extra/sequences/shifted/shifted.factor

   1 ! Copyright (C) 2013 John Benediktsson
   2 ! See https://factorcode.org/license.txt for BSD license
   3 USING: accessors kernel math sequences sequences.private ;
   4 IN: sequences.shifted
   5
   6 TUPLE: shifted
   7 { underlying read-only }
   8 { n integer read-only }
   9 { fill read-only } ;
  10
  11 C: <shifted> shifted
  12
  13 M: shifted length underlying>> length ;
  14
  15 M: shifted like underlying>> like ;
  16
  17 M: shifted new-sequence underlying>> new-sequence ;
  18
  19 M: shifted nth-unsafe
  20     [ n>> neg + ] [ underlying>> ] [ ] tri
  21     2over bounds-check? [ drop nth-unsafe ] [ 2nip fill>> ] if ;
  22
  23 M: shifted set-nth-unsafe
  24     [ n>> neg + ] [ underlying>> ] bi
  25     2dup bounds-check? [ set-nth-unsafe ] [ 3drop ] if ;
  26
  27 INSTANCE: shifted sequence