String != [Char]

[Greg Weber]

> 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.

Actually, inlining is a already a big problem with Text
https://github.com/bos/text/issues/19