D 2014-09-15T20:39:23.464
L Tcl_Obj\sSystem
P 73d68babc75501735b30e0b9ce8a172f24648139
U dgp
W 2071
<h1>Source Files</h1>
  *  portions of [/finfo?name=generic/tclObj.c|tclObj.c]

<h1>Public Routines</h1>
  *  Tcl_NewObj
  *  Tcl_DbNewObj
  *  TclFreeObj
  *  Tcl_DuplicateObj
  *  Tcl_GetString
  *  Tcl_GetStringFromObj
  *  Tcl_InvalidateStringRep
  *  Tcl_DbIncrRefCount
  *  Tcl_DbDecrRefCount
  *  Tcl_DbIsShared
  *  Tcl_InitObjHashTable

<h1>Private Routines</h1>
  *  TclObjBeingDeleted
  *  TclSetDuplicateObj
  *  TclCompareObjKeys
  *  TclFreeObjEntry
  *  TclHashObjKey
  *  Tcl_RepresentationCmd
  *  TclFreeIntRep

<h1>Directly Depends On Public Routines From</h1>
  *  [Allocation]
  *  [Hash Tables]
  *  [Threads]

<h1>Directly Depends On Private Routines From</h1>
  *  [Event Loops]

<h1>Discussion</h1>

If extensions need <b>TclObjBeingDeleted</b> then it
should be public.  Otherwise it should be file static.

<b>TclFreeIntRep</b> should be public.  There should be
no direct calling of another object type's procs.

There's code duplication in <b>TclHashObjKey</b> cribbed from
[Hash Tables].

Critical defect here: much of the API uses a <i>signed int</i> for object lengths (with negative numbers, typically -1, indicating “use strlen() to get the real length”). This is fine on 32-bit platforms, but massively wrong on 64-bit (except for ILP64 architectures, but that's a rare configuration).

There's a single avenue for transforming from one arbitrary object type to another -- through
the string rep.  This is effective, but limiting.  Fully internal transformations cheat to avoid
the problems, notably list to dict and back.  This suggests alternative exchange forms could
be useful.  The two that come to mind are containers -- effectively lists -- and bytearrays.

There's only a single alternative intrep recalled at any time.  This is sometimes unwelcome,
and a fair bit of trickery is employed in places to avoid loss of a particularly precious intrep.
Some consideration of a larger number of alternative representations able to co-exist
might be taken.  (Pros and cons)


Z 78822b65e05e76dd39e97821e09e39ef