) %s ", iPtr->numLevels,	\
		CURR_DEPTH,				\
		(size_t)(pc - codePtr->codeStart),		\
		GetOpcodeName(pc));				\
	printf a;						\
	TclPrintObject(stdout, objPtr, 30);			\
	fprintf(stdout, "\n");					\
	break;							\
    }
#   define O2S(objPtr) \

			    Tcl_Obj *const objv[]);
#endif /* TCL_COMPILE_STATS */
#ifdef TCL_COMPILE_DEBUG
static const char *	GetOpcodeName(const unsigned char *pc);
static void		PrintByteCodeInfo(ByteCode *codePtr);
static const char *	StringForResultCode(int result);
static void		ValidatePcAndStackTop(ByteCode *codePtr,
			    const unsigned char *pc, size_t stackTop,
			    int checkStack);
#endif /* TCL_COMPILE_DEBUG */
static ByteCode *	CompileExprObj(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void		DeleteExecStack(ExecStack *esPtr);
static void		DupExprCodeInternalRep(Tcl_Obj *srcPtr,
			    Tcl_Obj *copyPtr);
static Tcl_Obj *	ExecuteExtendedBinaryMathOp(Tcl_Interp *interp,

 *
 * Side effects:
 *	Almost certainly, depending on the ByteCode's instructions.
 *
 *----------------------------------------------------------------------
 */
#define	bcFramePtr	(&TD->cmdFrame)
#define	initCatchTop	(TD->stack-1)
#define	initTosPtr	(initCatchTop+codePtr->maxExceptDepth)
#define esPtr		(iPtr->execEnvPtr->execStackPtr)

int
TclNRExecuteByteCode(
    Tcl_Interp *interp,		/* Token for command interpreter. */
    ByteCode *codePtr)		/* The bytecode sequence to interpret. */
{

    TclResetRewriteEnsemble(interp, 1);

    /*
     * Push the callback for bytecode execution
     */

    TclNRAddCallback(interp, TEBCresume, TD, /* pc */ NULL,
	    /* cleanup */ NULL, INT2PTR(iPtr->evalFlags));

    /*
     * Reset discard result flag - because it is applicable for this call only,
     * and should not affect all the nested invocations may return result.
     */
    iPtr->evalFlags &= ~TCL_EVAL_DISCARD_RESULT;

#endif

    TEBC_DATA_DIG();

#ifdef TCL_COMPILE_DEBUG
    if (!pc && (tclTraceExec >= 2)) {
	PrintByteCodeInfo(codePtr);
	fprintf(stdout, "  Starting stack top=%" TCL_Z_MODIFIER "u\n", CURR_DEPTH);
	fflush(stdout);
    }
#endif

    if (!pc) {
	/* bytecode is starting from scratch */
	pc = codePtr->codeStart;

#ifdef TCL_COMPILE_DEBUG
    /*
     * Skip the stack depth check if an expansion is in progress.
     */

    CHECK_STACK();
    if (traceInstructions) {
	fprintf(stdout, "%2" TCL_Z_MODIFIER "u: %2" TCL_Z_MODIFIER "u ", iPtr->numLevels, CURR_DEPTH);
	TclPrintInstruction(codePtr, pc);
	fflush(stdout);
    }
#endif /* TCL_COMPILE_DEBUG */

    TCL_DTRACE_INST_NEXT();

	 * we do not define a special tclObjType for it. It is not dangerous
	 * as the obj is never passed anywhere, so that all manipulations are
	 * performed here and in INST_INVOKE_EXPANDED (in case of an expansion
	 * error, also in INST_EXPAND_STKTOP).
	 */

	TclNewObj(objPtr);
	objPtr->internalRep.twoPtrValue.ptr2 = UINT2PTR(CURR_DEPTH);
	objPtr->length = 0;
	PUSH_TAUX_OBJ(objPtr);
	TRACE(("=> mark depth as %" TCL_Z_MODIFIER "u\n", CURR_DEPTH));
	NEXT_INST_F(1, 0, 0);
    break;

    case INST_EXPAND_DROP:
	/*
	 * Drops an element of the auxObjList, popping stack elements to
	 * restore the stack to the state before the point where the aux
	 * element was created.
	 */

	CLANG_ASSERT(auxObjList);
	objc = CURR_DEPTH - PTR2UINT(auxObjList->internalRep.twoPtrValue.ptr2);
	POP_TAUX_OBJ();
#ifdef TCL_COMPILE_DEBUG
	/* Ugly abuse! */
	starting = 1;
#endif
	TRACE(("=> drop %" TCL_Z_MODIFIER "u items\n", objc));
	NEXT_INST_V(1, objc, 0);

    case INST_EXPAND_STKTOP: {
	size_t i;
	TEBCdata *newTD;
	ptrdiff_t oldCatchTopOff, oldTosPtrOff;

	/*
	 * Make sure that the element at stackTop is a list; if not, just
	 * leave with an error. Note that the element from the expand list
	 * will be removed at checkForCatch.
	 */

	auxObjList->length += objc - 1;
	if ((objc > 1) && (auxObjList->length > 0)) {
	    length = auxObjList->length /* Total expansion room we need */
		    + codePtr->maxStackDepth /* Beyond the original max */
		    - CURR_DEPTH;	/* Relative to where we are */
	    DECACHE_STACK_INFO();
	    oldCatchTopOff = catchTop - initCatchTop;
	    oldTosPtrOff = tosPtr - initTosPtr;
	    newTD = (TEBCdata *)
		    GrowEvaluationStack(iPtr->execEnvPtr, length, 1);

	    if (newTD != TD) {
		/*
		 * Change the global data to point to the new stack: move the
		 * TEBCdataPtr TD, recompute the position of every other
		 * stack-allocated parameter, update the stack pointers.
		 */

		TD = newTD;

		catchTop = initCatchTop + oldCatchTopOff;
		tosPtr = initTosPtr + oldTosPtrOff;
	    }
	}

	/*
	 * Expand the list at stacktop onto the stack; free the list. Knowing
	 * that it has a freeIntRepProc we use Tcl_DecrRefCount().
	 */

	TEBC_YIELD();
	/* add TEBCResume for object at top of stack */
	return TclNRExecuteByteCode(interp,
		    TclCompileObj(interp, OBJ_AT_TOS, NULL, 0));

    case INST_INVOKE_EXPANDED:
	CLANG_ASSERT(auxObjList);
	objc = CURR_DEPTH - PTR2UINT(auxObjList->internalRep.twoPtrValue.ptr2);
	POP_TAUX_OBJ();
	if (objc) {
	    pcAdjustment = 1;
	    goto doInvocation;
	}

	/*

	if (Tcl_IsShared(objResultPtr)) {
	    Tcl_Obj *newValue = Tcl_DuplicateObj(objResultPtr);

	    TclDecrRefCount(objResultPtr);
	    varPtr->value.objPtr = objResultPtr = newValue;
	    Tcl_IncrRefCount(newValue);
	}
	if (TclListObjAppendElements(interp, objResultPtr, objc, objv)
		!= TCL_OK) {
	    TRACE_ERROR(interp);
	    goto gotError;
	}
	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
	NEXT_INST_V(pcAdjustment, cleanup, 1);

	    } else {
		if (Tcl_IsShared(objResultPtr)) {
		    valueToAssign = Tcl_DuplicateObj(objResultPtr);
		    createdNewObj = 1;
		} else {
		    valueToAssign = objResultPtr;
		}
		if (TclListObjAppendElements(interp, valueToAssign,
			objc, objv) != TCL_OK) {
		    if (createdNewObj) {
			TclDecrRefCount(valueToAssign);
		    }
		    goto errorInLappendListPtr;
		}
	    }

		} else {
		    int shift = (int) w2;

		    /*
		     * Handle shifts within the native long range.
		     */

		    if (((size_t)shift < CHAR_BIT*sizeof(long))
			    && !((w1>0 ? w1 : ~w1) &
				-(1UL<<(CHAR_BIT*sizeof(long) - 1 - shift)))) {
			wResult = (Tcl_WideUInt)w1 << shift;
			goto wideResultOfArithmetic;
		    }
		}

    case INST_BEGIN_CATCH4:
	/*
	 * Record start of the catch command with exception range index equal
	 * to the operand. Push the current stack depth onto the special catch
	 * stack.
	 */

	*(++catchTop) = (Tcl_Obj *)UINT2PTR(CURR_DEPTH);
	TRACE(("%u => catchTop=%" TCL_Z_MODIFIER "u, stackTop=%" TCL_Z_MODIFIER "u\n",
		TclGetUInt4AtPtr(pc+1), (size_t)(catchTop - initCatchTop - 1),
		CURR_DEPTH));
	NEXT_INST_F(5, 0, 0);
    break;

    case INST_END_CATCH:
	catchTop--;
	DECACHE_STACK_INFO();
	Tcl_ResetResult(interp);
	CACHE_STACK_INFO();
	result = TCL_OK;
	TRACE(("=> catchTop=%" TCL_Z_MODIFIER "u\n", (size_t)(catchTop - initCatchTop - 1)));
	NEXT_INST_F(1, 0, 0);
    break;

    case INST_PUSH_RESULT:
	objResultPtr = Tcl_GetObjResult(interp);
	TRACE_WITH_OBJ(("=> "), objResultPtr);

	/*
	 * Clear all expansions that may have started after the last
	 * INST_BEGIN_CATCH.
	 */

	while (auxObjList) {
	    if ((catchTop != initCatchTop)
		    && (PTR2UINT(*catchTop) >
			PTR2UINT(auxObjList->internalRep.twoPtrValue.ptr2))) {
		break;
	    }
	    POP_TAUX_OBJ();
	}

	/*
	 * We must not catch if the script in progress has been canceled with

	 * "exception". It was found either by checkForCatch just above or by
	 * an instruction during break, continue, or error processing. Jump to
	 * its catchOffset after unwinding the operand stack to the depth it
	 * had when starting to execute the range's catch command.
	 */

    processCatch:
	while (CURR_DEPTH > PTR2UINT(*catchTop)) {
	    valuePtr = POP_OBJECT();
	    TclDecrRefCount(valuePtr);
	}
#ifdef TCL_COMPILE_DEBUG
	if (traceInstructions) {
	    fprintf(stdout, "  ... found catch at %" TCL_Z_MODIFIER "u, catchTop=%" TCL_Z_MODIFIER "u, "
		    "unwound to %" TCL_Z_MODIFIER "u, new pc %" TCL_Z_MODIFIER "u\n",
		    rangePtr->codeOffset, (size_t)(catchTop - initCatchTop - 1),
		    PTR2UINT(*catchTop), (size_t)rangePtr->catchOffset);
	}
#endif
	pc = (codePtr->codeStart + rangePtr->catchOffset);
	NEXT_INST_F(0, 0, 0);	/* Restart the execution loop at pc. */

	/*
	 * end of infinite loop dispatching on instructions.

	    objPtr = POP_OBJECT();
	    Tcl_DecrRefCount(objPtr);
	}

	if (tosPtr < initTosPtr) {
	    fprintf(stderr,
		    "\nTclNRExecuteByteCode: abnormal return at pc %" TCL_Z_MODIFIER "u: "
		    "stack top %" TCL_Z_MODIFIER "u < entry stack top %d\n",
		    (size_t)(pc - codePtr->codeStart),
		    CURR_DEPTH, 0);
	    Tcl_Panic("TclNRExecuteByteCode execution failure: end stack top < start stack top");
	}
	CLANG_ASSERT(bcFramePtr);
    }

    iPtr->cmdFramePtr = bcFramePtr->nextPtr;
    TclReleaseByteCode(codePtr);

#ifdef TCL_COMPILE_STATS
	    codePtr->numSrcBytes?
		    ((float)codePtr->structureSize)/codePtr->numSrcBytes :
#endif
	    0.0);

#ifdef TCL_COMPILE_STATS
    fprintf(stdout, "  Code %" TCL_Z_MODIFIER "u = header %" TCL_Z_MODIFIER "u+inst %" TCL_Z_MODIFIER
        "u+litObj %" TCL_Z_MODIFIER "u+exc %" TCL_Z_MODIFIER "u+aux %" TCL_Z_MODIFIER "u+cmdMap %" TCL_Z_MODIFIER "u\n",
	    codePtr->structureSize,
	    offsetof(ByteCode, localCachePtr),
	    codePtr->numCodeBytes,
	    codePtr->numLitObjects * sizeof(Tcl_Obj *),
	    codePtr->numExceptRanges*sizeof(ExceptionRange),
	    numAuxDataItems * sizeof(AuxData),
	    codePtr->numCmdLocBytes);
#endif /* TCL_COMPILE_STATS */
    if (procPtr != NULL) {

#ifdef TCL_COMPILE_DEBUG
static void
ValidatePcAndStackTop(
    ByteCode *codePtr,	/* The bytecode whose summary is printed to
				 * stdout. */
    const unsigned char *pc,	/* Points to first byte of a bytecode
				 * instruction. The program counter. */
    size_t stackTop,		/* Current stack top. Must be between
				 * stackLowerBound and stackUpperBound
				 * (inclusive). */
    int checkStack)		/* 0 if the stack depth check should be
				 * skipped. */
{
    size_t stackUpperBound = codePtr->maxStackDepth;
				/* Greatest legal value for stackTop. */
    size_t relativePc = (size_t)(pc - codePtr->codeStart);
    size_t codeStart = (size_t)codePtr->codeStart;
    size_t codeEnd = (size_t)
	    (codePtr->codeStart + codePtr->numCodeBytes);
    unsigned char opCode = *pc;

    if ((PTR2UINT(pc) < codeStart) || (PTR2UINT(pc) > codeEnd)) {
	fprintf(stderr, "\nBad instruction pc 0x%p in TclNRExecuteByteCode\n",
		pc);
	Tcl_Panic("TclNRExecuteByteCode execution failure: bad pc");
    }
    if (opCode >= LAST_INST_OPCODE) {
	fprintf(stderr, "\nBad opcode %u at pc %" TCL_Z_MODIFIER "u in TclNRExecuteByteCode\n",
		opCode, relativePc);
	Tcl_Panic("TclNRExecuteByteCode execution failure: bad opcode");
    }
    if (checkStack &&
	    (stackTop > stackUpperBound)) {
	size_t numChars;
	const char *cmd = GetSrcInfoForPc(pc, codePtr, &numChars, NULL, NULL);

	fprintf(stderr, "\nBad stack top %" TCL_Z_MODIFIER "u at pc %" TCL_Z_MODIFIER "u in TclNRExecuteByteCode (min 0, max %" TCL_Z_MODIFIER "u)",
		stackTop, relativePc, stackUpperBound);
	if (cmd != NULL) {
	    Tcl_Obj *message;

	    TclNewLiteralStringObj(message, "\n executing ");
	    Tcl_IncrRefCount(message);
	    Tcl_AppendLimitedToObj(message, cmd, numChars, 100, NULL);

	    + (statsPtr->numLiteralsCreated * sizeof(Tcl_Obj))
	    + statsPtr->totalLitStringBytes;
    totalCodeBytes = statsPtr->totalByteCodeBytes + totalLiteralBytes;

    numCurrentByteCodes =
	    statsPtr->numCompilations - statsPtr->numByteCodesFreed;
    currentHeaderBytes = numCurrentByteCodes
	    * offsetof(ByteCode, localCachePtr);
    literalMgmtBytes = sizeof(LiteralTable)
	    + (iPtr->literalTable.numBuckets * sizeof(LiteralEntry *))
	    + (iPtr->literalTable.numEntries * sizeof(LiteralEntry));
    currentLiteralBytes = literalMgmtBytes
	    + iPtr->literalTable.numEntries * sizeof(Tcl_Obj)
	    + statsPtr->currentLitStringBytes;
    currentCodeBytes = statsPtr->currentByteCodeBytes + currentLiteralBytes;

 */

static Tcl_HashEntry *
AllocArrayEntry(
    Tcl_HashTable *tablePtr,	/* Hash table. */
    void *keyPtr)			/* Key to store in the hash table entry. */
{


    Tcl_HashEntry *hPtr;
    TCL_HASH_TYPE count = tablePtr->keyType * sizeof(int);
    TCL_HASH_TYPE size = offsetof(Tcl_HashEntry, key) + count;

    if (size < sizeof(Tcl_HashEntry)) {
	size = sizeof(Tcl_HashEntry);
    }
    hPtr = (Tcl_HashEntry *)Tcl_Alloc(size);

    memcpy(hPtr->key.string, keyPtr, count);



    Tcl_SetHashValue(hPtr, NULL);

    return hPtr;
}

/*
 *----------------------------------------------------------------------

 */

static int
CompareArrayKeys(
    void *keyPtr,			/* New key to compare. */
    Tcl_HashEntry *hPtr)	/* Existing key to compare. */
{


    size_t count = hPtr->tablePtr->keyType * sizeof(int);




    return !memcmp(keyPtr, hPtr->key.string, count);






}

/*
 *----------------------------------------------------------------------
 *
 * HashArrayKey --
 *

    size_t size, allocsize;

    allocsize = size = strlen(string) + 1;
    if (size < sizeof(hPtr->key)) {
	allocsize = sizeof(hPtr->key);
    }
    hPtr = (Tcl_HashEntry *)Tcl_Alloc(offsetof(Tcl_HashEntry, key) + allocsize);
    memset(hPtr, 0, offsetof(Tcl_HashEntry, key) + allocsize);
    memcpy(hPtr->key.string, string, size);
    Tcl_SetHashValue(hPtr, NULL);
    return hPtr;
}

/*
 *----------------------------------------------------------------------

	}

	/*
	 * Append a space character (" ") if there is more text to follow
	 * (either another element from objv, or the message string).
	 */

	if (i + 1 < objc || message!=NULL) {
	    Tcl_AppendStringsToObj(objPtr, " ", NULL);
	}
    }

    /*
     * Add any trailing message bits and set the resulting string as the
     * interpreter result. Caller is responsible for reporting this as an

}

# TIP 431: temporary directory creation function
declare 258 {
    Tcl_Obj *TclpCreateTemporaryDirectory(Tcl_Obj *dirObj,
	    Tcl_Obj *basenameObj)
}
declare 259 {
    int	TclMSB(size_t n)
}

# TIP 625: for unit testing - create list objects with span
declare 260 {
    Tcl_Obj *TclListTestObj(int length, int leadingSpace, int endSpace)
}

# TIP 625: for unit testing - check list invariants
declare 261 {
    void TclListObjValidate(Tcl_Interp *interp, Tcl_Obj *listObj)
}


##############################################################################

# Define the platform specific internal Tcl interface. These functions are
# only available on the designated platform.

interface tclIntPlat

				 * strings; values have type (Namespace *). */
#else
    Tcl_HashTable *childTablePtr;
				/* Contains any child namespaces. Indexed by
				 * strings; values have type (Namespace *). If
				 * NULL, there are no children. */
#endif
#if TCL_MAJOR_VERSION > 8
    size_t nsId;		/* Unique id for the namespace. */
#else
    unsigned long nsId;
#endif
    Tcl_Interp *interp;	/* The interpreter containing this
				 * namespace. */
    int flags;			/* OR-ed combination of the namespace status
				 * flags NS_DYING and NS_DEAD listed below. */
    size_t activationCount;	/* Number of "activations" or active call
				 * frames for this namespace that are on the
				 * Tcl call stack. The namespace won't be

    Tcl_HashTable *hiddenCmdTablePtr;
				/* Hash table used by tclBasic.c to keep track
				 * of hidden commands on a per-interp
				 * basis. */
    void *interpInfo;	/* Information used by tclInterp.c to keep
				 * track of parent/child interps on a
				 * per-interp basis. */
#if TCL_MAJOR_VERSION > 8
    void (*optimizer)(void *envPtr);
#else
    union {
	void (*optimizer)(void *envPtr);
	Tcl_HashTable unused2;	/* No longer used (was mathFuncTable). The
				 * unused space in interp was repurposed for
				 * pluggable bytecode optimizers. The core
				 * contains one optimizer, which can be
				 * selectively overridden by extensions. */
    } extra;
#endif
    /*
     * Information related to procedures and variables. See tclProc.c and
     * tclVar.c for usage.
     */

    size_t numLevels;		/* Keeps track of how many nested calls to
				 * Tcl_Eval are in progress for this

#if defined(__APPLE__)
#define TCL_ALLOCALIGN	16
#else
#define TCL_ALLOCALIGN	(2*sizeof(void *))
#endif

/*
 * TCL_ALIGN is used to determine the offset needed to safely allocate any
 * data structure in memory. Given a starting offset or size, it "rounds up"
 * or "aligns" the offset to the next aligned (typically 8-byte) boundary so
 * that any data structure can be placed at the resulting offset without fear
 * of an alignment error. Note this is clamped to a minimum of 8 for API
 * compatibility.
 *
 * WARNING!! DO NOT USE THIS MACRO TO ALIGN POINTERS: it will produce the
 * wrong result on platforms that allocate addresses that are divisible by a
 * non-trivial factor of this alignment. Only use it for offsets or sizes.
 *
 * This macro is only used by tclCompile.c in the core (Bug 926445). It
 * however not be made file static, as extensions that touch bytecodes
 * (notably tbcload) require it.
 */

struct TclMaxAlignment {
    char unalign[8];
    union {
	long long maxAlignLongLong;
	double maxAlignDouble;
	void *maxAlignPointer;
    } aligned;
};
#define TCL_ALIGN_BYTES \
	offsetof(struct TclMaxAlignment, aligned)
#define TCL_ALIGN(x) \
	(((x) + (TCL_ALIGN_BYTES - 1)) & ~(TCL_ALIGN_BYTES - 1))

/*
 * A common panic alert when memory allocation fails.
 */

#define TclOOM(ptr, size) \
	((size) && ((ptr)||(Tcl_Panic("unable to alloc %" TCL_Z_MODIFIER "u bytes", (size_t)(size)),1)))

 */

#define	TCL_INVOKE_HIDDEN	(1<<0)
#define TCL_INVOKE_NO_UNKNOWN	(1<<1)
#define TCL_INVOKE_NO_TRACEBACK	(1<<2)

/*
 * ListSizeT is the type for holding list element counts. It's defined
 * simplify sharing source between Tcl8 and Tcl9.



