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Diffstat (limited to 'module/rnrs/6/exceptions.scm')
-rw-r--r-- | module/rnrs/6/exceptions.scm | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/module/rnrs/6/exceptions.scm b/module/rnrs/6/exceptions.scm new file mode 100644 index 000000000..eeea9238b --- /dev/null +++ b/module/rnrs/6/exceptions.scm @@ -0,0 +1,51 @@ +;;; exceptions.scm --- The R6RS exceptions library + +;; 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 + + +(library (rnrs exceptions (6)) + (export with-exception-handler raise raise-continuable) + (import (rnrs base (6)) + (rnrs conditions (6)) + (rnrs records procedural (6)) + (only (guile) with-throw-handler)) + + (define raise (@@ (rnrs records procedural) r6rs-raise)) + (define raise-continuable + (@@ (rnrs records procedural) r6rs-raise-continuable)) + (define raise-object-wrapper? + (@@ (rnrs records procedural) raise-object-wrapper?)) + (define raise-object-wrapper-obj + (@@ (rnrs records procedural) raise-object-wrapper-obj)) + (define raise-object-wrapper-continuation + (@@ (rnrs records procedural) raise-object-wrapper-continuation)) + + (define (with-exception-handler handler thunk) + (with-throw-handler 'r6rs:exception + thunk + (lambda (key . args) + (if (and (not (null? args)) + (raise-object-wrapper? (car args))) + (let* ((cargs (car args)) + (obj (raise-object-wrapper-obj cargs)) + (continuation (raise-object-wrapper-continuation cargs)) + (handler-return (handler obj))) + (if continuation + (continuation handler-return) + (raise (make-non-continuable-violation)))) + *unspecified*)))) +) |