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 ! Intervals are a pair of { start end }
11 TUPLE: interval-set { array uint-array read-only } ;
15 ERROR: not-an-interval-set obj ;
17 : check-interval-set ( map -- map )
18 dup interval-set? [ not-an-interval-set ] unless ; inline
22 : in? ( key set -- ? )
23 check-interval-set array>>
24 dupd [ <=> ] with search swap [
25 even? [ >= ] [ 1 - <= ] if
30 : spec>pairs ( sequence -- intervals )
31 [ dup number? [ dup 2array ] when ] map ;
33 : disjoint? ( node1 node2 -- ? )
34 [ second-unsafe ] [ first-unsafe ] bi* < ;
36 : (delete-redundancies) ( seq -- )
48 : delete-redundancies ( seq -- seq' )
49 ! If the next element is >= current one, leave out both
50 [ (delete-redundancies) ] uint-array{ } make ;
52 : make-intervals ( seq -- interval-set )
57 : >intervals ( seq -- seq' )
58 [ 1 + ] assoc-map concat ;
62 : <interval-set> ( specification -- interval-set )
64 >intervals make-intervals ;
68 :: or-step ( set1 set2 -- set1' set2' )
70 set1 second set2 first <=
71 [ set1 0 ] [ set2 2 ] if
72 [ second , ] [ set2 swap tail-slice ] bi*
75 : combine-or ( set1 set2 -- )
77 { [ over empty? ] [ % drop ] }
78 { [ dup empty? ] [ drop % ] }
88 : <interval-or> ( set1 set2 -- set )
90 [ combine-or ] uint-array{ } make
95 : prefix-0 ( seq -- 0seq )
96 0 over ?nth zero? [ rest ] [ 0 prefix ] if ;
98 : interval-max ( interval-set1 interval-set2 -- n )
99 [ array>> [ 0 ] [ last ] if-empty ] bi@ max ;
103 : <interval-not> ( set maximum -- set' )
104 [ array>> prefix-0 ] dip suffix make-intervals ;
106 : <interval-and> ( set1 set2 -- set )
108 [ '[ _ <interval-not> ] bi@ <interval-or> ] keep