-! Copyright (C) 2005, 2008 Slava Pestov.
+! 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 ;
+sequences.private accessors fry ;
IN: grouping
<PRIVATE
TUPLE: abstract-groups < chunking-seq ;
M: abstract-groups length
- [ seq>> length ] [ n>> ] bi [ + 1- ] keep /i ;
+ [ seq>> length ] [ n>> ] bi [ + 1 - ] keep /i ;
M: abstract-groups set-length
[ n>> * ] [ seq>> ] bi set-length ;
TUPLE: abstract-clumps < chunking-seq ;
M: abstract-clumps length
- [ seq>> length ] [ n>> ] bi - 1+ ;
+ [ seq>> length ] [ n>> ] bi - 1 + ;
M: abstract-clumps set-length
- [ n>> + 1- ] [ seq>> ] bi set-length ;
+ [ n>> + 1 - ] [ seq>> ] bi set-length ;
M: abstract-clumps group@
[ n>> over + ] [ seq>> ] bi ;
: 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? ;