Async JavaScript

Kaffeine

Kaffeine is a precompiler that touts itself as “Extended JavaScript.”^[64] Among other features, the language offers a simple syntactic sugar for un-nesting callbacks: just add ! after an async function’s name. Kaffeine assumes that the function takes a callback as its last argument and simply transforms all code after that call into the callback.

For example, in a jQuery application, it’s common to want everything to run from within a $ callback (after the document is ready). With Kaffeine, that’s easily done.

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Although it doesn’t have as big a following as CoffeeScript, features like this make Kaffeine well worth checking out. The CoffeeScript forks Coco and LiveScript ...