[project @ 2005-02-05 00:41:35 by ross]

[ghc-base.git] / Data / Version.hs

diff --git a/Data/Version.hs b/Data/Version.hs
index 959baf7..c52d21c 100644 (file)
--- a/Data/Version.hs
+++ b/Data/Version.hs
@@ -6,7 +6,7 @@
 -- 
 -- Maintainer  :  libraries@haskell.org
 -- Stability   :  experimental
--- Portability :  portable
+-- Portability :  non-portable (local universal quantification in ReadP)
 --
 -- A general library for representation and manipulation of versions.
 -- 
@@ -30,8 +30,27 @@ module Data.Version (
        showVersion, parseVersion,
   ) where
 
+import Prelude -- necessary to get dependencies right
+
+-- These #ifdefs are necessary because this code might be compiled as
+-- part of ghc/lib/compat, and hence might be compiled by an older version
+-- of GHC.  In which case, we might need to pick up ReadP from 
+-- Distribution.Compat.ReadP, because the version in 
+-- Text.ParserCombinators.ReadP doesn't have all the combinators we need.
+#if __GLASGOW_HASKELL__ >= 603 || __HUGS__ || __NHC__
 import Text.ParserCombinators.ReadP
+#else
+import Distribution.Compat.ReadP
+#endif
+
+#if !__GLASGOW_HASKELL__
+import Data.Typeable   ( Typeable, TyCon, mkTyCon, mkTyConApp )
+#elif __GLASGOW_HASKELL__ < 602
+import Data.Dynamic    ( Typeable(..), TyCon, mkTyCon, mkAppTy )
+#else
 import Data.Typeable   ( Typeable )
+#endif
+
 import Data.List       ( intersperse )
 import Control.Monad   ( liftM )
 import Data.Char       ( isDigit, isAlphaNum )
@@ -47,7 +66,7 @@ ordering on the 'versionBranch' fields (i.e. 2.1 > 2.0, 1.2.3 > 1.2.2,
 etc.).  This is expected to be sufficient for many uses, but note that
 you may need to use a more specific ordering for your versioning
 scheme.  For example, some versioning schemes may include pre-releases
-which have tags @"pre1"@, @"pre2"@, and so on, and these would need to
+which have tags @\"pre1\"@, @\"pre2\"@, and so on, and these would need to
 be taken into account when determining ordering.  In some cases, date
 ordering may be more appropriate, so the application would have to
 look for @date@ tags in the 'versionTags' field and compare those.
@@ -79,7 +98,25 @@ data Version =
                -- The interpretation of the list of tags is entirely dependent
                -- on the entity that this version applies to.
        }
-  deriving (Read,Show,Typeable)
+  deriving (Read,Show
+#if __GLASGOW_HASKELL__ >= 602
+       ,Typeable
+#endif
+       )
+
+#if !__GLASGOW_HASKELL__
+versionTc :: TyCon
+versionTc = mkTyCon "Version"
+
+instance Typeable Version where
+  typeOf _ = mkTyConApp versionTc []
+#elif __GLASGOW_HASKELL__ < 602
+versionTc :: TyCon
+versionTc = mkTyCon "Version"
+
+instance Typeable Version where
+  typeOf _ = mkAppTy versionTc []
+#endif
 
 instance Eq Version where
   v1 == v2  =  versionBranch v1 == versionBranch v2 
@@ -94,7 +131,7 @@ instance Ord Version where
 
 -- | Provides one possible concrete representation for 'Version'.  For
 -- a version with 'versionBranch' @= [1,2,3]@ and 'versionTags' 
--- @= ["tag1","tag2"]@, the output will be @1.2.3-tag1-tag2@.
+-- @= [\"tag1\",\"tag2\"]@, the output will be @1.2.3-tag1-tag2@.
 --
 showVersion :: Version -> String
 showVersion (Version branch tags)
@@ -103,7 +140,13 @@ showVersion (Version branch tags)
 
 -- | A parser for versions in the format produced by 'showVersion'.
 --
+#if __GLASGOW_HASKELL__ >= 603 || __HUGS__
 parseVersion :: ReadP Version
+#elif __NHC__
+parseVersion :: ReadPN r Version
+#else
+parseVersion :: ReadP r Version
+#endif
 parseVersion = do branch <- sepBy1 (liftM read $ munch1 isDigit) (char '.')
                   tags   <- many (char '-' >> munch1 isAlphaNum)
                   return Version{versionBranch=branch, versionTags=tags}