Refactor the imports of InteractiveContext

Instead of two fields
   ic_toplev_scope :: [Module]
   ic_imports      :: [ImportDecl RdrName]

we now just have one
   ic_imports :: [InteractiveImport]
with the auxiliary data type
   data InteractiveImport
    = IIDecl (ImportDecl RdrName)  -- Bring the exports of a particular module
    	   	       		   -- (filtered by an import decl) into scope

    | IIModule Module	-- Bring into scope the entire top-level envt of
    	     		-- of this module, including the things imported
			-- into it.

This makes lots of code less confusing.  No change in behaviour.
It's preparatory to fixing Trac #5147.

While I was at I also
  * Cleaned up the handling of the "implicit" Prelude import
    by adding a ideclImplicit field to ImportDecl.  This
    significantly reduces plumbing in the handling of
    the implicit Prelude import

  * Used record notation consistently for ImportDecl

1 files changed, 10 insertions, 2 deletions

diff --git a/compiler/hsSyn/HsImpExp.lhs b/compiler/hsSyn/HsImpExp.lhs
index 9dbb4417ae..0f7ad6e678 100644
--- a/compiler/hsSyn/HsImpExp.lhs
+++ b/compiler/hsSyn/HsImpExp.lhs
@@ -38,6 +38,7 @@ data ImportDecl name
       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)
@@ -48,6 +49,7 @@ simpleImportDecl mn = ImportDecl {
       ideclPkgQual   = Nothing,
       ideclSource    = False,
       ideclSafe      = True,
+      ideclImplicit  = False,
       ideclQualified = False,
       ideclAs        = Nothing,
       ideclHiding    = Nothing
@@ -56,11 +58,17 @@ simpleImportDecl mn = ImportDecl {
 
 \begin{code}
 instance (Outputable name) => Outputable (ImportDecl name) where
-    ppr (ImportDecl mod' pkg from safe qual as spec)
-      = hang (hsep [ptext (sLit "import"), ppr_imp from, pp_safe safe,
+    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)