Add -XPackageImports, new syntax for package-qualified imports

[ghc-hetmet.git] / compiler / main / Packages.lhs

diff --git a/compiler/main/Packages.lhs b/compiler/main/Packages.lhs
index 3e2c3ef..ace175d 100644 (file)
--- a/compiler/main/Packages.lhs
+++ b/compiler/main/Packages.lhs
@@ -413,11 +413,9 @@ findWiredInPackages dflags pkgs preload this_package = do
                           -> IO (Maybe (PackageIdentifier, PackageId))
        findWiredInPackage pkgs wired_pkg =
            let all_ps = [ p | p <- pkgs, p `matches` wired_pkg ] in
-          case filter exposed all_ps of
-               [] -> case all_ps of
-                        []   -> notfound
-                        many -> pick (head (sortByVersion many))
-               many  -> pick (head (sortByVersion many))
+          case all_ps of
+               []   -> notfound
+               many -> pick (head (sortByVersion many))
           where
                 suffixes = snd wired_pkg
                 notfound = do
@@ -444,9 +442,18 @@ findWiredInPackages dflags pkgs preload this_package = do
   let 
         wired_in_ids = catMaybes mb_wired_in_ids
 
-       deleteOtherWiredInPackages pkgs = filterOut bad pkgs
-         where bad p = any (p `matches`) wired_in_pkgids
-                     && package p `notElem` map fst wired_in_ids
+        -- this is old: we used to assume that if there were
+        -- multiple versions of wired-in packages installed that
+        -- they were mutually exclusive.  Now we're assuming that
+        -- you have one "main" version of each wired-in package
+        -- (the latest version), and the others are backward-compat
+        -- wrappers that depend on this one.  e.g. base-4.0 is the
+        -- latest, base-3.0 is a compat wrapper depending on base-4.0.
+        {-
+       deleteOtherWiredInPackages pkgs = filterOut bad pkgs
+         where bad p = any (p `matches`) wired_in_pkgids
+                      && package p `notElem` map fst wired_in_ids
+        -}
 
        updateWiredInDependencies pkgs = map upd_pkg pkgs
          where upd_pkg p = p{ package = upd_pid (package p),
@@ -457,9 +464,9 @@ findWiredInPackages dflags pkgs preload this_package = do
                                ((x, y):_) -> x{ pkgName = PackageName (packageIdString y),
                                                  pkgVersion = Version [] [] }
 
-        pkgs1 = deleteOtherWiredInPackages pkgs
+        -- pkgs1 = deleteOtherWiredInPackages pkgs
 
-        pkgs2 = updateWiredInDependencies pkgs1
+        pkgs2 = updateWiredInDependencies pkgs
 
         preload1 = map upd_pid preload