I'm currently adding type annotation to a personnal javascript module, but I'm currently stuck when trying to type function taking a regexp as a parameter, but none of the follwing tries is working :

/** @type {function(RegExp)} */
/** @type {function(regex)} */

I'm only getting :

WARNING - Bad type annotation. Unknown type regexp

What type should I use in the declaration? thanks.

I'm currently adding type annotation to a personnal javascript module, but I'm currently stuck when trying to type function taking a regexp as a parameter, but none of the follwing tries is working :

/** @type {function(RegExp)} */
/** @type {function(regex)} */

I'm only getting :

WARNING - Bad type annotation. Unknown type regexp

What type should I use in the declaration? thanks.

• javascript
• regex
• types
• google-closure-piler
• jsdoc

• The first annotation @type {function(RegExp)} should work. The examples I posted below both checked out okay using the Closure Compiler Service with verbose warnings. – Christopher Peisert Commented Jun 1, 2012 at 19:42
• sounds like you are missing externs. How are you running the piler? – John Commented Jun 2, 2012 at 2:29

2 Answers 2

The RegExp object is annotated for the Closure Compiler in the extern es3.js. Here is an example function that accepts a RegExp object.

/**
 * @param {RegExp} regex A regular expression object.
 * @param {string} text Text to match.
 * @return {string} The first match in text.
 */
var firstMatch = function(regex, text) {
  var match = regex.exec(text);
  return match[1];
};

var text = 'Where art thou?';
var regex = new RegExp('^\\W*(\\w+)\\b', 'g');
var firstWord = firstMatch(regex, text);
alert(firstWord); // displays "Where"

The same function annotated using @type:

/** @type {function(RegExp, string): string} */
var firstMatch = function(regex, text) {
  var match = regex.exec(text);
  return match[1];
};

Default Externs

The Closure Compiler includes default externs such as es3.js, es5.js, and es6.js. These externs files do not normally need to be explicitly specified, unless the following flag is set:

Closure Compiler Application: --use_only_custom_externs=true

Closure Compiler Service UI: @exclude_default_externs true

Closure Compiler Service API: exclude_default_externs=true

Additional Externs

There are additional externs available under contrib/externs that are not included by default. These externs may be specified with the --externs flag.

There's no separate regexp type in JSDoc according to GCC's list of types and regexp themselves have type "object". You can use @typedef to alias "regexp" to "object" if you wish to make your annotations more readable and meaningful. It will also allow to quickly adapt in future if this type is actually added - you will only need to remove or change alias.