mixin foo
mixin pet(name)

+foo
+pet('cat')

----------------------------------------------------

[
	["mixin", [
		["keyword", "mixin"],
		["function", "foo"]
	]],
	["mixin", [
		["keyword", "mixin"],
		["function", "pet"],
		["punctuation", "("],
		"name",
		["punctuation", ")"]
	]],

	["mixin", [
		["name", "+foo"]
	]],
	["mixin", [
		["name", "+pet"],
		["punctuation", "("],
		["string", "'cat'"],
		["punctuation", ")"]
	]]
]

----------------------------------------------------

Checks for mixins declaration and usage.