1 ! Copyright (C) 2007, 2008 Ryan Murphy, Doug Coleman,
3 ! See http://factorcode.org/license.txt for BSD license.
4 USING: kernel math sequences arrays assocs sequences.private
5 growable accessors math.order summary ;
8 GENERIC: heap-push* ( value key heap -- entry )
9 GENERIC: heap-peek ( heap -- value key )
10 GENERIC: heap-pop* ( heap -- )
11 GENERIC: heap-pop ( heap -- value key )
12 GENERIC: heap-delete ( entry heap -- )
13 GENERIC: heap-empty? ( heap -- ? )
14 GENERIC: heap-size ( heap -- n )
20 : <heap> ( class -- heap )
21 [ V{ } clone ] dip boa ; inline
23 TUPLE: entry value key heap index ;
25 : <entry> ( value key heap -- entry ) f entry boa ;
29 TUPLE: min-heap < heap ;
31 : <min-heap> ( -- min-heap ) min-heap <heap> ;
33 TUPLE: max-heap < heap ;
35 : <max-heap> ( -- max-heap ) max-heap <heap> ;
37 M: heap heap-empty? ( heap -- ? )
40 M: heap heap-size ( heap -- n )
45 : left ( n -- m ) 1 shift 1 + ; inline
47 : right ( n -- m ) 1 shift 2 + ; inline
49 : up ( n -- m ) 1- 2/ ; inline
51 : data-nth ( n heap -- entry )
52 data>> nth-unsafe ; inline
54 : left-value ( n heap -- entry )
55 [ left ] dip data-nth ; inline
57 : right-value ( n heap -- entry )
58 [ right ] dip data-nth ; inline
60 : data-set-nth ( entry n heap -- )
61 [ [ >>index drop ] 2keep ] dip
62 data>> set-nth-unsafe ; inline
64 : data-push ( entry heap -- n )
66 swap 2dup data>> ensure 2drop data-set-nth
69 : data-pop ( heap -- entry )
72 : data-pop* ( heap -- )
75 : data-first ( heap -- entry )
78 : data-exchange ( m n heap -- )
79 [ [ data-nth ] curry bi@ ]
80 [ [ data-set-nth ] curry bi@ ] 3bi ; inline
82 GENERIC: heap-compare ( pair1 pair2 heap -- ? )
84 : (heap-compare) ( pair1 pair2 heap -- <=> )
85 drop [ key>> ] compare ; inline
87 M: min-heap heap-compare (heap-compare) +gt+ eq? ;
89 M: max-heap heap-compare (heap-compare) +lt+ eq? ;
91 : heap-bounds-check? ( m heap -- ? )
94 : left-bounds-check? ( m heap -- ? )
95 [ left ] dip heap-bounds-check? ; inline
97 : right-bounds-check? ( m heap -- ? )
98 [ right ] dip heap-bounds-check? ; inline
100 : continue? ( m up[m] heap -- ? )
101 [ data-nth swap ] keep [ data-nth ] keep
102 heap-compare ; inline
106 : (up-heap) ( n heap -- )
109 [ data-exchange ] 2keep up-heap
114 : up-heap ( n heap -- )
115 over 0 > [ (up-heap) ] [ 2drop ] if ;
117 : (child) ( m heap -- n )
119 [ 2dup left-value ] dip
121 [ right ] [ left ] if ;
123 : child ( m heap -- n )
124 2dup right-bounds-check?
125 [ drop left ] [ (child) ] if ;
129 : (down-heap) ( m heap -- )
130 [ child ] 2keep swapd
134 [ data-exchange ] 2keep down-heap
137 : down-heap ( m heap -- )
138 2dup left-bounds-check? [ 2drop ] [ (down-heap) ] if ;
142 M: heap heap-push* ( value key heap -- entry )
143 [ <entry> dup ] keep [ data-push ] keep up-heap ;
145 : heap-push ( value key heap -- ) heap-push* drop ;
147 : heap-push-all ( assoc heap -- )
148 [ swapd heap-push ] curry assoc-each ;
150 : >entry< ( entry -- key value )
151 [ value>> ] [ key>> ] bi ;
153 M: heap heap-peek ( heap -- value key )
156 ERROR: bad-heap-delete ;
158 M: bad-heap-delete summary
159 drop "Invalid entry passed to heap-delete" ;
161 : entry>index ( entry heap -- n )
162 over heap>> eq? [ bad-heap-delete ] unless
165 M: heap heap-delete ( entry heap -- )
167 2dup heap-size 1- = [
170 [ nip data-pop ] 2keep
171 [ data-set-nth ] 2keep
175 M: heap heap-pop* ( heap -- )
176 dup data-first swap heap-delete ;
178 M: heap heap-pop ( heap -- value key )
179 dup data-first [ swap heap-delete ] keep >entry< ;
181 : heap-pop-all ( heap -- alist )
182 [ dup heap-empty? not ]
183 [ dup heap-pop swap 2array ]
186 : heap-values ( heap -- alist )
187 data>> [ value>> ] { } map-as ;
189 : slurp-heap ( heap quot: ( elt -- ) -- )
190 over heap-empty? [ 2drop ] [
191 [ [ heap-pop drop ] dip call ] [ slurp-heap ] 2bi
192 ] if ; inline recursive