angular.js/src/Angular.js

'use strict';

////////////////////////////////////

/**
 * @ngdoc function
 * @name angular.lowercase
 * @function
 *
 * @description Converts the specified string to lowercase.
 * @param {string} string String to be converted to lowercase.
 * @returns {string} Lowercased string.
 */
var lowercase = function(string){return isString(string) ? string.toLowerCase() : string;};


/**
 * @ngdoc function
 * @name angular.uppercase
 * @function
 *
 * @description Converts the specified string to uppercase.
 * @param {string} string String to be converted to uppercase.
 * @returns {string} Uppercased string.
 */
var uppercase = function(string){return isString(string) ? string.toUpperCase() : string;};


var manualLowercase = function(s) {
  return isString(s)
      ? s.replace(/[A-Z]/g, function(ch) {return fromCharCode(ch.charCodeAt(0) | 32);})
      : s;
};
var manualUppercase = function(s) {
  return isString(s)
      ? s.replace(/[a-z]/g, function(ch) {return fromCharCode(ch.charCodeAt(0) & ~32);})
      : s;
};


// String#toLowerCase and String#toUpperCase don't produce correct results in browsers with Turkish
// locale, for this reason we need to detect this case and redefine lowercase/uppercase methods
// with correct but slower alternatives.
if ('i' !== 'I'.toLowerCase()) {
  lowercase = manualLowercase;
  uppercase = manualUppercase;
}

function fromCharCode(code) {return String.fromCharCode(code);}


var Error             = window.Error,
    /** holds major version number for IE or NaN for real browsers */
    msie              = int((/msie (\d+)/.exec(lowercase(navigator.userAgent)) || [])[1]),
    jqLite,           // delay binding since jQuery could be loaded after us.
    jQuery,           // delay binding
    slice             = [].slice,
    push              = [].push,
    toString          = Object.prototype.toString,

    /** @name angular */
    angular           = window.angular || (window.angular = {}),
    angularModule,
    /** @name angular.module.ng */
    nodeName_,
    uid               = ['0', '0', '0'];

/**
 * @ngdoc function
 * @name angular.forEach
 * @function
 *
 * @description
 * Invokes the `iterator` function once for each item in `obj` collection, which can be either an
 * object or an array. The `iterator` function is invoked with `iterator(value, key)`, where `value`
 * is the value of an object property or an array element and `key` is the object property key or
 * array element index. Specifying a `context` for the function is optional.
 *
 * Note: this function was previously known as `angular.foreach`.
 *
   <pre>
     var values = {name: 'misko', gender: 'male'};
     var log = [];
     angular.forEach(values, function(value, key){
       this.push(key + ': ' + value);
     }, log);
     expect(log).toEqual(['name: misko', 'gender:male']);
   </pre>
 *
 * @param {Object|Array} obj Object to iterate over.
 * @param {Function} iterator Iterator function.
 * @param {Object=} context Object to become context (`this`) for the iterator function.
 * @returns {Object|Array} Reference to `obj`.
 */
function forEach(obj, iterator, context) {
  var key;
  if (obj) {
    if (isFunction(obj)){
      for (key in obj) {
        if (key != 'prototype' && key != 'length' && key != 'name' && obj.hasOwnProperty(key)) {
          iterator.call(context, obj[key], key);
        }
      }
    } else if (obj.forEach && obj.forEach !== forEach) {
      obj.forEach(iterator, context);
    } else if (isObject(obj) && isNumber(obj.length)) {
      for (key = 0; key < obj.length; key++)
        iterator.call(context, obj[key], key);
    } else {
      for (key in obj) {
        if (obj.hasOwnProperty(key)) {
          iterator.call(context, obj[key], key);
        }
      }
    }
  }
  return obj;
}

function sortedKeys(obj) {
  var keys = [];
  for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
      keys.push(key);
    }
  }
  return keys.sort();
}

function forEachSorted(obj, iterator, context) {
  var keys = sortedKeys(obj);
  for ( var i = 0; i < keys.length; i++) {
    iterator.call(context, obj[keys[i]], keys[i]);
  }
  return keys;
}


/**
 * when using forEach the params are value, key, but it is often useful to have key, value.
 * @param {function(string, *)} iteratorFn
 * @returns {function(*, string)}
 */
function reverseParams(iteratorFn) {
  return function(value, key) { iteratorFn(key, value) };
}

