factor/basis/interval-maps/interval-maps.factor

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2.1 KiB
Factor

! Copyright (C) 2008 Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays assocs binary-search grouping kernel
locals make math math.order sequences sequences.private sorting ;
IN: interval-maps
TUPLE: interval-map { array array read-only } ;
<PRIVATE
ALIAS: start first-unsafe
ALIAS: end second-unsafe
ALIAS: value third-unsafe
: find-interval ( key interval-map -- interval-node )
array>> [ start <=> ] with search nip ; inline
: interval-contains? ( key interval-node -- ? )
first2-unsafe between? ; inline
: all-intervals ( sequence -- intervals )
[ [ dup number? [ dup 2array ] when ] dip ] { } assoc-map-as ;
: disjoint? ( node1 node2 -- ? )
[ end ] [ start ] bi* < ;
: ensure-disjoint ( intervals -- intervals )
dup [ disjoint? ] monotonic?
[ "Intervals are not disjoint" throw ] unless ;
: >intervals ( specification -- intervals )
[ suffix ] { } assoc>map concat 3 group ;
ERROR: not-an-interval-map obj ;
: check-interval-map ( map -- map )
dup interval-map? [ not-an-interval-map ] unless ; inline
PRIVATE>
: interval-at* ( key map -- value ? )
check-interval-map
[ drop ] [ find-interval ] 2bi
[ nip ] [ interval-contains? ] 2bi
[ value t ] [ drop f f ] if ; inline
: interval-at ( key map -- value ) interval-at* drop ;
: interval-key? ( key map -- ? ) interval-at* nip ;
: interval-values ( map -- values )
check-interval-map array>> [ value ] map ;
: <interval-map> ( specification -- map )
all-intervals [ first second ] sort-with
>intervals ensure-disjoint interval-map boa ;
: <interval-set> ( specification -- map )
dup zip <interval-map> ;
:: coalesce ( alist -- specification )
! Only works with integer keys, because they're discrete
! Makes 2array keys
[
alist sort-keys unclip swap [ first2 dupd ] dip
[| oldkey oldval key val | ! Underneath is start
oldkey 1 + key =
oldval val = and
[ oldkey 2array oldval 2array , key ] unless
key val
] assoc-each [ 2array ] bi@ ,
] { } make ;