factor/basis/grouping/grouping.factor

104 lines
2.4 KiB
Factor

! Copyright (C) 2005, 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel math math.order strings arrays vectors sequences
sequences.private accessors fry ;
IN: grouping
<PRIVATE
TUPLE: chunking-seq { seq read-only } { n read-only } ;
: check-groups ( n -- n )
dup 0 <= [ "Invalid group count" throw ] when ; inline
: new-groups ( seq n class -- groups )
[ check-groups ] dip boa ; inline
GENERIC: group@ ( n groups -- from to seq )
M: chunking-seq set-nth group@ <slice> 0 swap copy ;
M: chunking-seq like drop { } like ; inline
INSTANCE: chunking-seq sequence
MIXIN: subseq-chunking
M: subseq-chunking nth group@ subseq ; inline
MIXIN: slice-chunking
M: slice-chunking nth group@ <slice> ; inline
M: slice-chunking nth-unsafe group@ slice boa ; inline
TUPLE: abstract-groups < chunking-seq ;
M: abstract-groups length
[ seq>> length ] [ n>> ] bi [ + 1 - ] keep /i ; inline
M: abstract-groups set-length
[ n>> * ] [ seq>> ] bi set-length ; inline
M: abstract-groups group@
[ n>> [ * dup ] keep + ] [ seq>> ] bi [ length min ] keep ; inline
TUPLE: abstract-clumps < chunking-seq ;
M: abstract-clumps length
[ seq>> length ] [ n>> ] bi - 1 + ; inline
M: abstract-clumps set-length
[ n>> + 1 - ] [ seq>> ] bi set-length ; inline
M: abstract-clumps group@
[ n>> over + ] [ seq>> ] bi ; inline
PRIVATE>
TUPLE: groups < abstract-groups ;
: <groups> ( seq n -- groups )
groups new-groups ; inline
INSTANCE: groups subseq-chunking
TUPLE: sliced-groups < abstract-groups ;
: <sliced-groups> ( seq n -- groups )
sliced-groups new-groups ; inline
INSTANCE: sliced-groups slice-chunking
TUPLE: clumps < abstract-clumps ;
: <clumps> ( seq n -- clumps )
clumps new-groups ; inline
INSTANCE: clumps subseq-chunking
TUPLE: sliced-clumps < abstract-clumps ;
: <sliced-clumps> ( seq n -- clumps )
sliced-clumps new-groups ; inline
INSTANCE: sliced-clumps slice-chunking
: group ( seq n -- array ) <groups> { } like ;
: clump ( seq n -- array ) <clumps> { } like ;
: monotonic? ( seq quot -- ? )
over length 2 < [ 2drop t ] [
over length 2 = [
[ first2-unsafe ] dip call
] [
[ 2 <sliced-clumps> ] dip
'[ first2-unsafe @ ] all?
] if
] if ; inline
: all-equal? ( seq -- ? ) [ = ] monotonic? ;
: all-eq? ( seq -- ? ) [ eq? ] monotonic? ;