visionmedia/jade — pull request #608 by chowey (2012-04-25 20:21:57+00:00)
Title: Patch block

Makes `block` function-like. This is useful for pretty printing.

`block`, as a statement in a mixin, renders the block at that point.

`block`, as a variable in a mixin, evaluates to `true` if the block is present, or `null` if the block is not present.

This uses `Function.call(context, args)` instead of `Function(args)` to do its magic. This has no negative performance impact from my tests. It also allows us to make mixin-only keywords in the future (i.e. keywords that evaluate to something dynamically at runtime that are available to mixins).