1 files changed, 51 insertions, 0 deletions
diff --git a/compiler/GHC/Unit/Module/ModDetails.hs b/compiler/GHC/Unit/Module/ModDetails.hs
new file mode 100644
index 0000000000..31b3bdb9a0
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+++ b/compiler/GHC/Unit/Module/ModDetails.hs
@@ -0,0 +1,51 @@
+module GHC.Unit.Module.ModDetails
+   ( ModDetails (..)
+   , emptyModDetails
+   )
+where
+
+import GHC.Core         ( CoreRule )
+import GHC.Core.FamInstEnv
+import GHC.Core.InstEnv ( ClsInst )
+
+import GHC.Types.Avail
+import GHC.Types.CompleteMatch
+import GHC.Types.TypeEnv
+import GHC.Types.Annotations ( Annotation )
+
+-- | The 'ModDetails' is essentially a cache for information in the 'ModIface'
+-- for home modules only. Information relating to packages will be loaded into
+-- global environments in 'ExternalPackageState'.
+data ModDetails = ModDetails
+   { -- The next two fields are created by the typechecker
+     md_exports   :: [AvailInfo]
+   , md_types     :: !TypeEnv
+      -- ^ Local type environment for this particular module
+      -- Includes Ids, TyCons, PatSyns
+
+   , md_insts     :: ![ClsInst]
+      -- ^ 'DFunId's for the instances in this module
+
+   , md_fam_insts :: ![FamInst]
+   , md_rules     :: ![CoreRule]
+      -- ^ Domain may include 'Id's from other modules
+
+   , md_anns      :: ![Annotation]
+      -- ^ Annotations present in this module: currently
+      -- they only annotate things also declared in this module
+
+   , md_complete_matches :: [CompleteMatch]
+      -- ^ Complete match pragmas for this module
+   }
+
+-- | Constructs an empty ModDetails
+emptyModDetails :: ModDetails
+emptyModDetails = ModDetails
+   { md_types            = emptyTypeEnv
+   , md_exports          = []
+   , md_insts            = []
+   , md_rules            = []
+   , md_fam_insts        = []
+   , md_anns             = []
+   , md_complete_matches = []
+   }