On Thu, 2008-02-21 at 13:37 +0100, Johan Tibell wrote:
I would be very happy if people didn't use the .Char8 versions of ByteString except for being able to write byte literals using pack. (I would be even happier if Haskell had byte literals.) If people start using ByteString in their library interfaces instead of String I'll be really miserable because I can't really use their libraries for writing applications that need to be internationalized because their libraries would be limited to ASCII.
Data.ByteString and Data.ByteString.Char8 uses the same ByteString type so I can take some bytes in UTF-32 which I read from the network and use Data.ByteString.Char8 functions on them which will fail. I prefer that a type that represent characters is guarded by encode and decode functions. If that's not the case it's easy to mix data in different encodings by mistake when e.g. writing web applications which involve data in several different encodings.
The intention of allowing both views on one data type was to support the myriad of mixed ascii / binary protocols with a minimum of fuss (there are loads of network protocols like this). The intention was never to support Unicode like String does. That's why we called it Char8, not Char. I do accept that because the Unicode version has not appeared yet people have been tempted to use ByteString for text, which is not appropriate. Duncan