Using the Event Table and the Events Menu

To trace program execution, choose the Trace, Trace <loc>, or Trace <var> selection from the Events menu. These choices are also available as Common Events buttons within the Event Table itself.

• Trace displays source lines in the command window before they are executed.

• Trace <loc> prompts for a source line. Prism displays a message immediately prior to the execution of this source line.

• Trace <var> prompts for a variable name. A message is printed when the variable's value changes. The variable can be an array, an array section, or a parallel variable, in which case a message is printed any time any element changes. This slows execution considerably.

In addition, Trace <cond> is available as a Common Events button. It prompts for a condition, which can be any expression that evaluates to true or false; see " Writing Expressions in Prism" for more information on writing expressions. The program displays a message when the condition is met. This also slows execution considerably.

For variations of these traces, you can create your own event in the Event Table. You can also use the Actions field to specify Prism commands that are to be executed along with the trace.

Deleting Traces via the Event Table

To delete a trace, choose the Delete selection from the Events menu, or use the Delete button in the Event Table. See " Deleting an Existing Event".