Remove Category.

prototype/Doubt/Category.swift

@@ -1,60 +1,3 @@
-/// A syntactic category to which nodes can belong.
-public enum Category: AlgebraicHashable, Comparable, CustomDebugStringConvertible, CustomJSONConvertible {
-	case Tag(String)
-
-
-	public var tag: String {
-		switch self {
-		case let .Tag(s):
-			return s
-		}
-	}
-
-
-	// MARK: AlgebraicHashable
-
-	public var hash: Hash {
-		return Hash("Tag", Hash(tag))
-	}
-
-
-	// MARK: CustomDebugStringConvertible
-
-	public var debugDescription: String {
-		switch self {
-		case let .Tag(s):
-			return ".Tag(\(s))"
-		}
-	}
-
-
-	// MARK: CustomJSONConvertible
-
-	public var JSON: Doubt.JSON {
-		switch self {
-		case let .Tag(s):
-			return [ "tag": .String(s) ]
-		}
-	}
-}
-
-
-// MARK: - Equatable
-
-public func == (left: Category, right: Category) -> Bool {
-	return left.tag == right.tag
-}
-
-
-// MARK: - Comparable
-
-public func < (left: Category, right: Category) -> Bool {
-	return left.tag < right.tag
-}
-
-
-// MARK: - Categorizable
-
 /// A type whose values belong to a set of categories.
 public protocol Categorizable {
 	typealias Category: Hashable