Tcl Library Procedures - Tcl_AllowExceptions manual page

Tcl/Tk

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NAME

Tcl_AllowExceptions - allow all exceptions in next script evaluation

SYNOPSIS

#include <tcl.h>
Tcl_AllowExceptions(interp)

ARGUMENTS

Tcl_Interp *interp (in): Interpreter in which script will be evaluated.

If a script is evaluated at top-level (i.e. no other scripts are pending evaluation when the script is invoked), and if the script terminates with a completion code other than TCL_OK, TCL_ERROR or TCL_RETURN, then Tcl normally converts this into a TCL_ERROR return with an appropriate message. The particular script evaluation procedures of Tcl that act in the manner are Tcl_EvalObjEx, Tcl_EvalObjv, Tcl_Eval, Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval and Tcl_VarEvalVA.

However, if Tcl_AllowExceptions is invoked immediately before calling one of those a procedures, then arbitrary completion codes are permitted from the script, and they are returned without modification. This is useful in cases where the caller can deal with exceptions such as TCL_BREAK or TCL_CONTINUE in a meaningful way.

KEYWORDS

continue, break, exception, interpreter

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