Reorganisation of the source tree

[ghc-hetmet.git] / compiler / hsSyn / HsImpExp.lhs

diff --git a/compiler/hsSyn/HsImpExp.lhs b/compiler/hsSyn/HsImpExp.lhs
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+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
+%
+\section[HsImpExp]{Abstract syntax: imports, exports, interfaces}
+
+\begin{code}
+module HsImpExp where
+
+#include "HsVersions.h"
+
+import Module          ( Module )
+import Outputable
+import FastString
+import SrcLoc          ( Located(..) )
+import Char            ( isAlpha )
+\end{code}
+
+%************************************************************************
+%*                                                                     *
+\subsection{Import and export declaration lists}
+%*                                                                     *
+%************************************************************************
+
+One per \tr{import} declaration in a module.
+\begin{code}
+type LImportDecl name = Located (ImportDecl name)
+
+data ImportDecl name
+  = ImportDecl   (Located Module)              -- module name
+                 Bool                          -- True <=> {-# SOURCE #-} import
+                 Bool                          -- True => qualified
+                 (Maybe Module)                -- as Module
+                 (Maybe (Bool, [LIE name]))    -- (True => hiding, names)
+\end{code}
+
+\begin{code}
+instance (Outputable name) => Outputable (ImportDecl name) where
+    ppr (ImportDecl mod from qual as spec)
+      = hang (hsep [ptext SLIT("import"), ppr_imp from, 
+                    pp_qual qual, ppr mod, pp_as as])
+            4 (pp_spec spec)
+      where
+       pp_qual False   = empty
+       pp_qual True    = ptext SLIT("qualified")
+
+       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, spec))
+                       = parens (interpp'SP spec)
+       pp_spec (Just (True, spec))
+                       = ptext SLIT("hiding") <+> parens (interpp'SP spec)
+
+ideclName (ImportDecl mod_nm _ _ _ _) = mod_nm
+\end{code}
+
+%************************************************************************
+%*                                                                     *
+\subsection{Imported and exported entities}
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+type LIE name = Located (IE name)
+
+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    Module         -- (Export Only)
+\end{code}
+
+\begin{code}
+ieName :: IE name -> name
+ieName (IEVar n)        = n
+ieName (IEThingAbs  n)   = n
+ieName (IEThingWith n _) = n
+ieName (IEThingAll  n)   = n
+
+ieNames :: IE a -> [a]
+ieNames (IEVar            n   ) = [n]
+ieNames (IEThingAbs       n   ) = [n]
+ieNames (IEThingAll       n   ) = [n]
+ieNames (IEThingWith      n ns) = n:ns
+ieNames (IEModuleContents _   ) = []
+\end{code}
+
+\begin{code}
+instance (Outputable name) => Outputable (IE name) where
+    ppr (IEVar         var)    = pprHsVar var
+    ppr (IEThingAbs    thing)  = ppr thing
+    ppr (IEThingAll    thing)  = hcat [ppr thing, text "(..)"]
+    ppr (IEThingWith thing withs)
+       = ppr thing <> parens (fsep (punctuate comma (map pprHsVar withs)))
+    ppr (IEModuleContents mod)
+       = ptext SLIT("module") <+> ppr mod
+\end{code}
+
+\begin{code}
+pprHsVar :: Outputable name => name -> SDoc
+pprHsVar v | isOperator ppr_v = parens ppr_v
+          | otherwise        = ppr_v
+          where
+            ppr_v = ppr v
+
+isOperator :: SDoc -> Bool
+isOperator ppr_v 
+  = case showSDocUnqual ppr_v of
+       ('(':s)   -> False              -- (), (,) etc
+       ('[':s)   -> False              -- []
+       ('$':c:s) -> not (isAlpha c)    -- Don't treat $d as an operator
+       (':':c:s) -> not (isAlpha c)    -- Don't treat :T as an operator
+       ('_':s)   -> False              -- Not an operator
+       (c:s)     -> not (isAlpha c)    -- Starts with non-alpha
+       other     -> False
+    -- We use (showSDoc (ppr v)), rather than isSymOcc (getOccName v) simply so
+    -- that we don't need NamedThing in the context of all these functions.
+    -- Gruesome, but simple.
+\end{code}
+