mes/module/mes/catch.mes
Jan Nieuwenhuizen 4c9690996c mes: Iterative recursive macro expand.
* src/mes.c (eval_apply): Iterative recursive macro expand.
* src/posix.c (set_current_input_port): Return previous port.
* module/mes/catch.mes (%eh): Use core:display.
* module/mes/display.mes (display-cut, display-cut2): Move macro
  definitions to toplevel.
2018-03-04 10:05:55 +01:00

57 lines
2 KiB
Scheme

;;; -*-scheme-*-
;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016,2018 Jan (janneke) 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 #f ;;(defined? 'simple-format)
(simple-format (current-error-port) "unhandled exception:~a:~a\n" key args)
(begin
(core:display-error "unhandled exception:")
(core:display-error key)
(core:display-error ":")
(core:write-error args)
(core:display-error "\n")))
(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