mirror of
https://git.savannah.gnu.org/git/guile.git
synced 2025-05-18 02:00:20 +02:00
9b2a2a391a
* module/language/tree-il/primitives.scm (define-primitive-expander): Allow quoted datums. Allow all self-evaluating expressions to be constants. (prompt, control): Add primitive expanders to turn these into @prompt and @control. * module/ice-9/control.scm: New module, for delimited continuation operators. * module/Makefile.am: Add.
42 lines
1.4 KiB
Scheme
42 lines
1.4 KiB
Scheme
;;; Beyond call/cc
|
|
|
|
;; Copyright (C) 2010 Free Software Foundation, Inc.
|
|
|
|
;;;; 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)
|
|
#:use-module (language tree-il primitives)
|
|
#:export (% prompt control))
|
|
|
|
(eval-when (eval load compile)
|
|
(load-extension "libguile" "scm_init_control")
|
|
(add-interesting-primitive! '@prompt)
|
|
(add-interesting-primitive! '@control)
|
|
|
|
(define (prompt tag thunk handler)
|
|
(@prompt tag thunk handler #f))
|
|
|
|
(define (control tag . args)
|
|
(apply @control tag 'throw args))
|
|
|
|
(define-syntax %
|
|
(syntax-rules ()
|
|
((_ expr handler)
|
|
(prompt (lambda () expr) handler))))
|
|
|
|
(add-interesting-primitive! 'prompt)
|
|
(add-interesting-primitive! 'control))
|