CoffeeScript 1.9 is Available, Introduces Generators Support
Generators are, in short functions which can be exited and later re-entered, guaranteeing that their variable bindings will be saved across re-entrances. CoffeeScript 1.9 defines a generator as any function that uses the new
yield keyword. This is an example of a simple generator:
foo = -> i = 0 yield i +1 yield i +2
Calling repeated time the generator will provide the yielded values in succession, that is 1, then 2.
Generators are part of the ECMAScript 6 proposal and have been previously introduced in node 0.11, although they are enabled only when you pass the
--harmony-generators flag to node. Generators have been shown to provide an alternative model to callbacks for handling async code, either used in conjunction with promises or not.
Other features provided by CoffeeScript 1.9 are:
- Improved parsing and error reporting for strings and regexs.
- New strategy to generate internal compiler variable names implying that parameters declared as
@parameterare no longer available as
examplewithin the function body.
- Fixed REPL compatibility with latest version of Node and lo.ja.