[project @ 2004-11-29 16:25:03 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcRnTypes.lhs

diff --git a/ghc/compiler/typecheck/TcRnTypes.lhs b/ghc/compiler/typecheck/TcRnTypes.lhs
index 055a2dd..3b71b1d 100644 (file)
--- a/ghc/compiler/typecheck/TcRnTypes.lhs
+++ b/ghc/compiler/typecheck/TcRnTypes.lhs
@@ -12,7 +12,7 @@ module TcRnTypes(
        IfGblEnv(..), IfLclEnv(..),
 
        -- Ranamer types
-       EntityUsage, emptyUsages, ErrCtxt,
+       ErrCtxt,
        ImportAvails(..), emptyImportAvails, plusImportAvails, 
        plusAvail, pruneAvails,  
        AvailEnv, emptyAvailEnv, unitAvailEnv, plusAvailEnv, 
@@ -56,7 +56,7 @@ import IOEnv
 import RdrName         ( GlobalRdrEnv, LocalRdrEnv )
 import Name            ( Name )
 import NameEnv
-import NameSet         ( NameSet, emptyNameSet, DefUses )
+import NameSet         ( NameSet, unionNameSets, DefUses )
 import OccName         ( OccEnv )
 import Var             ( Id, TyVar )
 import VarEnv          ( TidyEnv )
@@ -408,32 +408,6 @@ type ErrCtxt = [TidyEnv -> TcM (TidyEnv, Message)]
 
 %************************************************************************
 %*                                                                     *
-                       EntityUsage
-%*                                                                     *
-%************************************************************************
-
-EntityUsage tells what things are actually need in order to compile this
-module.  It is used for generating the usage-version field of the ModIface.
-
-Note that we do not record version info for entities from 
-other (non-home) packages.  If the package changes, GHC doesn't help.
-
-\begin{code}
-type EntityUsage = NameSet
-       -- The Names are all the (a) home-package
-       --                       (b) "big" (i.e. no data cons, class ops)
-       --                       (c) non-locally-defined
-       --                       (d) non-wired-in
-       -- names that have been slurped in so far.
-       -- This is used to generate the "usage" information for this module.
-
-emptyUsages :: EntityUsage
-emptyUsages = emptyNameSet
-\end{code}
-
-
-%************************************************************************
-%*                                                                     *
        Operations over ImportAvails
 %*                                                                     *
 %************************************************************************
@@ -449,27 +423,20 @@ It is used        * when processing the export list
 \begin{code}
 data ImportAvails 
    = ImportAvails {
-       imp_env :: AvailEnv,
-               -- All the things that are available from the import
-               -- Its domain is all the "main" things;
-               -- i.e. *excluding* class ops and constructors
-               --      (which appear inside their parent AvailTC)
-
-       imp_qual :: ModuleEnv AvailEnv,
-               -- Used to figure out "module M" export specifiers
+       imp_env :: ModuleEnv NameSet,
+               -- All the things imported, classified by 
+               -- the *module qualifier* for its import
+               --   e.g.        import List as Foo
+               -- would add a binding Foo |-> ...stuff from List...
+               -- to imp_env.
+               -- 
+               -- We need to classify them like this so that we can figure out 
+               -- "module M" export specifiers in an export list 
                -- (see 1.4 Report Section 5.1.1).  Ultimately, we want to find 
                -- everything that is unambiguously in scope as 'M.x'
                -- and where plain 'x' is (perhaps ambiguously) in scope.
                -- So the starting point is all things that are in scope as 'M.x',
                -- which is what this field tells us.
-               --
-               -- Domain is the *module qualifier* for imports.
-               --   e.g.        import List as Foo
-               -- would add a binding Foo |-> ...stuff from List...
-               -- to imp_qual.
-               -- We keep the stuff as an AvailEnv so that it's easy to 
-               -- combine stuff coming from different (unqualified) 
-               -- imports of the same module
 
        imp_mods :: ModuleEnv (Module, Maybe Bool, SrcSpan),
                -- Domain is all directly-imported modules
@@ -515,8 +482,7 @@ mkModDeps deps = foldl add emptyModuleEnv deps
                 add env elt@(m,_) = extendModuleEnv env m elt
 
 emptyImportAvails :: ImportAvails
-emptyImportAvails = ImportAvails { imp_env     = emptyAvailEnv, 
-                                  imp_qual     = emptyModuleEnv, 
+emptyImportAvails = ImportAvails { imp_env     = emptyModuleEnv, 
                                   imp_mods     = emptyModuleEnv,
                                   imp_dep_mods = emptyModuleEnv,
                                   imp_dep_pkgs = [],
@@ -524,12 +490,11 @@ emptyImportAvails = ImportAvails { imp_env        = emptyAvailEnv,
 
 plusImportAvails ::  ImportAvails ->  ImportAvails ->  ImportAvails
 plusImportAvails
-  (ImportAvails { imp_env = env1, imp_qual = unqual1, imp_mods = mods1,
+  (ImportAvails { imp_env = env1, imp_mods = mods1,
                  imp_dep_mods = dmods1, imp_dep_pkgs = dpkgs1, imp_orphs = orphs1 })
-  (ImportAvails { imp_env = env2, imp_qual = unqual2, imp_mods = mods2,
+  (ImportAvails { imp_env = env2, imp_mods = mods2,
                  imp_dep_mods = dmods2, imp_dep_pkgs = dpkgs2, imp_orphs = orphs2 })
-  = ImportAvails { imp_env      = env1 `plusAvailEnv` env2, 
-                  imp_qual     = plusModuleEnv_C plusAvailEnv unqual1 unqual2, 
+  = ImportAvails { imp_env      = plusModuleEnv_C unionNameSets env1 env2, 
                   imp_mods     = mods1  `plusModuleEnv` mods2, 
                   imp_dep_mods = plusModuleEnv_C plus_mod_dep dmods1 dmods2,   
                   imp_dep_pkgs = dpkgs1 `unionLists` dpkgs2,