tokens-append-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,
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//

// ## tokens

// ### appendBigrams
/**
 *
 * Generates bigrams from the input tokens and appends them to the input tokens.
 *
 * @alias tokens#appendBigrams
 * @param {string[]} tokens the input tokens.
 * @return {string[]} the input tokens appended with their bigrams.
 * @example
 * appendBigrams( [ 'he', 'acted', 'decisively', 'today' ] );
 * // -> [ 'he',
 * //      'acted',
 * //      'decisively',
 * //      'today',
 * //      'he_acted',
 * //      'acted_decisively',
 * //      'decisively_today' ]
 */
var appendBigrams = function ( tokens ) {
  var i, imax;
  for ( i = 0, imax = tokens.length - 1; i < imax; i += 1 ) {
    tokens.push( tokens[ i ] + '_' + tokens[ i + 1 ] );
  }
  return tokens;
}; // appendBigrams()

module.exports = appendBigrams;