For each for strings

[annevk]

URL could use this, to quote from the source:

<p>For each <var>codePoint</var> in <var>buffer</var>

How we're going to do this depends on the mutable/immutable conversation and whether strings are like lists or have their own list-like generic.

[domenic]

This is IMO a pretty good reason for basing strings on lists, even if that's a little strange otherwise.

[annevk]

I also just found replace on a byte sequence (although that could also end up being a string, if we do decoding earlier on).

[annevk]

But again, we should settle mutable/immutable first: #91.

[tabatkins]

As I argue in https://www.xanthir.com/b4wJ1, strings shouldn't be iterable by default. Not all of the arguments there apply to Infra, but the second one (no right way to iterate a string) absolutely does.

I think it would be fine to define For each code point and For each code unit that works over strings, tho.