factor/basis/math/intervals/intervals.factor

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Factor
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! Copyright (C) 2007, 2009 Slava Pestov, Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
! Based on Slate's src/unfinished/interval.slate by Brian Rice.
USING: accessors kernel sequences arrays math math.order
combinators generic layouts memoize ;
IN: math.intervals
SYMBOL: empty-interval
SINGLETON: full-interval
TUPLE: interval { from read-only } { to read-only } ;
: closed-point? ( from to -- ? )
2dup [ first ] bi@ number=
[ [ second ] both? ] [ 2drop f ] if ;
: <interval> ( from to -- interval )
{
{ [ 2dup [ first ] bi@ > ] [ 2drop empty-interval ] }
{ [ 2dup [ first ] bi@ number= ] [
2dup [ second ] both?
[ interval boa ] [ 2drop empty-interval ] if
] }
{ [ 2dup [ { -1/0. t } = ] [ { 1/0. t } = ] bi* and ] [
2drop full-interval
] }
[ interval boa ]
} cond ;
: open-point ( n -- endpoint ) f 2array ;
: closed-point ( n -- endpoint ) t 2array ;
: [a,b] ( a b -- interval )
[ closed-point ] dip closed-point <interval> ; foldable
: (a,b) ( a b -- interval )
[ open-point ] dip open-point <interval> ; foldable
: [a,b) ( a b -- interval )
[ closed-point ] dip open-point <interval> ; foldable
: (a,b] ( a b -- interval )
[ open-point ] dip closed-point <interval> ; foldable
: [a,a] ( a -- interval )
closed-point dup <interval> ; foldable
: [-inf,a] ( a -- interval ) -1/0. swap [a,b] ; inline
: [-inf,a) ( a -- interval ) -1/0. swap [a,b) ; inline
: [a,inf] ( a -- interval ) 1/0. [a,b] ; inline
: (a,inf] ( a -- interval ) 1/0. (a,b] ; inline
MEMO: [0,inf] ( -- interval ) 0 [a,inf] ; foldable
MEMO: fixnum-interval ( -- interval )
most-negative-fixnum most-positive-fixnum [a,b] ; inline
MEMO: array-capacity-interval ( -- interval )
0 max-array-capacity [a,b] ; inline
: [-inf,inf] ( -- interval ) full-interval ; inline
: compare-endpoints ( p1 p2 quot -- ? )
[ 2dup [ first ] bi@ ] dip call [
2drop t
] [
2dup [ first ] bi@ number= [
[ second ] bi@ not or
] [
2drop f
] if
] if ; inline
: endpoint= ( p1 p2 -- ? )
[ [ first ] bi@ number= ] [ [ second ] bi@ eq? ] 2bi and ;
: endpoint< ( p1 p2 -- ? ) [ < ] compare-endpoints ;
: endpoint<= ( p1 p2 -- ? ) [ endpoint< ] [ endpoint= ] 2bi or ;
: endpoint> ( p1 p2 -- ? ) [ > ] compare-endpoints ;
: endpoint>= ( p1 p2 -- ? ) [ endpoint> ] [ endpoint= ] 2bi or ;
: endpoint-min ( p1 p2 -- p3 ) [ endpoint< ] most ;
: endpoint-max ( p1 p2 -- p3 ) [ endpoint> ] most ;
: interval>points ( int -- from to )
[ from>> ] [ to>> ] bi ;
: points>interval ( seq -- interval nan? )
[ first fp-nan? not ] partition
[
[ [ ] [ endpoint-min ] map-reduce ]
[ [ ] [ endpoint-max ] map-reduce ] bi
<interval>
]
[ empty? not ]
bi* ;
: nan-ok ( interval nan? -- interval ) drop ; inline
