-- |

{-# LANGUAGE DeriveDataTypeable #-}

module Language.PureScript.Environment where

import Data.Data

import Data.Maybe (fromMaybe)

import qualified Data.Map as M

import Language.PureScript.Kinds

import Language.PureScript.Names

import Language.PureScript.TypeClassDictionaries

import Language.PureScript.Types

import qualified Language.PureScript.Constants as C

-- |

data Environment = Environment {

-- |

-- Value names currently in scope

--

names :: M.Map (ModuleName, Ident) (Type, NameKind, NameVisibility)

-- |

-- Type names currently in scope

--

, types :: M.Map (Qualified ProperName) (Kind, TypeKind)

-- |

-- Data constructors currently in scope, along with their associated data type constructors

--

, dataConstructors :: M.Map (Qualified ProperName) (DataDeclType, ProperName, Type, [Ident])

-- |

-- Type synonyms currently in scope

--

, typeSynonyms :: M.Map (Qualified ProperName) ([(String, Maybe Kind)], Type)

-- |

-- Available type class dictionaries

--

, typeClassDictionaries :: M.Map (Qualified Ident, Maybe ModuleName) TypeClassDictionaryInScope

-- |

-- Type classes

--

, typeClasses :: M.Map (Qualified ProperName) ([(String, Maybe Kind)], [(Ident, Type)], [Constraint])

} deriving (Show)

-- |

initEnvironment :: Environment

initEnvironment = Environment M.empty primTypes M.empty M.empty M.empty M.empty

-- |

data NameVisibility

-- |

-- The name is defined in the current binding group, but is not visible

--

= Undefined

-- |

-- The name is defined in the another binding group, or has been made visible by a function binder

--

| Defined deriving (Show, Eq)

-- |

data NameKind

-- |

-- A private value introduced as an artifact of code generation (class instances, class member

-- accessors, etc.)

--

= Private

-- |

-- A public value for a module member or foreing import declaration

--

| Public

-- |

-- A name for member introduced by foreign import

--

| External deriving (Show, Eq, Data, Typeable)

-- |

data TypeKind

-- |

-- Data type

--

= DataType [(String, Maybe Kind)] [(ProperName, [Type])]

-- |

-- Type synonym

--

| TypeSynonym

-- |

-- Foreign data

--

| ExternData

-- |

-- A local type variable

--

| LocalTypeVariable

-- |

-- A scoped type variable

--

| ScopedTypeVar

deriving (Show, Eq, Data, Typeable)

-- |

data DataDeclType

-- |

-- A standard data constructor

--

= Data

-- |

-- A newtype constructor

--

| Newtype deriving (Eq, Ord, Data, Typeable)

instance Show DataDeclType where

show Data = "data"

show Newtype = "newtype"

-- |

primName :: String -> Qualified ProperName

primName = Qualified (Just $ ModuleName [ProperName C.prim]) . ProperName

-- |

primTy :: String -> Type

primTy = TypeConstructor . primName

-- |

tyFunction :: Type

tyFunction = primTy "Function"

-- |

tyString :: Type

tyString = primTy "String"

-- |

tyChar :: Type

tyChar = primTy "Char"

-- |

tyNumber :: Type

tyNumber = primTy "Number"

-- |

tyInt :: Type

tyInt = primTy "Int"

-- |

tyBoolean :: Type

tyBoolean = primTy "Boolean"

-- |

tyArray :: Type

tyArray = primTy "Array"

-- |

tyObject :: Type

tyObject = primTy "Object"

-- |

isObject :: Type -> Bool

isObject = (==) tyObject . extract

where extract (TypeApp t _) = t

extract t = t

-- |

function :: Type -> Type -> Type

function t1 = TypeApp (TypeApp tyFunction t1)

-- |

primTypes :: M.Map (Qualified ProperName) (Kind, TypeKind)

primTypes = M.fromList [ (primName "Function" , (FunKind Star (FunKind Star Star), ExternData))

, (primName "Array" , (FunKind Star Star, ExternData))

, (primName "Object" , (FunKind (Row Star) Star, ExternData))

, (primName "String" , (Star, ExternData))

, (primName "Char" , (Star, ExternData))

, (primName "Number" , (Star, ExternData))

, (primName "Int" , (Star, ExternData))

, (primName "Boolean" , (Star, ExternData)) ]

-- |

lookupConstructor :: Environment -> Qualified ProperName -> (DataDeclType, ProperName, Type, [Ident])

lookupConstructor env ctor =

fromMaybe (error "Data constructor not found") $ ctor `M.lookup` dataConstructors env

-- |

isNewtypeConstructor :: Environment -> Qualified ProperName -> Bool

isNewtypeConstructor e ctor = case lookupConstructor e ctor of

(Newtype, _, _, _) -> True

(Data, _, _, _) -> False

-- |

lookupValue :: Environment -> Qualified Ident -> Maybe (Type, NameKind, NameVisibility)

lookupValue env (Qualified (Just mn) ident) = (mn, ident) `M.lookup` names env

lookupValue _ _ = Nothing