Personal tools

UTF-8

From HaskellWiki

(Difference between revisions)
Jump to: navigation, search
(question - what about other string encodings?)
 
(3 intermediate revisions by one user not shown)
Line 1: Line 1:
 
[[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
+
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
 +
 
 +
''What about other string encodings?''
 +
 
 +
== Example ==
 +
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)
 +
 
 +
<haskell>
 +
> import System.IO.UTF8
 +
> import Prelude hiding (readFile, writeFile)
 +
> import System.Environment (getArgs)
 +
</haskell>
 +
 
 +
The readFile and writeFile functions are the same as before...
  
 
<haskell>
 
<haskell>
import System.IO.UTF8
+
> main :: IO ()
import Prelude hiding (getContents, putStrLn)
+
> main =
 +
>  do args <- getArgs
 +
>    mapM_ reverseUTF8File args
  
main =
+
> reverseUTF8File :: FilePath -> IO ()
do putStrLn "what is your name? "
+
> reverseUTF8File f =
    name <- getContents
+
do c <- readFile f
    putStrLn $ "hello, " ++ name ++ "!"
+
>      writeFile (f ++ ".rev") $ reverseLines c
 +
>  where
 +
>    reverseLines = unlines . map reverse . lines
 
</haskell>
 
</haskell>

Latest revision as of 02:22, 22 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

What about other string encodings?

[edit] Example

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, writeFile)
> import System.Environment (getArgs)

The readFile and writeFile functions are the same as before...

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