[project @ 2005-01-18 12:18:11 by simonpj]

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

diff --git a/ghc/compiler/main/Packages.lhs b/ghc/compiler/main/Packages.lhs
index 081e801..93a8856 100644 (file)
--- a/ghc/compiler/main/Packages.lhs
+++ b/ghc/compiler/main/Packages.lhs
@@ -12,7 +12,8 @@ module Packages (
        extendPackageConfigMap, dumpPackages,
 
        -- * Reading the package config, and processing cmdline args
-       PackageState(..),
+       PackageIdH(..), isHomePackage,
+       PackageState(..), 
        initPackages,
        moduleToPackageConfig,
        getPackageDetails,
@@ -147,12 +148,22 @@ data PackageState = PackageState {
        -- exposed is True if the package exposes that module.
 
   -- The PackageIds of some known packages
-  basePackageId                :: Maybe PackageId,
-  rtsPackageId         :: Maybe PackageId,
-  haskell98PackageId   :: Maybe PackageId,
-  thPackageId          :: Maybe PackageId
+  basePackageId                :: PackageIdH,
+  rtsPackageId         :: PackageIdH,
+  haskell98PackageId   :: PackageIdH,
+  thPackageId          :: PackageIdH
   }
 
+data PackageIdH 
+   = HomePackage               -- The "home" package is the package curently
+                               -- being compiled
+   | ExtPackage PackageId      -- An "external" package is any other package
+
+
+isHomePackage :: PackageIdH -> Bool
+isHomePackage HomePackage    = True
+isHomePackage (ExtPackage _) = False
+
 -- A PackageConfigMap maps a PackageId to a PackageConfig
 type PackageConfigMap = UniqFM PackageConfig
 
@@ -311,12 +322,13 @@ mkPackageState dflags pkg_db = do
   -- Look up some known PackageIds
   --
   let
+       lookupPackageByName :: FastString -> PackageIdH
        lookupPackageByName nm = 
          case [ conf | p <- dep_exposed,
                        Just conf <- [lookupPackage pkg_db p],
                        nm == mkFastString (pkgName (package conf)) ] of
-               []     -> Nothing
-               (p:ps) -> Just (mkPackageId (package p))
+               []     -> HomePackage
+               (p:ps) -> ExtPackage (mkPackageId (package p))
 
        -- Get the PackageIds for some known packages (we know the names,
        -- but we don't know the versions).  Some of these packages might
@@ -329,7 +341,7 @@ mkPackageState dflags pkg_db = do
        -- add base & rts to the explicit packages
        basicLinkedPackages = [basePackageId,rtsPackageId]
        explicit' = addListToUniqSet explicit 
-                       [ p | Just p <- basicLinkedPackages ]
+                       [ p | ExtPackage p <- basicLinkedPackages ]
   --
   -- Close the explicit packages with their dependencies
   --