;; -*- mode: Lisp; Syntax: Common-Lisp; Package: cells; -*-
#|
Cells -- Automatic Dataflow Managememnt
Copyright (C) 1995, 2006 by Kenneth Tilton
This library is free software; you can redistribute it and/or
modify it under the terms of the Lisp Lesser GNU Public License
(http://opensource.franz.com/preamble.html), known as the LLGPL.
This library is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the Lisp Lesser GNU Public License for more details.
|#
(in-package :cells)
(eval-when (compile eval load)
(export '(c-envalue)))
(defstruct (c-envaluer (:conc-name nil))
envalue-rule)
(defmethod awaken-cell (c)
(declare (ignorable c)))
(defmethod awaken-cell ((c cell))
(assert (c-inputp c))
;
; nothing to calculate, but every cellular slot should be output
;
(trc nil "awaken cell observing" c)
(when (> *data-pulse-id* (c-pulse-observed c))
(setf (c-pulse-observed c) *data-pulse-id*)
(slot-value-observe (c-slot-name c) (c-model c) (c-value c) nil nil c)
(ephemeral-reset c)))
(defmethod awaken-cell ((c c-ruled))
(let (*depender*)
(calculate-and-set c :fn-awaken-cell nil)))
#+cormanlisp ; satisfy CormanCL bug
(defmethod awaken-cell ((c c-dependent))
(let (*depender*)
(trc nil "awaken-cell c-dependent clearing *depender*" c)
(calculate-and-set c :fn-awaken-cell nil)))
(defmethod awaken-cell ((c c-drifter))
;
; drifters *begin* valid, so the derived version's test for unbounditude
; would keep (drift) rule ever from being evaluated. correct solution
; (for another day) is to separate awakening (ie, linking to independent
; cs) from evaluation, tho also evaluating if necessary during
; awakening, because awakening's other role is to get an instance up to speed
; at once upon instantiation
;
(calculate-and-set c :fn-awaken-cell nil)
(cond ((c-validp c) (c-value c))
((c-unboundp c) nil)
(t "illegal state!!!")))
