Tcl_SaveResult(3) Tcl Library Procedures Tcl_SaveResult(3)
Tcl_SaveResult, Tcl_RestoreResult, Tcl_DiscardResult - save and restore
an interpreter's result
Tcl_Interp *interp (in) Interpreter for which state
should be saved.
Tcl_SavedResult *statePtr (in) Pointer to location where inter-
preter result should be saved or
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 rou-
tines 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 (e.g.
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 inter-
preter 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.
result, state, interp
Tcl 8.1 Tcl_SaveResult(3)