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authoraarne <aarne@cs.chalmers.se>2008-05-20 11:47:44 +0000
committeraarne <aarne@cs.chalmers.se>2008-05-20 11:47:44 +0000
commit31bf84122b21efb444aa8d055472e166ffb90783 (patch)
tree1f051909336f1534346bcccde8dda59beab02f64 /src-2.9/GF/Infra/PrintClass.hs
parent74f048dcf41de3540778de54dfa7541fa5b39c46 (diff)
moved all old source code to src-2.9 ; src will be for GF 3 development
Diffstat (limited to 'src-2.9/GF/Infra/PrintClass.hs')
-rw-r--r--src-2.9/GF/Infra/PrintClass.hs51
1 files changed, 51 insertions, 0 deletions
diff --git a/src-2.9/GF/Infra/PrintClass.hs b/src-2.9/GF/Infra/PrintClass.hs
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index 000000000..5e94984a6
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+++ b/src-2.9/GF/Infra/PrintClass.hs
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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"