Not to my knowledge. C++ and Java are statically typed and they, as far as I know, don't have distinction between string interface and implementation, just a s

Not to my knowledge. C++ and Java are statically typed and they, as far as I know, don't have distinction between string interface and implementation, just a standard string type. You can't make your own string implementation and make others (given that - would it exist - they use standard string interface) transparently accept them instead of language's standard string implementation. Even Haskell (with standard Prelude) doesn't have a readily available and widely accepted typeclass for strings. As String is just an alias to [Char], if library writer used that, they won't accept, say, Data.Text (I know, it's a bit distinct thing, but...)