Error Conditions

An error condition can occur because a command could not complete successfully or because of a mistake in a PML macro or function. The presence of an error normally has three effects:

• An Alert box appears which you must acknowledge.

• An error message is output together with a traceback of any calling macros or functions.

• Any currently running PML macros and functions are abandoned.

This example of an error is caused by an attempt to use a PML variable that does not exist:

(46,28) ERROR - Variable FRED not defined

The 46 is the module or program section, which identified the error and is the error code itself is 28.

If the input line had been typed interactively that is the end of the story. However, if the input line was part of a PML macro or function, the error may optionally be handled.