On Fri, May 15, 2009 at 4:02 AM, Simon Marlow
We ought to think about the interaction between text (and bytestring) and the new Unicode IO library. What does text have in the way of IO operations?
Nothing. It has pure functions for transcoding to/from ByteString. Those functions aren't general enough, since they throw errors if an encoding problem is encountered. We'll need to provide alternatives that require an error handler as a parameter, so that you can do nothing, throw an error, or provide a substitution character instead.
I've been wondering about what bytestring's hGetLine should do. Right now I have it doing decoding and then taking the low 8 bits, but that's not right. OTOH, looking for '\n' in a stream of bytes doesn't seem right. Maybe it should just be deprecated.
It should be deprecated once there's something sensible to replace it with. Note that "something sensible" isn't necessarily straightforward; Unicode specifies 7 different code point sequences as newline equivalents (LF, CR, CR+LF, NEL, FF, PS, LS).