/**
 * A consistent way of creating unique IDs in angular. The ID is a sequence of alpha numeric
 * characters such as '012ABC'. The reason why we are not using simply a number counter is that
 * the number string gets longer over time, and it can also overflow, where as the the nextId
 * will grow much slower, it is a string, and it will never overflow.
 *
 * @returns an unique alpha-numeric string
 */
function nextUid() {
  var index = uid.length;
  var digit;

  while(index) {
    index--;
    digit = uid[index].charCodeAt(0);
    if (digit == 57 /*'9'*/) {
      uid[index] = 'A';
      return uid.join('');
    }
    if (digit == 90  /*'Z'*/) {
      uid[index] = '0';
    } else {
      uid[index] = String.fromCharCode(digit + 1);
      return uid.join('');
    }
  }
  uid.unshift('0');
  return uid.join('');
}

/**
 * @ngdoc function
 * @name angular.extend
 * @function
 *
 * @description
 * Extends the destination object `dst` by copying all of the properties from the `src` object(s)
 * to `dst`. You can specify multiple `src` objects.
 *
 * @param {Object} dst Destination object.
 * @param {...Object} src Source object(s).
 */
function extend(dst) {
  forEach(arguments, function(obj){
    if (obj !== dst) {
      forEach(obj, function(value, key){
        dst[key] = value;
      });
    }
  });
  return dst;
}

function int(str) {
  return parseInt(str, 10);
}


function inherit(parent, extra) {
  return extend(new (extend(function() {}, {prototype:parent}))(), extra);
}


/**
 * @ngdoc function
 * @name angular.noop
 * @function
 *
 * @description
 * A function that performs no operations. This function can be useful when writing code in the
 * functional style.
   <pre>
     function foo(callback) {
       var result = calculateResult();
       (callback || angular.noop)(result);
     }
   </pre>
 */
function noop() {}
noop.$inject = [];


/**
 * @ngdoc function
 * @name angular.identity
 * @function
 *
 * @description
 * A function that returns its first argument. This function is useful when writing code in the
 * functional style.
 *
   <pre>
     function transformer(transformationFn, value) {
       return (transformationFn || identity)(value);
     };
   </pre>
 */
function identity($) {return $;}
identity.$inject = [];


function valueFn(value) {return function() {return value;};}

/**
 * @ngdoc function
 * @name angular.isUndefined
 * @function
 *
 * @description
 * Determines if a reference is undefined.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is undefined.
 */
function isUndefined(value){return typeof value == 'undefined';}


/**
 * @ngdoc function
 * @name angular.isDefined
 * @function
 *
 * @description
 * Determines if a reference is defined.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is defined.
 */
function isDefined(value){return typeof value != 'undefined';}


/**
 * @ngdoc function
 * @name angular.isObject
 * @function
 *
 * @description
 * Determines if a reference is an `Object`. Unlike `typeof` in JavaScript, `null`s are not
 * considered to be objects.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is an `Object` but not `null`.
 */
function isObject(value){return value != null && typeof value == 'object';}


/**
 * @ngdoc function
 * @name angular.isString
 * @function
 *
 * @description
 * Determines if a reference is a `String`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `String`.
 */
function isString(value){return typeof value == 'string';}


/**
 * @ngdoc function
 * @name angular.isNumber
 * @function
 *
 * @description
 * Determines if a reference is a `Number`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Number`.
 */
function isNumber(value){return typeof value == 'number';}


/**
 * @ngdoc function
 * @name angular.isDate
 * @function
 *
 * @description
 * Determines if a value is a date.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Date`.
 */
function isDate(value){
  return toString.apply(value) == '[object Date]';
}


/**
 * @ngdoc function
 * @name angular.isArray
 * @function
 *
 * @description
 * Determines if a reference is an `Array`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is an `Array`.
 */
function isArray(value) {
  return toString.apply(value) == '[object Array]';
}


/**
 * @ngdoc function
 * @name angular.isFunction
 * @function
 *
 * @description
 * Determines if a reference is a `Function`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Function`.
 */
function isFunction(value){return typeof value == 'function';}


