1 ! Copyright (C) 2007, 2008 Ryan Murphy, Doug Coleman,
3 ! See http://factorcode.org/license.txt for BSD license.
4 USING: accessors arrays assocs fry kernel kernel.private locals
5 math math.order math.private sequences sequences.private summary
9 GENERIC: heap-push* ( value key heap -- entry )
10 GENERIC: heap-peek ( heap -- value key )
11 GENERIC: heap-pop* ( heap -- )
12 GENERIC: heap-pop ( heap -- value key )
13 GENERIC: heap-delete ( entry heap -- )
14 GENERIC: heap-empty? ( heap -- ? )
15 GENERIC: heap-size ( heap -- n )
19 TUPLE: heap { data vector } ;
21 : <heap> ( class -- heap )
22 V{ } clone swap boa ; inline
24 TUPLE: entry value key heap index ;
26 : <entry> ( value key heap -- entry )
31 TUPLE: min-heap < heap ;
33 : <min-heap> ( -- min-heap ) min-heap <heap> ;
35 TUPLE: max-heap < heap ;
37 : <max-heap> ( -- max-heap ) max-heap <heap> ;
39 M: heap heap-empty? ( heap -- ? )
40 data>> empty? ; inline
42 M: heap heap-size ( heap -- n )
43 data>> length ; inline
48 { fixnum } declare 1 fixnum-shift-fast 1 fixnum+fast ; inline
51 { fixnum } declare 1 fixnum-shift-fast 2 fixnum+fast ; inline
54 { fixnum } declare 1 fixnum-fast 2/ ; inline
56 : data-nth ( n heap -- entry )
57 data>> nth-unsafe { entry } declare ; inline
59 : data-first ( heap -- entry )
62 : data-set-nth ( entry n heap -- )
63 [ [ >>index ] keep ] dip data>> set-nth-unsafe ; inline
65 : data-push ( entry heap -- n )
66 [ heap-size [ >>index ] keep ]
67 [ data>> [ set-nth ] 2keep drop ] bi ; inline
69 GENERIC: heap-compare ( entry1 entry2 heap -- ? )
71 M: min-heap heap-compare
72 drop { entry entry } declare [ key>> ] bi@ after? ; inline
74 M: max-heap heap-compare
75 drop { entry entry } declare [ key>> ] bi@ before? ; inline
77 : data-compare ( m n heap -- ? )
78 [ '[ _ data-nth ] bi@ ] [ heap-compare ] bi ; inline
82 : >entry< ( entry -- value key )
83 [ value>> ] [ key>> ] bi ; inline
85 M: heap heap-peek ( heap -- value key )
90 :: sift-down ( heap from to -- )
91 to heap data-nth :> tmp
93 to t [ over from > and ] [
96 dup tmp heap heap-compare [
97 rot heap data-set-nth t
103 tmp swap heap data-set-nth ; inline
108 [ <entry> dup ] [ data-push ] [ 0 rot sift-down ] tri ;
110 : heap-push ( value key heap -- )
113 : heap-push-all ( assoc heap -- )
114 '[ swap _ heap-push ] assoc-each ;
118 :: sift-up ( heap n -- )
119 heap heap-size :> end
120 n heap data-nth :> tmp
122 n dup left [ dup end < ] [
124 dup end < [ 2dup heap data-compare ] [ f ] if
126 [ heap data-nth swap heap data-set-nth ]
130 tmp over heap data-set-nth
131 heap n rot sift-down ; inline
136 dup data>> dup length 1 > [
137 [ pop ] [ set-first ] bi 0 sift-up
143 [ data-first >entry< ] [ heap-pop* ] bi ;
145 : slurp-heap ( ... heap quot: ( ... value key -- ... ) -- ... )
146 [ drop '[ _ heap-empty? ] ]
147 [ '[ _ heap-pop @ ] until ] 2bi ; inline
149 : heap-pop-all ( heap -- alist )
150 [ heap-size <vector> ] keep
151 [ swap 2array suffix! ] slurp-heap { } like ;
153 ERROR: bad-heap-delete ;
155 M: bad-heap-delete summary
156 drop "Invalid entry passed to heap-delete" ;
160 : entry>index ( entry heap -- n )
161 over heap>> eq? [ bad-heap-delete ] unless
162 index>> { fixnum } declare ; inline
168 2dup heap-size 1 - = [
173 [ swap sift-up ] 2tri
176 : >min-heap ( assoc -- min-heap )
177 dup assoc-size <vector> min-heap boa
178 [ heap-push-all ] keep ;
180 : >max-heap ( assoc -- max-heap )
181 dup assoc-size <vector> max-heap boa
182 [ heap-push-all ] keep ;