 */
#if TCL_MAJOR_VERSION > 8

typedef size_t ListSizeT;

/*
 * SSIZE_MAX, NOT SIZE_MAX as negative differences need to be expressed
 * between values of the ListSizeT type so limit the range to signed
 */
#define ListSizeT_MAX ((ListSizeT)PTRDIFF_MAX)

#else

typedef int ListSizeT;
#define ListSizeT_MAX INT_MAX

#endif

/*
 * ListStore --
 *
 * A Tcl list's internal representation is defined through three structures.
 *
 * A ListStore struct is a structure that includes a variable size array that
 * serves as storage for a Tcl list. A contiguous sequence of slots in the
 * array, the "in-use" area, holds valid pointers to Tcl_Obj values that
 * belong to one or more Tcl lists. The unused slots before and after these
 * are free slots that may be used to prepend and append without having to
 * reallocate the struct. The ListStore may be shared amongst multiple lists
 * and reference counted.
 *
 * A ListSpan struct defines a sequence of slots within a ListStore. This sequence
 * always lies within the "in-use" area of the ListStore. Like ListStore, the
 * structure may be shared among multiple lists and is reference counted.
 *
 * A ListRep struct holds the internal representation of a Tcl list as stored
 * in a Tcl_Obj. It is composed of a ListStore and a ListSpan that together
 * define the content of the list. The ListSpan specifies the range of slots
 * within the ListStore that hold elements for this list. The ListSpan is
 * optional in which case the list includes all the "in-use" slots of the
 * ListStore.
 *
 */
typedef struct ListStore {
    ListSizeT firstUsed;    /* Index of first slot in use within slots[] */
    ListSizeT numUsed;      /* Number of slots in use (starting firstUsed) */
    ListSizeT numAllocated; /* Total number of slots[] array slots. */
    size_t refCount;           /* Number of references to this instance */
    int flags;              /* LISTSTORE_* flags */
    Tcl_Obj *slots[TCLFLEXARRAY];      /* Variable size array. Grown as needed */
} ListStore;

#define LISTSTORE_CANONICAL 0x1 /* All Tcl_Obj's referencing this
                                   store have their string representation
                                   derived from the list representation */

/* Max number of elements that can be contained in a list */
#define LIST_MAX                                               \
    ((ListSizeT_MAX - offsetof(ListStore, slots)) \
		   / sizeof(Tcl_Obj *))
/* Memory size needed for a ListStore to hold numSlots_ elements */
#define LIST_SIZE(numSlots_) \
	(offsetof(ListStore, slots) + ((numSlots_) * sizeof(Tcl_Obj *)))

/*
 * ListSpan --
 * See comments above for ListStore
 */
typedef struct ListSpan {
    ListSizeT spanStart;    /* Starting index of the span */
    ListSizeT spanLength;   /* Number of elements in the span */
    size_t refCount;     /* Count of references to this span record */
} ListSpan;
#ifndef LIST_SPAN_THRESHOLD /* May be set on build line */
#define LIST_SPAN_THRESHOLD 101
#endif

/*
 * ListRep --
 * See comments above for ListStore
 */
typedef struct ListRep {
    ListStore *storePtr;/* element array shared amongst different lists */
    ListSpan *spanPtr;  /* If not NULL, the span holds the range of slots
                           within *storePtr that contain this list elements. */
} ListRep;

/*
 * Macros used to get access list internal representations.
 *
 * Naming conventions:
 * ListRep* - expect a pointer to a valid ListRep
 * ListObj* - expect a pointer to a Tcl_Obj whose internal type is known to
 *            be a list (tclListType). Will crash otherwise.
 * TclListObj* - expect a pointer to a Tcl_Obj whose internal type may or may not
 *            be tclListType. These will convert as needed and return error if
 *            conversion not possible.
 */

/* Returns the starting slot for this listRep in the contained ListStore */
#define ListRepStart(listRepPtr_)                               \
    ((listRepPtr_)->spanPtr ? (listRepPtr_)->spanPtr->spanStart \
			    : (listRepPtr_)->storePtr->firstUsed)

/* Returns the number of elements in this listRep */
#define ListRepLength(listRepPtr_)                               \
    ((listRepPtr_)->spanPtr ? (listRepPtr_)->spanPtr->spanLength \
			    : (listRepPtr_)->storePtr->numUsed)

/* Returns a pointer to the first slot containing this ListRep elements */
#define ListRepElementsBase(listRepPtr_) \
    (&(listRepPtr_)->storePtr->slots[ListRepStart(listRepPtr_)])

/* Stores the number of elements and base address of the element array */
#define ListRepElements(listRepPtr_, objc_, objv_) \
    (((objv_) = ListRepElementsBase(listRepPtr_)), \
     ((objc_) = ListRepLength(listRepPtr_)))

/* Returns 1/0 whether the ListRep's ListStore is shared. */
#define ListRepIsShared(listRepPtr_) ((listRepPtr_)->storePtr->refCount > 1)

/* Returns a pointer to the ListStore component */
#define ListObjStorePtr(listObj_) \
    ((ListStore *)((listObj_)->internalRep.twoPtrValue.ptr1))

/* Returns a pointer to the ListSpan component */
#define ListObjSpanPtr(listObj_) \
    ((ListSpan *)((listObj_)->internalRep.twoPtrValue.ptr2))

/* Returns the ListRep internal representaton in a Tcl_Obj */
#define ListObjGetRep(listObj_, listRepPtr_)                 \
    do {                                                     \
	(listRepPtr_)->storePtr = ListObjStorePtr(listObj_); \
	(listRepPtr_)->spanPtr = ListObjSpanPtr(listObj_);   \
    } while (0)

/* Returns the length of the list */
#define ListObjLength(listObj_, len_)                                         \
    ((len_) = ListObjSpanPtr(listObj_) ? ListObjSpanPtr(listObj_)->spanLength \
				       : ListObjStorePtr(listObj_)->numUsed)

/* Returns the starting slot index of this list's elements in the ListStore */
#define ListObjStart(listObj_)                                      \
    (ListObjSpanPtr(listObj_) ? ListObjSpanPtr(listObj_)->spanStart \
			      : ListObjStorePtr(listObj_)->firstUsed)

/* Stores the element count and base address of this list's elements */
#define ListObjGetElements(listObj_, objc_, objv_) \
    (((objv_) = &ListObjStorePtr(listObj_)->slots[ListObjStart(listObj_)]), \
     (ListObjLength(listObj_, (objc_))))

/*
 * Returns 1/0 whether the internal representation (not the Tcl_Obj itself)
 * is shared.  Note by intent this only checks for sharing of ListStore,
 * not spans.
 */
#define ListObjRepIsShared(listObj_) (ListObjStorePtr(listObj_)->refCount > 1)

/*
 * Certain commands like concat are optimized if an existing string
 * representation of a list object is known to be in canonical format (i.e.
 * generated from the list representation). There are three conditions when
 * this will be the case:
 * (1) No string representation exists which means it will obviously have
 * to be generated from the list representation when needed
 * (2) The ListStore flags is marked canonical. This is done at the time
 * the string representation is generated from the list IF the list
 * representation does not have a span (see comments in UpdateStringOfList).
 * (3) The list representation does not have a span component. This is
 * because list Tcl_Obj's with spans are always created from existing lists
 * and never from strings (see SetListFromAny) and thus their string
 * representation will always be canonical.
 */
#define ListObjIsCanonical(listObj_)                             \
    (((listObj_)->bytes == NULL)                                 \
     || (ListObjStorePtr(listObj_)->flags & LISTSTORE_CANONICAL) \
     || ListObjSpanPtr(listObj_) != NULL)

/*
 * Converts the Tcl_Obj to a list if it isn't one and stores the element
 * count and base address of this list's elements in objcPtr_ and objvPtr_.
 * Return TCL_OK on success or TCL_ERROR if the Tcl_Obj cannot be
 * converted to a list.
 */
#define TclListObjGetElementsM(interp_, listObj_, objcPtr_, objvPtr_)    \
    (((listObj_)->typePtr == &tclListType)                              \
	 ? ((ListObjGetElements((listObj_), *(objcPtr_), *(objvPtr_))), \
	    TCL_OK)                                                     \
	 : Tcl_ListObjGetElements(                                      \
	     (interp_), (listObj_), (objcPtr_), (objvPtr_)))

/*
 * Converts the Tcl_Obj to a list if it isn't one and stores the element
 * count in lenPtr_.  Returns TCL_OK on success or TCL_ERROR if the
 * Tcl_Obj cannot be converted to a list.
 */
#define TclListObjLengthM(interp_, listObj_, lenPtr_)         \
    (((listObj_)->typePtr == &tclListType)                   \
	 ? ((ListObjLength((listObj_), *(lenPtr_))), TCL_OK) \
	 : Tcl_ListObjLength((interp_), (listObj_), (lenPtr_)))

#define TclListObjIsCanonical(listObj_) \
    (((listObj_)->typePtr == &tclListType) ? ListObjIsCanonical((listObj_)) : 0)

/*
 * Modes for collecting (or not) in the implementations of TclNRForeachCmd,
 * TclNRLmapCmd and their compilations.
 */

#define TCL_EACH_KEEP_NONE  0	/* Discard iteration result like [foreach] */

			    Tcl_Obj *objv[], int objc,
			    void *codePtr, CmdFrame *cfPtr, int cmd, size_t pc);
MODULE_SCOPE void	TclArgumentBCRelease(Tcl_Interp *interp,
			    CmdFrame *cfPtr);
MODULE_SCOPE void	TclArgumentGet(Tcl_Interp *interp, Tcl_Obj *obj,
			    CmdFrame **cfPtrPtr, int *wordPtr);
MODULE_SCOPE int	TclAsyncNotifier(int sigNumber, Tcl_ThreadId threadId,
			    void *clientData, int *flagPtr, int value);
MODULE_SCOPE void	TclAsyncMarkFromNotifier(void);
MODULE_SCOPE void	TclBAConvertIndices(size_t index, unsigned int *hiPtr,
			    unsigned int *loPtr);
MODULE_SCOPE size_t	TclBAInvertIndices(unsigned int hi, unsigned int lo);
MODULE_SCOPE double	TclBignumToDouble(const void *bignum);
MODULE_SCOPE int	TclByteArrayMatch(const unsigned char *string,
			    size_t strLen, const unsigned char *pattern,

MODULE_SCOPE double	TclFloor(const void *a);
MODULE_SCOPE void	TclFormatNaN(double value, char *buffer);
MODULE_SCOPE int	TclFSFileAttrIndex(Tcl_Obj *pathPtr,
			    const char *attributeName, int *indexPtr);
MODULE_SCOPE Tcl_Command TclNRCreateCommandInNs(Tcl_Interp *interp,
			    const char *cmdName, Tcl_Namespace *nsPtr,
			    Tcl_ObjCmdProc *proc, Tcl_ObjCmdProc *nreProc,

			    void *clientData, Tcl_CmdDeleteProc *deleteProc);
MODULE_SCOPE int	TclNREvalFile(Tcl_Interp *interp, Tcl_Obj *pathPtr,
			    const char *encodingName);
MODULE_SCOPE void	TclFSUnloadTempFile(Tcl_LoadHandle loadHandle);
MODULE_SCOPE int *	TclGetAsyncReadyPtr(void);
MODULE_SCOPE Tcl_Obj *	TclGetBgErrorHandler(Tcl_Interp *interp);
MODULE_SCOPE int	TclGetChannelFromObj(Tcl_Interp *interp,
			    Tcl_Obj *objPtr, Tcl_Channel *chanPtr,

			    Tcl_Obj *listPtr, Tcl_Obj *argPtr);
MODULE_SCOPE Tcl_Obj *	TclLindexFlat(Tcl_Interp *interp, Tcl_Obj *listPtr,
			    size_t indexCount, Tcl_Obj *const indexArray[]);
/* TIP #280 */
MODULE_SCOPE void	TclListLines(Tcl_Obj *listObj, size_t line, int n,
			    int *lines, Tcl_Obj *const *elems);
MODULE_SCOPE Tcl_Obj *	TclListObjCopy(Tcl_Interp *interp, Tcl_Obj *listPtr);
MODULE_SCOPE int	TclListObjAppendElements(Tcl_Interp *interp,
			    Tcl_Obj *toObj, size_t elemCount,
			    Tcl_Obj *const elemObjv[]);
MODULE_SCOPE Tcl_Obj *	TclListObjRange(Tcl_Obj *listPtr, size_t fromIdx,
			    size_t toIdx);
MODULE_SCOPE Tcl_Obj *	TclLsetList(Tcl_Interp *interp, Tcl_Obj *listPtr,
			    Tcl_Obj *indexPtr, Tcl_Obj *valuePtr);
MODULE_SCOPE Tcl_Obj *	TclLsetFlat(Tcl_Interp *interp, Tcl_Obj *listPtr,
			    size_t indexCount, Tcl_Obj *const indexArray[],
			    Tcl_Obj *valuePtr);

			    int code, int level, Tcl_Obj *returnOpts);
MODULE_SCOPE int	TclpObjLstat(Tcl_Obj *pathPtr, Tcl_StatBuf *buf);
MODULE_SCOPE Tcl_Obj *	TclpTempFileName(void);
MODULE_SCOPE Tcl_Obj *  TclpTempFileNameForLibrary(Tcl_Interp *interp,
			    Tcl_Obj* pathPtr);
MODULE_SCOPE Tcl_Obj *	TclNewFSPathObj(Tcl_Obj *dirPtr, const char *addStrRep,
			    size_t len);
MODULE_SCOPE void	TclpAlertNotifier(void *clientData);
MODULE_SCOPE void *TclpNotifierData(void);
MODULE_SCOPE void	TclpServiceModeHook(int mode);
MODULE_SCOPE void	TclpSetTimer(const Tcl_Time *timePtr);
MODULE_SCOPE int	TclpWaitForEvent(const Tcl_Time *timePtr);
MODULE_SCOPE void	TclpCreateFileHandler(int fd, int mask,
			    Tcl_FileProc *proc, void *clientData);
MODULE_SCOPE int	TclpDeleteFile(const void *path);
MODULE_SCOPE void	TclpDeleteFileHandler(int fd);
MODULE_SCOPE void	TclpFinalizeCondition(Tcl_Condition *condPtr);
MODULE_SCOPE void	TclpFinalizeMutex(Tcl_Mutex *mutexPtr);
MODULE_SCOPE void	TclpFinalizeNotifier(void *clientData);
MODULE_SCOPE void	TclpFinalizePipes(void);
MODULE_SCOPE void	TclpFinalizeSockets(void);
MODULE_SCOPE int	TclCreateSocketAddress(Tcl_Interp *interp,
			    struct addrinfo **addrlist,
			    const char *host, int port, int willBind,
			    const char **errorMsgPtr);
MODULE_SCOPE int	TclpThreadCreate(Tcl_ThreadId *idPtr,
			    Tcl_ThreadCreateProc *proc, void *clientData,
			    size_t stackSize, int flags);
MODULE_SCOPE size_t	TclpFindVariable(const char *name, size_t *lengthPtr);
MODULE_SCOPE void	TclpInitLibraryPath(char **valuePtr,
			    TCL_HASH_TYPE *lengthPtr, Tcl_Encoding *encodingPtr);
MODULE_SCOPE void	TclpInitLock(void);
MODULE_SCOPE void *TclpInitNotifier(void);
MODULE_SCOPE void	TclpInitPlatform(void);
MODULE_SCOPE void	TclpInitUnlock(void);
MODULE_SCOPE Tcl_Obj *	TclpObjListVolumes(void);
MODULE_SCOPE void	TclpGlobalLock(void);
MODULE_SCOPE void	TclpGlobalUnlock(void);
MODULE_SCOPE int	TclpMatchFiles(Tcl_Interp *interp, char *separators,
			    Tcl_DString *dirPtr, char *pattern, char *tail);
MODULE_SCOPE int	TclpObjNormalizePath(Tcl_Interp *interp,
			    Tcl_Obj *pathPtr, int nextCheckpoint);
MODULE_SCOPE void	TclpNativeJoinPath(Tcl_Obj *prefix, const char *joining);
MODULE_SCOPE Tcl_Obj *	TclpNativeSplitPath(Tcl_Obj *pathPtr, size_t *lenPtr);
MODULE_SCOPE Tcl_PathType TclpGetNativePathType(Tcl_Obj *pathPtr,
			    size_t *driveNameLengthPtr, Tcl_Obj **driveNameRef);
MODULE_SCOPE int	TclCrossFilesystemCopy(Tcl_Interp *interp,
			    Tcl_Obj *source, Tcl_Obj *target);
MODULE_SCOPE int	TclpMatchInDirectory(Tcl_Interp *interp,
			    Tcl_Obj *resultPtr, Tcl_Obj *pathPtr,
			    const char *pattern, Tcl_GlobTypeData *types);
MODULE_SCOPE void *TclpGetNativeCwd(void *clientData);
MODULE_SCOPE Tcl_FSDupInternalRepProc TclNativeDupInternalRep;
MODULE_SCOPE Tcl_Obj *	TclpObjLink(Tcl_Obj *pathPtr, Tcl_Obj *toPtr,
			    int linkType);
MODULE_SCOPE int	TclpObjChdir(Tcl_Obj *pathPtr);
MODULE_SCOPE Tcl_Channel TclpOpenTemporaryFile(Tcl_Obj *dirObj,
			    Tcl_Obj *basenameObj, Tcl_Obj *extensionObj,
			    Tcl_Obj *resultingNameObj);

#if TCL_UTF_MAX > 3
#define TclUtfToUniChar(str, chPtr) \
	(((UCHAR(*(str))) < 0x80) ?		\
	    ((*(chPtr) = UCHAR(*(str))), 1)	\
	    : Tcl_UtfToUniChar(str, chPtr))
#else
#define TclUtfToUniChar(str, chPtr) \
	(((UCHAR(*(str))) < 0x80) ?		\
	    ((*(chPtr) = UCHAR(*(str))), 1)	\
	    : Tcl_UtfToChar16(str, chPtr))
#endif

/*
 *----------------------------------------------------------------
 * Macro counterpart of the Tcl_NumUtfChars() function. To be used in speed-
 * -sensitive points where it pays to avoid a function call in the common case
 * of counting along a string of all one-byte characters.  The ANSI C
 * "prototype" for this macro is:
 *
 * MODULE_SCOPE void	TclNumUtfCharsM(int | size_t numChars, const char *bytes,
 *				size_t numBytes);
 *----------------------------------------------------------------
 */

#define TclNumUtfCharsM(numChars, bytes, numBytes) \
    do { \
	size_t _count, _i = (numBytes); \

EXTERN void		TclStaticLibrary(Tcl_Interp *interp,
				const char *prefix,
				Tcl_LibraryInitProc *initProc,
				Tcl_LibraryInitProc *safeInitProc);
/* 258 */
EXTERN Tcl_Obj *	TclpCreateTemporaryDirectory(Tcl_Obj *dirObj,
				Tcl_Obj *basenameObj);
/* 259 */
EXTERN int		TclMSB(size_t n);
/* 260 */
EXTERN Tcl_Obj *	TclListTestObj(int length, int leadingSpace,
				int endSpace);
/* 261 */
EXTERN void		TclListObjValidate(Tcl_Interp *interp,
				Tcl_Obj *listObj);

typedef struct TclIntStubs {
    int magic;
    void *hooks;

    void (*reserved0)(void);
    void (*reserved1)(void);

