hsSyn/HsImpExp.lhs

% % (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % HsImpExp: Abstract syntax: imports, exports, interfaces \begin{code}

    {-# LANGUAGE DeriveDataTypeable #-}

    module HsImpExp where

    import Module           ( ModuleName )
    import HsDoc            ( HsDocString )
    import OccName          ( HasOccName(..), isTcOcc, isSymOcc )

    import Outputable
    import FastString
    import SrcLoc

    import Data.Data

\end{code} %************************************************************************ %* * \subsection{Import and export declaration lists} %* * %************************************************************************ One per \tr{import} declaration in a module. \begin{code}

    type LImportDecl name = Located (ImportDecl name)

    -- | A single Haskell @import@ declaration.
    data ImportDecl name
      = ImportDecl {
          ideclName      :: Located ModuleName, -- ^ Module name.
          ideclPkgQual   :: Maybe FastString,   -- ^ Package qualifier.
          ideclSource    :: Bool,               -- ^ True <=> {-# SOURCE #-} import
          ideclSafe      :: Bool,               -- ^ True => safe import
          ideclQualified :: Bool,               -- ^ True => qualified
          ideclImplicit  :: Bool,               -- ^ True => implicit import (of Prelude)
          ideclAs        :: Maybe ModuleName,   -- ^ as Module
          ideclHiding    :: Maybe (Bool, [LIE name]) -- ^ (True => hiding, names)
        } deriving (Data, Typeable)

    simpleImportDecl :: ModuleName -> ImportDecl name
    simpleImportDecl mn = ImportDecl {
          ideclName      = noLoc mn,
          ideclPkgQual   = Nothing,
          ideclSource    = False,
          ideclSafe      = False,
          ideclImplicit  = False,
          ideclQualified = False,
          ideclAs        = Nothing,
          ideclHiding    = Nothing
        }

\end{code} \begin{code}

    instance (OutputableBndr name, HasOccName name) => Outputable (ImportDecl name) where
        ppr (ImportDecl { ideclName = mod', ideclPkgQual = pkg
                        , ideclSource = from, ideclSafe = safe
                        , ideclQualified = qual, ideclImplicit = implicit
                        , ideclAs = as, ideclHiding = spec })
          = hang (hsep [ptext (sLit "import"), ppr_imp from, pp_implicit implicit, pp_safe safe,
                        pp_qual qual, pp_pkg pkg, ppr mod', pp_as as])
                 4 (pp_spec spec)
          where
            pp_implicit False = empty
            pp_implicit True = ptext (sLit ("(implicit)"))

            pp_pkg Nothing  = empty
            pp_pkg (Just p) = doubleQuotes (ftext p)

            pp_qual False   = empty
            pp_qual True    = ptext (sLit "qualified")

            pp_safe False   = empty
            pp_safe True    = ptext (sLit "safe")

            pp_as Nothing   = empty
            pp_as (Just a)  = ptext (sLit "as") <+> ppr a

            ppr_imp True  = ptext (sLit "{-# SOURCE #-}")
            ppr_imp False = empty

            pp_spec Nothing             = empty
            pp_spec (Just (False, ies)) = ppr_ies ies
            pp_spec (Just (True,  ies)) = ptext (sLit "hiding") <+> ppr_ies ies

            ppr_ies []  = ptext (sLit "()")
            ppr_ies ies = char '(' <+> interpp'SP ies <+> char ')'

\end{code} %************************************************************************ %* * \subsection{Imported and exported entities} %* * %************************************************************************ \begin{code}

    type LIE name = Located (IE name)

    -- | Imported or exported entity.
    data IE name
      = IEVar               name
      | IEThingAbs          name             -- ^ Class/Type (can't tell)
      | IEThingAll          name             -- ^ Class/Type plus all methods/constructors
      | IEThingWith         name [name]      -- ^ Class/Type plus some methods/constructors
      | IEModuleContents    ModuleName       -- ^ (Export Only)
      | IEGroup             Int HsDocString  -- ^ Doc section heading
      | IEDoc               HsDocString      -- ^ Some documentation
      | IEDocNamed          String           -- ^ Reference to named doc
      deriving (Eq, Data, Typeable)

\end{code} \begin{code}

    ieName :: IE name -> name
    ieName (IEVar n)         = n
    ieName (IEThingAbs  n)   = n
    ieName (IEThingWith n _) = n
    ieName (IEThingAll  n)   = n
    ieName _ = panic "ieName failed pattern match!"

    ieNames :: IE a -> [a]
    ieNames (IEVar            n   ) = [n]
    ieNames (IEThingAbs       n   ) = [n]
    ieNames (IEThingAll       n   ) = [n]
    ieNames (IEThingWith      n ns) = n : ns
    ieNames (IEModuleContents _   ) = []
    ieNames (IEGroup          _ _ ) = []
    ieNames (IEDoc            _   ) = []
    ieNames (IEDocNamed       _   ) = []

\end{code} \begin{code}

    pprImpExp :: (HasOccName name, OutputableBndr name) => name -> SDoc
    pprImpExp name = type_pref <+> pprPrefixOcc name
        where
        occ = occName name
        type_pref | isTcOcc occ && isSymOcc occ = ptext (sLit "type")
                  | otherwise                   = empty

    instance (HasOccName name, OutputableBndr name) => Outputable (IE name) where
        ppr (IEVar          var)    = pprPrefixOcc var
        ppr (IEThingAbs     thing)  = pprImpExp thing
        ppr (IEThingAll     thing)  = hcat [pprImpExp thing, text "(..)"]
        ppr (IEThingWith thing withs)
            = pprImpExp thing <> parens (fsep (punctuate comma (map pprImpExp withs)))
        ppr (IEModuleContents mod')
            = ptext (sLit "module") <+> ppr mod'
        ppr (IEGroup n _)           = text ("<IEGroup: " ++ (show n) ++ ">")
        ppr (IEDoc doc)             = ppr doc
        ppr (IEDocNamed string)     = text ("<IEDocNamed: " ++ string ++ ">")

\end{code}