factor/basis/wrap/wrap.factor

158 lines
3.7 KiB
Factor

USING: kernel sequences math arrays locals fry accessors
lists splitting call make combinators.short-circuit namespaces
grouping splitting.monotonic ;
IN: wrap
<PRIVATE
! 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 ;
: wrap ( elements line-max line-ideal -- paragraph )
[
line-ideal set
line-max set
initialize
[ wrap-step ] reduce
min-cost
post-process
] with-scope ;
PRIVATE>
TUPLE: segment key width break? ;
C: <segment> segment
<PRIVATE
: segments-length ( segments -- length )
[ width>> ] map sum ;
: make-element ( whites blacks -- element )
[ append ] [ [ segments-length ] bi@ ] 2bi <element> ;
: ?first2 ( seq -- first/f second/f )
[ 0 swap ?nth ]
[ 1 swap ?nth ] bi ;
: split-segments ( seq -- half-elements )
[ [ break?>> ] bi@ = ] monotonic-split ;
: ?first-break ( seq -- newseq f/element )
dup first first break?>>
[ unclip-slice f swap make-element ]
[ f ] if ;
: make-elements ( seq f/element -- elements )
[ 2 <groups> [ ?first2 make-element ] map ] dip
[ prefix ] when* ;
: segments>elements ( seq -- newseq )
split-segments ?first-break make-elements ;
PRIVATE>
: wrap-segments ( segments line-max line-ideal -- lines )
[ segments>elements ] 2dip wrap [ concat ] map ;
<PRIVATE
: split-lines ( string -- elements-lines )
string-lines [
" \t" split harvest
[ dup length 1 <element> ] map
] map ;
: join-elements ( wrapped-lines -- lines )
[ " " join ] map ;
: join-lines ( strings -- string )
"\n" join ;
PRIVATE>
: wrap-lines ( lines width -- newlines )
[ split-lines ] dip '[ _ dup wrap join-elements ] map concat ;
: wrap-string ( string width -- newstring )
wrap-lines join-lines ;
: wrap-indented-string ( string width indent -- newstring )
[ length - wrap-lines ] keep '[ _ prepend ] map join-lines ;