factor/extra/anagrams/anagrams.factor

36 lines
874 B
Factor

! Copyright (C) 2010 John Benediktsson
! See http://factorcode.org/license.txt for BSD license
USING: arrays ascii assocs fry io.encodings.ascii io.files
kernel math math.order memoize sequences sorting ;
IN: anagrams
: (all-anagrams) ( seq assoc -- )
'[ dup natural-sort _ push-at ] each ;
: all-anagrams ( seq -- assoc )
H{ } clone [ (all-anagrams) ] keep
[ nip length 1 > ] assoc-filter ;
MEMO: dict-words ( -- seq )
"/usr/share/dict/words" ascii file-lines [ >lower ] map ;
MEMO: dict-anagrams ( -- assoc )
dict-words all-anagrams ;
: anagrams ( str -- seq/f )
>lower natural-sort dict-anagrams at ;
: longest ( seq -- subseq )
dup 0 [ length max ] reduce '[ length _ = ] filter ;
: most-anagrams ( -- seq )
dict-anagrams values longest ;
: longest-anagrams ( -- seq )
dict-anagrams [ keys longest ] keep '[ _ at ] map ;