Support for a block of styles to mixins.

[chriseppstein]

This patch allows passing a ruleset to mixins for placement by the new @children directive. It is useful when abstracting a concept associated with selectors or directives.

[canweriotnow]

Wow... I can already think of multiple use cases for my current project. Awesome!

[nheinrich]

FANTASTIC

[chriseppstein]

Here's a gist where I first explored this concept. some of the comments there might be relevant: https://gist.github.com/407318

In particular, @hagenburger suggested using @content instead of @children.

I like @content but I'm worried that it might get used by the w3c someday.

[smt]

My favorite is @yield, but I would prefer @children over @content.

[doctyper]

Awesome!

In the context of @keyframes, I think it makes more sense to name the feature @content over @children (If I understand the syntax correctly):

@mixin keyframes {
    @-webkit-keyframes {
        @content;
    }

    @-moz-keyframes {
        @content;
    }
}

@include keyframes {
    0% {
        opacity: 1;
    }

    25% {
        opacity: 0.5;
    }

    50% {
        opacity: 0.25;
    }

    75% {
        opacity: 0;
    }
}

@yield is interesting though...

[chriseppstein]

Ah yes, this is a great use for @keyframes!

[nex3]

I think we should go for @content, with the usual assumption that the w3c moves slowly enough that we can migrate the syntax to avoid a conflict should they add support for it.