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 >r V{ } clone r> 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 : up-value ( n heap -- entry )
55 >r up r> data-nth ; inline
57 : left-value ( n heap -- entry )
58 >r left r> data-nth ; inline
60 : right-value ( n heap -- entry )
61 >r right r> data-nth ; inline
63 : data-set-nth ( entry n heap -- )
64 >r [ >>index drop ] 2keep r>
65 data>> set-nth-unsafe ;
67 : data-push ( entry heap -- n )
69 swap 2dup data>> ensure 2drop data-set-nth
72 : data-pop ( heap -- entry )
75 : data-pop* ( heap -- )
78 : data-peek ( heap -- entry )
81 : data-first ( heap -- entry )
84 : data-exchange ( m n heap -- )
85 [ tuck data-nth >r data-nth r> ] 3keep
86 tuck >r >r data-set-nth r> r> data-set-nth ; inline
88 GENERIC: heap-compare ( pair1 pair2 heap -- ? )
90 : (heap-compare) drop [ key>> ] compare ; inline
92 M: min-heap heap-compare (heap-compare) +gt+ eq? ;
94 M: max-heap heap-compare (heap-compare) +lt+ eq? ;
96 : heap-bounds-check? ( m heap -- ? )
99 : left-bounds-check? ( m heap -- ? )
100 >r left r> heap-bounds-check? ; inline
102 : right-bounds-check? ( m heap -- ? )
103 >r right r> heap-bounds-check? ; inline
105 : continue? ( m up[m] heap -- ? )
106 [ data-nth swap ] keep [ data-nth ] keep
107 heap-compare ; inline
111 : (up-heap) ( n heap -- )
114 [ data-exchange ] 2keep up-heap
119 : up-heap ( n heap -- )
120 over 0 > [ (up-heap) ] [ 2drop ] if ;
122 : (child) ( m heap -- n )
124 >r 2dup left-value r>
126 [ right ] [ left ] if ;
128 : child ( m heap -- n )
129 2dup right-bounds-check?
130 [ drop left ] [ (child) ] if ;
132 : swap-down ( m heap -- )
133 [ child ] 2keep data-exchange ;
137 : (down-heap) ( m heap -- )
138 [ child ] 2keep swapd
142 [ data-exchange ] 2keep down-heap
145 : down-heap ( m heap -- )
146 2dup left-bounds-check? [ 2drop ] [ (down-heap) ] if ;
150 M: heap heap-push* ( value key heap -- entry )
151 [ <entry> dup ] keep [ data-push ] keep up-heap ;
153 : heap-push ( value key heap -- ) heap-push* drop ;
155 : heap-push-all ( assoc heap -- )
156 [ swapd heap-push ] curry assoc-each ;
158 : >entry< ( entry -- key value )
159 [ value>> ] [ key>> ] bi ;
161 M: heap heap-peek ( heap -- value key )
164 ERROR: bad-heap-delete ;
166 M: bad-heap-delete summary
167 drop "Invalid entry passed to heap-delete" ;
169 : entry>index ( entry heap -- n )
170 over heap>> eq? [ bad-heap-delete ] unless
173 M: heap heap-delete ( entry heap -- )
175 2dup heap-size 1- = [
178 [ nip data-pop ] 2keep
179 [ data-set-nth ] 2keep
183 M: heap heap-pop* ( heap -- )
184 dup data-first swap heap-delete ;
186 M: heap heap-pop ( heap -- value key )
187 dup data-first [ swap heap-delete ] keep >entry< ;
189 : heap-pop-all ( heap -- alist )
190 [ dup heap-empty? not ]
191 [ dup heap-pop swap 2array ]
194 : slurp-heap ( heap quot: ( elt -- ) -- )
195 over heap-empty? [ 2drop ] [
196 [ [ heap-pop drop ] dip call ] [ slurp-heap ] 2bi
197 ] if ; inline recursive