summaryrefslogtreecommitdiff
path: root/module/rnrs/6/exceptions.scm
diff options
context:
space:
mode:
Diffstat (limited to 'module/rnrs/6/exceptions.scm')
-rw-r--r--module/rnrs/6/exceptions.scm51
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*))))
+)