Gecko [ contributie.vriendennsm.nl ]

Name	Size	Permission	Date
peg	[ DIR ]	drwxr-xr-x	2025-02-07 15:04
and-let-star.scm	2.53 KB	-rw-r--r--	2022-02-10 20:40
arrays.scm	2.63 KB	-rw-r--r--	2022-02-10 20:40
atomic.scm	1.55 KB	-rw-r--r--	2022-02-10 20:40
binary-ports.scm	2.71 KB	-rw-r--r--	2022-02-10 20:40
boot-9.scm	166.75 KB	-rw-r--r--	2022-02-10 20:40
buffered-input.scm	4.82 KB	-rw-r--r--	2022-02-10 20:40
calling.scm	10.54 KB	-rw-r--r--	2022-02-10 20:40
command-line.scm	18.6 KB	-rw-r--r--	2022-02-10 20:40
common-list.scm	8.95 KB	-rw-r--r--	2022-02-10 20:40
control.scm	4.08 KB	-rw-r--r--	2022-02-10 20:40
copy-tree.scm	3.05 KB	-rw-r--r--	2022-02-10 20:40
curried-definitions.scm	1.79 KB	-rw-r--r--	2022-02-10 20:40
deprecated.scm	1.54 KB	-rw-r--r--	2022-02-10 20:40
documentation.scm	7.41 KB	-rw-r--r--	2022-03-05 22:19
eval-string.scm	2.99 KB	-rw-r--r--	2022-02-10 20:40
eval.scm	25.08 KB	-rw-r--r--	2022-02-10 20:40
exceptions.scm	14.38 KB	-rw-r--r--	2022-02-10 20:40
expect.scm	5.5 KB	-rw-r--r--	2022-02-10 20:40
fdes-finalizers.scm	1.06 KB	-rw-r--r--	2022-02-10 20:40
format.scm	65.47 KB	-rw-r--r--	2022-02-10 20:40
ftw.scm	25.05 KB	-rw-r--r--	2022-02-10 20:40
futures.scm	10.49 KB	-rw-r--r--	2022-02-10 20:40
gap-buffer.scm	9.59 KB	-rw-r--r--	2022-02-10 20:40
getopt-long.scm	16.49 KB	-rw-r--r--	2022-02-10 20:40
hash-table.scm	1.77 KB	-rw-r--r--	2022-02-10 20:40
hcons.scm	2.55 KB	-rw-r--r--	2022-02-10 20:40
history.scm	2.29 KB	-rw-r--r--	2022-02-10 20:40
i18n.scm	20.51 KB	-rw-r--r--	2022-02-10 20:40
iconv.scm	3.19 KB	-rw-r--r--	2022-02-10 20:40
lineio.scm	3.85 KB	-rw-r--r--	2022-02-10 20:40
list.scm	1.29 KB	-rw-r--r--	2022-02-10 20:40
local-eval.scm	9.84 KB	-rw-r--r--	2022-02-10 20:40
ls.scm	3.2 KB	-rw-r--r--	2022-02-10 20:40
match.scm	2.18 KB	-rw-r--r--	2022-02-10 20:40
match.upstream.scm	37.33 KB	-rw-r--r--	2022-02-10 20:40
networking.scm	3.33 KB	-rw-r--r--	2022-02-10 20:40
null.scm	1.21 KB	-rw-r--r--	2022-02-10 20:40
occam-channel.scm	7.26 KB	-rw-r--r--	2022-02-10 20:40
optargs.scm	15.75 KB	-rw-r--r--	2022-02-10 20:40
peg.scm	1.64 KB	-rw-r--r--	2022-02-10 20:40
poe.scm	3.3 KB	-rw-r--r--	2022-02-10 20:40
poll.scm	5.79 KB	-rw-r--r--	2022-02-10 20:40
popen.scm	9.27 KB	-rw-r--r--	2022-02-10 20:40
ports.scm	19.08 KB	-rw-r--r--	2022-02-10 20:40
posix.scm	2.73 KB	-rw-r--r--	2022-02-10 20:40
pretty-print.scm	16.88 KB	-rw-r--r--	2022-02-10 20:40
psyntax-pp.scm	183.78 KB	-rw-r--r--	2022-02-10 20:40
psyntax.scm	149.4 KB	-rw-r--r--	2022-02-10 20:40
q.scm	4.2 KB	-rw-r--r--	2022-02-10 20:40
quasisyntax.scm	5.22 KB	-rw-r--r--	2022-02-10 20:40
r5rs.scm	1.56 KB	-rw-r--r--	2022-02-10 20:40
r6rs-libraries.scm	12.52 KB	-rw-r--r--	2022-02-10 20:40
r7rs-libraries.scm	4.28 KB	-rw-r--r--	2022-02-10 20:40
rdelim.scm	7.72 KB	-rw-r--r--	2022-02-10 20:40
read.scm	32.69 KB	-rw-r--r--	2022-02-10 20:40
readline.scm	9.56 KB	-rw-r--r--	2022-02-10 20:40
receive.scm	1.06 KB	-rw-r--r--	2022-02-10 20:40
regex.scm	8.87 KB	-rw-r--r--	2022-02-10 20:40
runq.scm	8.18 KB	-rw-r--r--	2022-02-10 20:40
rw.scm	1.02 KB	-rw-r--r--	2022-02-10 20:40
safe-r5rs.scm	7.5 KB	-rw-r--r--	2022-02-10 20:40
safe.scm	1.25 KB	-rw-r--r--	2022-02-10 20:40
sandbox.scm	34.24 KB	-rw-r--r--	2022-02-10 20:40
save-stack.scm	2.15 KB	-rw-r--r--	2022-02-10 20:40
scm-style-repl.scm	11.62 KB	-rw-r--r--	2022-02-10 20:40
serialize.scm	3.78 KB	-rw-r--r--	2022-02-10 20:40
session.scm	17.72 KB	-rw-r--r--	2022-02-10 20:40
slib.scm	1.55 KB	-rw-r--r--	2022-02-10 20:40
stack-catch.scm	1.94 KB	-rw-r--r--	2022-02-10 20:40
streams.scm	5.86 KB	-rw-r--r--	2022-02-10 20:40
string-fun.scm	9.68 KB	-rw-r--r--	2022-02-10 20:40
suspendable-ports.scm	29.86 KB	-rw-r--r--	2022-02-10 20:40
textual-ports.scm	2.29 KB	-rw-r--r--	2022-02-10 20:40
threads.scm	12.54 KB	-rw-r--r--	2022-02-10 20:40
time.scm	2.07 KB	-rw-r--r--	2022-02-10 20:40
top-repl.scm	2.63 KB	-rw-r--r--	2022-02-10 20:40
unicode.scm	1005 B	-rw-r--r--	2022-02-10 20:40
vlist.scm	21.56 KB	-rw-r--r--	2022-02-10 20:40
weak-vector.scm	1.2 KB	-rw-r--r--	2022-02-10 20:40

