;;; srfi-31.scm --- special form for recursive evaluation ;; Copyright (C) 2004, 2006, 2012 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 ;;; Original author: Rob Browning (define-module (srfi srfi-31) #:export (rec)) (cond-expand-provide (current-module) '(srfi-31)) (define-syntax rec (syntax-rules () "Return the given object, defined in a lexical environment where NAME is bound to itself." ((_ (name . formals) body ...) ; procedure (letrec ((name (lambda formals body ...))) name)) ((_ name expr) ; arbitrary object (letrec ((name expr)) name))))