/**
 * Checks if `obj` is a window object.
 *
 * @private
 * @param {*} obj Object to check
 * @returns {boolean} True if `obj` is a window obj.
 */
function isWindow(obj) {
  return obj && obj.document && obj.location && obj.alert && obj.setInterval;
}


function isScope(obj) {
  return obj && obj.$evalAsync && obj.$watch;
}


function isFile(obj) {
  return toString.apply(obj) === '[object File]';
}


function isBoolean(value) {
  return typeof value == 'boolean';
}


function trim(value) {
  return isString(value) ? value.replace(/^\s*/, '').replace(/\s*$/, '') : value;
}

/**
 * @ngdoc function
 * @name angular.isElement
 * @function
 *
 * @description
 * Determines if a reference is a DOM element (or wrapped jQuery element).
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a DOM element (or wrapped jQuery element).
 */
function isElement(node) {
  return node &&
    (node.nodeName  // we are a direct element
    || (node.bind && node.find));  // we have a bind and find method part of jQuery API
}

/**
 * @param str 'key1,key2,...'
 * @returns {object} in the form of {key1:true, key2:true, ...}
 */
function makeMap(str){
  var obj = {}, items = str.split(","), i;
  for ( i = 0; i < items.length; i++ )
    obj[ items[i] ] = true;
  return obj;
}


if (msie < 9) {
  nodeName_ = function(element) {
    element = element.nodeName ? element : element[0];
    return (element.scopeName && element.scopeName != 'HTML')
      ? uppercase(element.scopeName + ':' + element.nodeName) : element.nodeName;
  };
} else {
  nodeName_ = function(element) {
    return element.nodeName ? element.nodeName : element[0].nodeName;
  };
}


function map(obj, iterator, context) {
  var results = [];
  forEach(obj, function(value, index, list) {
    results.push(iterator.call(context, value, index, list));
  });
  return results;
}


/**
 * @description
 * Determines the number of elements in an array, the number of properties an object has, or
 * the length of a string.
 *
 * Note: This function is used to augment the Object type in Angular expressions. See
 * {@link angular.Object} for more information about Angular arrays.
 *
 * @param {Object|Array|string} obj Object, array, or string to inspect.
 * @param {boolean} [ownPropsOnly=false] Count only "own" properties in an object
 * @returns {number} The size of `obj` or `0` if `obj` is neither an object nor an array.
 */
function size(obj, ownPropsOnly) {
  var size = 0, key;

  if (isArray(obj) || isString(obj)) {
    return obj.length;
  } else if (isObject(obj)){
    for (key in obj)
      if (!ownPropsOnly || obj.hasOwnProperty(key))
        size++;
  }

  return size;
}


function includes(array, obj) {
  return indexOf(array, obj) != -1;
}

function indexOf(array, obj) {
  if (array.indexOf) return array.indexOf(obj);

  for ( var i = 0; i < array.length; i++) {
    if (obj === array[i]) return i;
  }
  return -1;
}

function arrayRemove(array, value) {
  var index = indexOf(array, value);
  if (index >=0)
    array.splice(index, 1);
  return value;
}

function isLeafNode (node) {
  if (node) {
    switch (node.nodeName) {
    case "OPTION":
    case "PRE":
    case "TITLE":
      return true;
    }
  }
  return false;
}

/**
 * @ngdoc function
 * @name angular.copy
 * @function
 *
 * @description
 * Creates a deep copy of `source`, which should be an object or an array.
 *
 * * If no destination is supplied, a copy of the object or array is created.
 * * If a destination is provided, all of its elements (for array) or properties (for objects)
 *   are deleted and then all elements/properties from the source are copied to it.
 * * If  `source` is not an object or array, `source` is returned.
 *
 * Note: this function is used to augment the Object type in Angular expressions. See
 * {@link angular.module.ng.$filter} for more information about Angular arrays.
 *
 * @param {*} source The source that will be used to make a copy.
 *                   Can be any type, including primitives, `null`, and `undefined`.
 * @param {(Object|Array)=} destination Destination into which the source is copied. If
 *     provided, must be of the same type as `source`.
 * @returns {*} The copy or updated `destination`, if `destination` was specified.
 */
function copy(source, destination){
  if (isWindow(source) || isScope(source)) throw Error("Can't copy Window or Scope");
  if (!destination) {
    destination = source;
    if (source) {
      if (isArray(source)) {
        destination = copy(source, []);
      } else if (isDate(source)) {
        destination = new Date(source.getTime());
      } else if (isObject(source)) {
        destination = copy(source, {});
      }
    }
  } else {
    if (source === destination) throw Error("Can't copy equivalent objects or arrays");
    if (isArray(source)) {
      while(destination.length) {
        destination.pop();
      }
      for ( var i = 0; i < source.length; i++) {
        destination.push(copy(source[i]));
      }
    } else {
      forEach(destination, function(value, key){
        delete destination[key];
      });
      for ( var key in source) {
        destination[key] = copy(source[key]);
      }
    }
  }
  return destination;
}

