-- Type specifications for Edoc XML -> Haskell converter.

module Language.Edoc.Xml2Hs.Type where

-- Internal structures to define the Erlang module. They are based on the
-- abovementioned DTD, but for simplification they are hand-coded rather than
-- automatically produced from the DTD. Only few tags are of interest
-- (mainly those related to toplevel typedefs, and argument types), the rest
-- will be skipped.

data EDocMod = EDocMod {
  em_name :: String
 ,em_args :: [String]
 ,em_tdefs :: [ETypeDef]
 ,em_funcs :: [EFunDecl]}
  deriving (Show)

data ErlName = ErlName {
  en_app :: String
 ,en_mod :: String
 ,en_name :: String}
  deriving (Show)

data ETypeDef = ETypeDef {
  td_ename :: ErlName
 ,td_argtypes :: [ErlType]
 ,td_type :: ErlType
 ,td_ldef :: [ELocDef]}
  deriving (Show)

data EFunDecl = EFunDecl {
  ef_name :: String
 ,ef_arity :: Int
 ,ef_args :: [String]
 ,ef_tspec :: [ETypeSpec]}
  deriving (Show)

data ETypeSpec = ETypeSpec {
  ts_ename :: ErlName
 ,ts_type :: ErlType
 ,ts_ldef :: [ELocDef]}
  deriving (Show)

-- Few shortcuts here:
-- 1. Union and Type are not made distinct since they are almost
-- identical. Union just holds a list of unionized types (so
-- there may be nested unions, despite the DTD).
-- 2. In the Localdef definition, the first argument is also ErlType
-- so there might be any type while the DTD says there may be only 
-- Typevar and Abstype.
-- 3. In the Record definition, strings are used where DTD says to use
-- Atoms; basically Strings and Atoms are equivalent in this case.
-- 4. ENothing is to be used when the type element is absent, to avoid
-- wrapping in Maybe.

data ErlType = ETypeVar String
             | EAtom String
             | EInteger Integer
             | EFloat Double
             | ENil
             | EAny
             | ENum
             | EList ErlType
             | ETuple [ErlType]
             | EFun [ErlType] ErlType
             | ERecord String [(String, ErlType)]
             | EAbsType ErlName [ErlType]
             | EUnion [ErlType]
             | ENothing
  deriving (Show)


data ELocDef = ELocDef ErlType ErlType
  deriving (Show)