Next: Action Variables, Previous: Past States, Up: Breakpoint Conditions [Contents][Index]
There are a few condition macros expanding to a list of other conditions:
unleash
Expands to [show(print),command(proceed)]
hide
Expands to [show(silent),command(proceed)]
leash
Expands to [show(print),command(ask)]
The user can also define condition macros using the hook predicate below.
breakpoint_expansion(+Macro, -Body) hook,development
user:breakpoint_expansion(+Macro, -Body)
This predicate is called with each (non-composite)
breakpoint test or action, as its first argument. If it
succeeds, then the term returned in the second argument
(Body
) is substituted for the original condition. The expansion
is done at the time the breakpoint is added.
Note that Body can be composite, but it cannot be of form
Tests-Actions
. This means that the whole Body
will be interpreted as being in either the test or the action part,
depending on the context.
The built-in breakpoint conditions cannot be redefined using this predicate. See mpg-ref-breakpoint_expansion.