concordance.js

// task
// Reetesh Kumar
// http://reet.herokuapp.com
// https://github.com/krreet/node_concordance

// This is a way of making something available to another JS file in node
module.exports = {

  // An object that does classification with us of words
  Concordance: class {

    constructor(stopWords) {
      this.dict = {};
      this.keys = [];
      this.stopWords = stopWords;
    }

    // Splitting up the text
    split(text) {
      // Split into array of tokens
      return text.split(/\W+/);
    }

    // A function to validate a toke
    validate(token) {

      return /\w{2,}/.test(token) && (!(/\d+/.test(token)) && !(this.stopWords.indexOf(token) > -1));


    }





    // Process new text
    process(data) {

      //data here is json 
      // console.log(data.xlData);


      // var json = JSON.stringify(data.xlData);
      // //use fs to write the file to disk

      // var fs = require('fs');
      // fs.writeFileSync('myjsonfile.json', json, 'utf8');


      var tokens = this.split(data);
      //console.log(tokens.length);
      // For every token
      for (var i = 0; i < tokens.length; i++) {
        // Lowercase everything to ignore case
        var token = tokens[i].toLowerCase();
        if (this.validate(token)) {
          // Increase the count for the token
          this.increment(token);
        }
      }
    }

    // An array of keys
    getKeys() {
      return this.keys;
    }

    // Get the count for a word
    getCount(word) {
      return this.dict[word];
    }

    // Increment the count for a word
    increment(word) {
      // Is this a new word?
      if (!this.dict[word]) {
        this.dict[word] = 1;
        this.keys.push(word);
        // Otherwise just increment its count
      } else {
        this.dict[word]++;
      }
    }

    // Sort array of keys by counts
    sortByCount() {
      // For this function to work for sorting, I have
      // to store a reference to this so the context is not lost!
      var concordance = this;

      // A fancy way to sort each element
      // Compare the counts
      function sorter(a, b) {
        var diff = concordance.getCount(b) - concordance.getCount(a);
        return diff;
      }

      // Sort using the function above!
      this.keys.sort(sorter);
    }
  }
};