    Tcl_Obj * (*tclPtrGetVar) (Tcl_Interp *interp, Tcl_Var varPtr, Tcl_Var arrayPtr, Tcl_Obj *part1Ptr, Tcl_Obj *part2Ptr, int flags); /* 252 */
    Tcl_Obj * (*tclPtrSetVar) (Tcl_Interp *interp, Tcl_Var varPtr, Tcl_Var arrayPtr, Tcl_Obj *part1Ptr, Tcl_Obj *part2Ptr, Tcl_Obj *newValuePtr, int flags); /* 253 */
    Tcl_Obj * (*tclPtrIncrObjVar) (Tcl_Interp *interp, Tcl_Var varPtr, Tcl_Var arrayPtr, Tcl_Obj *part1Ptr, Tcl_Obj *part2Ptr, Tcl_Obj *incrPtr, int flags); /* 254 */
    int (*tclPtrObjMakeUpvar) (Tcl_Interp *interp, Tcl_Var otherPtr, Tcl_Obj *myNamePtr, int myFlags); /* 255 */
    int (*tclPtrUnsetVar) (Tcl_Interp *interp, Tcl_Var varPtr, Tcl_Var arrayPtr, Tcl_Obj *part1Ptr, Tcl_Obj *part2Ptr, int flags); /* 256 */
    void (*tclStaticLibrary) (Tcl_Interp *interp, const char *prefix, Tcl_LibraryInitProc *initProc, Tcl_LibraryInitProc *safeInitProc); /* 257 */
    Tcl_Obj * (*tclpCreateTemporaryDirectory) (Tcl_Obj *dirObj, Tcl_Obj *basenameObj); /* 258 */


    int (*tclMSB) (size_t n); /* 259 */
    Tcl_Obj * (*tclListTestObj) (int length, int leadingSpace, int endSpace); /* 260 */
    void (*tclListObjValidate) (Tcl_Interp *interp, Tcl_Obj *listObj); /* 261 */
} TclIntStubs;

extern const TclIntStubs *tclIntStubsPtr;

#ifdef __cplusplus
}
#endif

	(tclIntStubsPtr->tclPtrObjMakeUpvar) /* 255 */
#define TclPtrUnsetVar \
	(tclIntStubsPtr->tclPtrUnsetVar) /* 256 */
#define TclStaticLibrary \
	(tclIntStubsPtr->tclStaticLibrary) /* 257 */
#define TclpCreateTemporaryDirectory \
	(tclIntStubsPtr->tclpCreateTemporaryDirectory) /* 258 */


#define TclMSB \
	(tclIntStubsPtr->tclMSB) /* 259 */
#define TclListTestObj \
	(tclIntStubsPtr->tclListTestObj) /* 260 */
#define TclListObjValidate \
	(tclIntStubsPtr->tclListObjValidate) /* 261 */

#endif /* defined(USE_TCL_STUBS) */

/* !END!: Do not edit above this line. */

#if defined(USE_TCL_STUBS)
#undef Tcl_StaticLibrary

    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument vector. */
{
    Alias *aliasPtr = (Alias *)clientData;
    int prefc, cmdc, i;
    Tcl_Obj **prefv, **cmdv;
    Tcl_Obj *listPtr;
    ListRep listRep;
    int flags = TCL_EVAL_INVOKE;

    /*
     * Append the arguments to the command prefix and invoke the command in
     * the target interp's global namespace.
     */

    prefc = aliasPtr->objc;
    prefv = &aliasPtr->objPtr;
    cmdc = prefc + objc - 1;

    /* TODO - encapsulate this into tclListObj.c */
    listPtr = Tcl_NewListObj(cmdc, NULL);
    ListObjGetRep(listPtr, &listRep);
    cmdv = ListRepElementsBase(&listRep);
    listRep.storePtr->numUsed = cmdc;
    if (listRep.spanPtr) {
	listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
	listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
    }

    prefv = &aliasPtr->objPtr;
    memcpy(cmdv, prefv, prefc * sizeof(Tcl_Obj *));
    memcpy(cmdv+prefc, objv+1, (objc-1) * sizeof(Tcl_Obj *));

    for (i=0; i<cmdc; i++) {
	Tcl_IncrRefCount(cmdv[i]);
    }

    /*
     * Use the ensemble rewriting machinery to ensure correct error messages:

/*
 * tclListObj.c --
 *
 *	This file contains functions that implement the Tcl list object type.
 *


 * Copyright © 2022 Ashok P. Nadkarni.  All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include <assert.h>

/*
 * TODO - memmove is fast. Measure at what size we should prefer memmove
 * (for unshared objects only) in lieu of range operations. On the other
 * hand, more cache dirtied?
 */

/*
 * Macros for validation and bug checking.
 */

/*
 * Control whether asserts are enabled. Always enable in debug builds. In non-debug
 * builds, can be set with cdebug="-DENABLE_LIST_ASSERTS" on the nmake command line.
 */
#ifdef ENABLE_LIST_ASSERTS
# ifdef NDEBUG
#  undef NDEBUG /* Activate assert() macro */
# endif
#else
# ifndef NDEBUG
#  define ENABLE_LIST_ASSERTS /* Always activate list asserts in debug mode */
# endif
#endif

#ifdef ENABLE_LIST_ASSERTS

#define LIST_ASSERT(cond_) assert(cond_) /* TODO - is there a Tcl-specific one? */
/*
 * LIST_INDEX_ASSERT is to catch errors with negative indices and counts
 * being passed AFTER validation. On Tcl9 length types are unsigned hence
 * the checks against LIST_MAX. On Tcl8 length types are signed hence the
 * also checks against 0.
 */
#define LIST_INDEX_ASSERT(idxarg_)                                 \
    do {                                                           \
	ListSizeT idx_ = (idxarg_); /* To guard against ++ etc. */ \
	LIST_ASSERT(idx_ != TCL_INDEX_NONE && idx_ < LIST_MAX);                 \
    } while (0)
/* Ditto for counts except upper limit is different */
#define LIST_COUNT_ASSERT(countarg_)                                   \
    do {                                                               \
	ListSizeT count_ = (countarg_); /* To guard against ++ etc. */ \
	LIST_ASSERT(count_ != TCL_INDEX_NONE && count_ <= LIST_MAX);                \
    } while (0)

#else

#define LIST_ASSERT(cond_) ((void) 0)
#define LIST_INDEX_ASSERT(idx_) ((void) 0)
#define LIST_COUNT_ASSERT(count_) ((void) 0)

#endif

/* Checks for when caller should have already converted to internal list type */
#define LIST_ASSERT_TYPE(listObj_) \
    LIST_ASSERT((listObj_)->typePtr == &tclListType);


/*
 * If ENABLE_LIST_INVARIANTS is enabled (-DENABLE_LIST_INVARIANTS from the
 * command line), the entire list internal representation is checked for
 * inconsistencies. This has a non-trivial cost so has to be separately
 * enabled and not part of assertions checking. However, the test suite does
 * invoke ListRepValidate directly even without ENABLE_LIST_INVARIANTS.
 */
#ifdef ENABLE_LIST_INVARIANTS
#define LISTREP_CHECK(listRepPtr_) ListRepValidate(listRepPtr_, __FILE__, __LINE__)
#else
#define LISTREP_CHECK(listRepPtr_) (void) 0
#endif

/*
 * Flags used for controlling behavior of allocation of list
 * internal representations.
 *
 * If the LISTREP_PANIC_ON_FAIL bit is set, the function will panic if
 * list is too large or memory cannot be allocated. Without the flag
 * a NULL pointer is returned.
 *
 * The LISTREP_SPACE_FAVOR_NONE, LISTREP_SPACE_FAVOR_FRONT,
 * LISTREP_SPACE_FAVOR_BACK, LISTREP_SPACE_ONLY_BACK flags are used to
 * control additional space when allocating.
 * - If none of these flags is present, the exact space requested is
 *   allocated, nothing more.
 * - Otherwise, if only LISTREP_FAVOR_FRONT is present, extra space is
 *   allocated with more towards the front.
 * - Conversely, if only LISTREP_FAVOR_BACK is present extra space is allocated
 *   with more to the back.
 * - If both flags are present (LISTREP_SPACE_FAVOR_NONE), the extra space
 *   is equally apportioned.
 * - Finally if LISTREP_SPACE_ONLY_BACK is present, ALL extra space is at
 *   the back.
 */
#define LISTREP_PANIC_ON_FAIL         0x00000001
#define LISTREP_SPACE_FAVOR_FRONT     0x00000002
#define LISTREP_SPACE_FAVOR_BACK      0x00000004
#define LISTREP_SPACE_ONLY_BACK       0x00000008
#define LISTREP_SPACE_FAVOR_NONE \
    (LISTREP_SPACE_FAVOR_FRONT | LISTREP_SPACE_FAVOR_BACK)
#define LISTREP_SPACE_FLAGS                               \
    (LISTREP_SPACE_FAVOR_FRONT | LISTREP_SPACE_FAVOR_BACK \
     | LISTREP_SPACE_ONLY_BACK)

/*
 * Prototypes for non-inline static functions defined later in this file:
 */
static int	MemoryAllocationError(Tcl_Interp *, size_t size);
static int	ListLimitExceededError(Tcl_Interp *);
static ListStore *ListStoreNew(ListSizeT objc, Tcl_Obj *const objv[], int flags);
static int	ListRepInit(ListSizeT objc, Tcl_Obj *const objv[], int flags, ListRep *);
static int	ListRepInitAttempt(Tcl_Interp *,
		    ListSizeT objc,
		    Tcl_Obj *const objv[],
		    ListRep *);
static void	ListRepClone(ListRep *fromRepPtr, ListRep *toRepPtr, int flags);
static void	ListRepUnsharedFreeUnreferenced(const ListRep *repPtr);
static int	TclListObjGetRep(Tcl_Interp *, Tcl_Obj *listPtr, ListRep *repPtr);
static void	ListRepRange(ListRep *srcRepPtr,
		    ListSizeT rangeStart,
		    ListSizeT rangeEnd,
		    int preserveSrcRep,
		    ListRep *rangeRepPtr);
static ListStore *ListStoreReallocate(ListStore *storePtr, ListSizeT numSlots);
static void	ListRepValidate(const ListRep *repPtr, const char *file,
		    int lineNum);
static void	DupListInternalRep(Tcl_Obj *srcPtr, Tcl_Obj *copyPtr);
static void	FreeListInternalRep(Tcl_Obj *listPtr);
static int	SetListFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void	UpdateStringOfList(Tcl_Obj *listPtr);

/*
 * The structure below defines the list Tcl object type by means of functions
 * that can be invoked by generic object code.
 *
 * The internal representation of a list object is ListRep defined in tcl.h.






 */

const Tcl_ObjType tclListType = {
    "list",			/* name */
    FreeListInternalRep,	/* freeIntRepProc */
    DupListInternalRep,		/* dupIntRepProc */
    UpdateStringOfList,		/* updateStringProc */
    SetListFromAny		/* setFromAnyProc */
};

/* Macros to manipulate the List internal rep */
#define ListRepIncrRefs(repPtr_)            \
    do {                                    \
	(repPtr_)->storePtr->refCount++;    \
	if ((repPtr_)->spanPtr)             \
	    (repPtr_)->spanPtr->refCount++; \
    } while (0)

/* Returns number of free unused slots at the back of the ListRep's ListStore */
#define ListRepNumFreeTail(repPtr_) \
    ((repPtr_)->storePtr->numAllocated \
     - ((repPtr_)->storePtr->firstUsed + (repPtr_)->storePtr->numUsed))

/* Returns number of free unused slots at the front of the ListRep's ListStore */
#define ListRepNumFreeHead(repPtr_) ((repPtr_)->storePtr->firstUsed)

/* Returns a pointer to the slot corresponding to list index listIdx_ */
#define ListRepSlotPtr(repPtr_, listIdx_) \
    (&(repPtr_)->storePtr->slots[ListRepStart(repPtr_) + (listIdx_)])

/*
 * Macros to replace the internal representation in a Tcl_Obj. There are
 * subtle differences in each so make sure to use the right one to avoid
 * memory leaks, access to freed memory and the like.
 *
 * ListObjStompRep - assumes the Tcl_Obj internal representation can be
 * overwritten AND that the passed ListRep already has reference counts that
 * include the reference from the Tcl_Obj. Basically just copies the pointers
 * and sets the internal Tcl_Obj type to list
 *
 * ListObjOverwriteRep - like ListObjOverwriteRep but additionally
 * increments reference counts on the passed ListRep. Generally used when
 * the string representation of the Tcl_Obj is not to be modified.
 *
 * ListObjReplaceRepAndInvalidate - Like ListObjOverwriteRep but additionally
 * assumes the Tcl_Obj internal rep is valid (and possibly even same as
 * passed ListRep) and frees it first. Additionally invalidates the string
 * representation. Generally used when modifying a Tcl_Obj value.
 */
#define ListObjStompRep(objPtr_, repPtr_)                              \
    do {                                                               \
	(objPtr_)->internalRep.twoPtrValue.ptr1 = (repPtr_)->storePtr; \
	(objPtr_)->internalRep.twoPtrValue.ptr2 = (repPtr_)->spanPtr;  \
	(objPtr_)->typePtr = &tclListType;                             \
    } while (0)

#define ListObjOverwriteRep(objPtr_, repPtr_) \
    do {                                      \
	ListRepIncrRefs(repPtr_);             \
	ListObjStompRep(objPtr_, repPtr_);    \
    } while (0)

#define ListObjReplaceRepAndInvalidate(objPtr_, repPtr_)           \
    do {                                                           \
	/* Note order important, don't use ListObjOverwriteRep! */ \
	ListRepIncrRefs(repPtr_);                                  \
	TclFreeInternalRep(objPtr_);                               \
	TclInvalidateStringRep(objPtr_);                           \
	ListObjStompRep(objPtr_, repPtr_);                         \
    } while (0)

/*
 *------------------------------------------------------------------------
 *
 * ListSpanNew --
 *
 *    Allocates and initializes memory for a new ListSpan. The reference
 *    count on the returned struct is 0.
 *
 * Results:
 *    Non-NULL pointer to the allocated ListSpan.
 *
 * Side effects:
 *    The function will panic on memory allocation failure.
 *
 *------------------------------------------------------------------------
 */
static inline ListSpan *
ListSpanNew(
    ListSizeT firstSlot, /* Starting slot index of the span */
    ListSizeT numSlots)  /* Number of slots covered by the span */
{
    ListSpan *spanPtr = (ListSpan *) Tcl_Alloc(sizeof(*spanPtr));
    spanPtr->refCount = 0;
    spanPtr->spanStart = firstSlot;
    spanPtr->spanLength = numSlots;
    return spanPtr;
}

/*
 *------------------------------------------------------------------------
 *
 * ListSpanDecrRefs --
 *
 *   Decrements the reference count on a span, freeing the memory if
 *   it drops to zero or less.
 *
 * Results:
 *   None.
 *
 * Side effects:
 *   The memory may be freed.
 *
 *------------------------------------------------------------------------
 */
static inline void
ListSpanDecrRefs(ListSpan *spanPtr)
{
    if (spanPtr->refCount <= 1) {
	Tcl_Free(spanPtr);
    } else {
	spanPtr->refCount -= 1;
    }
}

/*
 *------------------------------------------------------------------------
 *
 * ListSpanMerited --
 *
 *    Creation of a new list may sometimes be done as a span on existing
 *    storage instead of allocating new. The tradeoff is that if the
 *    original list is released, the new span-based list may hold on to
 *    more memory than desired. This function implements heuristics for
 *    deciding which option is better.
 *
 * Results:
 *    Returns non-0 if a span-based list is likely to be more optimal
 *    and 0 if not.
 *
 * Side effects:
 *    None.
 *
 *------------------------------------------------------------------------
 */
static inline int
ListSpanMerited(
    ListSizeT length,                 /* Length of the proposed span */
    ListSizeT usedStorageLength,      /* Number of slots currently in used */
    ListSizeT allocatedStorageLength) /* Length of the currently allocation */
{
    /*
     TODO
     - heuristics thresholds need to be determined
     - currently, information about the sharing (ref count) of existing
       storage is not passed. Perhaps it should be. For example if the
       existing storage has a "large" ref count, then it might make sense
       to do even a small span.
     */

    if (length < LIST_SPAN_THRESHOLD) {
	return 0;/* No span for small lists */
    }
    if (length < (allocatedStorageLength / 2 - allocatedStorageLength / 8)) {
	return 0; /* No span if less than 3/8 of allocation */
    }
    if (length < usedStorageLength / 2) {
	return 0; /* No span if less than half current storage */
    }

    return 1;
}

/*
 *------------------------------------------------------------------------
 *
 * ListStoreUpSize --
 *
 *    For reasons of efficiency, extra space is allocated for a ListStore
 *    compared to what was requested. This function calculates how many
 *    slots should actually be allocated for a given request size.
 *
 * Results:
 *    Number of slots to allocate.
 *
 * Side effects:
 *    None.
 *
 *------------------------------------------------------------------------
 */
static inline ListSizeT
ListStoreUpSize(ListSizeT numSlotsRequested) {
    /* TODO -how much extra? May be double only for smaller requests? */
    return numSlotsRequested < (LIST_MAX / 2) ? 2 * numSlotsRequested
						 : LIST_MAX;
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepFreeUnreferenced --
 *
 *    Inline wrapper for ListRepUnsharedFreeUnreferenced that does quick checks
 *    before calling it.
 *
 *    IMPORTANT: this function must not be called on an internal
 *    representation of a Tcl_Obj that is itself shared.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    See comments for ListRepUnsharedFreeUnreferenced.
 *
 *------------------------------------------------------------------------
 */
static inline void
ListRepFreeUnreferenced(const ListRep *repPtr)
{
    if (! ListRepIsShared(repPtr) && repPtr->spanPtr) {
        /* T:listrep-1.5.1 */
	ListRepUnsharedFreeUnreferenced(repPtr);
    }
}

/*
 *------------------------------------------------------------------------
 *
 * ObjArrayIncrRefs --
 *
 *    Increments the reference counts for Tcl_Obj's in a subarray.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    As above.
 *
 *------------------------------------------------------------------------
 */
static inline void
ObjArrayIncrRefs(
    Tcl_Obj * const *objv,  /* Pointer to the array */
    ListSizeT startIdx,     /* Starting index of subarray within objv */
    ListSizeT count)        /* Number of elements in the subarray */
{
    Tcl_Obj * const *end;
    LIST_INDEX_ASSERT(startIdx);
    LIST_COUNT_ASSERT(count);
    objv += startIdx;
    end = objv + count;
    while (objv < end) {
	Tcl_IncrRefCount(*objv);
	++objv;
    }
}

/*
 *------------------------------------------------------------------------
 *
 * ObjArrayDecrRefs --
 *
 *    Decrements the reference counts for Tcl_Obj's in a subarray.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    As above.
 *
 *------------------------------------------------------------------------
 */
static inline void
ObjArrayDecrRefs(
    Tcl_Obj * const *objv, /* Pointer to the array */
    ListSizeT startIdx,    /* Starting index of subarray within objv */
    ListSizeT count)       /* Number of elements in the subarray */
{
    Tcl_Obj * const *end;
    LIST_INDEX_ASSERT(startIdx);
    LIST_COUNT_ASSERT(count);
    objv += startIdx;
    end = objv + count;
    while (objv < end) {
	Tcl_DecrRefCount(*objv);
	++objv;
    }
}

/*
 *------------------------------------------------------------------------
 *
 * ObjArrayCopy --
 *
 *    Copies an array of Tcl_Obj* pointers.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Reference counts on copied Tcl_Obj's are incremented.
 *
 *------------------------------------------------------------------------
 */
static inline void
ObjArrayCopy(
    Tcl_Obj **to,          /* Destination */
    ListSizeT count,       /* Number of pointers to copy */
    Tcl_Obj *const from[]) /* Source array of Tcl_Obj* */
{
    Tcl_Obj **end;
    LIST_COUNT_ASSERT(count);
    end = to + count;
    /* TODO - would memmove followed by separate IncrRef loop be faster? */
    while (to < end) {
	Tcl_IncrRefCount(*from);
	*to++ = *from++;
    }
}