/**
 * Create a shallow copy of an object
 */
function shallowCopy(src, dst) {
  dst = dst || {};

  for(var key in src) {
    if (src.hasOwnProperty(key) && key.substr(0, 2) !== '$$') {
      dst[key] = src[key];
    }
  }

  return dst;
}


/**
 * @ngdoc function
 * @name angular.equals
 * @function
 *
 * @description
 * Determines if two objects or two values are equivalent. Supports value types, arrays and
 * objects.
 *
 * Two objects or values are considered equivalent if at least one of the following is true:
 *
 * * Both objects or values pass `===` comparison.
 * * Both objects or values are of the same type and all of their properties pass `===` comparison.
 * * Both values are NaN. (In JavasScript, NaN == NaN => false. But we consider two NaN as equal)
 *
 * During a property comparision, properties of `function` type and properties with names
 * that begin with `$` are ignored.
 *
 * Scope and DOMWindow objects are being compared only be identify (`===`).
 *
 * @param {*} o1 Object or value to compare.
 * @param {*} o2 Object or value to compare.
 * @returns {boolean} True if arguments are equal.
 */
function equals(o1, o2) {
  if (o1 === o2) return true;
  if (o1 === null || o2 === null) return false;
  if (o1 !== o1 && o2 !== o2) return true; // NaN === NaN
  var t1 = typeof o1, t2 = typeof o2, length, key, keySet;
  if (t1 == t2) {
    if (t1 == 'object') {
      if (isArray(o1)) {
        if ((length = o1.length) == o2.length) {
          for(key=0; key<length; key++) {
            if (!equals(o1[key], o2[key])) return false;
          }
          return true;
        }
      } else if (isDate(o1)) {
        return isDate(o2) && o1.getTime() == o2.getTime();
      } else {
        if (isScope(o1) || isScope(o2) || isWindow(o1) || isWindow(o2)) return false;
        keySet = {};
        for(key in o1) {
          if (key.charAt(0) !== '$' && !isFunction(o1[key]) && !equals(o1[key], o2[key])) {
            return false;
          }
          keySet[key] = true;
        }
        for(key in o2) {
          if (!keySet[key] && key.charAt(0) !== '$' && !isFunction(o2[key])) return false;
        }
        return true;
      }
    }
  }
  return false;
}


function concat(array1, array2, index) {
  return array1.concat(slice.call(array2, index));
}

function sliceArgs(args, startIndex) {
  return slice.call(args, startIndex || 0);
}


/**
 * @ngdoc function
 * @name angular.bind
 * @function
 *
 * @description
 * Returns a function which calls function `fn` bound to `self` (`self` becomes the `this` for
 * `fn`). You can supply optional `args` that are are prebound to the function. This feature is also
 * known as [function currying](http://en.wikipedia.org/wiki/Currying).
 *
 * @param {Object} self Context which `fn` should be evaluated in.
 * @param {function()} fn Function to be bound.
 * @param {...*} args Optional arguments to be prebound to the `fn` function call.
 * @returns {function()} Function that wraps the `fn` with all the specified bindings.
 */
function bind(self, fn) {
  var curryArgs = arguments.length > 2 ? sliceArgs(arguments, 2) : [];
  if (isFunction(fn) && !(fn instanceof RegExp)) {
    return curryArgs.length
      ? function() {
          return arguments.length
            ? fn.apply(self, curryArgs.concat(slice.call(arguments, 0)))
            : fn.apply(self, curryArgs);
        }
      : function() {
          return arguments.length
            ? fn.apply(self, arguments)
            : fn.call(self);
        };
  } else {
    // in IE, native methods are not functions so they cannot be bound (note: they don't need to be)
    return fn;
  }
}


function toJsonReplacer(key, value) {
  var val = value;

