Various small utility functions for user scripts

utils.js

;(function(name, definition) {
  var moduleObj = definition();

  // AMD Module
  if (typeof define === 'function') {
    define(moduleObj);
  }
  // CommonJS Module
  else if (typeof module !== 'undefined' && module.exports) {
    module.exports = moduleObj;
  }
  // Assign to the global object (window)
  else {
    this[name] = moduleObj;
  }
})('utils', function() {
  'use strict';

  return {

    /**
     * Simple string substution function.
     *
     *   fmt('x={0}, y={1}', 12, 4) -> 'x=12, y=4'
     *   fmt('x={x}, y={y}', { x: 12, y: 4 }) -> 'x=12, y=4'
     *   fmt('x={x}, y={{moo}}', { x: 12, y: 4 }) -> 'x=12, y={moo}'
     *   fmt('{x}: {y.thing}', { x: 'foo', y: { thing: 'bar' }}) -> 'foo: bar'
     *   fmt('{x}: {y.a[1]}', { x: 'foo', y: { thing: 'bar', a: [6, 7] }}) -> 'foo: 7'
     *   fmt('{0[2]}, {0[-2]}', [{ x: 12, y: 4 }, 7, 120, 777, 999]) -> '120, 777'
     *   fmt('{0[-5].y}', [{ x: 12, y: 4 }, 7, 120, 777, 999]) -> '4'
     *   fmt('{a[-5].x}', {a: [{ x: 12, y: 4 }, 7, 120, 777, 999]}) -> '12'
     *
     * @param {String} format
     * @param {Object|Object+} data
     * @return {String}
     */
    format: function(formatString, data) {
      data = arguments.length == 2 && typeof data === "object" && !Array.isArray(data)
        ? data
        : [].slice.call(arguments, 1);

      return formatString
        .replace(/\{\{/g, String.fromCharCode(0))
        .replace(/\}\}/g, String.fromCharCode(1))
        .replace(/\{([^}]+)\}/g, function(match, path) {
          try {
            var p = path.replace(/\[(-?\w+)\]/g, '.$1').split('.');
            //console.log('path="%s" (%s), data=%s', path, p.toSource(), data.toSource());
            return String(p.reduce(function(o, n) {
              return o.slice && !isNaN(n) ? o.slice(n).shift() :  o[n];
            }, data));
          }
          catch (ex) {
            return match;
          }
        })
        .replace(/\x00/g, "{")
        .replace(/\x01/g, "}");
    }

  };

});