Import guile-1.8 as multiple upstream tarball component

[lilypond.git] / guile18 / ice-9 / stack-catch.scm

diff --git a/guile18/ice-9/stack-catch.scm b/guile18/ice-9/stack-catch.scm
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+;;; installed-scm-file
+
+;;;;   Copyright (C) 2001, 2006 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 2.1 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
+;;;; 
+
+(define-module (ice-9 stack-catch)
+  :export (stack-catch))
+
+(define (stack-catch key thunk handler)
+  "Like @code{catch}, invoke @var{thunk} in the dynamic context of
+@var{handler} for exceptions matching @var{key}, but also save the
+current stack state in the @var{the-last-stack} fluid, for the purpose
+of debugging or re-throwing of an error.  If thunk throws to the
+symbol @var{key}, then @var{handler} is invoked this way:\n
+@example
+ (handler key args ...)
+@end example\n
+@var{key} is a symbol or #t.\n
+@var{thunk} takes no arguments.  If @var{thunk} returns normally, that
+is the return value of @code{catch}.\n
+Handler is invoked outside the scope of its own @code{catch}.  If
+@var{handler} again throws to the same key, a new handler from further
+up the call chain is invoked.\n
+If the key is @code{#t}, then a throw to @emph{any} symbol will match
+this call to @code{catch}."
+  (catch key
+        thunk
+        handler
+        lazy-handler-dispatch))