24 Jul '16, 2pm

@deech By extension CoffeeScript. For-comprehensions compile to for-loops:

Besides being used as an ordinary programming language, CoffeeScript may also be written in "literate" mode. If you name your file with a .litcoffee extension, you can write it as a Markdown document — a document that also happens to be executable CoffeeScript code. The compiler will treat any indented blocks (Markdown's way of indicating source code) as code, and ignore the rest as comments.

Full article: http://coffeescript.org/#loops