Tcl_SaveResult(), Tcl_RestoreResult(), Tcl_DiscardResult()

save and restore an interpreter's result 

Tcl Library Procedures


SYNOPSIS

#include <tcl.h>

Tcl_SaveResult(interp, statePtr)

Tcl_RestoreResult(interp, statePtr)

Tcl_DiscardResult(statePtr)


ARGUMENTS

Tcl_Interp *interp (in) 

Interpreter for which state should be saved.

Tcl_SavedResult *statePtr (in) 

Pointer to location where interpreter result should be saved or restored.


DESCRIPTION

These routines allows a C procedure to take a snapshot of the current interpreter result so that it can be restored after a call to Tcl_Eval() or some other routine that modifies the interpreter result. These routines are passed a pointer to a structure that is used to store enough information to restore the interpreter result state. This structure can be allocated on the stack of the calling procedure. These routines do not save the state of any error information in the interpreter (for example, the errorCode or errorInfo variables).

Tcl_SaveResult() moves the string and object results of interp into the location specified by statePtr. Tcl_SaveResult() clears the result for interp and leaves the result in its normal empty initialized state.

Tcl_RestoreResult() moves the string and object results from statePtr back into interp. Any result or error that was already in the interpreter will be cleared. The statePtr is left in an uninitialized state and cannot be used until another call to Tcl_SaveResult().

Tcl_DiscardResult() releases the saved interpreter state stored at statePtr. The state structure is left in an uninitialized state and cannot be used until another call to Tcl_SaveResult().

Once Tcl_SaveResult() is called to save the interpreter result, either Tcl_RestoreResult() or Tcl_DiscardResult() must be called to properly clean up the memory associated with the saved state.


PORTABILITY

Windows Server 2012. Windows 8.1. Windows Server 2012 R2. Windows 10. Windows Server 2016. Windows Server 2019.


AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


PTC MKS Toolkit 10.3 Documentation Build 39.