: nan-not-ok ( interval nan? -- interval ) [ drop full-interval ] when ; inline
: (interval-op) ( p1 p2 quot -- p3 )
[ [ first ] [ first ] [ call ] tri* ]
[ drop [ second ] both? ]
3bi 2array ; inline
: interval-op ( i1 i2 quot -- i3 nan? )
{
[ [ from>> ] [ from>> ] [ ] tri* (interval-op) ]
[ [ to>> ] [ from>> ] [ ] tri* (interval-op) ]
[ [ to>> ] [ to>> ] [ ] tri* (interval-op) ]
[ [ from>> ] [ to>> ] [ ] tri* (interval-op) ]
} 3cleave 4array points>interval ; inline
: do-empty-interval ( i1 i2 quot -- i3 )
{
{ [ pick empty-interval eq? ] [ 2drop ] }
{ [ over empty-interval eq? ] [ drop nip ] }
{ [ pick full-interval eq? ] [ 2drop ] }
{ [ over full-interval eq? ] [ drop nip ] }
[ call ]
} cond ; inline
: interval+ ( i1 i2 -- i3 )
[ [ + ] interval-op nan-ok ] do-empty-interval ;
: interval- ( i1 i2 -- i3 )
[ [ - ] interval-op nan-ok ] do-empty-interval ;
: interval-intersect ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ drop ] }
{ [ dup empty-interval eq? ] [ nip ] }
{ [ over full-interval eq? ] [ nip ] }
{ [ dup full-interval eq? ] [ drop ] }
[
[ interval>points ] bi@
[ [ swap endpoint< ] most ]
[ [ swap endpoint> ] most ] bi-curry* bi*
<interval>
]
} cond ;
: intervals-intersect? ( i1 i2 -- ? )
interval-intersect empty-interval eq? not ;
: interval-union ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ nip ] }
{ [ dup empty-interval eq? ] [ drop ] }
{ [ over full-interval eq? ] [ drop ] }
{ [ dup full-interval eq? ] [ nip ] }
[ [ interval>points 2array ] bi@ append points>interval nan-not-ok ]
} cond ;
: interval-subset? ( i1 i2 -- ? )
dupd interval-intersect = ;
: interval-contains? ( x int -- ? )
dup empty-interval eq? [ 2drop f ] [
dup full-interval eq? [ 2drop t ] [
[ from>> first2 [ >= ] [ > ] if ]
[ to>> first2 [ <= ] [ < ] if ]
2bi and
] if
] if ;
: interval-zero? ( int -- ? )
0 swap interval-contains? ;
: interval* ( i1 i2 -- i3 )
[ [ [ * ] interval-op nan-ok ] do-empty-interval ]
[ [ interval-zero? ] either? ]
2bi [ 0 [a,a] interval-union ] when ;
: interval-1+ ( i1 -- i2 ) 1 [a,a] interval+ ;
: interval-1- ( i1 -- i2 ) -1 [a,a] interval+ ;
: interval-neg ( i1 -- i2 ) -1 [a,a] interval* ;
: interval-bitnot ( i1 -- i2 ) interval-neg interval-1- ;
: interval-sq ( i1 -- i2 ) dup interval* ;
: special-interval? ( interval -- ? )
{ empty-interval full-interval } memq? ;
: interval-singleton? ( int -- ? )
dup special-interval? [
drop f
] [
interval>points
2dup [ second ] both?
[ [ first ] bi@ number= ]
[ 2drop f ] if
] if ;
: interval-length ( int -- n )
{
{ [ dup empty-interval eq? ] [ drop 0 ] }
{ [ dup full-interval eq? ] [ drop 1/0. ] }
[ interval>points [ first ] bi@ swap - ]
} cond ;
: interval-closure ( i1 -- i2 )
dup [ interval>points [ first ] bi@ [a,b] ] when ;
: interval-integer-op ( i1 i2 quot -- i3 )
[
2dup [ interval>points [ first integer? ] both? ] both?
