mdw@git.distorted.org.uk Git - sod/blob - pre-reorg/output.lisp

   1 ;;; -*-lisp-*-
   2 ;;;
   3 ;;; Output driver for SOD translator
   4 ;;;
   5 ;;; (c) 2009 Straylight/Edgeware
   6 ;;;
   7
   8 ;;;----- Licensing notice ---------------------------------------------------
   9 ;;;
  10 ;;; This file is part of the Simple Object Definition system.
  11 ;;;
  12 ;;; SOD is free software; you can redistribute it and/or modify
  13 ;;; it under the terms of the GNU General Public License as published by
  14 ;;; the Free Software Foundation; either version 2 of the License, or
  15 ;;; (at your option) any later version.
  16 ;;;
  17 ;;; SOD is distributed in the hope that it will be useful,
  18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;;; GNU General Public License for more details.
  21 ;;;
  22 ;;; You should have received a copy of the GNU General Public License
  23 ;;; along with SOD; if not, write to the Free Software Foundation,
  24 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 (cl:in-package #:sod)
  27
  28 ;;;--------------------------------------------------------------------------
  29 ;;; Sequencing machinery.
  30
  31 (defclass sequencer-item ()
  32   ((name :initarg :name :reader sequencer-item-name)
  33    (functions :initarg :functions :initform nil
  34               :type list :accessor sequencer-item-functions))
  35   (:documentation
  36    "Represents a distinct item to be sequenced by a SEQUENCER.
  37
  38    A SEQUENCER-ITEM maintains a list of FUNCTIONS which are invoked when the
  39    sequencer is invoked.  This class is not intended to be subclassed."))
  40
  41 ;;;--------------------------------------------------------------------------
  42 ;;; Output preparation.
  43
  44 (defvar *seen-announcement*)            ;Keep me unbound!
  45 #+hmm
  46 (defmethod add-output-hooks :around (object reason sequencer &rest stuff)
  47   "Arrange not to invoke any object more than once during a particular
  48    announcement."
  49   (declare (ignore stuff))
  50   (cond ((not (boundp '*seen-announcement*))
  51          (let ((*seen-announcement* (make-hash-table)))
  52            (setf (gethash object *seen-announcement*) t)
  53            (call-next-method)))
  54         ((gethash object *seen-announcement*)
  55          nil)
  56         (t
  57          (setf (gethash object *seen-announcement*) t)
  58          (call-next-method))))
  59
  60 ;;;--------------------------------------------------------------------------
  61 ;;; Utility macro.
  62
  63 ;;;----- That's all, folks --------------------------------------------------