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 vectors fry combinators ;
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 )
18 TUPLE: heap { data vector } ;
20 : <heap> ( class -- heap )
21 [ V{ } clone ] dip boa ; inline
23 TUPLE: entry value key heap index ;
25 : <entry> ( value key heap -- entry )
30 TUPLE: min-heap < heap ;
32 : <min-heap> ( -- min-heap ) min-heap <heap> ;
34 TUPLE: max-heap < heap ;
36 : <max-heap> ( -- max-heap ) max-heap <heap> ;
38 M: heap heap-empty? ( heap -- ? )
39 data>> empty? ; inline
41 M: heap heap-size ( heap -- n )
42 data>> length ; inline
46 : left ( n -- m ) 1 shift 1 + ; inline
48 : right ( n -- m ) 1 shift 2 + ; inline
50 : up ( n -- m ) 1 - 2/ ; inline
52 : data-nth ( n heap -- entry )
53 data>> nth-unsafe ; inline
55 : left-value ( n heap -- entry )
56 [ left ] dip data-nth ; inline
58 : right-value ( n heap -- entry )
59 [ right ] dip data-nth ; inline
61 : data-set-nth ( entry n heap -- )
62 [ [ >>index drop ] [ ] 2bi ] dip
63 data>> set-nth-unsafe ; inline
65 : data-push ( entry heap -- n )
67 swap 2dup data>> ensure 2drop data-set-nth
71 : data-first ( heap -- entry )
74 : data-exchange ( m n heap -- )
75 [ '[ _ data-nth ] bi@ ]
76 [ '[ _ data-set-nth ] bi@ ] 3bi ; inline
78 GENERIC: heap-compare ( entry1 entry2 heap -- ? )
80 : (heap-compare) ( entry1 entry2 heap -- <=> )
81 drop [ key>> ] compare ; inline
83 M: min-heap heap-compare (heap-compare) +gt+ eq? ;
85 M: max-heap heap-compare (heap-compare) +lt+ eq? ;
87 : heap-bounds-check? ( m heap -- ? )
90 : left-bounds-check? ( m heap -- ? )
91 [ left ] dip heap-bounds-check? ; inline
93 : right-bounds-check? ( m heap -- ? )
94 [ right ] dip heap-bounds-check? ; inline
96 : continue? ( m n heap -- ? )
99 [ 2nip ] 3tri heap-compare ; inline
103 : (up-heap) ( n heap -- )
106 [ data-exchange ] [ up-heap ] 2bi
109 ] if ; inline recursive
111 : up-heap ( n heap -- )
112 over 0 > [ (up-heap) ] [ 2drop ] if ; inline recursive
114 : (child) ( m heap -- n )
115 { [ drop ] [ left-value ] [ right-value ] [ nip ] } 2cleave
116 heap-compare [ right ] [ left ] if ; inline
118 : child ( m heap -- n )
119 2dup right-bounds-check?
120 [ drop left ] [ (child) ] if ; inline
124 : (down-heap) ( m heap -- )
125 [ drop ] [ child ] [ nip ] 2tri
129 [ data-exchange ] [ down-heap ] 2bi
130 ] if ; inline recursive
132 : down-heap ( m heap -- )
133 2dup left-bounds-check? [ 2drop ] [ (down-heap) ] if ; inline recursive
137 M: heap heap-push* ( value key heap -- entry )
138 [ <entry> dup ] [ data-push ] [ ] tri up-heap ;
140 : heap-push ( value key heap -- ) heap-push* drop ;
142 : heap-push-all ( assoc heap -- )
143 '[ swap _ heap-push ] assoc-each ;
145 : >entry< ( entry -- value key )
146 [ value>> ] [ key>> ] bi ; inline
148 M: heap heap-peek ( heap -- value key )
151 ERROR: bad-heap-delete ;
153 M: bad-heap-delete summary
154 drop "Invalid entry passed to heap-delete" ;
156 : entry>index ( entry heap -- n )
157 over heap>> eq? [ bad-heap-delete ] unless
160 M: heap heap-delete ( entry heap -- )
161 [ entry>index ] [ ] bi
162 2dup heap-size 1 - = [
171 M: heap heap-pop* ( heap -- )
172 [ data-first ] keep heap-delete ;
174 M: heap heap-pop ( heap -- value key )
176 [ heap-delete ] [ drop ] 2bi >entry< ;
178 : heap-pop-all ( heap -- alist )
179 [ dup heap-empty? not ]
180 [ dup heap-pop swap 2array ]
183 : slurp-heap ( heap quot: ( elt -- ) -- )
184 over heap-empty? [ 2drop ] [
185 [ [ heap-pop drop ] dip call ] [ slurp-heap ] 2bi
186 ] if ; inline recursive