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 classes combinators kernel make math math.order sequences
5 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 } ;
13 : interval-in? ( key set -- ? )
14 interval-set check-instance array>>
15 dupd [ <=> ] with search swap [
16 even? [ >= ] [ 1 - <= ] if
21 : spec>pairs ( sequence -- intervals )
22 [ dup number? [ dup 2array ] when ] map ;
24 : disjoint? ( node1 node2 -- ? )
25 [ second-unsafe ] [ first-unsafe ] bi* < ;
27 : (delete-redundancies) ( seq -- )
39 : delete-redundancies ( seq -- seq' )
40 ! If the next element is >= current one, leave out both
41 [ (delete-redundancies) ] uint-array{ } make ;
43 : make-intervals ( seq -- interval-set )
48 : >intervals ( seq -- seq' )
49 [ 1 + ] assoc-map concat ;
53 : <interval-set> ( specification -- interval-set )
55 >intervals make-intervals ;
59 :: or-step ( set1 set2 -- set1' set2' )
61 set1 second set2 first <=
62 [ set1 0 ] [ set2 2 ] if
63 [ second , ] [ set2 swap tail-slice ] bi*
66 : combine-or ( set1 set2 -- )
68 { [ over empty? ] [ % drop ] }
69 { [ dup empty? ] [ drop % ] }
79 : <interval-or> ( set1 set2 -- set )
81 [ combine-or ] uint-array{ } make
86 : prefix-0 ( seq -- 0seq )
87 0 over ?nth zero? [ rest ] [ 0 prefix ] if ;
89 : interval-max ( interval-set1 interval-set2 -- n )
90 [ array>> [ 0 ] [ last ] if-empty ] bi@ max ;
94 : <interval-not> ( set maximum -- set' )
95 [ array>> prefix-0 ] dip suffix make-intervals ;
97 : <interval-and> ( set1 set2 -- set )
99 [ '[ _ <interval-not> ] bi@ <interval-or> ] keep