11.23 util.toposort - Topological sort

Module: util.toposort

Implements topological sort algorithm.

Function: topological-sort graph &optional eqproc

Graph represents a directed acyclic graph (DAG) by a list of connections, where each connection is the form

(<node> <downstream> <downstream2> ...)

that means a node <node> is connected to other nodes <downstream> etc. <node> can be arbitrary object, as far as it can be compared by the procedure eqproc, which is eqv? by default (See section 6.1 Equivalence). Returns a list of <node>s sorted topologically.

If the graph contains circular reference, an error is signalled.