Labels:book | poster | reckoner | sky | tree | windowpane OCR: II-46 Mops General Reference By saying "if no error occurs" we really mean that THROW not take an error exit. THROW pops the top item on the stack. and if it is non- -zero, restores the stacks where they were when the current CATCH was called (assuming that at least one CATCH effect) Then the non- zero yalue, assumed to be an error code, is pushed onto the stack and ex ecution continues straight after the C ATCH If THROW finds a zero value on top of the stacl it means no error, and execution continues normally From this you can see that C ATCH and THROW provide a flexible means of unwinding out of deeply nested code if an occurs If CATCH catches an error, but doesn't want to recognize that particular error code it can simply re- THROW 1 If no CATCH is in effect when an C011T occurs, Mops t ...