] dip [ 2drop [-inf,inf] ] if ; inline
: interval-shift ( i1 i2 -- i3 )
#! Inaccurate; could be tighter
[
[
[ interval-closure ] bi@
[ shift ] interval-op nan-not-ok
] interval-integer-op
] do-empty-interval ;
: interval-shift-safe ( i1 i2 -- i3 )
[
dup to>> first 100 > [
2drop [-inf,inf]
] [
interval-shift
] if
] do-empty-interval ;
: interval-max ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ drop ] }
{ [ dup empty-interval eq? ] [ nip ] }
{ [ 2dup [ full-interval eq? ] both? ] [ drop ] }
{ [ over full-interval eq? ] [ nip from>> first [a,inf] ] }
{ [ dup full-interval eq? ] [ drop from>> first [a,inf] ] }
[ [ interval-closure ] bi@ [ max ] interval-op nan-not-ok ]
} cond ;
: interval-min ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ drop ] }
{ [ dup empty-interval eq? ] [ nip ] }
{ [ 2dup [ full-interval eq? ] both? ] [ drop ] }
{ [ over full-interval eq? ] [ nip to>> first [-inf,a] ] }
{ [ dup full-interval eq? ] [ drop to>> first [-inf,a] ] }
[ [ interval-closure ] bi@ [ min ] interval-op nan-not-ok ]
} cond ;
: interval-interior ( i1 -- i2 )
dup special-interval? [
interval>points [ first ] bi@ (a,b)
] unless ;
: interval-division-op ( i1 i2 quot -- i3 )
{
{ [ 0 pick interval-closure interval-contains? ] [ 3drop [-inf,inf] ] }
{ [ pick interval-zero? ] [ call 0 [a,a] interval-union ] }
[ call ]
} cond ; inline
: interval/ ( i1 i2 -- i3 )
[ [ [ / ] interval-op nan-not-ok ] interval-division-op ] do-empty-interval ;
: interval/-safe ( i1 i2 -- i3 )
#! Just a hack to make the compiler work if bootstrap.math
#! is not loaded.
\ integer \ / method [ interval/ ] [ 2drop f ] if ;
: interval/i ( i1 i2 -- i3 )
[
[
[
[ interval-closure ] bi@
[ /i ] interval-op nan-not-ok
] interval-integer-op
] interval-division-op
] do-empty-interval ;
: interval/f ( i1 i2 -- i3 )
[ [ [ /f ] interval-op nan-not-ok ] interval-division-op ] do-empty-interval ;
: (interval-abs) ( i1 -- i2 )
interval>points [ first2 [ abs ] dip 2array ] bi@ 2array ;
: interval-abs ( i1 -- i2 )
{
{ [ dup empty-interval eq? ] [ ] }
{ [ dup full-interval eq? ] [ drop [0,inf] ] }
{ [ 0 over interval-contains? ] [ (interval-abs) { 0 t } suffix points>interval nan-not-ok ] }
[ (interval-abs) points>interval nan-not-ok ]
} cond ;
: interval-absq ( i1 -- i2 )
interval-abs interval-sq ;
: interval-recip ( i1 -- i2 ) 1 [a,a] swap interval/ ;
: interval-2/ ( i1 -- i2 ) -1 [a,a] interval-shift ;
SYMBOL: incomparable
: left-endpoint-< ( i1 i2 -- ? )
[ swap interval-subset? ]
[ nip interval-singleton? ]
[ [ from>> ] bi@ endpoint= ]
2tri and and ;
: right-endpoint-< ( i1 i2 -- ? )
[ interval-subset? ]
[ drop interval-singleton? ]
[ [ to>> ] bi@ endpoint= ]
2tri and and ;
: (interval<) ( i1 i2 -- i1 i2 ? )
2dup [ from>> ] bi@ endpoint< ;
: interval< ( i1 i2 -- ? )
{
