Hello Ketil, Friday, February 1, 2008, 4:29:02 PM, you wrote:
may be it's too draconian restriction but i proposed just to use new library in the new code.
For backwards compatibility, I agree it would be preferable to retain the current default implementation, but opinions appear to differ. Whatever.
the problem is not abstract "backward compatibility" but programs that switches from the old lib to the new one. they should get exactly the old services for old names - in order to not rewrite program new programs what need new behavior just need to import new interface which may provide UTF-8 encoding for text files by default
f <- openFile "name" content <- readLine f -- read first line using Latin-1 f' <- withEncoding (lookup content) f str <- readLine f' -- read second line using encoding given on first line
This is clear enough, but for the BOM-dependent decoding, you may have to do the equivalent of having the next call to 'readLine' re-read the first line instead.
it's not a problem - file pointer is retained in f and f' just interprets the bytes it read: f <- openFile "name" bom <- readBytes 4 f -- read first 4 bytes vRewind f f' <- withEncoding (lookup bom) f str <- readLine f' -- read first line using BOM encoding -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com