On Fri, Mar 23, 2012 at 1:24 PM, Greg Weber
I would really just like for someone to show me how to create a wiki proposal page :)
This proposal doesn't have to break any codebases. One possibility is to add the Text type to the standard while keeping String and marking it as deprecated.
I'm in favour of this. In fact, I'm not sure if I would even deprecate String. I think just adding Text or something Text-like to the standard would be a good step towards encouraging libraries to use it as their first choice. It might, however, be wise to first adopt GHC's OverloadedStrings proposal so that the syntax for using string alternatives is more convenient. I'm inclined to start slow and small: OverloadedStrings is already in use, and makes sense with overloaded numeric literals that we already have, so I think it's reasonable to push for including that in the standard. I don't think that blessing any other string type is going to be very successful *without* OverloadedStrings, and I think that Duncan is right that we want to introduce a new type before removing the old one. With regards to performance of fromString, I feel like if it was a serious problem (and how many really big strings are going to be built that way?) then an effort to do some special-case inlining (after all, the parameters are constant and specified at compile time) might be beneficial. With regards to a general string API, I don't think a typeclass is the correct solution (except for string literals); my view is that things like ListLike may be practical but are awkward to use, and ambiguity problems only make things more upsetting. I think we should just take the abstract Text type and API, and leave implementors to do whatever they want behind that.