{ [ 2dup [ special-interval? ] either? ] [ incomparable ] }
{ [ 2dup interval-intersect empty-interval eq? ] [ (interval<) ] }
{ [ 2dup left-endpoint-< ] [ f ] }
{ [ 2dup right-endpoint-< ] [ f ] }
[ incomparable ]
} cond 2nip ;
: left-endpoint-<= ( i1 i2 -- ? )
[ from>> ] [ to>> ] bi* endpoint= ;
: right-endpoint-<= ( i1 i2 -- ? )
[ to>> ] [ from>> ] bi* endpoint= ;
: interval<= ( i1 i2 -- ? )
{
{ [ 2dup [ special-interval? ] either? ] [ incomparable ] }
{ [ 2dup interval-intersect empty-interval eq? ] [ (interval<) ] }
{ [ 2dup right-endpoint-<= ] [ t ] }
[ incomparable ]
} cond 2nip ;
: interval> ( i1 i2 -- ? )
swap interval< ;
: interval>= ( i1 i2 -- ? )
swap interval<= ;
: interval-mod ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ swap ] }
{ [ dup empty-interval eq? ] [ ] }
{ [ dup full-interval eq? ] [ ] }
[ interval-abs to>> first [ neg ] keep (a,b) ]
} cond
swap 0 [a,a] interval>= t eq? [ [0,inf] interval-intersect ] when ;
: (rem-range) ( i -- i' ) interval-abs to>> first 0 swap [a,b) ;
: interval-rem ( i1 i2 -- i3 )
{
{ [ over empty-interval eq? ] [ drop ] }
{ [ dup empty-interval eq? ] [ nip ] }
{ [ dup full-interval eq? ] [ 2drop [0,inf] ] }
[ nip (rem-range) ]
} cond ;
: interval-bitand-pos ( i1 i2 -- ? )
[ to>> first ] bi@ min 0 swap [a,b] ;
: interval-bitand-neg ( i1 i2 -- ? )
dup from>> first 0 < [ drop ] [ nip ] if
0 swap to>> first [a,b] ;
: interval-nonnegative? ( i -- ? )
from>> first 0 >= ;
: interval-bitand ( i1 i2 -- i3 )
#! Inaccurate.
[
{
{
[ 2dup [ interval-nonnegative? ] both? ]
[ interval-bitand-pos ]
}
{
[ 2dup [ interval-nonnegative? ] either? ]
[ interval-bitand-neg ]
}
[ 2drop [-inf,inf] ]
} cond
] do-empty-interval ;
: interval-bitor ( i1 i2 -- i3 )
#! Inaccurate.
[
2dup [ interval-nonnegative? ] both?
[
[ interval>points [ first ] bi@ ] bi@
4array supremum 0 swap >integer next-power-of-2 [a,b]
] [ 2drop [-inf,inf] ] if
] do-empty-interval ;
: interval-bitxor ( i1 i2 -- i3 )
#! Inaccurate.
interval-bitor ;
: interval-log2 ( i1 -- i2 )
{
{ empty-interval [ empty-interval ] }
{ full-interval [ [0,inf] ] }
[
to>> first 1 max dup most-positive-fixnum >
[ drop full-interval interval-log2 ]
[ 1 + >integer log2 0 swap [a,b] ]
if
]
} case ;
: assume< ( i1 i2 -- i3 )
dup special-interval? [ drop ] [
to>> first [-inf,a) interval-intersect
] if ;
: assume<= ( i1 i2 -- i3 )
dup special-interval? [ drop ] [
to>> first [-inf,a] interval-intersect
] if ;
: assume> ( i1 i2 -- i3 )
dup special-interval? [ drop ] [
from>> first (a,inf] interval-intersect
] if ;
: assume>= ( i1 i2 -- i3 )
dup special-interval? [ drop ] [
from>> first [a,inf] interval-intersect
] if ;
: integral-closure ( i1 -- i2 )
dup special-interval? [
[ from>> first2 [ 1 + ] unless ]
[ to>> first2 [ 1 - ] unless ]
bi [a,b]
] unless ;