! Copyright (C) 2009 Daniel Ehrenberg
+! Copyright (C) 2017 John Benediktsson
! See http://factorcode.org/license.txt for BSD license.
-USING: kernel sequences math arrays locals fry accessors
-lists splitting call make combinators.short-circuit namespaces
-grouping splitting.monotonic ;
+USING: accessors arrays kernel math sequences sequences.private ;
IN: wrap
-! black is the text length, white is the whitespace length
TUPLE: element contents black white ;
-C: <element> element
-
-: element-length ( element -- n )
- [ black>> ] [ white>> ] bi + ;
-
-: swons ( cdr car -- cons )
- swap cons ;
-
-: unswons ( cons -- cdr car )
- [ cdr ] [ car ] bi ;
-
-: 1list? ( list -- ? )
- { [ ] [ cdr +nil+ = ] } 1&& ;
-
-: lists>arrays ( lists -- arrays )
- [ list>seq ] lmap>array ;
-
-TUPLE: paragraph lines head-width tail-cost ;
-C: <paragraph> paragraph
-
-SYMBOL: line-max
-SYMBOL: line-ideal
-
-: deviation ( length -- n )
- line-ideal get - sq ;
-
-: top-fits? ( paragraph -- ? )
- [ head-width>> ]
- [ lines>> 1list? line-ideal line-max ? get ] bi <= ;
-: fits? ( paragraph -- ? )
- ! Make this not count spaces at end
- { [ lines>> car 1list? ] [ top-fits? ] } 1|| ;
-
-:: min-by ( seq quot -- elt )
- f 1.0/0.0 seq [| key value new |
- new quot call :> newvalue
- newvalue value < [ new newvalue ] [ key value ] if
- ] each drop ; inline
-
-: paragraph-cost ( paragraph -- cost )
- [ head-width>> deviation ]
- [ tail-cost>> ] bi + ;
-
-: min-cost ( paragraphs -- paragraph )
- [ paragraph-cost ] min-by ;
-
-: new-line ( paragraph element -- paragraph )
- [ [ lines>> ] [ 1list ] bi* swons ]
- [ nip black>> ]
- [ drop paragraph-cost ] 2tri
- <paragraph> ;
-
-: glue ( paragraph element -- paragraph )
- [ [ lines>> unswons ] dip swons swons ]
- [ [ head-width>> ] [ element-length ] bi* + ]
- [ drop tail-cost>> ] 2tri
- <paragraph> ;
-
-: wrap-step ( paragraphs element -- paragraphs )
- [ '[ _ glue ] map ]
- [ [ min-cost ] dip new-line ]
- 2bi prefix
- [ fits? ] filter ;
-
-: 1paragraph ( element -- paragraph )
- [ 1list 1list ]
- [ black>> ] bi
- 0 <paragraph> ;
-
-: post-process ( paragraph -- array )
- lines>> lists>arrays
- [ [ contents>> ] map ] map ;
-
-: initialize ( elements -- elements paragraph )
- <reversed> unclip-slice 1paragraph 1array ;
+C: <element> element
-: wrap ( elements line-max line-ideal -- paragraph )
- [
- line-ideal set
- line-max set
- initialize
- [ wrap-step ] reduce
- min-cost
- post-process
- ] with-scope ;
+:: wrap ( elements width -- array )
+ elements length integer>fixnum-strict :> #elements
+ elements [ black>> ] { } map-as :> black
+ elements [ white>> ] { } map-as :> white
+
+ #elements 1 + f <array> :> minima
+ #elements 1 + 0 <array> :> breaks
+
+ 0 0 minima set-nth-unsafe
+
+ minima [| base i |
+ 0 i 1 + [ dup #elements <= ] [| j |
+ j 1 - black nth-unsafe + dup :> w
+ j 1 - white nth-unsafe +
+
+ w width > [
+ j 1 - i = [
+ 0 j minima set-nth-unsafe
+ i j breaks set-nth-unsafe
+ ] when #elements
+ ] [
+ base
+ j #elements = [ width w - sq + ] unless :> cost
+ j minima nth-unsafe [ cost >= ] [ t ] if* [
+ cost j minima set-nth-unsafe
+ i j breaks set-nth-unsafe
+ ] when j
+ ] if 1 +
+ ] while 2drop
+ ] each-index
+
+ #elements [ dup 0 > ] [
+ [ breaks nth dup ] keep elements <slice>
+ [ contents>> ] map
+ ] produce nip reverse ;