/*
 *------------------------------------------------------------------------
 *
 * MemoryAllocationError --
 *
 *    Generates a memory allocation failure error.
 *
 * Results:
 *    Always TCL_ERROR.
 *
 * Side effects:
 *    Error message and code are stored in the interpreter if not NULL.
 *
 *------------------------------------------------------------------------
 */
static int
MemoryAllocationError(
    Tcl_Interp *interp, /* Interpreter for error message. May be NULL */
    ListSizeT size)        /* Size of attempted allocation that failed */
{
    if (interp != NULL) {
	Tcl_SetObjResult(
	    interp,
	    Tcl_ObjPrintf(
		"list construction failed: unable to alloc %" TCL_LL_MODIFIER
		"u bytes",
		(Tcl_WideInt)size));
	Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
    }
    return TCL_ERROR;
}

/*
 *------------------------------------------------------------------------
 *
 * ListLimitExceeded --
 *
 *    Generates an error for exceeding maximum list size.
 *
 * Results:
 *    Always TCL_ERROR.
 *
 * Side effects:
 *    Error message and code are stored in the interpreter if not NULL.
 *
 *------------------------------------------------------------------------
 */
static int
ListLimitExceededError(Tcl_Interp *interp)
{
    if (interp != NULL) {
	Tcl_SetObjResult(
	    interp,
	    Tcl_NewStringObj("max length of a Tcl list exceeded", -1));
	Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
    }
    return TCL_ERROR;
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepUnsharedShiftDown --
 *
 *    Shifts the "in-use" contents in the ListStore for a ListRep down
 *    by the given number of slots. The ListStore must be unshared and
 *    the free space at the front of the storage area must be big enough.
 *    It is the caller's responsibility to check.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The contents of the ListRep's ListStore area are shifted down in the
 *    storage area. The ListRep's ListSpan is updated accordingly.
 *
 *------------------------------------------------------------------------
 */
static inline void
ListRepUnsharedShiftDown(ListRep *repPtr, ListSizeT shiftCount)
{
    ListStore *storePtr;

    LISTREP_CHECK(repPtr);
    LIST_ASSERT(!ListRepIsShared(repPtr));

    storePtr = repPtr->storePtr;

    LIST_COUNT_ASSERT(shiftCount);
    LIST_ASSERT(storePtr->firstUsed >= shiftCount);

    memmove(&storePtr->slots[storePtr->firstUsed - shiftCount],
	    &storePtr->slots[storePtr->firstUsed],
	    storePtr->numUsed * sizeof(Tcl_Obj *));
    storePtr->firstUsed -= shiftCount;
    if (repPtr->spanPtr) {
	repPtr->spanPtr->spanStart -= shiftCount;
	LIST_ASSERT(repPtr->spanPtr->spanLength == storePtr->numUsed);
    } else {
	/*
	 * If there was no span, firstUsed must have been 0 (Invariant)
	 * AND shiftCount must have been 0 (<= firstUsed on call)
	 * In other words, this would have been a no-op
	 */

	LIST_ASSERT(storePtr->firstUsed == 0);
	LIST_ASSERT(shiftCount == 0);
    }

    LISTREP_CHECK(repPtr);
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepUnsharedShiftUp --
 *
 *    Shifts the "in-use" contents in the ListStore for a ListRep up
 *    by the given number of slots. The ListStore must be unshared and
 *    the free space at the back of the storage area must be big enough.
 *    It is the caller's responsibility to check.
 *    TODO - this function is not currently used.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The contents of the ListRep's ListStore area are shifted up in the
 *    storage area. The ListRep's ListSpan is updated accordingly.
 *
 *------------------------------------------------------------------------
 */
#if 0
static inline void
ListRepUnsharedShiftUp(ListRep *repPtr, ListSizeT shiftCount)
{
    ListStore *storePtr;

    LISTREP_CHECK(repPtr);
    LIST_ASSERT(!ListRepIsShared(repPtr));
    LIST_COUNT_ASSERT(shiftCount);

    storePtr = repPtr->storePtr;
    LIST_ASSERT((storePtr->firstUsed + storePtr->numUsed + shiftCount)
		<= storePtr->numAllocated);

    memmove(&storePtr->slots[storePtr->firstUsed + shiftCount],
	    &storePtr->slots[storePtr->firstUsed],
	    storePtr->numUsed * sizeof(Tcl_Obj *));
    storePtr->firstUsed += shiftCount;
    if (repPtr->spanPtr) {
	repPtr->spanPtr->spanStart += shiftCount;
    } else {
	/* No span means entire original list is span */
	/* Should have been zero before shift - Invariant TBD */
	LIST_ASSERT(storePtr->firstUsed == shiftCount);
	repPtr->spanPtr = ListSpanNew(shiftCount, storePtr->numUsed);
    }

    LISTREP_CHECK(repPtr);
}
#endif

/*
 *------------------------------------------------------------------------
 *
 * ListRepValidate --
 *
 *	Checks all invariants for a ListRep and panics on failure.
 *	Note this is independent of NDEBUG, assert etc.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Panics if any invariant is not met.
 *
 *------------------------------------------------------------------------
 */
static void
ListRepValidate(const ListRep *repPtr, const char *file, int lineNum)
{
    ListStore *storePtr = repPtr->storePtr;
    const char *condition;

    (void)storePtr; /* To stop gcc from whining about unused vars */

#define INVARIANT(cond_)        \
    do {                        \
	if (!(cond_)) {         \
	    condition = #cond_; \
	    goto failure;       \
	}                       \
    } while (0)

    /* Separate each condition so line number gives exact reason for failure */
    INVARIANT(storePtr != NULL);
    INVARIANT(storePtr->numAllocated <= LIST_MAX);
    INVARIANT(storePtr->firstUsed < storePtr->numAllocated);
    INVARIANT(storePtr->numUsed <= storePtr->numAllocated);
    INVARIANT(storePtr->firstUsed <= (storePtr->numAllocated - storePtr->numUsed));

    if (! ListRepIsShared(repPtr)) {
	/*
	 * If this is the only reference and there is no span, then store
	 * occupancy must begin at 0
	 */
	INVARIANT(repPtr->spanPtr || repPtr->storePtr->firstUsed == 0);
    }

    INVARIANT(ListRepStart(repPtr) >= storePtr->firstUsed);
    INVARIANT(ListRepLength(repPtr) <= storePtr->numUsed);
    INVARIANT(ListRepStart(repPtr) <= (storePtr->firstUsed + storePtr->numUsed - ListRepLength(repPtr)));

#undef INVARIANT

    return;

failure:
    Tcl_Panic("List internal failure in %s line %d. Condition: %s",
	      file,
	      lineNum,
	      condition);
}

/*
 *------------------------------------------------------------------------
 *
 * TclListObjValidate --
 *
 *    Wrapper around ListRepValidate. Primarily used from test suite.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Will panic if internal structure is not consistent or if object
 *    cannot be converted to a list object.
 *
 *------------------------------------------------------------------------
 */
void
TclListObjValidate(Tcl_Interp *interp, Tcl_Obj *listObj)
{
    ListRep listRep;
    if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {
	Tcl_Panic("Object passed to TclListObjValidate cannot be converted to "
		  "a list object.");
    }
    ListRepValidate(&listRep, __FILE__, __LINE__);
}

/*
 *----------------------------------------------------------------------
 *
 * ListStoreNew --
 *
 *	Allocates a new ListStore with space for at least objc elements. objc
 *	must be > 0.  If objv!=NULL, initializes with the first objc values

 *	in that array.  If objv==NULL, initalize 0 elements, with space
 *	to add objc more.
 *
 *      Normally the function allocates the exact space requested unless
 *      the flags arguments has any LISTREP_SPACE_*
 *      bits set. See the comments for those #defines.
 *

 * Results:
 *      On success, a pointer to the allocated ListStore is returned.
 *      On allocation failure, panics if LISTREP_PANIC_ON_FAIL is set in
 *      flags; otherwise returns NULL.
 *
 * Side effects:

 *	The ref counts of the elements in objv are incremented on success
 *	since the returned ListStore references them.
 *
 *----------------------------------------------------------------------
 */

static ListStore *
ListStoreNew(
    ListSizeT objc,
    Tcl_Obj *const objv[],
    int flags)
{
    ListStore *storePtr;
    ListSizeT capacity;

    /*
     * First check to see if we'd overflow and try to allocate an object
     * larger than our memory allocator allows.
     */
    if (objc > LIST_MAX) {
	if (flags & LISTREP_PANIC_ON_FAIL) {
	    Tcl_Panic("max length of a Tcl list exceeded");
	}
	return NULL;
    }

    if (flags & LISTREP_SPACE_FLAGS) {
	capacity = ListStoreUpSize(objc);
    } else {
	capacity = objc;
    }

    storePtr = (ListStore *)Tcl_AttemptAlloc(LIST_SIZE(capacity));
    if (storePtr == NULL && capacity != objc) {
	capacity = objc; /* Try allocating exact size */
	storePtr = (ListStore *)Tcl_AttemptAlloc(LIST_SIZE(capacity));
    }
    if (storePtr == NULL) {
	if (flags & LISTREP_PANIC_ON_FAIL) {
	    Tcl_Panic("list creation failed: unable to alloc %" TCL_Z_MODIFIER "u bytes",
		    LIST_SIZE(objc));
	}
	return NULL;
    }


    storePtr->refCount = 0;
    storePtr->flags = 0;
    storePtr->numAllocated = capacity;
    if (capacity == objc) {
	storePtr->firstUsed = 0;
    } else {
	ListSizeT extra = capacity - objc;
	int spaceFlags = flags & LISTREP_SPACE_FLAGS;
	if (spaceFlags == LISTREP_SPACE_ONLY_BACK) {
	    storePtr->firstUsed = 0;
	} else if (spaceFlags == LISTREP_SPACE_FAVOR_FRONT) {
	    /* Leave more space in the front */
	    storePtr->firstUsed =
		extra - (extra / 4); /* NOT same as 3*extra/4 */
	} else if (spaceFlags == LISTREP_SPACE_FAVOR_BACK) {
	    /* Leave more space in the back */
	    storePtr->firstUsed = extra / 4;
	} else {
	    /* Apportion equally */
	    storePtr->firstUsed = extra / 2;
	}
    }

    if (objv) {
	storePtr->numUsed = objc;

	ObjArrayCopy(&storePtr->slots[storePtr->firstUsed], objc, objv);






    } else {
	storePtr->numUsed = 0;
    }

    return storePtr;
}

/*
 *------------------------------------------------------------------------
 *
 * ListStoreReallocate --
 *
 *    Reallocates the memory for a ListStore.
 *
 * Results:
 *    Pointer to the ListStore which may be the same as storePtr or pointer
 *    to a new block of memory. On reallocation failure, NULL is returned.
 *
 *
 * Side effects:
 *    The memory pointed to by storePtr is freed if it a new block has to
 *    be returned.
 *
 *
 *------------------------------------------------------------------------
 */
ListStore *
ListStoreReallocate (ListStore *storePtr, ListSizeT numSlots)
{
    ListSizeT newCapacity;
    ListStore *newStorePtr;

    newCapacity = ListStoreUpSize(numSlots);
    newStorePtr =
	(ListStore *)Tcl_AttemptRealloc(storePtr, LIST_SIZE(newCapacity));
    if (newStorePtr == NULL) {
	newCapacity = numSlots;
	newStorePtr = (ListStore *)Tcl_AttemptRealloc(storePtr,
						    LIST_SIZE(newCapacity));
	if (newStorePtr == NULL)
	    return NULL;
    }
    /* Only the capacity has changed, fix it in the header */
    newStorePtr->numAllocated = newCapacity;
    return newStorePtr;
}

/*
 *----------------------------------------------------------------------
 *
 * ListRepInit --
 *
 *      Initializes a ListRep to hold a list internal representation
 *      with space for objc elements.
 *
 *      objc must be > 0. If objv!=NULL, initializes with the first objc
 *      values in that array. If objv==NULL, initalize list internal rep to
 *      have 0 elements, with space to add objc more.
 *
 *	Normally the function allocates the exact space requested unless
 *	the flags arguments has one of the LISTREP_SPACE_* bits set.
 *	See the comments for those #defines.
 *
 *      The reference counts of the ListStore and ListSpan (if present)
 *	pointed to by the initialized repPtr are set to zero.
 *	Caller has to manage them as necessary.
 *
 * Results:
 *      On success, TCL_OK is returned with *listRepPtr initialized.
 *      On failure, panics if LISTREP_PANIC_ON_FAIL is set in flags; otherwise
 *	returns TCL_ERROR with *listRepPtr fields set to NULL.
 *
 * Side effects:
 *	The ref counts of the elements in objv are incremented since the
 *	resulting list now refers to them.
 *
 *----------------------------------------------------------------------
 */
static int
ListRepInit(
    ListSizeT objc,
    Tcl_Obj *const objv[],
    int flags,
    ListRep *repPtr
    )
{
    ListStore *storePtr;

    storePtr = ListStoreNew(objc, objv, flags);
    if (storePtr) {
	repPtr->storePtr = storePtr;
	if (storePtr->firstUsed == 0) {
	    repPtr->spanPtr = NULL;
	} else {
	    repPtr->spanPtr =
		ListSpanNew(storePtr->firstUsed, storePtr->numUsed);
	}
	return TCL_OK;
    }
    /*
     * Initialize to keep gcc happy at the call site. Else it complains
     * about possibly uninitialized use.
     */
    repPtr->storePtr = NULL;
    repPtr->spanPtr = NULL;
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * ListRepInitAttempt --
 *
 *	Creates a list internal rep with space for objc elements. See
 *	ListRepInit for requirements for parameters (in particular objc must
 *	be > 0). This function only adds error messages to the interpreter if
 *	not NULL.
 *
 *      The reference counts of the ListStore and ListSpan (if present)
 *	pointed to by the initialized repPtr are set to zero.
 *	Caller has to manage them as necessary.
 *
 * Results:
 *      On success, TCL_OK is returned with *listRepPtr initialized.
 *	On allocation failure, returnes TCL_ERROR with an error message
 *	in the interpreter if non-NULL.
 *
 * Side effects:
 *	The ref counts of the elements in objv are incremented since the
 *	resulting list now refers to them.
 *
 *----------------------------------------------------------------------
 */

static int
ListRepInitAttempt(
    Tcl_Interp *interp,
    ListSizeT objc,
    Tcl_Obj *const objv[],
    ListRep *repPtr)
{
    int result = ListRepInit(objc, objv, 0, repPtr);

    if (result != TCL_OK && interp != NULL) {
	if (objc > LIST_MAX) {
	    ListLimitExceededError(interp);


	} else {


	    MemoryAllocationError(interp, LIST_SIZE(objc));
	}
    }
    return result;
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepClone --
 *
 *    Does a deep clone of an existing ListRep.
 *
 *    Normally the function allocates the exact space needed unless
 *    the flags arguments has one of the LISTREP_SPACE_* bits set.
 *    See the comments for those #defines.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The toRepPtr location is initialized with the ListStore and ListSpan
 *    (if needed) containing a copy of the list elements in fromRepPtr.
 *    The function will panic if memory cannot be allocated.
 *
 *------------------------------------------------------------------------
 */
static void
ListRepClone(ListRep *fromRepPtr, ListRep *toRepPtr, int flags)
{
    Tcl_Obj **fromObjs;
    ListSizeT numFrom;

    ListRepElements(fromRepPtr, numFrom, fromObjs);
    ListRepInit(numFrom, fromObjs, flags | LISTREP_PANIC_ON_FAIL, toRepPtr);
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepUnsharedFreeUnreferenced --
 *
 *    Frees any Tcl_Obj's from the "in-use" area of the ListStore for a
 *    ListRep that are not actually references from any lists.
 *
 *    IMPORTANT: this function must not be called on a shared internal
 *    representation or the internal representation of a shared Tcl_Obj.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The firstUsed and numUsed fields of the ListStore are updated to
 *    reflect the new "in-use" extent.
 *
 *------------------------------------------------------------------------
 */
static void ListRepUnsharedFreeUnreferenced(const ListRep *repPtr)
{
    ListSizeT count;
    ListStore *storePtr;
    ListSpan *spanPtr;

    LIST_ASSERT(!ListRepIsShared(repPtr));
    LISTREP_CHECK(repPtr);

    storePtr = repPtr->storePtr;
    spanPtr = repPtr->spanPtr;
    if (spanPtr == NULL) {
	LIST_ASSERT(storePtr->firstUsed == 0); /* Invariant TBD */
	return;
    }

    /* Collect garbage at front */
    count = spanPtr->spanStart - storePtr->firstUsed;
    LIST_COUNT_ASSERT(count);
    if (count > 0) {
        /* T:listrep-1.5.1,6.{1:8} */
	ObjArrayDecrRefs(storePtr->slots, storePtr->firstUsed, count);
	storePtr->firstUsed = spanPtr->spanStart;
	LIST_ASSERT(storePtr->numUsed >= count);
	storePtr->numUsed -= count;
    }

    /* Collect garbage at back */
    count = (storePtr->firstUsed + storePtr->numUsed)
	  - (spanPtr->spanStart + spanPtr->spanLength);
    LIST_COUNT_ASSERT(count);
    if (count > 0) {
        /* T:listrep-6.{1:8} */
	ObjArrayDecrRefs(
	    storePtr->slots, spanPtr->spanStart + spanPtr->spanLength, count);
	LIST_ASSERT(storePtr->numUsed >= count);
	storePtr->numUsed -= count;
    }

    LIST_ASSERT(ListRepStart(repPtr) == storePtr->firstUsed);
    LIST_ASSERT(ListRepLength(repPtr) == storePtr->numUsed);
    LISTREP_CHECK(repPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_NewListObj --
 *
 *	This function is normally called when not debugging: i.e., when
 *	TCL_MEM_DEBUG is not defined. It creates a new list object from an

 *	(objc,objv) array: that is, each of the objc elements of the array
 *	referenced by objv is inserted as an element into a new Tcl object.
 *

 *	When TCL_MEM_DEBUG is defined, this function just returns the result
 *	of calling the debugging version Tcl_DbNewListObj.
 *
 * Results:
 *	A new list object is returned that is initialized from the object
 *	pointers in objv. If objc is less than or equal to zero, an empty
 *	object is returned. The new object's string representation is left
 *	NULL. The resulting new list object has ref count 0.
 *
 * Side effects:

 *	The ref counts of the elements in objv are incremented since the
 *	resulting list now refers to them.
 *
 *----------------------------------------------------------------------
 */

#ifdef TCL_MEM_DEBUG
#undef Tcl_NewListObj

Tcl_Obj *
Tcl_NewListObj(
    ListSizeT objc,		/* Count of objects referenced by objv. */
    Tcl_Obj *const objv[])	/* An array of pointers to Tcl objects. */
{
    return Tcl_DbNewListObj(objc, objv, "unknown", 0);
}

#else /* if not TCL_MEM_DEBUG */

Tcl_Obj *
Tcl_NewListObj(
    ListSizeT objc,		/* Count of objects referenced by objv. */
    Tcl_Obj *const objv[])	/* An array of pointers to Tcl objects. */
{
    ListRep listRep;
    Tcl_Obj *listObj;

    TclNewObj(listObj);

    if (objc + 1 <= 1) {
	return listObj;
    }




    ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);

    ListObjReplaceRepAndInvalidate(listObj, &listRep);






    return listObj;
}
#endif /* if TCL_MEM_DEBUG */

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DbNewListObj --
 *
 *	This function is normally called when debugging: i.e., when
 *	TCL_MEM_DEBUG is defined. It creates new list objects. It is the same
 *	as the Tcl_NewListObj function above except that it calls
 *	Tcl_DbCkalloc directly with the file name and line number from its
 *	caller. This simplifies debugging since then the [memory active]
 *	command will report the correct file name and line number when
 *	reporting objects that haven't been freed.
 *
 *	When TCL_MEM_DEBUG is not defined, this function just returns the
 *	result of calling Tcl_NewListObj.
 *
 * Results:
 *	A new list object is returned that is initialized from the object
 *	pointers in objv. If objc is less than or equal to zero, an empty
 *	object is returned. The new object's string representation is left
 *	NULL. The new list object has ref count 0.
 *
 * Side effects:
 *	The ref counts of the elements in objv are incremented since the
 *	resulting list now refers to them.
 *
 *----------------------------------------------------------------------
 */

#ifdef TCL_MEM_DEBUG

Tcl_Obj *
Tcl_DbNewListObj(
    ListSizeT objc,		/* Count of objects referenced by objv. */
    Tcl_Obj *const objv[],	/* An array of pointers to Tcl objects. */
    const char *file,		/* The name of the source file calling this
				 * function; used for debugging. */
    int line)			/* Line number in the source file; used for
				 * debugging. */
{
    Tcl_Obj *listObj;
    ListRep listRep;

