Basic completion in GHCi

This patch adds completion support to GHCi when readline is being
used.  Completion of identifiers (in scope only, but including
qualified identifiers) in expressions is provided.  Also, completion
of commands (:cmd), and special completion for certain commands
(eg. module names for the :module command) are also provided.

1 files changed, 23 insertions, 2 deletions

diff --git a/ghc/compiler/main/GHC.hs b/ghc/compiler/main/GHC.hs
index b5707c7886..6f6b7c8e38 100644
--- a/ghc/compiler/main/GHC.hs
+++ b/ghc/compiler/main/GHC.hs
@@ -62,6 +62,7 @@ module GHC (
 #ifdef GHCI
 	setContext, getContext,	
 	getNamesInScope,
+	getRdrNamesInScope,
 	moduleIsInterpreted,
 	getInfo,
 	exprType,
@@ -83,6 +84,7 @@ module GHC (
 	Name, 
 	nameModule, nameParent_maybe, pprParenSymName, nameSrcLoc,
 	NamedThing(..),
+	RdrName(Qual,Unqual),
 	
 	-- ** Identifiers
 	Id, idType,
@@ -176,7 +178,7 @@ import GHC.Exts		( unsafeCoerce# )
 
 import Packages		( initPackages )
 import NameSet		( NameSet, nameSetToList, elemNameSet )
-import RdrName		( GlobalRdrEnv, GlobalRdrElt(..), RdrName, 
+import RdrName		( GlobalRdrEnv, GlobalRdrElt(..), RdrName(..), 
 			  globalRdrEnvElts )
 import HsSyn
 import Type		( Kind, Type, dropForAlls, PredType, ThetaType,
@@ -199,7 +201,7 @@ import DataCon		( DataCon, dataConWrapId, dataConSig, dataConTyCon,
 			  dataConFieldLabels, dataConStrictMarks, 
 			  dataConIsInfix, isVanillaDataCon )
 import Name		( Name, nameModule, NamedThing(..), nameParent_maybe,
-			  nameSrcLoc )
+			  nameSrcLoc, nameOccName )
 import OccName		( parenSymOcc )
 import NameEnv		( nameEnvElts )
 import InstEnv		( Instance, instanceDFunId, pprInstance, pprInstanceHdr )
@@ -1887,6 +1889,25 @@ getNamesInScope :: Session -> IO [Name]
 getNamesInScope s = withSession s $ \hsc_env -> do
   return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
 
+getRdrNamesInScope :: Session -> IO [RdrName]
+getRdrNamesInScope  s = withSession s $ \hsc_env -> do
+  let env = ic_rn_gbl_env (hsc_IC hsc_env)
+  return (concat (map greToRdrNames (globalRdrEnvElts env)))
+
+-- ToDo: move to RdrName
+greToRdrNames :: GlobalRdrElt -> [RdrName]
+greToRdrNames GRE{ gre_name = name, gre_prov = prov }
+  = case prov of
+     LocalDef -> [unqual]
+     Imported specs -> concat (map do_spec (map is_decl specs))
+  where
+    occ = nameOccName name
+    unqual = Unqual occ
+    do_spec decl_spec
+	| is_qual decl_spec = [qual]
+	| otherwise         = [unqual,qual]
+	where qual = Qual (is_as decl_spec) occ
+
 -- | Parses a string as an identifier, and returns the list of 'Name's that
 -- the identifier can refer to in the current interactive context.
 parseName :: Session -> String -> IO [Name]