factor/basis/wrap/wrap.factor

79 lines
2.4 KiB
Factor

! Copyright (C) 2009 Daniel Ehrenberg
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays combinators combinators.short-circuit
fry kernel kernel.private lists locals math sequences typed ;
IN: wrap
! black is the text length, white is the whitespace length
TUPLE: element contents black white ;
C: <element> element
<PRIVATE
: element-length ( element -- n )
[ black>> ] [ white>> ] bi + ; inline
TUPLE: paragraph line-max line-ideal lines head-width tail-cost ;
C: <paragraph> paragraph
TYPED: top-fits? ( paragraph: paragraph -- ? )
[ head-width>> ]
[ dup lines>> 1list? [ line-ideal>> ] [ line-max>> ] if ] bi <= ; inline
TYPED: fits? ( paragraph: paragraph -- ? )
! Make this not count spaces at end
{ [ lines>> car 1list? ] [ top-fits? ] } 1|| ; inline
:: min-by ( seq quot -- elt )
f 1/0. seq [| key value newkey |
newkey quot call :> newvalue
newvalue value < [ newkey newvalue ] [ key value ] if
] each drop ; inline
TYPED: paragraph-cost ( paragraph: paragraph -- cost )
dup lines>> 1list? [ drop 0 ] [
[ [ head-width>> ] [ line-ideal>> ] bi - sq ]
[ tail-cost>> ] bi +
] if ; inline
: min-cost ( paragraphs -- paragraph )
[ paragraph-cost ] min-by ; inline
TYPED: new-line ( paragraph: paragraph element: element -- paragraph )
{
[ drop [ line-max>> ] [ line-ideal>> ] bi ]
[ [ lines>> ] [ 1list ] bi* swons ]
[ nip black>> ]
[ drop paragraph-cost ]
} 2cleave <paragraph> ; inline
TYPED: add-element ( paragraph: paragraph element: element -- )
[ element-length [ + ] curry change-head-width ]
[ [ [ unswons ] dip swons swons ] curry change-lines ]
bi drop ; inline
TYPED: wrap-step ( paragraphs: array element: element -- paragraphs )
[ [ min-cost ] dip new-line ]
[ dupd '[ _ add-element ] each ]
2bi swap prefix { array } declare
[ fits? ] filter ;
: 1paragraph ( line-max line-ideal element -- paragraph )
[ 1list 1list ] [ black>> ] bi 0 <paragraph> ;
: post-process ( paragraph -- array )
lines>> [ [ contents>> ] lmap>array ] lmap>array ;
: initialize ( line-max line-ideal elements -- elements paragraph )
reverse unclip [ -rot ] dip 1paragraph 1array ;
PRIVATE>
: wrap ( elements line-max line-ideal -- array )
rot [ 2drop { } ] [
initialize
[ wrap-step ] reduce
min-cost
post-process
] if-empty ;