    TclDbNewObj(listObj, file, line);

    if (objc + 1 <= 1) {
	return listObj;
    }




    ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);

    ListObjReplaceRepAndInvalidate(listObj, &listRep);







    return listObj;
}

#else /* if not TCL_MEM_DEBUG */

Tcl_Obj *
Tcl_DbNewListObj(
    ListSizeT objc,		/* Count of objects referenced by objv. */
    Tcl_Obj *const objv[],	/* An array of pointers to Tcl objects. */
    TCL_UNUSED(const char *) /*file*/,
    TCL_UNUSED(int) /*line*/)
{
    return Tcl_NewListObj(objc, objv);
}
#endif /* TCL_MEM_DEBUG */

/*
 *------------------------------------------------------------------------
 *
 * TclNewListObj2 --
 *
 *    Create a new Tcl_Obj list comprising of the concatenation of two
 *    Tcl_Obj* arrays.
 *    TODO - currently this function is not used within tclListObj but
 *    need to see if it would be useful in other files that preallocate
 *    lists and then append.
 *
 * Results:
 *    Non-NULL pointer to the allocate Tcl_Obj.
 *
 * Side effects:
 *    None.
 *
 *------------------------------------------------------------------------
 */
Tcl_Obj *
TclNewListObj2(
    ListSizeT objc1,		/* Count of objects referenced by objv1. */
    Tcl_Obj *const objv1[],	/* First array of pointers to Tcl objects. */
    ListSizeT objc2,		/* Count of objects referenced by objv2. */
    Tcl_Obj *const objv2[]	/* Second array of pointers to Tcl objects. */
)
{
    Tcl_Obj *listObj;
    ListStore *storePtr;
    ListSizeT objc = objc1 + objc2;

    listObj = Tcl_NewListObj(objc, NULL);
    if (objc == 0) {
	return listObj; /* An empty object */
    }
    LIST_ASSERT_TYPE(listObj);

    storePtr = ListObjStorePtr(listObj);

    LIST_ASSERT(ListObjSpanPtr(listObj) == NULL);
    LIST_ASSERT(storePtr->firstUsed == 0);
    LIST_ASSERT(storePtr->numUsed == 0);
    LIST_ASSERT(storePtr->numAllocated >= objc);

    if (objc1) {
	ObjArrayCopy(storePtr->slots, objc1, objv1);
    }
    if (objc2) {
	ObjArrayCopy(&storePtr->slots[objc1], objc2, objv2);
    }
    storePtr->numUsed = objc;
    return listObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TclListObjGetRep --
 *
 *	This function returns a copy of the ListRep stored
 *	as the internal representation of an object. The reference
 *	counts of the (ListStore, ListSpan) contained in the representation
 *	are NOT incremented.
 *
 * Results:
 *	The return value is normally TCL_OK; in this case *listRepP
 *	is set to a copy of the descriptor stored as the internal
 *	representation of the Tcl_Obj containing a list. if listPtr does not
 *	refer to a list object and the object can not be converted to one,
 *	TCL_ERROR is returned and an error message will be left in the
 *	interpreter's result if interp is not NULL.
 *
 * Side effects:
 *	The possible conversion of the object referenced by listPtr
 *	to a list object. *repPtr is initialized to the internal rep
 *      if result is TCL_OK, or set to NULL on error.
 *----------------------------------------------------------------------
 */

static int
TclListObjGetRep(
    Tcl_Interp *interp, /* Used to report errors if not NULL. */
    Tcl_Obj *listObj,   /* List object for which an element array is
			 * to be returned. */
    ListRep *repPtr) /* Location to store descriptor */
{
    if (!TclHasInternalRep(listObj, &tclListType)) {
	int result;
	result = SetListFromAny(interp, listObj);
	if (result != TCL_OK) {
	    /* Init to keep gcc happy wrt uninitialized fields at call site */
	    repPtr->storePtr = NULL;
	    repPtr->spanPtr = NULL;
	    return result;
	}
    }
    ListObjGetRep(listObj, repPtr);
    LISTREP_CHECK(repPtr);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetListObj --
 *
 *	Modify an object to be a list containing each of the objc elements of
 *	the object array referenced by objv.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The object is made a list object and is initialized from the object
 *	pointers in objv. If objc is less than or equal to zero, an empty
 *	object is returned. The new object's string representation is left
 *	NULL. The ref counts of the elements in objv are incremented since the
 *	list now refers to them. The object's old string and internal
 *	representations are freed and its type is set NULL.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetListObj(
    Tcl_Obj *objPtr,		/* Object whose internal rep to init. */
    ListSizeT objc,		/* Count of objects referenced by objv. */
    Tcl_Obj *const objv[])	/* An array of pointers to Tcl objects. */
{


    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object", "Tcl_SetListObj");
    }








    /*
     * Set the object's type to "list" and initialize the internal rep.
     * However, if there are no elements to put in the list, just give the
     * object an empty string rep and a NULL type. NOTE ListRepInit must
     * not be called with objc == 0!
     */

    if (objc + 1 > 1) {
	ListRep listRep;
	/* TODO - perhaps ask for extra space? */
	ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);
	ListObjReplaceRepAndInvalidate(objPtr, &listRep);
    } else {
	TclFreeInternalRep(objPtr);
	TclInvalidateStringRep(objPtr);
	Tcl_InitStringRep(objPtr, NULL, 0);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclListObjCopy --
 *
 *	Makes a "pure list" copy of a list value. This provides for the C
 *	level a counterpart of the [lrange $list 0 end] command, while using
 *	internals details to be as efficient as possible.
 *
 * Results:
 *	Normally returns a pointer to a new Tcl_Obj, that contains the same
 *	list value as *listPtr does. The returned Tcl_Obj has a refCount of
 *	zero. If *listPtr does not hold a list, NULL is returned, and if
 *	interp is non-NULL, an error message is recorded there.

 *
 * Side effects:
 *	None.

 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclListObjCopy(
    Tcl_Interp *interp,		/* Used to report errors if not NULL. */
    Tcl_Obj *listObj)		/* List object for which an element array is
				 * to be returned. */
{
    Tcl_Obj *copyObj;


    if (!TclHasInternalRep(listObj, &tclListType)) {

	if (SetListFromAny(interp, listObj) != TCL_OK) {
	    return NULL;
	}
    }

    TclNewObj(copyObj);
    TclInvalidateStringRep(copyObj);
    DupListInternalRep(listObj, copyObj);
    return copyObj;
}

/*
 *------------------------------------------------------------------------
 *
 * ListRepRange --
 *
 *	Initializes a ListRep as a range within the passed ListRep.
 *	The range limits are clamped to the list boundaries.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *      The ListStore and ListSpan referenced by in the returned ListRep
 *      may or may not be the same as those passed in. For example, the
 *      ListStore may differ because the range is small enough that a new
 *      ListStore is more memory-optimal. The ListSpan may differ because
 *      it is NULL or shared. Regardless, reference counts on the returned
 *      values are not incremented. Generally, ListObjReplaceRepAndInvalidate
 *      may be used to store the new ListRep back into an object or a
 *      ListRepIncrRefs followed by ListRepDecrRefs to free in case of errors.
 *	Any other use should be carefully reconsidered.
 *      TODO WARNING:- this is an awkward interface and easy for caller
 *      to get wrong. Mostly due to refcount combinations. Perhaps passing
 *      in the source listObj instead of source listRep might simplify.
 *
 *------------------------------------------------------------------------
 */
static void
ListRepRange(
    ListRep *srcRepPtr,    /* Contains source of the range */
    ListSizeT rangeStart,  /* Index of first element to include */
    ListSizeT rangeEnd,    /* Index of last element to include */
    int preserveSrcRep,    /* If true, srcRepPtr contents must not be
			      modified (generally because a shared Tcl_Obj
			      references it) */
    ListRep *rangeRepPtr)  /* Output. Must NOT be == srcRepPtr */
{
    Tcl_Obj **srcElems;
    ListSizeT numSrcElems = ListRepLength(srcRepPtr);
    ListSizeT rangeLen;
    ListSizeT numAfterRangeEnd;

    LISTREP_CHECK(srcRepPtr);

    /* Take the opportunity to garbage collect */
    /* TODO - we probably do not need the preserveSrcRep here unlike later */
    if (!preserveSrcRep) {
        /* T:listrep-1.{4,5,8,9},2.{4:7},3.{15:18},4.{7,8} */
	ListRepFreeUnreferenced(srcRepPtr);
    } /* else T:listrep-2.{4.2,4.3,5.2,5.3,6.2,7.2,8.1} */

    if (rangeStart == TCL_INDEX_NONE) {
	rangeStart = 0;
    }
    if ((rangeEnd != TCL_INDEX_NONE) && (rangeEnd >= numSrcElems)) {
	rangeEnd = numSrcElems - 1;
    }
    if (rangeStart + 1 > rangeEnd + 1) {
	/* Empty list of capacity 1. */
	ListRepInit(1, NULL, LISTREP_PANIC_ON_FAIL, rangeRepPtr);
	return;
    }

    rangeLen = rangeEnd - rangeStart + 1;

    /*
     * We can create a range one of four ways:
     *  (0) Range encapsulates entire list
     *  (1) Special case: deleting in-place from end of an unshared object
     *  (2) Use a ListSpan referencing the current ListStore
     *  (3) Creating a new ListStore
     *  (4) Removing all elements outside the range in the current ListStore
     * Option (4) may only be done if caller has not disallowed it AND
     * the ListStore is not shared.
     *
     * The choice depends on heuristics related to speed and memory.
     * TODO - heuristics below need to be measured and tuned.
     *
     * Note: Even if nothing below cause any changes, we still want the
     * string-canonizing effect of [lrange 0 end] so the Tcl_Obj should not
     * be returned as is even if the range encompasses the whole list.
     */
    if (rangeStart == 0 && rangeEnd == (numSrcElems-1)) {
	/* Option 0 - entire list. This may be used to canonicalize */
        /* T:listrep-1.10.1,2.8.1 */
	*rangeRepPtr = *srcRepPtr; /* Not ref counts not incremented */
    } else if (rangeStart == 0 && (!preserveSrcRep)
	       && (!ListRepIsShared(srcRepPtr) && srcRepPtr->spanPtr == NULL)) {
	/* Option 1 - Special case unshared, exclude end elements, no span  */
	LIST_ASSERT(srcRepPtr->storePtr->firstUsed == 0); /* If no span */
	ListRepElements(srcRepPtr, numSrcElems, srcElems);
	numAfterRangeEnd = numSrcElems - (rangeEnd + 1);
	/* Assert: Because numSrcElems > rangeEnd earlier */
	if (numAfterRangeEnd != 0) {
            /* T:listrep-1.{8,9} */
	    ObjArrayDecrRefs(srcElems, rangeEnd + 1, numAfterRangeEnd);
	}
	/* srcRepPtr->storePtr->firstUsed,numAllocated unchanged */
	srcRepPtr->storePtr->numUsed = rangeLen;
	srcRepPtr->storePtr->flags = 0;
	rangeRepPtr->storePtr = srcRepPtr->storePtr; /* Note no incr ref */
	rangeRepPtr->spanPtr = NULL;
    } else if (ListSpanMerited(rangeLen,
			       srcRepPtr->storePtr->numUsed,
			       srcRepPtr->storePtr->numAllocated)) {
	/* Option 2 - because span would be most efficient */
	ListSizeT spanStart = ListRepStart(srcRepPtr) + rangeStart;
	if (!preserveSrcRep && srcRepPtr->spanPtr
	    && srcRepPtr->spanPtr->refCount <= 1) {
	    /* If span is not shared reuse it */
            /* T:listrep-2.7.3,3.{16,18} */
	    srcRepPtr->spanPtr->spanStart = spanStart;
	    srcRepPtr->spanPtr->spanLength = rangeLen;
	    *rangeRepPtr = *srcRepPtr;
	} else {
	    /* Span not present or is shared. */
            /* T:listrep-1.5,2.{5,7},4.{7,8} */
	    rangeRepPtr->storePtr = srcRepPtr->storePtr;
	    rangeRepPtr->spanPtr = ListSpanNew(spanStart, rangeLen);
	}
        /*
         * We have potentially created a new internal representation that
         * references the same storage as srcRep but not yet incremented its
         * reference count. So do NOT call freezombies if preserveSrcRep
         * is mandated.
         */
	if (!preserveSrcRep) {
            /* T:listrep-1.{5.1,5.2,5.4},2.{5,7},3.{16,18},4.{7,8} */
	    ListRepFreeUnreferenced(rangeRepPtr);
	}
    } else if (preserveSrcRep || ListRepIsShared(srcRepPtr)) {
	/* Option 3 - span or modification in place not allowed/desired */
        /* T:listrep-2.{4,6} */
	ListRepElements(srcRepPtr, numSrcElems, srcElems);
	/* TODO - allocate extra space? */
	ListRepInit(rangeLen,
		    &srcElems[rangeStart],
		    LISTREP_PANIC_ON_FAIL,
		    rangeRepPtr);
    } else {
	/*
	 * Option 4 - modify in place. Note that because of the invariant
	 * that spanless list stores must start at 0, we have to move
	 * everything to the front.
	 * TODO - perhaps if a span already exists, no need to move to front?
	 * or maybe no need to move all the way to the front?
	 * TODO - if range is small relative to allocation, allocate new?
	 */

	/* Asserts follow from call to ListRepFreeUnreferenced earlier */
	LIST_ASSERT(!preserveSrcRep);
	LIST_ASSERT(!ListRepIsShared(srcRepPtr));
	LIST_ASSERT(ListRepStart(srcRepPtr) == srcRepPtr->storePtr->firstUsed);
	LIST_ASSERT(ListRepLength(srcRepPtr) == srcRepPtr->storePtr->numUsed);

	ListRepElements(srcRepPtr, numSrcElems, srcElems);

	/* Free leading elements outside range */
	if (rangeStart != 0) {
            /* T:listrep-1.4,3.15 */
	    ObjArrayDecrRefs(srcElems, 0, rangeStart);
	}
	/* Ditto for trailing */
	numAfterRangeEnd = numSrcElems - (rangeEnd + 1);
	/* Assert: Because numSrcElems > rangeEnd earlier */
	if (numAfterRangeEnd != 0) {
            /* T:listrep-3.17 */
	    ObjArrayDecrRefs(srcElems, rangeEnd + 1, numAfterRangeEnd);
	}
	memmove(&srcRepPtr->storePtr->slots[0],
		&srcRepPtr->storePtr
		     ->slots[srcRepPtr->storePtr->firstUsed + rangeStart],
		rangeLen * sizeof(Tcl_Obj *));
	srcRepPtr->storePtr->firstUsed = 0;
	srcRepPtr->storePtr->numUsed = rangeLen;
	srcRepPtr->storePtr->flags = 0;
	if (srcRepPtr->spanPtr) {
	    /* In case the source has a span, update it for consistency */
            /* T:listrep-3.{15,17} */
	    srcRepPtr->spanPtr->spanStart = srcRepPtr->storePtr->firstUsed;
	    srcRepPtr->spanPtr->spanLength = srcRepPtr->storePtr->numUsed;
	}
	rangeRepPtr->storePtr = srcRepPtr->storePtr;
	rangeRepPtr->spanPtr = NULL;
    }

    /* TODO - call freezombies here if !preserveSrcRep? */

    /* Note ref counts intentionally not incremented */
    LISTREP_CHECK(rangeRepPtr);
    return;
}

/*
 *----------------------------------------------------------------------
 *
 * TclListObjRange --
 *
 *	Makes a slice of a list value.
 *      *listObj must be known to be a valid list.
 *
 * Results:
 *	Returns a pointer to the sliced list.
 *      This may be a new object or the same object if not shared.
 *	Returns NULL if passed listObj was not a list and could not be
 *	converted to one.
 *
 * Side effects:
 *	The possible conversion of the object referenced by listPtr
 *	to a list object.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclListObjRange(
    Tcl_Obj *listObj,		/* List object to take a range from. */
    ListSizeT rangeStart,	/* Index of first element to include. */
    ListSizeT rangeEnd)		/* Index of last element to include. */
{

    ListRep listRep;
    ListRep resultRep;


    int isShared;
    if (TclListObjGetRep(NULL, listObj, &listRep) != TCL_OK)








	return NULL;

















    isShared = Tcl_IsShared(listObj);





    ListRepRange(&listRep, rangeStart, rangeEnd, isShared, &resultRep);






    if (isShared) {




        /* T:listrep-1.10.1,2.{4.2,4.3,5.2,5.3,6.2,7.2,8.1} */
	TclNewObj(listObj);
    } /* T:listrep-1.{4.3,5.1,5.2} */
    ListObjReplaceRepAndInvalidate(listObj, &resultRep);
    return listObj;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjGetElements --
 *
 *	This function returns an (objc,objv) array of the elements in a list
 *	object.

 *

 * Results:
 *	The return value is normally TCL_OK; in this case *objcPtr is set to
 *	the count of list elements and *objvPtr is set to a pointer to an
 *	array of (*objcPtr) pointers to each list element. If listPtr does not
 *	refer to a list object and the object can not be converted to one,
 *	TCL_ERROR is returned and an error message will be left in the
 *	interpreter's result if interp is not NULL.
 *
 *	The objects referenced by the returned array should be treated as
 *	readonly and their ref counts are _not_ incremented; the caller must
 *	do that if it holds on to a reference. Furthermore, the pointer and
 *	length returned by this function may change as soon as any function is
 *	called on the list object; be careful about retaining the pointer in a
 *	local data structure.
 *





 * Side effects:

 *	The possible conversion of the object referenced by listPtr
 *	to a list object.
 *
 *----------------------------------------------------------------------
 */

#undef Tcl_ListObjGetElements
int
Tcl_ListObjGetElements(
    Tcl_Interp *interp,		/* Used to report errors if not NULL. */
    Tcl_Obj *objPtr,		/* List object for which an element array is
				 * to be returned. */
    ListSizeT *objcPtr,		/* Where to store the count of objects
				 * referenced by objv. */
    Tcl_Obj ***objvPtr)		/* Where to store the pointer to an array of
				 * pointers to the list's objects. */
{
    ListRep listRep;


    if (TclListObjGetRep(interp, objPtr, &listRep) != TCL_OK)








	return TCL_ERROR;







    ListRepElements(&listRep, *objcPtr, *objvPtr);

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjAppendList --
 *
 *	This function appends the elements in the list fromObj
 *	to toObj. toObj must not be shared else the function will panic.
 *
 * Results:

 *	The return value is normally TCL_OK. If fromObj or toObj do not



 *	refer to list values, TCL_ERROR is returned and an error message is


 *	left in the interpreter's result if interp is not NULL.
 *
 * Side effects:

 *	The reference counts of the elements in fromObj are incremented

 *	since the list now refers to them. toObj and fromObj are
 *	converted, if necessary, to list objects. Also, appending the new
 *	elements may cause toObj's array of element pointers to grow.
 *	toObj's old string representation, if any, is invalidated.

