/*
 * tclCompExpr.c --
 *
 *	This file contains the code to parse and compile Tcl expressions
 *	and implementations of the Tcl commands corresponding to expression
 *	operators, such as the command ::tcl::mathop::+ .
 *
 * Contributions from Don Porter, NIST, 2006-2007. (not subject to US copyright)
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclCompExpr.c,v 1.82 2007/08/27 15:12:38 dgp Exp $
 */

#include "tclInt.h"
#include "tclCompile.h"		/* CompileEnv */

/*
 * Expression parsing takes place in the routine ParseExpr().  It takes a

 *
 * Side effects:
 *	Adds instructions to envPtr to evaluate the expression at runtime.
 *
 *----------------------------------------------------------------------
 */

/* TODO: Convert this to return void.  Generate error throwing bytecode
 * for syntax errors instead of failing to compile. */
int
TclCompileExpr(
    Tcl_Interp *interp,		/* Used for error reporting. */
    const char *script,		/* The source script to compile. */
    int numBytes,		/* Number of bytes in script. */
    CompileEnv *envPtr)		/* Holds resulting instructions. */
{
    OpNode *opTree = NULL;	/* Will point to the tree of operators */

	TclAdvanceLines(&envPtr->line, script,
		script + TclParseAllWhiteSpace(script, numBytes));

	Tcl_ListObjGetElements(NULL, litList, &objc, (Tcl_Obj ***)&litObjv);
	Tcl_ListObjGetElements(NULL, funcList, &objc, &funcObjv);
	CompileExprTree(interp, opTree, 0, &litObjv, funcObjv,
		parsePtr->tokenPtr, envPtr, 1 /* optimize */);


    }

    Tcl_FreeParse(parsePtr);
    TclStackFree(interp, parsePtr);
    Tcl_DecrRefCount(funcList);
    Tcl_DecrRefCount(litList);
    ckfree((char *) opTree);
    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * ExecConstantExprTree --
 *	Compiles and executes bytecode for the subexpression tree at index

	    if (optimize && nodes[next].constant) {
		Tcl_InterpState save = Tcl_SaveInterpState(interp, TCL_OK);
		if (ExecConstantExprTree(interp, nodes, next, litObjvPtr)
			== TCL_OK) {
		    TclEmitPush(TclAddLiteralObj(envPtr,
			    Tcl_GetObjResult(interp), NULL), envPtr);
		} else {
		    char *cmd;
		    int length;
		    Tcl_Obj *returnCmd;
		    Tcl_Parse *parsePtr = (Tcl_Parse *)
			    TclStackAlloc(interp, sizeof(Tcl_Parse));

		    TclNewLiteralStringObj(returnCmd, "return ");
		    Tcl_IncrRefCount(returnCmd);
		    Tcl_AppendObjToObj(returnCmd,
			    Tcl_GetReturnOptions(interp, TCL_ERROR));
		    Tcl_ListObjAppendElement(NULL, returnCmd,
			    Tcl_GetObjResult(interp));
		    cmd = Tcl_GetStringFromObj(returnCmd, &length);
		    Tcl_ParseCommand(interp, cmd, length, 0, parsePtr);
		    TclCompileReturnCmd(interp, parsePtr, envPtr);
		    Tcl_DecrRefCount(returnCmd);
		    Tcl_FreeParse(parsePtr);
		    TclStackFree(interp, parsePtr);
		}
		Tcl_RestoreInterpState(interp, save);
		convert = 0;
	    } else {
		nodePtr = nodes + next;
	    }
	}