/extra/sequences/abbrev/abbrev.factor

 1! Copyright (C) 2009 Maximilian Lupke.
 2! See http://factorcode.org/license.txt for BSD license.
 3USING: arrays assocs fry kernel math.ranges sequences ;
 4IN: sequences.abbrev
 5
 6<PRIVATE
 7
 8: prefixes ( seq -- prefixes )
 9    dup length [1,b] [ head ] with map ;
10
11: (abbrev) ( seq -- assoc )
12    [ prefixes ] keep 1array '[ _ ] H{ } map>assoc ;
13
14: assoc-merge ( assoc1 assoc2 -- assoc3 )
15    [ '[ over _ at dup [ append ] [ drop ] if ] assoc-map ] keep swap assoc-union ;
16
17PRIVATE>
18
19: abbrev ( seqs -- assoc )
20    [ (abbrev) ] map H{ } [ assoc-merge ] reduce ;
21
22: unique-abbrev ( seqs -- assoc )
23    abbrev [ nip length 1 = ] assoc-filter ;