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authoraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
committeraarne <aarne@cs.chalmers.se>2008-06-25 16:54:35 +0000
commite9e80fc389365e24d4300d7d5390c7d833a96c50 (patch)
treef0b58473adaa670bd8fc52ada419d8cad470ee03 /src/GF/Infra/PrintClass.hs
parentb96b36f43de3e2f8b58d5f539daa6f6d47f25870 (diff)
changed names of resource-1.3; added a note on homepage on release
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+module GF.Infra.PrintClass where
+
+import Data.List (intersperse)
+
+class Print a where
+ prt :: a -> String
+ prtList :: [a] -> String
+ prtList as = "[" ++ prtSep "," as ++ "]"
+
+prtSep :: Print a => String -> [a] -> String
+prtSep sep = concat . intersperse sep . map prt
+
+prtBefore :: Print a => String -> [a] -> String
+prtBefore before = prtBeforeAfter before ""
+
+prtAfter :: Print a => String -> [a] -> String
+prtAfter after = prtBeforeAfter "" after
+
+prtBeforeAfter :: Print a => String -> String -> [a] -> String
+prtBeforeAfter before after as = concat [ before ++ prt a ++ after | a <- as ]
+
+prtPairList :: (Print a, Print b) => String -> String -> [(a,b)] -> String
+prtPairList comma sep xys = prtSep sep [ prt x ++ comma ++ prt y | (x,y) <- xys ]
+prIO :: Print a => a -> IO ()
+prIO = putStr . prt
+
+instance Print a => Print [a] where
+ prt = prtList
+
+instance (Print a, Print b) => Print (a, b) where
+ prt (a, b) = "(" ++ prt a ++ "," ++ prt b ++ ")"
+
+instance (Print a, Print b, Print c) => Print (a, b, c) where
+ prt (a, b, c) = "(" ++ prt a ++ "," ++ prt b ++ "," ++ prt c ++ ")"
+
+instance (Print a, Print b, Print c, Print d) => Print (a, b, c, d) where
+ prt (a, b, c, d) = "(" ++ prt a ++ "," ++ prt b ++ "," ++ prt c ++ "," ++ prt d ++ ")"
+
+instance Print Char where
+ prt = return
+ prtList = id
+
+instance Print Int where
+ prt = show
+
+instance Print Integer where
+ prt = show
+
+instance Print a => Print (Maybe a) where
+ prt (Just a) = prt a
+ prt Nothing = "Nothing"