Cabal-syntax/src/Distribution/Types/Module.hs

   1 {-# LANGUAGE DeriveDataTypeable #-}
   2 {-# LANGUAGE DeriveGeneric #-}
   3 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
   4
   5 module Distribution.Types.Module
   6   ( Module (..)
   7   ) where
   8
   9 import Distribution.Compat.Prelude
  10 import Prelude ()
  11
  12 import qualified Distribution.Compat.CharParsing as P
  13 import Distribution.ModuleName
  14 import Distribution.Parsec
  15 import Distribution.Pretty
  16 import Distribution.Types.UnitId
  17 import qualified Text.PrettyPrint as Disp
  18
  19 -- | A module identity uniquely identifies a Haskell module by
  20 -- qualifying a 'ModuleName' with the 'UnitId' which defined
  21 -- it.  This type distinguishes between two packages
  22 -- which provide a module with the same name, or a module
  23 -- from the same package compiled with different dependencies.
  24 -- There are a few cases where Cabal needs to know about
  25 -- module identities, e.g., when writing out reexported modules in
  26 -- the 'InstalledPackageInfo'.
  27 data Module
  28   = Module DefUnitId ModuleName
  29   deriving (Generic, Read, Show, Eq, Ord, Typeable, Data)
  30
  31 instance Binary Module
  32 instance Structured Module
  33
  34 instance Pretty Module where
  35   pretty (Module uid mod_name) =
  36     pretty uid <<>> Disp.text ":" <<>> pretty mod_name
  37
  38 instance Parsec Module where
  39   parsec = do
  40     uid <- parsec
  41     _ <- P.char ':'
  42     mod_name <- parsec
  43     return (Module uid mod_name)
  44
  45 instance NFData Module where
  46   rnf (Module uid mod_name) = rnf uid `seq` rnf mod_name