52 lines
1.4 KiB
Factor
52 lines
1.4 KiB
Factor
! Copyright (C) 2008 Alex Chapman
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! See http://factorcode.org/license.txt for BSD license.
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USING: accessors assocs hashtables hashtables.private kernel sequences vectors ;
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IN: digraphs
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TUPLE: digraph < hashtable ;
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: <digraph> ( -- digraph )
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0 digraph new [ reset-hash ] keep ;
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TUPLE: vertex value edges ;
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: <vertex> ( value -- vertex )
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V{ } clone vertex boa ;
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: add-vertex ( key value digraph -- )
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[ <vertex> swap ] dip set-at ;
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: children ( key digraph -- seq )
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at edges>> ;
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: @edges ( from to digraph -- to edges ) swapd at edges>> ;
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: add-edge ( from to digraph -- ) @edges push ;
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: delete-edge ( from to digraph -- ) @edges remove! drop ;
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: delete-to-edges ( to digraph -- )
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[ nip dupd edges>> remove! drop ] assoc-each drop ;
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: delete-vertex ( key digraph -- )
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2dup delete-at delete-to-edges ;
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: unvisited? ( unvisited key -- ? ) swap key? ;
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: visited ( unvisited key -- ) swap delete-at ;
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DEFER: (topological-sort)
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: visit-children ( seq unvisited key -- seq unvisited )
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over children [ (topological-sort) ] each ;
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: (topological-sort) ( seq unvisited key -- seq unvisited )
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2dup unvisited? [
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[ visit-children ] keep 2dup visited pick push
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] [
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drop
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] if ;
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: topological-sort ( digraph -- seq )
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[ V{ } clone ] dip [ clone ] keep
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[ drop (topological-sort) ] assoc-each drop reverse ;
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: topological-sorted-values ( digraph -- seq )
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dup topological-sort swap [ at value>> ] curry map ;
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