tokens-bigrams.js

//     wink-nlp-utils
//     NLP Functions for amplifying negations, managing elisions,
//     creating ngrams, stems, phonetic codes to tokens and more.
//
//     Copyright (C) 2017-18  GRAYPE Systems Private Limited
//
//     This file is part of “wink-nlp-utils”.
//
//     Permission is hereby granted, free of charge, to any person obtaining a
//     copy of this software and associated documentation files (the "Software"),
//     to deal in the Software without restriction, including without limitation
//     the rights to use, copy, modify, merge, publish, distribute, sublicense,
//     and/or sell copies of the Software, and to permit persons to whom the
//     Software is furnished to do so, subject to the following conditions:
//
//     The above copyright notice and this permission notice shall be included
//     in all copies or substantial portions of the Software.
//
//     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//     OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
//     THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//     DEALINGS IN THE SOFTWARE.

//

// ## tokens

// ### bigrams
/**
 *
 * Generates bigrams from the input tokens.
 *
 * @alias tokens#bigrams
 * @param {string[]} tokens the input tokens.
 * @return {string[]} the bigrams.
 * @example
 * bigrams( [ 'he', 'acted', 'decisively', 'today' ] );
 * // -> [ [ 'he', 'acted' ],
 * //      [ 'acted', 'decisively' ],
 * //      [ 'decisively', 'today' ] ]
 */
var bigrams = function ( tokens ) {
  // Bigrams will be stored here.
  var bgs = [];
  // Helper variables.
  var i, imax;
  // Create bigrams.
  for ( i = 0, imax = tokens.length - 1; i < imax; i += 1 ) {
    bgs.push( [ tokens[ i ], tokens[ i + 1 ] ] );
  }
  return bgs;
}; // bigrams()

module.exports = bigrams;