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
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 1)
(##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?