 *
 *----------------------------------------------------------------------
 */

int
Tcl_ListObjAppendList(
    Tcl_Interp *interp,		/* Used to report errors if not NULL. */
    Tcl_Obj *toObj,		/* List object to append elements to. */
    Tcl_Obj *fromObj)		/* List obj with elements to append. */
{
    ListSizeT objc;
    Tcl_Obj **objv;

    if (Tcl_IsShared(toObj)) {
	Tcl_Panic("%s called with shared object", "Tcl_ListObjAppendList");
    }





    if (TclListObjGetElementsM(interp, fromObj, &objc, &objv) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Insert the new elements starting after the lists's last element.
     * Delete zero existing elements.
     */

    return TclListObjAppendElements(interp, toObj, objc, objv);
}

/*
 *------------------------------------------------------------------------
 *
 * TclListObjAppendElements --
 *
 *      Appends multiple elements to a Tcl_Obj list object. If
 *      the passed Tcl_Obj is not a list object, it will be converted to one
 *      and an error raised if the conversion fails.
 *
 * 	The Tcl_Obj must not be shared though the internal representation
 * 	may be.
 *
 * Results:
 *	On success, TCL_OK is returned with the specified elements appended.
 *	On failure, TCL_ERROR is returned with an error message in the
 *	interpreter if not NULL.
 *
 * Side effects:
 *    None.
 *
 *------------------------------------------------------------------------
 */
 int TclListObjAppendElements (
    Tcl_Interp *interp,		/* Used to report errors if not NULL. */
    Tcl_Obj *toObj,		/* List object to append */
    ListSizeT elemCount,        /* Number of elements in elemObjs[] */
    Tcl_Obj * const elemObjv[])	/* Objects to append to toObj's list. */
{
    ListRep listRep;
    Tcl_Obj **toObjv;
    ListSizeT toLen;
    ListSizeT finalLen;

    if (Tcl_IsShared(toObj)) {
	Tcl_Panic("%s called with shared object", "TclListObjAppendElements");
    }

    if (TclListObjGetRep(interp, toObj, &listRep) != TCL_OK)
	return TCL_ERROR; /* Cannot be converted to a list */

    if (elemCount == 0)
	return TCL_OK; /* Nothing to do. Note AFTER check for list above */

    ListRepElements(&listRep, toLen, toObjv);
    if (elemCount > LIST_MAX || toLen > (LIST_MAX - elemCount)) {
	return ListLimitExceededError(interp);
    }

    finalLen = toLen + elemCount;
    if (!ListRepIsShared(&listRep)) {
	/*
	 * Reuse storage if possible. Even if too small, realloc-ing instead
	 * of creating a new ListStore will save us on manipulating Tcl_Obj
	 * reference counts on the elements which is a substantial cost
	 * if the list is not small.
	 */
	ListSizeT numTailFree;

	ListRepFreeUnreferenced(&listRep); /* Collect garbage before checking room */

	LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);
	LIST_ASSERT(ListRepLength(&listRep) == listRep.storePtr->numUsed);
	LIST_ASSERT(toLen == listRep.storePtr->numUsed);

	if (finalLen > listRep.storePtr->numAllocated) {
	    /* T:listrep-1.{2,11},3.6 */
	    ListStore *newStorePtr;
	    newStorePtr = ListStoreReallocate(listRep.storePtr, finalLen);
	    if (newStorePtr == NULL) {
		return MemoryAllocationError(interp, LIST_SIZE(finalLen));
	    }
	    LIST_ASSERT(newStorePtr->numAllocated >= finalLen);
	    listRep.storePtr = newStorePtr;
	    /*
	     * WARNING: at this point the Tcl_Obj internal rep potentially
	     * points to freed storage if the reallocation returned a
	     * different location. Overwrite it to bring it back in sync.
	     */
	    ListObjStompRep(toObj, &listRep);
	} /* else T:listrep-3.{4,5} */
	LIST_ASSERT(listRep.storePtr->numAllocated >= finalLen);
	/* Current store big enough */
	numTailFree = ListRepNumFreeTail(&listRep);
	LIST_ASSERT((numTailFree + listRep.storePtr->firstUsed)
		    >= elemCount); /* Total free */
	if (numTailFree < elemCount) {
	    /* Not enough room at back. Move some to front */
            /* T:listrep-3.5 */
	    ListSizeT shiftCount = elemCount - numTailFree;
	    /* Divide remaining space between front and back */
	    shiftCount += (listRep.storePtr->numAllocated - finalLen) / 2;
	    LIST_ASSERT(shiftCount <= listRep.storePtr->firstUsed);
	    if (shiftCount) {
                /* T:listrep-3.5 */
		ListRepUnsharedShiftDown(&listRep, shiftCount);
            }
	} /* else T:listrep-3.{4,6} */
	ObjArrayCopy(&listRep.storePtr->slots[ListRepStart(&listRep)
					      + ListRepLength(&listRep)],
		     elemCount,
		     elemObjv);
	listRep.storePtr->numUsed = finalLen;
	if (listRep.spanPtr) {
            /* T:listrep-3.{4,5,6} */
	    LIST_ASSERT(listRep.spanPtr->spanStart
			== listRep.storePtr->firstUsed);
	    listRep.spanPtr->spanLength = finalLen;
	} /* else T:listrep-3.6.3 */
	LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);
	LIST_ASSERT(ListRepLength(&listRep) == finalLen);
	LISTREP_CHECK(&listRep);

	ListObjReplaceRepAndInvalidate(toObj, &listRep);
	return TCL_OK;
    }

    /*
     * Have to make a new list rep, either shared or no room in old one.
     * If the old list did not have a span (all elements at front), do
     * not leave space in the front either, assuming all appends and no
     * prepends.
     */
    if (ListRepInit(finalLen,
		    NULL,
		    listRep.spanPtr ? LISTREP_SPACE_FAVOR_BACK
				    : LISTREP_SPACE_ONLY_BACK,
		    &listRep)
	!= TCL_OK) {
	return TCL_ERROR;
    }
    LIST_ASSERT(listRep.storePtr->numAllocated >= finalLen);

    if (toLen) {
        /* T:listrep-2.{2,9},4.5 */
	ObjArrayCopy(ListRepSlotPtr(&listRep, 0), toLen, toObjv);
    }
    ObjArrayCopy(ListRepSlotPtr(&listRep, toLen), elemCount, elemObjv);
    listRep.storePtr->numUsed = finalLen;
    if (listRep.spanPtr) {
        /* T:listrep-4.5 */
	LIST_ASSERT(listRep.spanPtr->spanStart == listRep.storePtr->firstUsed);
	listRep.spanPtr->spanLength = finalLen;
    }
    LISTREP_CHECK(&listRep);
    ListObjReplaceRepAndInvalidate(toObj, &listRep);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjAppendElement --
 *
 *	This function is a special purpose version of Tcl_ListObjAppendList:
 *	it appends a single object referenced by elemObj to the list object
 *	referenced by toObj. If toObj is not already a list object, an
 *	attempt will be made to convert it to one.
 *
 * Results:

 *	The return value is normally TCL_OK; in this case elemObj is added to


 *	the end of toObj's list. If toObj does not refer to a list object


 *	and the object can not be converted to one, TCL_ERROR is returned and
 *	an error message will be left in the interpreter's result if interp is
 *	not NULL.
 *
 * Side effects:


 *	The ref count of elemObj is incremented since the list now refers to
 *	it. toObj will be converted, if necessary, to a list object. Also,
 *	appending the new element may cause listObj's array of element
 *	pointers to grow. toObj's old string representation, if any, is
 *	invalidated.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_ListObjAppendElement(
    Tcl_Interp *interp,		/* Used to report errors if not NULL. */
    Tcl_Obj *toObj,		/* List object to append elemObj to. */
    Tcl_Obj *elemObj)		/* Object to append to toObj's list. */
{









































    /*


     * TODO - compare perf with 8.6 to see if worth optimizing single


















































     * element case








     */









    return TclListObjAppendElements(interp, toObj, 1, &elemObj);



























}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjIndex --
 *
 *	This function returns a pointer to the index'th object from the list
 *	referenced by listPtr. The first element has index 0. If index is
 *	negative or greater than or equal to the number of elements in the
 *	list, a NULL is returned. If listPtr is not a list object, an attempt
 *	will be made to convert it to a list.
 *
 * Results:

 *	The return value is normally TCL_OK; in this case objPtrPtr is set to
 *	the Tcl_Obj pointer for the index'th list element or NULL if index is
 *	out of range. This object should be treated as readonly and its ref
 *	count is _not_ incremented; the caller must do that if it holds on to
 *	the reference. If listPtr does not refer to a list and can't be

 *	converted to one, TCL_ERROR is returned and an error message is left


 *	in the interpreter's result if interp is not NULL.
 *
 * Side effects:

 *	listPtr will be converted, if necessary, to a list object.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_ListObjIndex(
    Tcl_Interp *interp,  /* Used to report errors if not NULL. */
    Tcl_Obj *listObj,    /* List object to index into. */
    ListSizeT index,           /* Index of element to return. */
    Tcl_Obj **objPtrPtr) /* The resulting Tcl_Obj* is stored here. */
{
    Tcl_Obj **elemObjs;
    ListSizeT numElems;



    /*
     * TODO
     * Unlike the original list code, this does not optimize for lindex'ing
     * an empty string when the internal rep is not already a list. On the
     * other hand, this code will be faster for the case where the object
     * is currently a dict. Benchmark the two cases.
     */


    if (TclListObjGetElementsM(interp, listObj, &numElems, &elemObjs)
	!= TCL_OK) {
	return TCL_ERROR;
    }



    if (index >= numElems) {
	*objPtrPtr = NULL;
    } else {
	*objPtrPtr = elemObjs[index];
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjLength --
 *
 *	This function returns the number of elements in a list object. If the
 *	object is not already a list object, an attempt will be made to
 *	convert it to one.
 *
 * Results:

 *	The return value is normally TCL_OK; in this case *intPtr will be set

 *	to the integer count of list elements. If listPtr does not refer to a
 *	list object and the object can not be converted to one, TCL_ERROR is
 *	returned and an error message will be left in the interpreter's result
 *	if interp is not NULL.

 *

 * Side effects:
 *	The possible conversion of the argument object to a list object.

 *
 *----------------------------------------------------------------------
 */

#undef Tcl_ListObjLength
int
Tcl_ListObjLength(
    Tcl_Interp *interp,	/* Used to report errors if not NULL. */
    Tcl_Obj *listObj,	/* List object whose #elements to return. */
    ListSizeT *lenPtr)	/* The resulting int is stored here. */
{
    ListRep listRep;



    /*
     * TODO
     * Unlike the original list code, this does not optimize for lindex'ing
     * an empty string when the internal rep is not already a list. On the
     * other hand, this code will be faster for the case where the object
     * is currently a dict. Benchmark the two cases.

     */
    if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {
	return TCL_ERROR;
    }






    *lenPtr = ListRepLength(&listRep);

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListObjReplace --
 *
 *	This function replaces zero or more elements of the list referenced by
 *	listObj with the objects from an (objc,objv) array. The objc elements
 *	of the array referenced by objv replace the count elements in listPtr
 *	starting at first.
 *
 *	If the argument first is zero or negative, it refers to the first
 *	element. If first is greater than or equal to the number of elements
 *	in the list, then no elements are deleted; the new elements are

 *	appended to the list. Count gives the number of elements to replace.
 *	If count is zero or negative then no elements are deleted; the new
 *	elements are simply inserted before first.
 *



 *	The argument objv refers to an array of objc pointers to the new
 *	elements to be added to listPtr in place of those that were deleted.
 *	If objv is NULL, no new elements are added. If listPtr is not a list
 *	object, an attempt will be made to convert it to one.
 *
 * Results:
 *	The return value is normally TCL_OK. If listPtr does not refer to a
 *	list object and can not be converted to one, TCL_ERROR is returned and

 *	an error message will be left in the interpreter's result if interp is
 *	not NULL.
 *
 * Side effects:


 *	The ref counts of the objc elements in objv are incremented since the

 *	resulting list now refers to them. Similarly, the ref counts for

 *	replaced objects are decremented. listObj is converted, if necessary,
 *	to a list object. listObj's old string representation, if any, is
 *	freed.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_ListObjReplace(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *listObj,		/* List object whose elements to replace. */
    ListSizeT first,		/* Index of first element to replace. */
    ListSizeT numToDelete,	/* Number of elements to replace. */
    ListSizeT numToInsert,	/* Number of objects to insert. */
    Tcl_Obj *const insertObjs[])/* Tcl objects to insert */

{
    ListRep listRep;
    ListSizeT origListLen;
    ptrdiff_t lenChange;
    ptrdiff_t leadSegmentLen;
    ptrdiff_t tailSegmentLen;
    ListSizeT numFreeSlots;
    ptrdiff_t leadShift;
    ptrdiff_t tailShift;
    Tcl_Obj **listObjs;

    int favor;

    if (Tcl_IsShared(listObj)) {
	Tcl_Panic("%s called with shared object", "Tcl_ListObjReplace");
    }




    if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK)



	return TCL_ERROR; /* Cannot be converted to a list */




    /* TODO - will need modification if Tcl9 sticks to unsigned indices */






    /* Make limits sane */







    origListLen = ListRepLength(&listRep);



    if (first == TCL_INDEX_NONE) {
	first = 0;
    }
    if (first > origListLen) {
	first = origListLen;	/* So we'll insert after last element. */
    }
    if (numToDelete == TCL_INDEX_NONE) {
	numToDelete = 0;
    } else if (first > ListSizeT_MAX - numToDelete /* Handle integer overflow */
             || origListLen < first + numToDelete) {
	numToDelete = origListLen - first;
    }

    if (numToInsert > ListSizeT_MAX - (origListLen - numToDelete)) {
	return ListLimitExceededError(interp);
    }


    if ((first+numToDelete) >= origListLen) {
	/* Operating at back of list. Favor leaving space at back */
	favor = LISTREP_SPACE_FAVOR_BACK;
    } else if (first == 0) {
	/* Operating on front of list. Favor leaving space in front */
	favor = LISTREP_SPACE_FAVOR_FRONT;
    } else {
	/* Operating on middle of list. */
	favor = LISTREP_SPACE_FAVOR_NONE;
    }

    /*
     * There are a number of special cases to consider from an optimization
     * point of view.
     * (1) Pure deletes (numToInsert==0) from the front or back can be treated
     * as a range op irrespective of whether the ListStore is shared or not
     * (2) Pure inserts (numToDelete == 0)
     *   (2a) Pure inserts at the back can be treated as appends
     *   (2b) Pure inserts from the *front* can be optimized under certain
     *   conditions by inserting before first ListStore slot in use if there
     *   is room, again irrespective of sharing
     * (3) If the ListStore is shared OR there is insufficient free space
     * OR existing allocation is too large compared to new size, create
     * a new ListStore
     * (4) Unshared ListStore with sufficient free space. Delete, shift and
     * insert within the ListStore.
     */

    /* Note: do not do TclInvalidateStringRep as yet in case there are errors */

    /* Check Case (1) - Treat pure deletes from front or back as range ops */
    if (numToInsert == 0) {
	if (numToDelete == 0) {
	    /*
             * Should force canonical even for no-op. Remember Tcl_Obj unshared
             * so OK to invalidate string rep
             */
            /* T:listrep-1.10,2.8 */
	    TclInvalidateStringRep(listObj);
	    return TCL_OK;
	}
	if (first == 0) {
	    /* Delete from front, so return tail. */
            /* T:listrep-1.{4,5},2.{4,5},3.{15,16},4.7 */
	    ListRep tailRep;

	    ListRepRange(&listRep, numToDelete, origListLen-1, 0, &tailRep);
	    ListObjReplaceRepAndInvalidate(listObj, &tailRep);
	    return TCL_OK;
	} else if ((first+numToDelete) >= origListLen) {
	    /* Delete from tail, so return head */
            /* T:listrep-1.{8,9},2.{6,7},3.{17,18},4.8 */
	    ListRep headRep;
	    ListRepRange(&listRep, 0, first-1, 0, &headRep);
	    ListObjReplaceRepAndInvalidate(listObj, &headRep);
	    return TCL_OK;
	}




	/* Deletion from middle. Fall through to general case */
    }

    /* Garbage collect before checking the pure insert optimization */
    ListRepFreeUnreferenced(&listRep);

    /*
     * Check Case (2) - pure inserts under certain conditions:
     */




    if (numToDelete == 0) {
	/* Case (2a) - Append to list. */
	if (first == origListLen) {
            /* T:listrep-1.11,2.9,3.{5,6},2.2.1 */
	    return TclListObjAppendElements(
		interp, listObj, numToInsert, insertObjs);
	}

	/*
	 * Case (2b) - pure inserts at front under some circumstances
	 * (i) Insertion must be at head of list
	 * (ii) The list's span must be at head of the in-use slots in the store
	 * (iii) There must be unused room at front of the store
	 * NOTE THIS IS TRUE EVEN IF THE ListStore IS SHARED as it will not
	 * affect the other Tcl_Obj's referencing this ListStore.
	 */
	if (first == 0 &&                                            /* (i) */
	    ListRepStart(&listRep) == listRep.storePtr->firstUsed && /* (ii) */
	    numToInsert <= listRep.storePtr->firstUsed               /* (iii) */
	) {
	    ListSizeT newLen;
	    LIST_ASSERT(numToInsert); /* Else would have returned above */
	    listRep.storePtr->firstUsed -= numToInsert;
	    ObjArrayCopy(&listRep.storePtr->slots[listRep.storePtr->firstUsed],
			 numToInsert,
			 insertObjs);
	    listRep.storePtr->numUsed += numToInsert;
	    newLen = listRep.spanPtr->spanLength + numToInsert;
	    if (listRep.spanPtr && listRep.spanPtr->refCount <= 1) {
		/* An unshared span record, re-use it */
                /* T:listrep-3.1 */
		listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
		listRep.spanPtr->spanLength = newLen;
	    } else {
		/* Need a new span record */
		if (listRep.storePtr->firstUsed == 0) {
		    listRep.spanPtr = NULL;
		} else {
                    /* T:listrep-4.3 */
		    listRep.spanPtr =
			ListSpanNew(listRep.storePtr->firstUsed, newLen);
		}




	    }


	    ListObjReplaceRepAndInvalidate(listObj, &listRep);
	    return TCL_OK;
	}

    }

    /* Just for readability of the code */
    lenChange = numToInsert - numToDelete;
    leadSegmentLen = first;
    tailSegmentLen = origListLen - (first + numToDelete);
    numFreeSlots = listRep.storePtr->numAllocated - listRep.storePtr->numUsed;

    /*

     * Before further processing, if unshared, try and reallocate to avoid
     * new allocation below. This avoids expensive ref count manipulation
     * later by not having to go through the ListRepInit and
     * ListObjReplaceAndInvalidate below.
     * TODO - we could be smarter about the reallocate. Use of realloc
     * means all new free space is at the back. Instead, the realloc could
     * be an explicit alloc and memmove which would let us redistribute
     * free space.
     */
    if ((ptrdiff_t)numFreeSlots < lenChange && !ListRepIsShared(&listRep)) {
	/* T:listrep-1.{1,3,14,18,21},3.{3,10,11,14,27,32,41} */
	ListStore *newStorePtr =
	    ListStoreReallocate(listRep.storePtr, origListLen + lenChange);
	if (newStorePtr == NULL) {
	    return MemoryAllocationError(interp,
					 LIST_SIZE(origListLen + lenChange));
	}
	listRep.storePtr = newStorePtr;
	numFreeSlots =


	    listRep.storePtr->numAllocated - listRep.storePtr->numUsed;
	/*
	 * WARNING: at this point the Tcl_Obj internal rep potentially
	 * points to freed storage if the reallocation returned a
	 * different location. Overwrite it to bring it back in sync.
	 */
	ListObjStompRep(listObj, &listRep);
    }



    /*
     * Case (3) a new ListStore is required
     * (a) The passed-in ListStore is shared
     * (b) There is not enough free space in the unshared passed-in ListStore
     * (c) The new unshared size is much "smaller" (TODO) than the allocated space
     * TODO - for unshared case ONLY, consider a "move" based implementation
     */
    if (ListRepIsShared(&listRep) || /* 3a */
	(ptrdiff_t)numFreeSlots < lenChange ||  /* 3b */
	(origListLen + lenChange) < (listRep.storePtr->numAllocated / 4) /* 3c */
    ) {
	ListRep newRep;
	Tcl_Obj **toObjs;
	listObjs = &listRep.storePtr->slots[ListRepStart(&listRep)];
	ListRepInit(origListLen + lenChange,
		    NULL,
		    LISTREP_PANIC_ON_FAIL | favor,
		    &newRep);
	toObjs = ListRepSlotPtr(&newRep, 0);
	if (leadSegmentLen > 0) {
            /* T:listrep-2.{2,3,13:18},4.{6,9,13:18} */
	    ObjArrayCopy(toObjs, leadSegmentLen, listObjs);
	}
	if (numToInsert > 0) {
            /* T:listrep-2.{1,2,3,10:18},4.{1,2,4,6,10:18} */
	    ObjArrayCopy(&toObjs[leadSegmentLen],
			 numToInsert,
			 insertObjs);
	}
	if (tailSegmentLen > 0) {
            /* T:listrep-2.{1,2,3,10:15},4.{1,2,4,6,9:12,16:18} */
	    ObjArrayCopy(&toObjs[leadSegmentLen + numToInsert],

			 tailSegmentLen,
			 &listObjs[leadSegmentLen+numToDelete]);
	}
	newRep.storePtr->numUsed = origListLen + lenChange;
	if (newRep.spanPtr) {
            /* T:listrep-2.{1,2,3,10:18},4.{1,2,4,6,9:18} */
	    newRep.spanPtr->spanLength = newRep.storePtr->numUsed;
	}

	LISTREP_CHECK(&newRep);
	ListObjReplaceRepAndInvalidate(listObj, &newRep);


	return TCL_OK;
    }

    /*
     * Case (4) - unshared ListStore with sufficient room.
     * After deleting elements, there will be a corresponding gap. If this
     * gap does not match number of insertions, either the lead segment,
     * or the tail segment, or both will have to be moved.
     * The general strategy is to move the fewest number of elements. If
     *
     * TODO - what about appends to unshared ? Is below sufficiently optimal?
     */

    /* Following must hold for unshared listreps after ListRepFreeUnreferenced above */
    LIST_ASSERT(origListLen == listRep.storePtr->numUsed);
    LIST_ASSERT(origListLen == ListRepLength(&listRep));
    LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);

    LIST_ASSERT((numToDelete + numToInsert) > 0);


    /* Base of slot array holding the list elements */
    listObjs = &listRep.storePtr->slots[ListRepStart(&listRep)];


    /*
     * Free up elements to be deleted. Before that, increment the ref counts
     * for objects to be inserted in case there is overlap. T:listobj-11.1
     */
    if (numToInsert) {
	/* T:listrep-1.{1,3,12:21},3.{2,3,7:14,23:41} */
	ObjArrayIncrRefs(insertObjs, 0, numToInsert);
    }
    if (numToDelete) {
        /* T:listrep-1.{6,7,12:21},3.{19:41} */
	ObjArrayDecrRefs(listObjs, first, numToDelete);
    }

    /*
     * TODO - below the moves are optimized but this may result in needing a
     * span allocation. Perhaps for small lists, it may be more efficient to
     * just move everything up front and save on allocating a span.
     */

    /*
     * Calculate shifts if necessary to accomodate insertions.
     * NOTE: all indices are relative to listObjs which is not necessarily the
     * start of the ListStore storage area.

