factor/basis/help/crossref/crossref.factor

34 lines
1.0 KiB
Factor

! Copyright (C) 2005, 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: arrays definitions generic assocs math fry
io kernel namespaces prettyprint prettyprint.sections
sequences words summary classes help.topics help.markup ;
IN: help.crossref
: article-links ( topic elements -- seq )
[ article-content ] dip
collect-elements ;
: article-children ( topic -- seq )
{ $subsection $subsections } article-links [ >link ] map ;
: help-path ( topic -- seq )
[ article-parent ] follow rest ;
: set-article-parents ( parent article -- )
article-children [ set-article-parent ] with each ;
: xref-article ( topic -- )
dup set-article-parents ;
: prev/next ( obj seq n -- obj' )
[ [ index dup ] keep ] dip swap
'[ _ + _ ?nth ] when ;
: prev/next-article ( article n -- article' )
[ dup article-parent dup ] dip
'[ article-children _ prev/next ] [ 2drop f ] if ;
: prev-article ( article -- prev ) -1 prev/next-article ;
: next-article ( article -- next ) 1 prev/next-article ;