This library provides tools to control the Prolog debuggers. Traditionally this code was built-in. Because these tools are only required in (interactive) debugging sessions they have been moved into the library.
informational
, with one of the following terms, where Spec
is of the form M:Head.
spy(Spec)
nospy(Spec)
error(Formal, Context)
exceptions that
unify with
Exception. The tracer is started when a matching exception is
raised. This predicate enables debug mode using debug/0
to get more context about the exception. Even with debug mode disabled
exceptions are still trapped and thus one may call nodebug/0
to run in normal mode after installing a trap.
The predicate notrap/1 removes matching (unifying) traps.