Re: [gambit-list] how does make-default-entry-hook work?

Urgh ...

(define (setup hook) (let ((settings (##closure-ref hook 1))) (##vector-set! settings 1 #t) (if (##not (##memq proc ##trace-list)) (set! ##trace-list (##cons proc ##trace-list)))))

does ##closure-ref do what I think it does? (break the closure abstraction ... and is the "1" like saying "the first var [which just so happens to be settings]")

this seems awfully hairy + brittle

On Sun, Feb 22, 2009 at 11:33 PM, lowly coder lowlycoder@huoyanjinjing.comwrote:

In lib/_repl.scm:

(define-prim (##make-default-entry-hook) (let ((settings (##vector #f #f))) (lambda (proc args execute) (if (##vector-ref settings 0) (##step-on)) ;; turn on single-stepping (if (##vector-ref settings

(##trace-generate

     (##make-call-form

proc (##argument-list-remove-absent! args '())

##max-fixnum)

execute

#f)

    (execute)))))

how does this code work at all? isn't settings #f #f, which would mean the first if does nothing, and the first part of the second if also does nothing?

is there some funky dynamic-wind / dynamic scope going on here?