{-
(c) The University of Glasgow 2006
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

\section{Haskell abstract syntax definition}

This module glues together the pieces of the Haskell abstract syntax,
which is declared in the various \tr{Hs*} modules.  This module,
therefore, is almost nothing but re-exporting.
-}

{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE UndecidableInstances #-} -- Wrinkle in Note [Trees That Grow]
                                      -- in module GHC.Hs.Extension
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleInstances #-} -- For deriving instance Data

module GHC.Hs (
        module GHC.Hs.Binds,
        module GHC.Hs.Decls,
        module GHC.Hs.Expr,
        module GHC.Hs.ImpExp,
        module GHC.Hs.Lit,
        module GHC.Hs.Pat,
        module GHC.Hs.Type,
        module GHC.Hs.Utils,
        module GHC.Hs.Doc,
        module GHC.Hs.Extension,
        Fixity,

        HsModule(..),
) where

-- friends:
import GHC.Prelude

import GHC.Hs.Decls
import GHC.Hs.Binds
import GHC.Hs.Expr
import GHC.Hs.ImpExp
import GHC.Hs.Lit
import GHC.Hs.Extension
import GHC.Hs.Pat
import GHC.Hs.Type
import GHC.Types.Basic ( Fixity, WarningTxt )
import GHC.Hs.Utils
import GHC.Hs.Doc
import GHC.Hs.Instances () -- For Data instances

-- others:
import GHC.Utils.Outputable
import GHC.Types.SrcLoc
import GHC.Unit.Module ( ModuleName )

-- libraries:
import Data.Data hiding ( Fixity )

-- | Haskell Module
--
-- All we actually declare here is the top-level structure for a module.
data HsModule
  = HsModule {
      HsModule -> LayoutInfo
hsmodLayout :: LayoutInfo,
        -- ^ Layout info for the module.
        -- For incomplete modules (e.g. the output of parseHeader), it is NoLayoutInfo.
      HsModule -> Maybe (Located ModuleName)
hsmodName :: Maybe (Located ModuleName),
        -- ^ @Nothing@: \"module X where\" is omitted (in which case the next
        --     field is Nothing too)
      HsModule -> Maybe (Located [LIE GhcPs])
hsmodExports :: Maybe (Located [LIE GhcPs]),
        -- ^ Export list
        --
        --  - @Nothing@: export list omitted, so export everything
        --
        --  - @Just []@: export /nothing/
        --
        --  - @Just [...]@: as you would expect...
        --
        --
        --  - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen'
        --                                   ,'GHC.Parser.Annotation.AnnClose'

        -- For details on above see note [Api annotations] in GHC.Parser.Annotation
      HsModule -> [LImportDecl GhcPs]
hsmodImports :: [LImportDecl GhcPs],
        -- ^ We snaffle interesting stuff out of the imported interfaces early
        -- on, adding that info to TyDecls/etc; so this list is often empty,
        -- downstream.
      HsModule -> [LHsDecl GhcPs]
hsmodDecls :: [LHsDecl GhcPs],
        -- ^ Type, class, value, and interface signature decls
      HsModule -> Maybe (Located WarningTxt)
hsmodDeprecMessage :: Maybe (Located WarningTxt),
        -- ^ reason\/explanation for warning/deprecation of this module
        --
        --  - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen'
        --                                   ,'GHC.Parser.Annotation.AnnClose'
        --

        -- For details on above see note [Api annotations] in GHC.Parser.Annotation
      HsModule -> Maybe LHsDocString
hsmodHaddockModHeader :: Maybe LHsDocString
        -- ^ Haddock module info and description, unparsed
        --
        --  - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen'
        --                                   ,'GHC.Parser.Annotation.AnnClose'

        -- For details on above see note [Api annotations] in GHC.Parser.Annotation
   }
     -- ^ 'GHC.Parser.Annotation.AnnKeywordId's
     --
     --  - 'GHC.Parser.Annotation.AnnModule','GHC.Parser.Annotation.AnnWhere'
     --
     --  - 'GHC.Parser.Annotation.AnnOpen','GHC.Parser.Annotation.AnnSemi',
     --    'GHC.Parser.Annotation.AnnClose' for explicit braces and semi around
     --    hsmodImports,hsmodDecls if this style is used.