     *
     * leadShift - how much to shift the lead segment
     * tailShift - how much to shift the tail segment
     * insertTarget - index where to insert.
     */

    if (lenChange == 0) {
	/* T:listrep-1.{12,15,19},3.{23,28,33}. Exact fit */
	leadShift = 0;
	tailShift = 0;
    } else if (lenChange < 0) {
	/*


	 * More deletions than insertions. The gap after deletions is large
	 * enough for insertions. Move a segment depending on size.
	 */
	if (leadSegmentLen > tailSegmentLen) {
	    /* Tail segment smaller. Insert after lead, move tail down */
            /* T:listrep-1.{7,17,20},3.{21,2229,35} */
	    leadShift = 0;
	    tailShift = lenChange;
	} else {
	    /* Lead segment smaller. Insert before tail, move lead up */
            /* T:listrep-1.{6,13,16},3.{19,20,24,34} */
	    leadShift = -lenChange;
	    tailShift = 0;
	}


    } else {
	LIST_ASSERT(lenChange > 0); /* Reminder */

	/*
	 * We need to make room for the insertions. Again we have multiple
	 * possibilities. We may be able to get by just shifting one segment
	 * or need to shift both. In the former case, favor shifting the
	 * smaller segment.
	 */
	ptrdiff_t leadSpace = ListRepNumFreeHead(&listRep);
	ptrdiff_t tailSpace = ListRepNumFreeTail(&listRep);
	ptrdiff_t finalFreeSpace = leadSpace + tailSpace - lenChange;

	LIST_ASSERT((leadSpace + tailSpace) >= lenChange);
	if (leadSpace >= lenChange

	    && (leadSegmentLen < tailSegmentLen || tailSpace < lenChange)) {
	    /* Move only lead to the front to make more room */
            /* T:listrep-3.25,36,38, */
	    leadShift = -lenChange;
	    tailShift = 0;
	    /*
	     * Redistribute the remaining free space between the front and
	     * back if either there is no tail space left or if the
	     * entire list is the head anyways. This is an important
	     * optimization for further operations like further asymmetric
	     * insertions.
	     */
	    if (finalFreeSpace > 1 && (tailSpace == 0 || tailSegmentLen == 0)) {
		ptrdiff_t postShiftLeadSpace = leadSpace - lenChange;
		if (postShiftLeadSpace > (finalFreeSpace/2)) {
		    ListSizeT extraShift = postShiftLeadSpace - (finalFreeSpace / 2);
		    leadShift -= extraShift;
		    tailShift = -extraShift; /* Move tail to the front as well */
		}
	    } /* else T:listrep-3.{7,12,25,38} */
	    LIST_ASSERT(leadShift >= 0 || leadSpace >= -leadShift);
	} else if (tailSpace >= lenChange) {
	    /* Move only tail segment to the back to make more room. */
            /* T:listrep-3.{8,10,11,14,26,27,30,32,37,39,41} */
	    leadShift = 0;
	    tailShift = lenChange;
	    /*
	     * See comments above. This is analogous.
	     */
	    if (finalFreeSpace > 1 && (leadSpace == 0 || leadSegmentLen == 0)) {
		ptrdiff_t postShiftTailSpace = tailSpace - lenChange;
		if (postShiftTailSpace > (finalFreeSpace/2)) {
		    /* T:listrep-1.{1,3,14,18,21},3.{2,3,26,27} */
		    ListSizeT extraShift = postShiftTailSpace - (finalFreeSpace / 2);
		    tailShift += extraShift;
		    leadShift = extraShift; /* Move head to the back as well */
		}


	    }

	    LIST_ASSERT(tailShift <= tailSpace);
	} else {
	    /*
	     * Both lead and tail need to be shifted to make room.
	     * Divide remaining free space equally between front and back.
	     */
            /* T:listrep-3.{9,13,31,40} */
	    LIST_ASSERT(leadSpace < lenChange);
	    LIST_ASSERT(tailSpace < lenChange);

	    /*
	     * leadShift = leadSpace - (finalFreeSpace/2)
	     * Thus leadShift <= leadSpace
	     * Also,
	     * = leadSpace - (leadSpace + tailSpace - lenChange)/2
	     * = leadSpace/2 - tailSpace/2 + lenChange/2
	     * >= 0 because lenChange > tailSpace
	     */
	    leadShift = leadSpace - (finalFreeSpace / 2);
	    tailShift = lenChange - leadShift;
	    if (tailShift > tailSpace) {
		/* Account for integer division errors */
		leadShift += 1;
		tailShift -= 1;
	    }
	    /*


	     * Following must be true because otherwise one of the previous
	     * if clauses would have been taken.
	     */
	    LIST_ASSERT(leadShift > 0 && leadShift < lenChange);
	    LIST_ASSERT(tailShift > 0 && tailShift < lenChange);
	    leadShift = -leadShift; /* Lead is actually shifted downward */
	}
    }


    /* Careful about order of moves! */
    if (leadShift > 0) {

	/* Will happen when we have to make room at bottom */
	if (tailShift != 0 && tailSegmentLen != 0) {
            /* T:listrep-1.{1,3,14,18},3.{2,3,26,27} */
	    ListSizeT tailStart = leadSegmentLen + numToDelete;
	    memmove(&listObjs[tailStart + tailShift],
		    &listObjs[tailStart],
		    tailSegmentLen * sizeof(Tcl_Obj *));
	}
	if (leadSegmentLen != 0) {
            /* T:listrep-1.{3,6,16,18,21},3.{19,20,34} */
	    memmove(&listObjs[leadShift],
		    &listObjs[0],
		    leadSegmentLen * sizeof(Tcl_Obj *));
	}
    } else {
	if (leadShift != 0 && leadSegmentLen != 0) {
            /* T:listrep-3.{7,9,12,13,31,36,38,40} */
	    memmove(&listObjs[leadShift],
		    &listObjs[0],
		    leadSegmentLen * sizeof(Tcl_Obj *));
	}
	if (tailShift != 0 && tailSegmentLen != 0) {



            /* T:listrep-1.{7,17},3.{8:11,13,14,21,22,35,37,39:41} */
	    ListSizeT tailStart = leadSegmentLen + numToDelete;
	    memmove(&listObjs[tailStart + tailShift],
		    &listObjs[tailStart],
		    tailSegmentLen * sizeof(Tcl_Obj *));
	}


    }
    if (numToInsert) {
	/* Do NOT use ObjArrayCopy here since we have already incr'ed ref counts */
        /* T:listrep-1.{1,3,12:21},3.{2,3,7:14,23:41} */
	memmove(&listObjs[leadSegmentLen + leadShift],
		insertObjs,
		numToInsert * sizeof(Tcl_Obj *));
    }




    listRep.storePtr->firstUsed += leadShift;
    listRep.storePtr->numUsed = origListLen + lenChange;
    listRep.storePtr->flags = 0;


    if (listRep.spanPtr && listRep.spanPtr->refCount <= 1) {
	/* An unshared span record, re-use it, even if not required */
        /* T:listrep-3.{2,3,7:14},3.{19:41} */
	listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
	listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
    } else {
	/* Need a new span record */
	if (listRep.storePtr->firstUsed == 0) {
            /* T:listrep-1.{7,12,15,17,19,20} */
	    listRep.spanPtr = NULL;
	} else {
            /* T:listrep-1.{1,3,6.1,13,14,16,18,21} */
	    listRep.spanPtr = ListSpanNew(listRep.storePtr->firstUsed,
					  listRep.storePtr->numUsed);
	}
    }

    LISTREP_CHECK(&listRep);
    ListObjReplaceRepAndInvalidate(listObj, &listRep);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclLindexList --
 *
 *	This procedure handles the 'lindex' command when objc==3.
 *
 * Results:
 *	Returns a pointer to the object extracted, or NULL if an error
 *	occurred. The returned object already includes one reference count for
 *	the pointer returned.
 *
 * Side effects:
 *	None.


 *
 * Notes:
 *	This procedure is implemented entirely as a wrapper around
 *	TclLindexFlat. All it does is reconfigure the argument format into the
 *	form required by TclLindexFlat, while taking care to manage shimmering
 *	in such a way that we tend to keep the most useful internalreps and/or
 *	avoid the most expensive conversions.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclLindexList(
    Tcl_Interp *interp,		/* Tcl interpreter. */
    Tcl_Obj *listObj,		/* List being unpacked. */
    Tcl_Obj *argObj)		/* Index or index list. */
{

    ListSizeT index;			/* Index into the list. */
    Tcl_Obj *indexListCopy;
    Tcl_Obj **indexObjs;
    ListSizeT numIndexObjs;

    /*
     * Determine whether argPtr designates a list or a single index. We have
     * to be careful about the order of the checks to avoid repeated
     * shimmering; if internal rep is already a list do not shimmer it.
     * see TIP#22 and TIP#33 for the details.
     */

    if (!TclHasInternalRep(argObj, &tclListType)

	&& TclGetIntForIndexM(NULL, argObj, ListSizeT_MAX - 1, &index)
	       == TCL_OK) {
	/*
	 * argPtr designates a single index.
	 */

	return TclLindexFlat(interp, listObj, 1, &argObj);
    }

    /*
     * Here we make a private copy of the index list argument to avoid any
     * shimmering issues that might invalidate the indices array below while
     * we are still using it. This is probably unnecessary. It does not appear
     * that any damaging shimmering is possible, and no test has been devised
     * to show any error when this private copy is not made. But it's cheap,
     * and it offers some future-proofing insurance in case the TclLindexFlat
     * implementation changes in some unexpected way, or some new form of
     * trace or callback permits things to happen that the current
     * implementation does not.
     */

    indexListCopy = TclListObjCopy(NULL, argObj);
    if (indexListCopy == NULL) {
	/*
	 * The argument is neither an index nor a well-formed list.
	 * Report the error via TclLindexFlat.
	 * TODO - This is as original. why not directly return an error?
	 */

	return TclLindexFlat(interp, listObj, 1, &argObj);
    }


    ListObjGetElements(indexListCopy, numIndexObjs, indexObjs);


    listObj = TclLindexFlat(interp, listObj, numIndexObjs, indexObjs);

    Tcl_DecrRefCount(indexListCopy);
    return listObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TclLindexFlat --
 *
 *	This procedure is the core of the 'lindex' command, with all index
 *	arguments presented as a flat list.
 *
 * Results:
 *	Returns a pointer to the object extracted, or NULL if an error
 *	occurred. The returned object already includes one reference count for
 *	the pointer returned.
 *


 * Side effects:
 *	None.
 *
 * Notes:
 *	The reference count of the returned object includes one reference
 *	corresponding to the pointer returned. Thus, the calling code will
 *	usually do something like:
 *		Tcl_SetObjResult(interp, result);
 *		Tcl_DecrRefCount(result);
 *

 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclLindexFlat(
    Tcl_Interp *interp,		/* Tcl interpreter. */
    Tcl_Obj *listObj,		/* Tcl object representing the list. */
    ListSizeT indexCount,		/* Count of indices. */
    Tcl_Obj *const indexArray[])/* Array of pointers to Tcl objects that
				 * represent the indices in the list. */
{
    ListSizeT i;

    Tcl_IncrRefCount(listObj);

    for (i=0 ; i<indexCount && listObj ; i++) {
	ListSizeT index, listLen = 0;
	Tcl_Obj **elemPtrs = NULL, *sublistCopy;

	/*
	 * Here we make a private copy of the current sublist, so we avoid any
	 * shimmering issues that might invalidate the elemPtr array below
	 * while we are still using it. See test lindex-8.4.
	 */

	sublistCopy = TclListObjCopy(interp, listObj);
	Tcl_DecrRefCount(listObj);
	listObj = NULL;

	if (sublistCopy == NULL) {

	    /* The sublist is not a list at all => error.  */


	    break;
	}
	LIST_ASSERT_TYPE(sublistCopy);
	ListObjGetElements(sublistCopy, listLen, elemPtrs);

	if (TclGetIntForIndexM(interp, indexArray[i], /*endValue*/ listLen-1,
		&index) == TCL_OK) {
	    if (index >= listLen) {
		/*
		 * Index is out of range. Break out of loop with empty result.
		 * First check remaining indices for validity
		 */

		while (++i < indexCount) {
		    if (TclGetIntForIndexM(
			    interp, indexArray[i], ListSizeT_MAX - 1, &index)
			!= TCL_OK) {
			Tcl_DecrRefCount(sublistCopy);
			return NULL;
		    }
		}
		TclNewObj(listObj);
	    } else {

		/* Extract the pointer to the appropriate element. */


		listObj = elemPtrs[index];
	    }
	    Tcl_IncrRefCount(listObj);
	}
	Tcl_DecrRefCount(sublistCopy);
    }

    return listObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TclLsetList --
 *
 *	Core of the 'lset' command when objc == 4. Objv[2] may be either a
 *	scalar index or a list of indices.
 *      It also handles 'lpop' when given a NULL value.
 *
 * Results:
 *	Returns the new value of the list variable, or NULL if there was an
 *	error. The returned object includes one reference count for the
 *	pointer returned.
 *
 * Side effects:
 *	None.
 *

 * Notes:
 *	This procedure is implemented entirely as a wrapper around
 *	TclLsetFlat. All it does is reconfigure the argument format into the
 *	form required by TclLsetFlat, while taking care to manage shimmering
 *	in such a way that we tend to keep the most useful internalreps and/or
 *	avoid the most expensive conversions.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclLsetList(
    Tcl_Interp *interp,		/* Tcl interpreter. */
    Tcl_Obj *listObj,		/* Pointer to the list being modified. */
    Tcl_Obj *indexArgObj,	/* Index or index-list arg to 'lset'. */
    Tcl_Obj *valueObj)		/* Value arg to 'lset' or NULL to 'lpop'. */
{
    ListSizeT indexCount = 0;   /* Number of indices in the index list. */
    Tcl_Obj **indices = NULL;	/* Vector of indices in the index list. */
    Tcl_Obj *retValueObj;	/* Pointer to the list to be returned. */
    ListSizeT index;            /* Current index in the list - discarded. */
    Tcl_Obj *indexListCopy;


    /*
     * Determine whether the index arg designates a list or a single index.
     * We have to be careful about the order of the checks to avoid repeated
     * shimmering; see TIP #22 and #23 for details.
     */

    if (!TclHasInternalRep(indexArgObj, &tclListType)

	&& TclGetIntForIndexM(NULL, indexArgObj, ListSizeT_MAX - 1, &index)

	       == TCL_OK) {
	/* indexArgPtr designates a single index. */

        /* T:listrep-1.{2.1,12.1,15.1,19.1},2.{2.3,9.3,10.1,13.1,16.1}, 3.{4,5,6}.3 */
	return TclLsetFlat(interp, listObj, 1, &indexArgObj, valueObj);
    }


    indexListCopy = TclListObjCopy(NULL, indexArgObj);
    if (indexListCopy == NULL) {
	/*
	 * indexArgPtr designates something that is neither an index nor a
	 * well formed list. Report the error via TclLsetFlat.
	 */

	return TclLsetFlat(interp, listObj, 1, &indexArgObj, valueObj);
    }
    LIST_ASSERT_TYPE(indexListCopy);
    ListObjGetElements(indexListCopy, indexCount, indices);

    /*
     * Let TclLsetFlat handle the actual lset'ting.
     */

    retValueObj = TclLsetFlat(interp, listObj, indexCount, indices, valueObj);

    Tcl_DecrRefCount(indexListCopy);
    return retValueObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TclLsetFlat --
 *
 *	Core engine of the 'lset' command.
 *      It also handles 'lpop' when given a NULL value.
 *
 * Results:
 *	Returns the new value of the list variable, or NULL if an error
 *	occurred. The returned object includes one reference count for the
 *	pointer returned.
 *

 * Side effects:
 *	On entry, the reference count of the variable value does not reflect
 *	any references held on the stack. The first action of this function is
 *	to determine whether the object is shared, and to duplicate it if it
 *	is. The reference count of the duplicate is incremented. At this


 *	point, the reference count will be 1 for either case, so that the


 *	object will appear to be unshared.
 *
 *	If an error occurs, and the object has been duplicated, the reference
 *	count on the duplicate is decremented so that it is now 0: this
 *	dismisses any memory that was allocated by this function.
 *



 *	If no error occurs, the reference count of the original object is

 *	incremented if the object has not been duplicated, and nothing is done
 *	to a reference count of the duplicate. Now the reference count of an
 *	unduplicated object is 2 (the returned pointer, plus the one stored in
 *	the variable). The reference count of a duplicate object is 1,
 *	reflecting that the returned pointer is the only active reference. The
 *	caller is expected to store the returned value back in the variable
 *	and decrement its reference count. (INST_STORE_* does exactly this.)
 *







 *----------------------------------------------------------------------
 */

Tcl_Obj *
TclLsetFlat(
    Tcl_Interp *interp,		/* Tcl interpreter. */
    Tcl_Obj *listObj,		/* Pointer to the list being modified. */
    ListSizeT indexCount,		/* Number of index args. */
    Tcl_Obj *const indexArray[],
				/* Index args. */
    Tcl_Obj *valueObj)		/* Value arg to 'lset' or NULL to 'lpop'. */
{
    ListSizeT index, len;
	int result;
    Tcl_Obj *subListObj, *retValueObj;
    Tcl_Obj *pendingInvalidates[10];
    Tcl_Obj **pendingInvalidatesPtr = pendingInvalidates;
    ListSizeT numPendingInvalidates = 0;

    /*
     * If there are no indices, simply return the new value.  (Without
     * indices, [lset] is a synonym for [set].
     * [lpop] does not use this but protect for NULL valueObj just in case.
     */

    if (indexCount == 0) {
	if (valueObj != NULL) {
	    Tcl_IncrRefCount(valueObj);
	}
	return valueObj;
    }

    /*
     * If the list is shared, make a copy we can modify (copy-on-write).  We
     * use Tcl_DuplicateObj() instead of TclListObjCopy() for a few reasons:
     * 1) we have not yet confirmed listObj is actually a list; 2) We make a
     * verbatim copy of any existing string rep, and when we combine that with
     * the delayed invalidation of string reps of modified Tcl_Obj's
     * implemented below, the outcome is that any error condition that causes
     * this routine to return NULL, will leave the string rep of listObj and
     * all elements to be unchanged.
     */

    subListObj = Tcl_IsShared(listObj) ? Tcl_DuplicateObj(listObj) : listObj;

    /*
     * Anchor the linked list of Tcl_Obj's whose string reps must be
     * invalidated if the operation succeeds.
     */

    retValueObj = subListObj;

    result = TCL_OK;

    /* Allocate if static array for pending invalidations is too small */
    if (indexCount
        > (int) (sizeof(pendingInvalidates) / sizeof(pendingInvalidates[0]))) {
	pendingInvalidatesPtr =
	    (Tcl_Obj **) Tcl_Alloc(indexCount * sizeof(*pendingInvalidatesPtr));
    }

    /*
     * Loop through all the index arguments, and for each one dive into the
     * appropriate sublist.
     */

    do {
	ListSizeT elemCount;
	Tcl_Obj *parentList, **elemPtrs;