  if (/^\$+/.test(key)) {
    val = undefined;
  } else if (isWindow(value)) {
    val = '$WINDOW';
  } else if (value &&  document === value) {
    val = '$DOCUMENT';
  } else if (isScope(value)) {
    val = '$SCOPE';
  }

  return val;
}


/**
 * @ngdoc function
 * @name angular.toJson
 * @function
 *
 * @description
 * Serializes input into a JSON-formatted string.
 *
 * @param {Object|Array|Date|string|number} obj Input to be serialized into JSON.
 * @param {boolean=} pretty If set to true, the JSON output will contain newlines and whitespace.
 * @returns {string} Jsonified string representing `obj`.
 */
function toJson(obj, pretty) {
  return JSON.stringify(obj, toJsonReplacer, pretty ? '  ' : null);
}


/**
 * @ngdoc function
 * @name angular.fromJson
 * @function
 *
 * @description
 * Deserializes a JSON string.
 *
 * @param {string} json JSON string to deserialize.
 * @returns {Object|Array|Date|string|number} Deserialized thingy.
 */
function fromJson(json) {
  return isString(json)
      ? JSON.parse(json)
      : json;
}


function toBoolean(value) {
  if (value && value.length !== 0) {
    var v = lowercase("" + value);
    value = !(v == 'f' || v == '0' || v == 'false' || v == 'no' || v == 'n' || v == '[]');
  } else {
    value = false;
  }
  return value;
}

/**
 * @returns {string} Returns the string representation of the element.
 */
function startingTag(element) {
  element = jqLite(element).clone();
  try {
    // turns out IE does not let you set .html() on elements which
    // are not allowed to have children. So we just ignore it.
    element.html('');
  } catch(e) {}
  return jqLite('<div>').append(element).html().match(/^(<[^>]+>)/)[1];
}


/////////////////////////////////////////////////

/**
 * Parses an escaped url query string into key-value pairs.
 * @returns Object.<(string|boolean)>
 */
function parseKeyValue(/**string*/keyValue) {
  var obj = {}, key_value, key;
  forEach((keyValue || "").split('&'), function(keyValue){
    if (keyValue) {
      key_value = keyValue.split('=');
      key = decodeURIComponent(key_value[0]);
      obj[key] = isDefined(key_value[1]) ? decodeURIComponent(key_value[1]) : true;
    }
  });
  return obj;
}

function toKeyValue(obj) {
  var parts = [];
  forEach(obj, function(value, key) {
    parts.push(encodeUriQuery(key, true) + (value === true ? '' : '=' + encodeUriQuery(value, true)));
  });
  return parts.length ? parts.join('&') : '';
}


/**
 * We need our custom mehtod because encodeURIComponent is too agressive and doesn't follow
 * http://www.ietf.org/rfc/rfc3986.txt with regards to the character set (pchar) allowed in path
 * segments:
 *    segment       = *pchar
 *    pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
 *    pct-encoded   = "%" HEXDIG HEXDIG
 *    unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
 *    sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
 *                     / "*" / "+" / "," / ";" / "="
 */
function encodeUriSegment(val) {
  return encodeUriQuery(val, true).
             replace(/%26/gi, '&').
             replace(/%3D/gi, '=').
             replace(/%2B/gi, '+');
}


/**
 * This method is intended for encoding *key* or *value* parts of query component. We need a custom
 * method becuase encodeURIComponent is too agressive and encodes stuff that doesn't have to be
 * encoded per http://tools.ietf.org/html/rfc3986:
 *    query       = *( pchar / "/" / "?" )
 *    pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
 *    unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
 *    pct-encoded   = "%" HEXDIG HEXDIG
 *    sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
 *                     / "*" / "+" / "," / ";" / "="
 */
function encodeUriQuery(val, pctEncodeSpaces) {
  return encodeURIComponent(val).
             replace(/%40/gi, '@').
             replace(/%3A/gi, ':').
             replace(/%24/g, '$').
             replace(/%2C/gi, ',').
             replace((pctEncodeSpaces ? null : /%20/g), '+');
}


