A little constraint solver. Given a graph of nodes, and a propagate function that propagates constraints from node to nodes, the solver propagates the constraints until no change occurs. It computes the strongly connected components, and performs a topological sort of the condensed graph to minimalize the number of calls to propagate. License: AGPL3 Copyright Pascal J. Bourguignon 2011 - 2015 This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <http://www.gnu.org/licenses/>

( solve-constraints edges propagate) |
function |

DO: Calls PROPAGATE on each edge until PROPAGATE returns NIL for all arcs. EDGES: A list of edges (from to). The nodes FROM and EDGE must be comparable with EQL. PROPAGATE: A function taking the nodes FROM and TO of an edge as argument, and returning whether changes occured.