State:		Final
Type:		Project
Tcl-Version:	8.4
Vote:		Done
Post-History:	
Author:		Miguel Sofer <msofer@users.sourceforge.net>
Created:	28-Aug-2001

Abstract

This TIP replaces Tcl_EvalTokens with Tcl_EvalTokensStandard, which obeys the standard result management conventions for script evaluation functions.

Rationale

The standard call interface for Tcl_Eval* functions returns a Tcl completion code (TCL_OK, TCL_ERROR, TCL_RETURN, TCL_BREAK, or TCL_CONTINUE), and sets a result object in the interpreter. The single exception is the function Tcl_EvalTokens, that returns a pointer to the result object, or a NULL when an exception occurs. This effectively transforms all exceptions into errors. This TIP proposes to replace Tcl_EvalTokens with a new function Tcl_EvalTokensStandard that performs the same chores but adheres to the standard call interface.

There are two arguments for the replacement of Tcl_EvalTokens:

• Present a consistent call interface to all Tcl_Eval* functions.

• Allow the return of non-error exceptional returns when evaluating tokens; the impossibility to do this is the cause of Bugs #455151 (https://sourceforge.net/tracker/index.php?func=detail&aid=455151&group\_id=10894&atid=110894\) and #219384 (https://sourceforge.net/tracker/index.php?func=detail&aid=219384&group\_id=10894&atid=110894\)

Proposed Change

The proposal is to deprecate the use of Tcl_EvalTokens and replace it with a new Tcl_EvalTokensStandard. The core should only use the new function, the old one remains only for backward compatibility with extensions.

The proposal is implemented in the patch included in [Bug: 455151] https://sourceforge.net/tracker/index.php?func=detail&aid=455151&group\_id=10894&atid=110894

Copyright

This document has been placed in the public domain.