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33.3.6 Evaluator trap options

[FIXME: These flags, together with their corresponding handlers, are not user level options. Probably this entire section should be moved to the documentation about the low-level programmer debugging interface.]

Here is the list of evaluator trap options generated by typing (traps 'full) in Guile. You can also see the default values.

exit-frame      no      Trap when exiting eval or apply.
apply-frame     no      Trap when entering apply.
enter-frame     no      Trap when eval enters new frame.
traps		yes	Enable evaluator traps.

key cont tailp

apply-frame-handler

Called when a procedure is being applied. Called if: evaluator traps are enabled [traps interface], and either apply-frame is enabled [traps interface], or trace mode is on [debug-options interface], and the procedure being called has the trace property enabled. If cheap traps are enabled [debug-options interface], cont is a debug object, otherwise it is a restartable continuation. tailp is true if this is a tail call

key cont retval

exit-frame-handler

Called when a value is returned from a procedure. Called if: evaluator traps are enabled [traps interface], and either exit-frame is enabled [traps interface], or trace mode is on [debug-options interface], and the procedure being called has the trace property enabled. If cheap traps are enabled [debug-options interface], cont is a debug object, otherwise it is a restartable continuation. retval is the return value.