factor/extra/sequences/repeating/repeating.factor

37 lines
877 B
Factor

! Copyright (C) 2008 Alex Chapman
! Copyright (C) 2012 John Benediktsson
! See http;//factorcode.org/license.txt for BSD license
USING: accessors circular kernel math sequences sequences.private ;
IN: sequences.repeating
TUPLE: cycles circular length ;
: <cycles> ( seq length -- cycles )
[ <circular> ] dip cycles boa ;
: cycle ( seq length -- new-seq )
dupd <cycles> swap like ;
M: cycles length length>> ;
M: cycles set-length length<< ;
M: cycles virtual@ ( n seq -- n' seq' ) circular>> ;
M: cycles virtual-exemplar circular>> ;
INSTANCE: cycles virtual-sequence
TUPLE: repeats seq length ;
: <repeats> ( seq times -- repeats )
[ dup length ] dip * repeats boa ;
: repeat ( seq times -- new-seq )
dupd <repeats> swap like ;
M: repeats length length>> ;
M: repeats nth-unsafe seq>> [ length /i ] keep nth ;
INSTANCE: repeats immutable-sequence