NetRexx: Tracing

Tracing

Defined as part of the language, NetRexx tracing often provides useful debugging information. The flow of execution of programs may be traced, and the execution trace can be viewed as it occurs or captured in a file. The trace can show each clause as it is executed, and optionally show the results of expressions, etc. For example, the program:

  trace results
  number=1/7
  parse number before '.' after
  say after'.'before

would result in the trace:

  2 *=*   number=1/7
    >v> number "0.142857143"
  3 *=*   parse number before '.' after
    >v> before "0"
    >v> after "142857143"
  4 *=*   say after'.'before
    >>> "142857143.0"

where the lines marked with '*=*' are the statements in the program, lines with '>v>' show results assigned to local variables, and lines with '>>>' show results of un-named expressions.

[ previous section | contents | next section ]