module Casui.Name where

import Casui.Utils

import Data.Unique
import Data.List

type Symbol = String


class HasName t where
  nameOf :: t -> Name
  
instance HasName Name where
  nameOf = id

instance HasName FullName where
  nameOf (FullName Builtin l) = Name $ "builtin" : l
  nameOf (FullName _ l) = Name $ l

matchName :: Name -> FullName -> Bool
matchName (Name n) (FullName i fn) =
  case dropSame (reverse n) (reverse fn) of
    ([], _) -> True
    (["builtin"],[]) -> i == Builtin
    _otherwise -> False

data Name = Name [Symbol]
          deriving Eq

data FullName = FullName FileId [Symbol]
              deriving Eq

data FileId = Builtin | Lexical | FileId Unique
                 deriving Eq

instance Show Name where
  show (Name l) = (concat $ intersperse ":" l)
                                         
instance Show FullName where
  show (FullName i l) = concat $ intersperse ":" $ if show i == "" then l else show i : l

instance Show FileId where
  show Builtin = "builtin"
  show Lexical = "lexical"
  show (FileId i) = "#e" ++ show (hashUnique i)

instance FName Name where
  fullName e s = Name $ show e : splitChar ':' s
  
instance FName FullName where
  fullName i s = FullName i $ splitChar ':' s

builtin :: FName n => String -> n
builtin s = fullName Builtin s

class (Eq n, Show n) => FName n where
  fullName :: FileId -> String -> n

mkName :: String -> Name
mkName = Name . splitChar ':'


catNames :: Name -> Name -> Name
catNames (Name a) (Name b) = Name $ a ++ b