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|
----------------------------------------------------------------------
-- |
-- Module : PrintParser
-- Maintainer : PL
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/04/21 16:23:16 $
-- > CVS $Author: bringert $
-- > CVS $Revision: 1.3 $
--
-- Pretty-printing of parser objects
-----------------------------------------------------------------------------
module GF.Printing.PrintParser (Print(..),
prtBefore, prtAfter, prtSep,
prtBeforeAfter,
prIO
) where
-- haskell modules:
import Data.List (intersperse)
-- gf modules:
import GF.Data.Operations (Err(..))
import GF.Infra.Ident (Ident(..))
import qualified GF.Canon.PrintGFC as P
------------------------------------------------------------
prtBefore :: Print a => String -> [a] -> String
prtBefore before = prtBeforeAfter before ""
prtAfter :: Print a => String -> [a] -> String
prtAfter after = prtBeforeAfter "" after
prtSep :: Print a => String -> [a] -> String
prtSep sep = concat . intersperse sep . map prt
prtBeforeAfter :: Print a => String -> String -> [a] -> String
prtBeforeAfter before after as = concat [ before ++ prt a ++ after | a <- as ]
prIO :: Print a => a -> IO ()
prIO = putStr . prt
class Print a where
prt :: a -> String
prtList :: [a] -> String
prtList as = "[" ++ prtSep "," as ++ "]"
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"
instance Print a => Print (Err a) where
prt (Ok a) = prt a
prt (Bad str) = str
instance Print Ident where
prt ident = str
where str = P.printTree ident
|
