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7.5.4 Breakpoints

(require 'break)

— Function: init-debug

If your Scheme implementation does not support break or abort, a message will appear when you (require 'break) or (require 'debug) telling you to type (init-debug). This is in order to establish a top-level continuation. Typing (init-debug) at top level sets up a continuation for break.

— Function: breakpoint arg1 ...

Returns from the top level continuation and pushes the continuation from which it was called on a continuation stack.

— Function: continue

Pops the topmost continuation off of the continuation stack and returns an unspecified value to it.

— Function: continue arg1 ...

Pops the topmost continuation off of the continuation stack and returns arg1 ... to it.

— Macro: break proc1 ...

Redefines the top-level named procedures given as arguments so that breakpoint is called before calling proc1 ....

— Macro: break

With no arguments, makes sure that all the currently broken identifiers are broken (even if those identifiers have been redefined) and returns a list of the broken identifiers.

— Macro: unbreak proc1 ...

Turns breakpoints off for its arguments.

— Macro: unbreak

With no arguments, unbreaks all currently broken identifiers and returns a list of these formerly broken identifiers.

These are procedures for breaking. If defmacros are not natively supported by your implementation, these might be more convenient to use.

— Function: breakf proc
— Function: breakf proc name

To break, type

          (set! symbol (breakf symbol))

or

          (set! symbol (breakf symbol 'symbol))

or

          (define symbol (breakf function))

or

          (define symbol (breakf function 'symbol))
— Function: unbreakf proc

To unbreak, type

          (set! symbol (unbreakf symbol))