Rename

;;; Beyond call/cc

;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 3 of the License, or (at your option) any later version.
;;;; 
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;;; Lesser General Public License for more details.
;;;; 
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

;;; Code:

(define-module (ice-9 control)
  #:re-export (call-with-prompt abort-to-prompt
               default-prompt-tag make-prompt-tag)
  #:export (% abort shift reset shift* reset*
            call-with-escape-continuation call/ec
            let-escape-continuation let/ec
            suspendable-continuation?))

(load-extension (string-append "libguile-" (effective-version))
                "scm_init_ice_9_control")

(define (abort . args)
  (apply abort-to-prompt (default-prompt-tag) args))

(define-syntax %
  (syntax-rules ()
    ((_ expr)
     (call-with-prompt (default-prompt-tag)
                       (lambda () expr)
                       default-prompt-handler))
    ((_ expr handler)
     (call-with-prompt (default-prompt-tag)
                       (lambda () expr)
                       handler))
    ((_ tag expr handler)
     (call-with-prompt tag
                       (lambda () expr)
                       handler))))

;; Each prompt tag has a type -- an expected set of arguments, and an unwritten
;; contract of what its handler will do on an abort. In the case of the default
;; prompt tag, we could choose to return values, exit nonlocally, or punt to the
;; user.
;;
;; We choose the latter, by requiring that the user return one value, a
;; procedure, to an abort to the prompt tag. That argument is then invoked with
;; the continuation as an argument, within a reinstated default prompt. In this
;; way the return value(s) from a default prompt are under the user's control.
(define (default-prompt-handler k proc)
  (% (default-prompt-tag)
     (proc k)
     default-prompt-handler))

;; Kindly provided by Wolfgang J Moeller <wjm@heenes.com>, modelled
;; after the ones by Oleg Kiselyov in
;; http://okmij.org/ftp/Scheme/delim-control-n.scm, which are in the
;; public domain, as noted at the top of http://okmij.org/ftp/.
;; 
(define-syntax-rule (reset . body)
  (call-with-prompt (default-prompt-tag)
                    (lambda () . body)
                    (lambda (cont f) (f cont))))

(define-syntax-rule (shift var . body)
  (abort-to-prompt (default-prompt-tag)
                   (lambda (cont)
                     ((lambda (var) (reset . body))
                      (lambda vals (reset (apply cont vals)))))))

(define (reset* thunk)
  (reset (thunk)))

(define (shift* fc)
  (shift c (fc c)))

(define (call-with-escape-continuation proc)
  "Call PROC with an escape continuation."
  (let ((tag (list 'call/ec)))
    (call-with-prompt tag
                      (lambda ()
                        (proc (lambda args
                                (apply abort-to-prompt tag args))))
                      (lambda (_ . args)
                        (apply values args)))))

(define call/ec call-with-escape-continuation)

(define-syntax-rule (let-escape-continuation k body ...)
  "Bind K to an escape continuation within the lexical extent of BODY."
  (let ((tag (list 'let/ec)))
    (call-with-prompt tag
                      (lambda ()
                        (let ((k (lambda args
                                   (apply abort-to-prompt tag args))))
                          body ...))
                      (lambda (_ . results)
                        (apply values results)))))

(define-syntax-rule (let/ec k body ...)
  (let-escape-continuation k body ...))