/**
 * @ngdoc directive
 * @name angular.module.ng.$compileProvider.directive.ngApp
 *
 * @element ANY
 * @param {angular.Module} ngApp on optional application
 *   {@link angular.module module} name to load.
 *
 * @description
 *
 * Use this directive to auto-bootstrap on application. Only
 * one directive can be used per HTML document. The directive
 * designates the root of the application and is typically placed
 * ot the root of the page.
 *
 * In the example below if the `ngApp` directive would not be placed
 * on the `html` element then the document would not be compiled
 * and the `{{ 1+2 }}` would not be resolved to `3`.
 *
 * `ngApp` is the easiest way to bootstrap an application.
 *
 <doc:example>
   <doc:source>
    I can add: 1 + 2 =  {{ 1+2 }}
   </doc:source>
 </doc:example>
 *
 */
function angularInit(element, bootstrap) {
  var elements = [element],
      appElement,
      module,
      names = ['ng:app', 'ng-app', 'x-ng-app', 'data-ng-app'],
      NG_APP_CLASS_REGEXP = /\sng[:\-]app(:\s*([\w\d_]+);?)?\s/;

  function append(element) {
    element && elements.push(element);
  }

  forEach(names, function(name) {
    names[name] = true;
    append(document.getElementById(name));
    name = name.replace(':', '\\:');
    if (element.querySelectorAll) {
      forEach(element.querySelectorAll('.' + name), append);
      forEach(element.querySelectorAll('.' + name + '\\:'), append);
      forEach(element.querySelectorAll('[' + name + ']'), append);
    }
  });

  forEach(elements, function(element) {
    if (!appElement) {
      var className = ' ' + element.className + ' ';
      var match = NG_APP_CLASS_REGEXP.exec(className);
      if (match) {
        appElement = element;
        module = (match[2] || '').replace(/\s+/g, ',');
      } else {
        forEach(element.attributes, function(attr) {
          if (!appElement && names[attr.name]) {
            appElement = element;
            module = attr.value;
          }
        });
      }
    }
  });
  if (appElement) {
    bootstrap(appElement, module ? [module] : []);
  }
}

/**
 * @ngdoc function
 * @name angular.bootstrap
 * @description
 * Use this function to manually start up angular application.
 *
 * See: {@link guide/dev_guide.bootstrap.manual_bootstrap Bootstrap}
 *
 * @param {Element} element DOM element which is the root of angular application.
 * @param {Array<String|Function>=} modules an array of module declarations. See: {@link angular.module modules}
 * @returns {angular.module.auto.$injector} Returns the newly created injector for this app.
 */
function bootstrap(element, modules) {
  element = jqLite(element);
  modules = modules || [];
  modules.unshift(['$provide', function($provide) {
    $provide.value('$rootElement', element);
  }]);
  modules.unshift('ng');
  var injector = createInjector(modules);
  injector.invoke(
    ['$rootScope', '$rootElement', '$compile', '$injector', function(scope, element, compile, injector){
      scope.$apply(function() {
        element.data('$injector', injector);
        compile(element)(scope);
      });
    }]
  );
  return injector;
}

var SNAKE_CASE_REGEXP = /[A-Z]/g;
function snake_case(name, separator){
  separator = separator || '_';
  return name.replace(SNAKE_CASE_REGEXP, function(letter, pos) {
    return (pos ? separator : '') + letter.toLowerCase();
  });
}

function bindJQuery() {
  // bind to jQuery if present;
  jQuery = window.jQuery;
  // reset to jQuery or default to us.
  if (jQuery) {
    jqLite = jQuery;
    extend(jQuery.fn, {
      scope: JQLitePrototype.scope,
      controller: JQLitePrototype.controller,
      injector: JQLitePrototype.injector,
      inheritedData: JQLitePrototype.inheritedData
    });
    JQLitePatchJQueryRemove('remove', true);
    JQLitePatchJQueryRemove('empty');
    JQLitePatchJQueryRemove('html');
  } else {
    jqLite = JQLite;
  }
  angular.element = jqLite;
}

/**
 * throw error of the argument is falsy.
 */
function assertArg(arg, name, reason) {
  if (!arg) {
    throw new Error("Argument '" + (name || '?') + "' is " + (reason || "required"));
  }
  return arg;
}

function assertArgFn(arg, name, acceptArrayAnnotation) {
  if (acceptArrayAnnotation && isArray(arg)) {
      arg = arg[arg.length - 1];
  }

  assertArg(isFunction(arg), name, 'not a function, got ' +
      (arg && typeof arg == 'object' ? arg.constructor.name || 'Object' : typeof arg));
  return arg;
}