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Diffstat (limited to 'module/ice-9/stack-catch.scm')
| -rw-r--r-- | module/ice-9/stack-catch.scm | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/module/ice-9/stack-catch.scm b/module/ice-9/stack-catch.scm new file mode 100644 index 000000000..f7b207535 --- /dev/null +++ b/module/ice-9/stack-catch.scm @@ -0,0 +1,43 @@ +;;; 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 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 +;;;; + +(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 + default-pre-unwind-handler)) |