Difference between revisions of "UTF-8"

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(whoops, reuse the same example, why don't we)
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[[Category:Code]]
 
[[Category:Code]]
  
The simplest solution seems to be to use the [http://hackage.haskell.org/cgi-bin/hackage-scripts/package/utf8-string utf8-string package] from Galois.  It provides a drop-in replacement for System.IO
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The simplest solution seems to be to use the [http://hackage.haskell.org/cgi-bin/hackage-scripts/package/utf8-string utf8-string package] from Galois.  It  
 +
provides a drop-in replacement for System.IO
 +
 
 +
== Example ==
 +
 
 +
This example reverses every line in a file (saving the results in the file + ".rev")
 +
 
 +
If we use a function from <code>System.IO.UTF8</code>, we should also hide the equivalent one from the Prelude.  (Alternatively, we could import the UTF8 module qualified)
  
 
<haskell>
 
<haskell>
import System.IO.UTF8
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> import System.IO.UTF8
import Prelude hiding (getContents, putStrLn)
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> import Prelude hiding (readFile)
 +
</haskell>
  
main =
+
<haskell>
  do putStrLn "what is your name? "
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> main :: IO ()
     name <- getContents
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> main =
    putStrLn $ "hello, " ++ name ++ "!"
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> do args <- getArgs
</haskell>
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>     mapM_ reverseUTF8File args
 +
 +
> reverseUTF8File :: FilePath -> IO ()
 +
> reverseUTF8File f =
 +
>  do f <- readFile f
 +
>      writeFile (f ++ ".rev) $ reverseLines f
 +
>  where
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>    reverseLines = unlines . map reverse . lines
 +
<haskell></haskell>

Revision as of 09:28, 21 July 2008


The simplest solution seems to be to use the utf8-string package from Galois. It provides a drop-in replacement for System.IO

Example

This example reverses every line in a file (saving the results in the file + ".rev")

If we use a function from System.IO.UTF8, we should also hide the equivalent one from the Prelude. (Alternatively, we could import the UTF8 module qualified)

> import System.IO.UTF8
> import Prelude hiding (readFile)
> main :: IO ()
> main =
>  do args <- getArgs
>     mapM_ reverseUTF8File args
 
> reverseUTF8File :: FilePath -> IO ()
> reverseUTF8File f =
>   do f <- readFile f
>      writeFile (f ++ ".rev) $ reverseLines f
>   where
>     reverseLines = unlines . map reverse . lines
<haskell>