nl_tokens: Search for the first keyword match given phrase .
pl_tokens: function seekVanguard ( phrase ) { phrase = _adaptKey ( phrase ) ; var kdx = reduce ( KEY_INDEX , phrase ) ; // look back for the first record block containing keyword for the specified phrase if ( phrase <= _adaptKey ( kdx . last_word ) ) { var index = kdx . index - 1 , prev ; while ( prev = KEY_INDEX [ index ] ) { if ( _adaptKey ( prev . last_word ) !== _adaptKey ( kdx . last_word ) ) { break ; } kdx = prev ; index -- ; } } return loadKeys ( kdx ) . <mask> ( function ( list ) { var idx = shrink ( list , phrase ) ; // look back for the first matched keyword position while ( idx > 0 ) { if ( _adaptKey ( list [ -- idx ] ) !== _adaptKey ( phrase ) ) { idx ++ ; break ; } } return [ kdx , Math . min ( idx , list . length - 1 ) , list ] ; } ) ; }