-- Haskell types to support the language tags

module Types where 

type Language = String 
type Extlang = Maybe String -- Only one extlang authorized
type Script = Maybe String
type Region = Maybe String
type Singleton = Char
type Variants = [Variant]
type Variant = String
type Extension = (Singleton, [String])
type Extensions = [Extension]

type Grandfathered = String
type Privateuse = [String]

data Tag = Tag Language Extlang Script Region Variants Extensions | GF Grandfathered | Priv Privateuse deriving (Show, Eq) 
-- TODO: warning, Eq must 
-- be redefined because it needs to take into account case-insensitivity and 
-- (maybe) canonicalization