mes/module/mes/catch.mes
Jan Nieuwenhuizen 08562b168d test: Add syntax tests.
* tests/syntax.test: New file.
* tests/syntax.test-guile: New file.

fixup: 1b0696f9 (Jan Nieuwenhuizen 2018-01-01 15:53:13 +0100 40) ,        (lambda ()
2018-01-01 15:53:13 +01:00

57 lines
2.1 KiB
Scheme

;;; -*-scheme-*-
;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016,2018 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; This file is part of Mes.
;;;
;;; Mes is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; Mes 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 General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Mes. If not, see <http://www.gnu.org/licenses/>.
(mes-use-module (mes let))
(mes-use-module (mes fluids))
(define %eh (make-fluid
(lambda (key . args)
(if (defined? 'simple-format)
(simple-format (current-error-port) "unhandled exception:~a:~a\n" key args)
(begin
(display "unhandled exception:" (current-error-port))
(display key (current-error-port))
(display ":" (current-error-port))
(display args (current-error-port))
(newline (current-error-port))))
(exit 1))))
(define (catch key thunk handler)
(let ((previous-eh (fluid-ref %eh)))
(with-fluid*
%eh #f
(lambda ()
(call/cc
(lambda (cc)
(fluid-set! %eh
(lambda (k . args)
(let ((handler (if (or (eq? key #t) (eq? key k)) handler
previous-eh)))
(cc
(lambda (x)
(apply handler (cons k args)))))))
(thunk)))))))
(define (throw key . args)
(let ((handler (fluid-ref %eh)))
(apply handler (cons key args))))
(define with-throw-handler catch) ; FIXME: hack for Nyacc 0.75