heaps: simplify code a little, use locals to expose heap-delete logic.

freebsd-work
John Benediktsson 2019-01-10 16:44:22 -08:00
parent 1c28d326b1
commit d29052c7b9
2 changed files with 22 additions and 37 deletions

View File

@ -29,6 +29,9 @@ IN: heaps.tests
DEFER: (assert-heap-invariant)
: heapdata-compare ( m n heap -- ? )
[ data>> [ nth ] curry bi@ ] keep heap-compare ; inline
: ((assert-heap-invariant)) ( parent child heap heap-size -- )
pick over < [
[ [ heapdata-compare f assert= ] 2keep ] dip

View File

@ -6,9 +6,6 @@ kernel.private locals math math.order math.private sequences
sequences.private summary vectors ;
IN: heaps
! names and optimizations copied from pypy's heapq.py,
! refer to it from in depth explanations of the optimizations.
GENERIC: heap-push* ( value key heap -- entry )
GENERIC: heap-peek ( heap -- value key )
GENERIC: heap-pop* ( heap -- )
@ -73,12 +70,6 @@ M: min-heap heap-compare
M: max-heap heap-compare
drop { entry entry } declare [ key>> ] bi@ before? ; inline
: (heapdata-compare) ( m n data heap -- ? )
[ '[ _ data-nth ] bi@ ] [ heap-compare ] bi* ; inline
: heapdata-compare ( m n heap -- ? )
[ data>> ] keep (heapdata-compare) ; inline
PRIVATE>
: >entry< ( entry -- value key )
@ -89,7 +80,10 @@ M: heap heap-peek ( heap -- value key )
<PRIVATE
! called bubble-up in the litterature... but we keep pypy's name.
! names and optimizations inspired by cpython/Lib/heapq.py,
! refer to it from in depth explanations of the optimizations.
! called bubble-up in the literature... but we keep cpython's name.
:: sift-down ( heap from to -- )
heap data>> :> data
to data data-nth :> tmp
@ -119,8 +113,8 @@ M: heap heap-push*
<PRIVATE
! called bubble-down in the litterature... but we keep pypy's name.
! A quote from pypy's implementation:
! called bubble-down in the literature... but we keep cpython's name.
! A quote from cpython's implementation:
! > We *could* break out of the loop as soon as we find a pos where newitem <=
! > both its children, but turns out that's not a good idea [...]
! Indeed the code is 33% slower if we remove this optmization.
@ -132,7 +126,7 @@ M: heap heap-push*
n dup left [ dup end < ] [
dup 1 fixnum+fast
dup end < [
2dup data heap (heapdata-compare)
2dup [ data data-nth ] bi@ heap heap-compare
] [ f ] if
[ nip ] [ drop ] if
[ data data-nth swap data data-set-nth ]
@ -142,17 +136,11 @@ M: heap heap-push*
tmp over data data-set-nth
heap n rot sift-down ; inline
: (heap-pop*) ( heap data -- )
[ first f >>index drop ] [ pop ] [ set-first ] tri 0 sift-up ; inline
PRIVATE>
M: heap heap-pop*
dup data>> dup length 1 > [
(heap-pop*)
] [
pop f >>index 2drop
] if ; inline
dup data>> f over first index<< [ pop ] keep
[ 2drop ] [ set-first 0 sift-up ] if-empty ;
: heap-pop ( heap -- value key )
[ heap-peek ] [ heap-pop* ] bi ;
@ -179,22 +167,16 @@ M: bad-heap-delete summary
PRIVATE>
: ((heap-delete)) ( n heap -- )
2dup [ dup up ] dip heapdata-compare
[ swap sift-up ] [ 0 rot sift-down ] if ;
: (heap-delete) ( n heap -- )
[ nip data>> pop ]
[ data>> data-set-nth ]
[ ((heap-delete)) ] 2tri ;
M: heap heap-delete
[ entry>index ] [ f rot index<< ] 2bi
{
{ [ 2dup heap-size 1 - = ] [ nip data>> pop* ] }
{ [ over zero? ] [ nip dup data>> (heap-pop*) ] }
[ (heap-delete) ]
} cond ;
M:: heap heap-delete ( entry heap -- )
entry heap entry>index :> n
heap data>> :> data
data pop :> nth-entry
f entry index<<
n data length = [
nth-entry n data data-set-nth
n 0 = [ t ] [ nth-entry n up data data-nth heap heap-compare ] if
[ heap n sift-up ] [ heap 0 n sift-down ] if
] unless ;
: >min-heap ( assoc -- min-heap )
dup assoc-size <vector> min-heap boa