Although you can enter the word in full, only the capitalized
and highlighted letter is needed; all characters following it are
ignored. That is why these are referred to as alphabetic character
options.
TRACE actions correspond to the alphabetic character options
as follows:
- All
- Traces (that is, displays) all clauses before execution.
- Commands
- Traces all commands before execution. If the command results in
an error or failure 1 ,tracing also displays the return code from the command.
- Error
- Traces any command resulting in an error or failure 1 after execution,
together with the return code from the command.
- Failure
- Traces any command resulting in a failure 1 after execution,
together with the return code from the command. This is the same as
the Normal option.
- Intermediates
- Traces all clauses before execution. Also traces intermediate
results during evaluation of expressions and substituted names.
- Labels
- Traces only labels passed during execution. This is especially
useful with debug mode, when the language processor pauses after each
label. It also helps the user to note all internal subroutine calls
and transfers of control because of the SIGNAL instruction.
- Normal
- Traces any command resulting in a negative return code after execution,
together with the return code from the command. This is the default
setting.
- Off
- Traces nothing and resets the special prefix options (described
later) to OFF.
- Results
- Traces all clauses before execution. Displays final results (contrast
with Intermediates, preceding) of evaluating an expression.
Also displays values assigned during PULL, ARG, and PARSE instructions. This setting is recommended for general debugging.
- Scan
- Traces all remaining clauses in the data without them being processed.
Basic checking (for missing ENDs and so forth) is carried out, and
the trace is formatted as usual. This is valid only if the TRACE
S clause itself is not nested in any other instruction (including
INTERPRET or interactive debug) or in an internal routine.