On Mon, Mar 19, 2012 at 8:45 AM, Thomas Schilling
Regarding the type class for converting to and from that type, there is a perhaps more complicated question: The current fromString method uses String as the source type which causes unnecessary overhead. This is unfortunate since GHC's built-in mechanism actually uses unpackCString[Utf8]# which constructs the inefficient String representation from a compact memory representation. I think it would be best if the new fromString/fromText class allowed an efficient mechanism like that. unpackCString# has type Addr# -> [Char] which is obviously GHC-specific.
I've been thinking about this question as well. How about class IsString s where unpackCString :: Ptr Word8 -> CSize -> s It's morally equivalent of unpackCString#, but uses standard Haskell types. -- Johan