USING: accessors assocs fry general-utils grouping kernel
locals math.order regexp sequences sorting splitting ;
IN: sentences


: abbrev-pattern ( -- regexp )
    R/ ((\w\.)+\w)|((\w\.){2,}) / ;    ! a.m as well as N.B. and N.B.A or N.B.A.
    
: sort-slices-by-from ( slices -- slices' )
    [ [ from>> ] bi@ <=> ] sort ;
    
: naive-sentence-split ( str -- lines )
    R/ .[.?!:]+/ [ re-split ] [ all-matching-slices ] bi-curry bi append
    sort-slices-by-from 
    2 <groups> 
    [ concat trim-spaces ] map
    harvest ;
    
: abbreviations ( string -- abbrevs )    
    abbrev-pattern all-matching-subseqs [ trim-spaces ] map ;

! to solve complicated periods in sentences, regexp couldn't catch all sentences.    
: (abbrev-replace-pairs) ( abbrevs -- pairs ) 
    dup [ { CHAR: . } "。" replace1 ] map zip ;

: reverse-pairs ( pairs -- sriap )
    [ values ] [ keys ] bi zip ;
    
: replace-all ( text pairs -- text' )
    [ first2 replace-subseq ] each ;  
    
:: sentence-split ( text -- sentences )    
    text abbreviations
    (abbrev-replace-pairs) :> pairs
    text pairs replace-all
    naive-sentence-split 
    pairs reverse-pairs '[ _ replace-all ] map ;