1;;; 2;;; srfi-190 - Coroutine generator 3;;; 4;;; Copyright (c) 2020 Shiro Kawai <shiro@acm.org> 5;;; 6;;; Redistribution and use in source and binary forms, with or without 7;;; modification, are permitted provided that the following conditions 8;;; are met: 9;;; 10;;; 1. Redistributions of source code must retain the above copyright 11;;; notice, this list of conditions and the following disclaimer. 12;;; 13;;; 2. Redistributions in binary form must reproduce the above copyright 14;;; notice, this list of conditions and the following disclaimer in the 15;;; documentation and/or other materials provided with the distribution. 16;;; 17;;; 3. Neither the name of the authors nor the names of its contributors 18;;; may be used to endorse or promote products derived from this 19;;; software without specific prior written permission. 20;;; 21;;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22;;; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23;;; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24;;; A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25;;; OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26;;; SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 27;;; TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 28;;; PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29;;; LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30;;; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31;;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32;;; 33 34;; EXPERIMENTAL - not using identifier syntax 35;; NB: This isn't correct. See the mail archive of srfi-190. 36 37(define-module srfi-190 38 (use gauche.generator) 39 (export coroutine-generator yield define-coroutine-generator)) 40(select-module srfi-190) 41 42(define yield-proc 43 (make-parameter (^_ (error "yield used outside coroutine generator")))) 44 45(define (yield x) ((yield-proc) x)) 46 47(define-syntax coroutine-generator 48 (syntax-rules () 49 [(_ . body) 50 (make-coroutine-generator 51 (^[%yield] 52 (parameterize ((yield-proc %yield)) 53 . body)))])) 54 55(define-syntax define-coroutine-generator 56 (syntax-rules () 57 [(_ name . body) (define name (coroutine-generator . body))])) 58