     -- For details on above see note [Api annotations] in GHC.Parser.Annotation

deriving instance Data HsModule

instance Outputable HsModule where

    ppr :: HsModule -> SDoc
ppr (HsModule LayoutInfo
_ Maybe (Located ModuleName)
Nothing Maybe (Located [LIE GhcPs])
_ [LImportDecl GhcPs]
imports [LHsDecl GhcPs]
decls Maybe (Located WarningTxt)
_ Maybe LHsDocString
mbDoc)
      = Maybe LHsDocString -> SDoc
forall t. Outputable t => Maybe t -> SDoc
pp_mb Maybe LHsDocString
mbDoc SDoc -> SDoc -> SDoc
$$ [LImportDecl GhcPs] -> SDoc
forall t. Outputable t => [t] -> SDoc
pp_nonnull [LImportDecl GhcPs]
imports
                    SDoc -> SDoc -> SDoc
$$ [LHsDecl GhcPs] -> SDoc
forall t. Outputable t => [t] -> SDoc
pp_nonnull [LHsDecl GhcPs]
decls

    ppr (HsModule LayoutInfo
_ (Just Located ModuleName
name) Maybe (Located [LIE GhcPs])
exports [LImportDecl GhcPs]
imports [LHsDecl GhcPs]
decls Maybe (Located WarningTxt)
deprec Maybe LHsDocString
mbDoc)
      = [SDoc] -> SDoc
vcat [
            Maybe LHsDocString -> SDoc
forall t. Outputable t => Maybe t -> SDoc
pp_mb Maybe LHsDocString
mbDoc,
            case Maybe (Located [LIE GhcPs])
exports of
              Maybe (Located [LIE GhcPs])
Nothing -> SDoc -> SDoc
pp_header (String -> SDoc
text String
"where")
              Just Located [LIE GhcPs]
es -> [SDoc] -> SDoc
vcat [
                           SDoc -> SDoc
pp_header SDoc
lparen,
                           Int -> SDoc -> SDoc
nest Int
8 ([SDoc] -> SDoc
fsep (SDoc -> [SDoc] -> [SDoc]
punctuate SDoc
comma ((LIE GhcPs -> SDoc) -> [LIE GhcPs] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map LIE GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr (Located [LIE GhcPs] -> [LIE GhcPs]
forall l e. GenLocated l e -> e
unLoc Located [LIE GhcPs]
es)))),
                           Int -> SDoc -> SDoc
nest Int
4 (String -> SDoc
text String
") where")
                          ],
            [LImportDecl GhcPs] -> SDoc
forall t. Outputable t => [t] -> SDoc
pp_nonnull [LImportDecl GhcPs]
imports,
            [LHsDecl GhcPs] -> SDoc
forall t. Outputable t => [t] -> SDoc
pp_nonnull [LHsDecl GhcPs]
decls
          ]
      where
        pp_header :: SDoc -> SDoc
pp_header SDoc
rest = case Maybe (Located WarningTxt)
deprec of
           Maybe (Located WarningTxt)
Nothing -> SDoc
pp_modname SDoc -> SDoc -> SDoc
<+> SDoc
rest
           Just Located WarningTxt
d -> [SDoc] -> SDoc
vcat [ SDoc
pp_modname, Located WarningTxt -> SDoc
forall a. Outputable a => a -> SDoc
ppr Located WarningTxt
d, SDoc
rest ]

        pp_modname :: SDoc
pp_modname = String -> SDoc
text String
"module" SDoc -> SDoc -> SDoc
<+> Located ModuleName -> SDoc
forall a. Outputable a => a -> SDoc
ppr Located ModuleName
name

pp_mb :: Outputable t => Maybe t -> SDoc
pp_mb :: forall t. Outputable t => Maybe t -> SDoc
pp_mb (Just t
x) = t -> SDoc
forall a. Outputable a => a -> SDoc
ppr t
x
pp_mb Maybe t
Nothing  = SDoc
empty

pp_nonnull :: Outputable t => [t] -> SDoc
pp_nonnull :: forall t. Outputable t => [t] -> SDoc
pp_nonnull [] = SDoc
empty
pp_nonnull [t]
xs = [SDoc] -> SDoc
vcat ((t -> SDoc) -> [t] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map t -> SDoc
forall a. Outputable a => a -> SDoc
ppr [t]
xs)