Hi, Thomas Schilling wrote:
I agree that the language standard should not prescribe the implementation of a Text datatype. It should instead require an abstract data type (which may just be a newtype wrapper for [Char] in some implementations) and a (minimal) set of operations on it.
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.
Is this still a problem if String would be replaced by an implementation-dependend newtype? Presumably, GHC would use a more efficient representation behind the newtype, so the following would be efficient in practice (or not?) newtype String = ... class IsString a where fromString :: String -> a The standard could even prescribe that an instance for [Char] exists: explode :: String -> [Char] explode = ... instance IsString [Char] where fromString = explode Tillmann