"Hard-Coded" versus Dynamic Trapping

Chapter 4-5: The Debugger

“Hard-Coded” versus Dynamic Trapping

If you insert only one TRAP statement in an event point, you have several alternatives upon reaching the debugger screen:

· By selecting go, you can execute from the TRAP statement all the way through to the logical end of a process. To reach the logical end of a process, you may be taken through the invocation of one or more automatic children along the way. The only exception is that, if the routine involves a loop that causes the logic to re-execute the TRAP statement, processing is interrupted again at the TRAP until the loop ends.

· By pressing enter you can single-step through a routine, one statement at a time, beginning with the TRAP statement.

· You can set additional break points dynamically by positioning the cursor on any desired statement line and pressing select (F3) to clear or set a TRAP. When you select go, you execute from the TRAP statement up to (but not including) the next break point.

· By selecting step/end, you can step directly to the last statement in the current event point (and execute all the statements along the way). If, at this point, you press enter, you execute the last statement of the current event point and automatically step to the first statement of the next event point within the current process. In this way, you can debug more than one routine with only a single TRAP statement. If there are no more event points, you are taken to the normal end of the process.

You can use select to “turn on” and “turn off” a trap on any line, including TRAP statements. If you turn off a TRAP statement, it is simply bypassed during execution. The debugger alerts you to the statements that are in active trap mode; these active lines are brightened. To reverse the existing active/inactive status, simply position the cursor anywhere on the desired statement and press select (F3). If a line was previously brightened, it reverts to normal color, and vice-versa. In this way, you control which lines have a TRAP set and, therefore, where break points occur when you execute a process by selecting the go option.

APPX Application Design Manual (01/13/03)