79 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			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 ;
 |