1 ! Copyright (C) 2009 Daniel Ehrenberg.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors alien.c-types arrays assocs binary-search
4 combinators fry grouping kernel locals make math math.order
5 sequences sequences.private sorting specialized-arrays ;
6 SPECIALIZED-ARRAY: uint
8 ! Sets of positive integers
10 TUPLE: interval-set { array uint-array read-only } ;
14 ERROR: not-an-interval-set obj ;
16 : check-interval-set ( map -- map )
17 dup interval-set? [ throw-not-an-interval-set ] unless ; inline
21 : in? ( key set -- ? )
22 check-interval-set array>>
23 dupd [ <=> ] with search swap [
24 even? [ >= ] [ 1 - <= ] if
29 : spec>pairs ( sequence -- intervals )
30 [ dup number? [ dup 2array ] when ] map ;
32 ALIAS: start first-unsafe
33 ALIAS: end second-unsafe
35 : disjoint? ( node1 node2 -- ? )
36 [ end ] [ start ] bi* < ;
38 : (delete-redundancies) ( seq -- )
50 : delete-redundancies ( seq -- seq' )
51 ! If the next element is >= current one, leave out both
52 [ (delete-redundancies) ] uint-array{ } make ;
54 : make-intervals ( seq -- interval-set )
59 : >intervals ( seq -- seq' )
60 [ 1 + ] assoc-map concat ;
64 : <interval-set> ( specification -- interval-set )
66 >intervals make-intervals ;
70 :: or-step ( set1 set2 -- set1' set2' )
72 set1 second set2 first <=
73 [ set1 0 ] [ set2 2 ] if
74 [ second , ] [ set2 swap tail-slice ] bi*
77 : combine-or ( set1 set2 -- )
79 { [ over empty? ] [ % drop ] }
80 { [ dup empty? ] [ drop % ] }
90 : <interval-or> ( set1 set2 -- set )
92 [ combine-or ] uint-array{ } make
97 : prefix-0 ( seq -- 0seq )
98 0 over ?nth zero? [ rest ] [ 0 prefix ] if ;
100 : interval-max ( interval-set1 interval-set2 -- n )
101 [ array>> [ 0 ] [ last ] if-empty ] bi@ max ;
105 : <interval-not> ( set maximum -- set' )
106 [ array>> prefix-0 ] dip suffix make-intervals ;
108 : <interval-and> ( set1 set2 -- set )
110 [ '[ _ <interval-not> ] bi@ <interval-or> ] keep