index.js

/*!
 * get-value <https://github.com/jonschlinkert/get-value>
 *
 * Copyright (c) 2014-2015, Jon Schlinkert.
 * Licensed under the MIT License.
 */

module.exports = function(obj, prop, a, b, c) {
  if (!isObject(obj) || !prop) {
    return obj;
  }

  prop = toString(prop);

  // allowing for multiple properties to be passed as
  // a string or array, but much faster (3-4x) than doing
  // `[].slice.call(arguments)`
  if (a) prop += '.' + toString(a);
  if (b) prop += '.' + toString(b);
  if (c) prop += '.' + toString(c);

  if (prop in obj) {
    return obj[prop];
  }

  var segs = prop.split('.');
  var len = segs.length;
  var i = -1;

  while (obj && (++i < len)) {
    var key = segs[i];
    while (key[key.length - 1] === '\\') {
      key = key.slice(0, -1) + '.' + segs[++i];
    }
    obj = obj[key];
  }
  return obj;
};

function isObject(val) {
  return val !== null && (typeof val === 'object' || typeof val === 'function');
}

function toString(val) {
  if (!val) return '';
  if (Array.isArray(val)) {
    return val.join('.');
  }
  return val;
}