Neural network indentation detection

neural-network.js

var brain = require("brain");

// initalize network from previously trained state 
var trained = {}; // Too big to display! see https://gist.github.com/harthur/3d5c24a04e509284940d
var network = new brain.NeuralNetwork().fromJSON(trained);

function detectIndent(lines) {
  // get widths used in file and what % of file
  var percentages = getWidthPercentages(lines);

  var results = network.run(percentages);

  // from results, pick indent with the highest signal
  var max = 0,indent = null;
  for (var width in results) {
    var prob = results[width];
    if (prob > max) {
      indent = width;
      max = prob;
    }
  }
  return indent;
}

/**
 * Get indent widths used, and the % of lines using each.
 * Return ex: {2: 0.33, 4: 0.51, 6: 0.13, 8: 0.03, 17: 0.01}
 */
function getWidthPercentages(lines) {
  var counts = {}; // # spaces -> # lines with that width
  var total = 0;   // # of indented lines

  lines.forEach(function (text) {
    var width = leadingSpaces(text);

    if (width > 0) {
      counts[width] = (counts[width] || 0) + 1;
      total++;
    }
  });

  // turn counts into % of lines
  for (var width in counts) {
    counts[width] = counts[width] / total;
  }
  return counts;
}