	/*
	 * Check for the possible error conditions...
	 */

	if (TclListObjGetElementsM(interp, subListObj, &elemCount, &elemPtrs)
	    != TCL_OK) {
	    /* ...the sublist we're indexing into isn't a list at all. */
	    result = TCL_ERROR;
	    break;
	}

	/*
	 * WARNING: the macro TclGetIntForIndexM is not safe for
	 * post-increments, avoid '*indexArray++' here.
	 */

	if (TclGetIntForIndexM(interp, *indexArray, elemCount - 1, &index)
	    != TCL_OK) {
	    /* ...the index we're trying to use isn't an index at all. */
	    result = TCL_ERROR;
	    indexArray++; /* Why bother with this increment? TBD */
	    break;
	}
	indexArray++;

	if (index > elemCount
	    || (valueObj == NULL && index >= elemCount)) {
	    /* ...the index points outside the sublist. */
	    if (interp != NULL) {
		Tcl_SetObjResult(interp,
		                 Tcl_ObjPrintf("index \"%s\" out of range",
		                               Tcl_GetString(indexArray[-1])));
		Tcl_SetErrorCode(interp,
		                 "TCL",
		                 "VALUE",
		                 "INDEX"
		                 "OUTOFRANGE",
		                 NULL);
	    }
	    result = TCL_ERROR;
	    break;
	}

	/*
	 * No error conditions.  As long as we're not yet on the last index,
	 * determine the next sublist for the next pass through the loop,
	 * and take steps to make sure it is an unshared copy, as we intend
	 * to modify it.
	 */

	if (--indexCount) {
	    parentList = subListObj;
	    if (index == elemCount) {
		TclNewObj(subListObj);
	    } else {
		subListObj = elemPtrs[index];
	    }
	    if (Tcl_IsShared(subListObj)) {
		subListObj = Tcl_DuplicateObj(subListObj);
	    }

	    /*
	     * Replace the original elemPtr[index] in parentList with a copy
	     * we know to be unshared.  This call will also deal with the
	     * situation where parentList shares its internalrep with other
	     * Tcl_Obj's.  Dealing with the shared internalrep case can
	     * cause subListObj to become shared again, so detect that case
	     * and make and store another copy.
	     */

	    if (index == elemCount) {
		Tcl_ListObjAppendElement(NULL, parentList, subListObj);
	    } else {
		TclListObjSetElement(NULL, parentList, index, subListObj);
	    }
	    if (Tcl_IsShared(subListObj)) {
		subListObj = Tcl_DuplicateObj(subListObj);
		TclListObjSetElement(NULL, parentList, index, subListObj);
	    }

	    /*
	     * The TclListObjSetElement() calls do not spoil the string rep
	     * of parentList, and that's fine for now, since all we've done
	     * so far is replace a list element with an unshared copy.  The
	     * list value remains the same, so the string rep. is still
	     * valid, and unchanged, which is good because if this whole
	     * routine returns NULL, we'd like to leave no change to the
	     * value of the lset variable.  Later on, when we set valueObj
	     * in its proper place, then all containing lists will have
	     * their values changed, and will need their string reps
	     * spoiled.  We maintain a list of all those Tcl_Obj's (via a
	     * little internalrep surgery) so we can spoil them at that
	     * time.
	     */



	    pendingInvalidatesPtr[numPendingInvalidates] = parentList;
	    ++numPendingInvalidates;
	}
    } while (indexCount > 0);

    /*
     * Either we've detected and error condition, and exited the loop with
     * result == TCL_ERROR, or we've successfully reached the last index, and
     * we're ready to store valueObj. On success, we need to invalidate
     * the string representations of intermediate lists whose contained
     * list element would have changed.
     */
    if (result == TCL_OK) {
	while (numPendingInvalidates > 0) {
	    Tcl_Obj *objPtr;





	    --numPendingInvalidates;

	    objPtr = pendingInvalidatesPtr[numPendingInvalidates];


	    if (result == TCL_OK) {

		/*
		 * We're going to store valueObj, so spoil string reps of all
		 * containing lists.
		 * TODO - historically, the storing of the internal rep was done
		 * because the ptr2 field of the internal rep was used to chain
		 * objects whose string rep needed to be invalidated. Now this
		 * is no longer the case, so replacing of the internal rep
		 * should not be needed. The TclInvalidateStringRep should
		 * suffice. Formulate a test case before changing.
		 */
		ListRep objInternalRep;
		TclListObjGetRep(NULL, objPtr, &objInternalRep);
		ListObjReplaceRepAndInvalidate(objPtr, &objInternalRep);
	    }




	}



    }

    if (pendingInvalidatesPtr != pendingInvalidates)
	Tcl_Free(pendingInvalidatesPtr);

    if (result != TCL_OK) {
	/*
	 * Error return; message is already in interp. Clean up any excess
	 * memory.
	 */

	if (retValueObj != listObj) {
	    Tcl_DecrRefCount(retValueObj);
	}
	return NULL;
    }

    /*
     * Store valueObj in proper sublist and return. The -1 is to avoid a
     * compiler warning (not a problem because we checked that we have a
     * proper list - or something convertible to one - above).
     */

    len = -1;
    TclListObjLengthM(NULL, subListObj, &len);
    if (valueObj == NULL) {
        /* T:listrep-1.{4.2,5.4,6.1,7.1,8.3},2.{4,5}.4 */
	Tcl_ListObjReplace(NULL, subListObj, index, 1, 0, NULL);
    } else if (index == len) {
        /* T:listrep-1.2.1,2.{2.3,9.3},3.{4,5,6}.3 */
	Tcl_ListObjAppendElement(NULL, subListObj, valueObj);
    } else {
        /* T:listrep-1.{12.1,15.1,19.1},2.{10,13,16}.1 */
	TclListObjSetElement(NULL, subListObj, index, valueObj);
	TclInvalidateStringRep(subListObj);
    }
    Tcl_IncrRefCount(retValueObj);
    return retValueObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TclListObjSetElement --
 *
 *	Set a single element of a list to a specified value
 *



 * Results:

 *	The return value is normally TCL_OK. If listObj does not refer to a





 *	list object and cannot be converted to one, TCL_ERROR is returned and
 *	an error message will be left in the interpreter result if interp is




 *	not NULL. Similarly, if index designates an element outside the range
 *	[0..listLength-1], where listLength is the count of elements in the
 *	list object designated by listObj, TCL_ERROR is returned and an error
 *	message is left in the interpreter result.
 *
 * Side effects:

 *	Tcl_Panic if listObj designates a shared object. Otherwise, attempts
 *	to convert it to a list with a non-shared internal rep. Decrements the

 *	ref count of the object at the specified index within the list,
 *	replaces with the object designated by valueObj, and increments the
 *	ref count of the replacement object.
 *

 *----------------------------------------------------------------------
 */

int
TclListObjSetElement(
    Tcl_Interp *interp,		/* Tcl interpreter; used for error reporting
				 * if not NULL. */
    Tcl_Obj *listObj,		/* List object in which element should be
				 * stored. */
    ListSizeT index,		/* Index of element to store. */
    Tcl_Obj *valueObj)		/* Tcl object to store in the designated list
				 * element. */
{
    ListRep listRep;

    Tcl_Obj **elemPtrs;         /* Pointers to elements of the list. */
    ListSizeT elemCount;		/* Number of elements in the list. */


    /* Ensure that the listObj parameter designates an unshared list. */


    if (Tcl_IsShared(listObj)) {
	Tcl_Panic("%s called with shared object", "TclListObjSetElement");
    }





    if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {








	return TCL_ERROR;
    }







    elemCount = ListRepLength(&listRep);


    /* Ensure that the index is in bounds. */


    if (index>=elemCount) {
	if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"index \"%" TCL_Z_MODIFIER "u\" out of range", index));
	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "INDEX",
		    "OUTOFRANGE", NULL);
	}
	return TCL_ERROR;
    }

    /*
     * Note - garbage collect this only AFTER checking indices above.
     * Do not want to modify listrep and then not store it back in listObj.
     */
    ListRepFreeUnreferenced(&listRep);

    /* Replace a shared internal rep with an unshared copy */
    if (listRep.storePtr->refCount > 1) {
	ListRep newInternalRep;

        /* T:listrep-2.{10,13,16}.1 */









	/* TODO - leave extra space? */





	ListRepClone(&listRep, &newInternalRep, LISTREP_PANIC_ON_FAIL);
	listRep = newInternalRep;
    } /* else T:listrep-1.{12.1,15.1,19.1} */








    /* Retrieve element array AFTER potential cloning above */
    ListRepElements(&listRep, elemCount, elemPtrs);

    /*
     * Add a reference to the new list element and remove from old before
     * replacing it. Order is important!
     */
    Tcl_IncrRefCount(valueObj);
    Tcl_DecrRefCount(elemPtrs[index]);





    elemPtrs[index] = valueObj;




    /* Internal rep may be cloned so replace */





    ListObjReplaceRepAndInvalidate(listObj, &listRep);


    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeListInternalRep --
 *
 *	Deallocate the storage associated with a list object's internal
 *	representation.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees listPtr's List* internal representation, if no longer shared.
 *	May decrement the ref counts of element objects, which may free them.
 *
 *----------------------------------------------------------------------
 */

static void
FreeListInternalRep(
    Tcl_Obj *listObj)		/* List object with internal rep to free. */
{
    ListRep listRep;



    ListObjGetRep(listObj, &listRep);
    if (listRep.storePtr->refCount-- <= 1) {
	ObjArrayDecrRefs(
	    listRep.storePtr->slots,
	    listRep.storePtr->firstUsed, listRep.storePtr->numUsed);

	Tcl_Free(listRep.storePtr);
    }
    if (listRep.spanPtr) {
	ListSpanDecrRefs(listRep.spanPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * DupListInternalRep --
 *
 *	Initialize the internal representation of a list Tcl_Obj to share the
 *	internal representation of an existing list object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The reference count of the List internal rep is incremented.
 *
 *----------------------------------------------------------------------
 */

static void
DupListInternalRep(
    Tcl_Obj *srcObj,		/* Object with internal rep to copy. */
    Tcl_Obj *copyObj)		/* Object with internal rep to set. */
{
    ListRep listRep;
    ListObjGetRep(srcObj, &listRep);

    ListObjOverwriteRep(copyObj, &listRep);

}

/*
 *----------------------------------------------------------------------
 *
 * SetListFromAny --
 *
 *	Attempt to generate a list internal form for the Tcl object "objPtr".
 *
 * Results:

 *	The return value is TCL_OK or TCL_ERROR. If an error occurs during

 *	conversion, an error message is left in the interpreter's result

 *	unless "interp" is NULL.
 *
 * Side effects:

 *	If no error occurs, a list is stored as "objPtr"s internal

 *	representation.
 *
 *----------------------------------------------------------------------
 */

static int
SetListFromAny(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *objPtr)		/* The object to convert. */
{

    Tcl_Obj **elemPtrs;
    ListRep listRep;

    /*
     * Dictionaries are a special case; they have a string representation such
     * that *all* valid dictionaries are valid lists. Hence we can convert
     * more directly. Only do this when there's no existing string rep; if
     * there is, it is the string rep that's authoritative (because it could
     * describe duplicate keys).
     */

    if (!TclHasStringRep(objPtr) && TclHasInternalRep(objPtr, &tclDictType)) {
	Tcl_Obj *keyPtr, *valuePtr;
	Tcl_DictSearch search;
	int done;
	ListSizeT size;

	/*
	 * Create the new list representation. Note that we do not need to do
	 * anything with the string representation as the transformation (and
	 * the reverse back to a dictionary) are both order-preserving. Also
	 * note that since we know we've got a valid dictionary (by
	 * representation) we also know that fetching the size of the
	 * dictionary or iterating over it will not fail.
	 */

	Tcl_DictObjSize(NULL, objPtr, &size);
	/* TODO - leave space in front and/or back? */
	if (ListRepInitAttempt(
		interp, size > 0 ? 2 * size : 1, NULL, &listRep)
	    != TCL_OK) {
	    return TCL_ERROR;
	}

	LIST_ASSERT(listRep.spanPtr == NULL); /* Guard against future changes */
	LIST_ASSERT(listRep.storePtr->firstUsed == 0);
	LIST_ASSERT((listRep.storePtr->flags & LISTSTORE_CANONICAL) == 0);

	listRep.storePtr->numUsed = 2 * size;

	/* Populate the list representation. */


	elemPtrs = listRep.storePtr->slots;
	Tcl_DictObjFirst(NULL, objPtr, &search, &keyPtr, &valuePtr, &done);
	while (!done) {
	    *elemPtrs++ = keyPtr;
	    *elemPtrs++ = valuePtr;
	    Tcl_IncrRefCount(keyPtr);
	    Tcl_IncrRefCount(valuePtr);
	    Tcl_DictObjNext(&search, &keyPtr, &valuePtr, &done);
	}
    } else {
	ListSizeT estCount, length;
	const char *limit, *nextElem = Tcl_GetStringFromObj(objPtr, &length);

	/*
	 * Allocate enough space to hold a (Tcl_Obj *) for each
	 * (possible) list element.
	 */

	estCount = TclMaxListLength(nextElem, length, &limit);
	estCount += (estCount == 0);	/* Smallest list struct holds 1
					 * element. */
	/* TODO - allocate additional space? */
	if (ListRepInitAttempt(interp, estCount, NULL, &listRep)
	    != TCL_OK) {
	    return TCL_ERROR;
	}

	LIST_ASSERT(listRep.spanPtr == NULL); /* Guard against future changes */
	LIST_ASSERT(listRep.storePtr->firstUsed == 0);

	elemPtrs = listRep.storePtr->slots;


	/* Each iteration, parse and store a list element. */


	while (nextElem < limit) {
	    const char *elemStart;
	    char *check;
	    ListSizeT elemSize;
	    int literal;

	    if (TCL_OK != TclFindElement(interp, nextElem, limit - nextElem,
		    &elemStart, &nextElem, &elemSize, &literal)) {
fail:
		while (--elemPtrs >= listRep.storePtr->slots) {
		    Tcl_DecrRefCount(*elemPtrs);
		}
		Tcl_Free(listRep.storePtr);
		return TCL_ERROR;
	    }
	    if (elemStart == limit) {
		break;
	    }

	    TclNewObj(*elemPtrs);
	    TclInvalidateStringRep(*elemPtrs);
	    check = Tcl_InitStringRep(*elemPtrs, literal ? elemStart : NULL,
		    elemSize);
	    if (elemSize && check == NULL) {
		MemoryAllocationError(interp, elemSize);




		goto fail;
	    }
	    if (!literal) {
		Tcl_InitStringRep(*elemPtrs, NULL,
			TclCopyAndCollapse(elemSize, elemStart, check));
	    }

	    Tcl_IncrRefCount(*elemPtrs++);/* Since list now holds ref to it. */
	}

	listRep.storePtr->numUsed =
	    elemPtrs - listRep.storePtr->slots;
    }

    LISTREP_CHECK(&listRep);

    /*
     * Store the new internalRep. We do this as late
     * as possible to allow the conversion code, in particular
     * Tcl_GetStringFromObj, to use the old internalRep.
     */

    /*
     * Note old string representation NOT to be invalidated.
     * So do NOT use ListObjReplaceRepAndInvalidate. InternalRep to be freed AFTER
     * IncrRefs so do not use ListObjOverwriteRep
     */
    ListRepIncrRefs(&listRep);
    TclFreeInternalRep(objPtr);
    objPtr->internalRep.twoPtrValue.ptr1 = listRep.storePtr;
    objPtr->internalRep.twoPtrValue.ptr2 = listRep.spanPtr;
    objPtr->typePtr = &tclListType;

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * UpdateStringOfList --
 *
 *	Update the string representation for a list object. Note: This

 *	function does not invalidate an existing old string rep so storage
 *	will be lost if this has not already been done.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The object's string is set to a valid string that results from the
 *	list-to-string conversion. This string will be empty if the list has
 *	no elements. The list internal representation should not be NULL and
 *	we assume it is not NULL.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateStringOfList(
    Tcl_Obj *listObj)		/* List object with string rep to update. */
{
#   define LOCAL_SIZE 64
    char localFlags[LOCAL_SIZE], *flagPtr = NULL;
    ListSizeT numElems, i, length, bytesNeeded = 0;
    const char *elem, *start;
    char *dst;
    Tcl_Obj **elemPtrs;
    ListRep listRep;


    ListObjGetRep(listObj, &listRep);
    LISTREP_CHECK(&listRep);

    ListRepElements(&listRep, numElems, elemPtrs);

    /*
     * Mark the list as being canonical; although it will now have a string
     * rep, it is one we derived through proper "canonical" quoting and so
     * it's known to be free from nasties relating to [concat] and [eval].
     * However, we only do this if this is not a spanned list. Marking the
     * storage canonical for a spanned list make ALL lists using the storage
     * canonical which is not right. (Consider a list generated from a
     * string and then this function called for a spanned list generated
     * from it). On the other hand, a spanned list is always canonical
     * (never generated from a string) so it does not have to be explicitly
     * marked as such. The ListObjIsCanonical macro takes this into account.
     * See the comments there.
     */
    if (listRep.spanPtr == NULL) {
	LIST_ASSERT(listRep.storePtr->firstUsed == 0);/* Invariant */
	listRep.storePtr->flags |= LISTSTORE_CANONICAL;
    }



    /* Handle empty list case first, so rest of the routine is simpler. */


    if (numElems == 0) {
	Tcl_InitStringRep(listObj, NULL, 0);
	return;
    }


    /* Pass 1: estimate space, gather flags. */


    if (numElems <= LOCAL_SIZE) {
	flagPtr = localFlags;
    } else {

	/* We know numElems <= LIST_MAX, so this is safe. */


	flagPtr = (char *)Tcl_Alloc(numElems);
    }

    for (i = 0; i < numElems; i++) {
	flagPtr[i] = (i ? TCL_DONT_QUOTE_HASH : 0);
	elem = Tcl_GetStringFromObj(elemPtrs[i], &length);
	bytesNeeded += TclScanElement(elem, length, flagPtr+i);
	if (bytesNeeded > SIZE_MAX - numElems) {
	    Tcl_Panic("max size for a Tcl value (%" TCL_Z_MODIFIER "u bytes) exceeded", SIZE_MAX);
	}
    }
    bytesNeeded += numElems - 1;

    /*
     * Pass 2: copy into string rep buffer.
     */

    start = dst = Tcl_InitStringRep(listObj, NULL, bytesNeeded);
    TclOOM(dst, bytesNeeded);
    for (i = 0; i < numElems; i++) {
	flagPtr[i] |= (i ? TCL_DONT_QUOTE_HASH : 0);
	elem = Tcl_GetStringFromObj(elemPtrs[i], &length);
	dst += TclConvertElement(elem, length, dst, flagPtr[i]);
	*dst++ = ' ';
    }

    /* Set the string length to what was actually written, the safe choice */
    (void) Tcl_InitStringRep(listObj, NULL, dst - 1 - start);

    if (flagPtr != localFlags) {
	Tcl_Free(flagPtr);
    }
}

/*
 *------------------------------------------------------------------------
 *
 * TclListTestObj --
 *
 *    Returns a list object with a specific internal rep and content.
 *    Used specifically for testing so span can be controlled explicitly.
 *
 * Results:
 *    Pointer to the Tcl_Obj containing the list.
 *
 * Side effects:
 *    None.
 *
 *------------------------------------------------------------------------
 */
Tcl_Obj *
TclListTestObj (int length, int leadingSpace, int endSpace)
{
    if (length < 0)
	length = 0;
    if (leadingSpace < 0)
	leadingSpace = 0;
    if (endSpace < 0)
	endSpace = 0;

    ListRep listRep;
    ListSizeT capacity;
    Tcl_Obj *listObj;

    TclNewObj(listObj);

    /* Only a test object so ignoring overflow checks */
    capacity = length + leadingSpace + endSpace;
    if (capacity == 0) {
	return listObj;
    }

    ListRepInit(capacity, NULL, 0, &listRep);

    ListStore *storePtr = listRep.storePtr;
    int i;
    for (i = 0; i < length; ++i) {
	storePtr->slots[i + leadingSpace] = Tcl_NewIntObj(i);
	Tcl_IncrRefCount(storePtr->slots[i + leadingSpace]);
    }
    storePtr->firstUsed = leadingSpace;
    storePtr->numUsed = length;
    if (leadingSpace != 0) {
	listRep.spanPtr = ListSpanNew(leadingSpace, length);
    }
    ListObjReplaceRepAndInvalidate(listObj, &listRep);
    return listObj;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */