Hi Damien,
Maybe I'm missing something, but shoudn't it be:
(define-syntax for
(lambda (stx)
(syntax-case stx ()
((kwd (init test incrmt) body ...)
(with-syntax ((BREAK (datum->syntax (syntax kwd) 'break))
(CONTINUE (datum->syntax (syntax kwd) 'continue)))
(syntax
(call/cc
(lambda (escape)
(let ((BREAK escape))
init
(let loop ()
(when test
(call/cc
(lambda (next)
(let ((CONTINUE next))
(let () ;; allow definitions
body ...)))) ; end call/cc
incrmt
(loop))) ; end let loop
))))) ;; close with-syntax
))))
?
On Fri, Sep 13, 2024 at 8:53 AM Damien Mattei <damien.mat...@gmail.com> wrote:
>
> hello,
>
> i believed call/cc allowed to return value but i have this macro and i can
> use continuation, but the value is not passed to the continuation:
>
> (define-syntax for
> (lambda (stx)
> (syntax-case stx ()
> ((kwd (init test incrmt) body ...)
>
> (with-syntax ((BREAK (datum->syntax (syntax kwd) 'break))
> (CONTINUE (datum->syntax (syntax kwd) 'continue)))
>
> (syntax
> (call/cc
> (lambda (escape)
> (let-syntax ((BREAK (identifier-syntax (escape))))
> init
> (let loop ()
> (when test
> (call/cc
> (lambda (next)
> (let-syntax ((CONTINUE (identifier-syntax (next))))
> (let () ;; allow definitions
> body ...)))) ; end call/cc
> incrmt
> (loop))) ; end let loop
> ))))) ;; close with-syntax
> ))))
>
>
> mattei@acer:~$ guile
> GNU Guile 3.0.9
> Copyright (C) 1995-2023 Free Software Foundation, Inc.
>
> Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
> This program is free software, and you are welcome to redistribute it
> under certain conditions; type `,show c' for details.
>
> Enter `,help' for help.
> scheme@(guile-user)> (use-modules (Scheme+))
> WARNING: (Scheme+): imported module (if-then-else) overrides core binding
> `if'
> WARNING: (Scheme+): imported module (when-unless) overrides core binding
> `when'
> WARNING: (Scheme+): imported module (when-unless) overrides core binding
> `unless'
>
> scheme@(guile-user)> (for ((define i 0) (< i 5) (set! i (+ i 1))) (define x
> 7) (display i) (newline) (when (= i 2) (break "finish")))
> 0
> 1
> 2
>
> here i should get "finish" at REPL but nothing happens?
>
> regards
