/* Array utilities. */
var arrays = {
  /* Like Python's |range|, but without |step|. */
  range: function(start, stop) {
    if (stop === undefined) {
      stop = start;
      start = 0;
    }

    var result = new Array(Math.max(0, stop - start));
    for (var i = 0, j = start; j < stop; i++, j++) {
      result[i] = j;
    }
    return result;
  },

  find: function(array, callback) {
    var length = array.length;
    for (var i = 0; i < length; i++) {
      if (callback(array[i])) {
        return array[i];
      }
    }
  },

  indexOf: function(array, callback) {
    var length = array.length;
    for (var i = 0; i < length; i++) {
      if (callback(array[i])) {
        return i;
      }
    }
    return -1;
  },

  contains: function(array, value) {
    /*
     * Stupid IE does not have Array.prototype.indexOf, otherwise this function
     * would be a one-liner.
     */
    var length = array.length;
    for (var i = 0; i < length; i++) {
      if (array[i] === value) {
        return true;
      }
    }
    return false;
  },

  each: function(array, callback) {
    var length = array.length;
    for (var i = 0; i < length; i++) {
      callback(array[i], i);
    }
  },

  map: function(array, callback) {
    var result = [];
    var length = array.length;
    for (var i = 0; i < length; i++) {
      result[i] = callback(array[i], i);
    }
    return result;
  },

  pluck: function(array, key) {
    return arrays.map(array, function (e) { return e[key]; });
  }
};

module.exports = arrays;