This tries to clarify a few things regarding fmt syntax:
- The comment on `Parser::word` seems to be wrong, as that
underscore-prefixed words are just fine. This was changed in
https://github.com/rust-lang/rust/pull/66847.
- I struggled to follow the description of the width argument. It
referred to a "second argument", but I don't know what second argument
it is referring to (which is the first?). Either way, I rewrote the
paragraph to try to be a little more explicit, and to use shorter
sentences.
- The description of the precision argument wasn't really clear about
the distinction of an Nth argument and a named argument. I added
a sentence to try to emphasize the difference.
- `IDENTIFIER_OR_KEYWORD` was changed recently in
https://github.com/rust-lang/reference/pull/2049 to include bare `_`.
But fmt named arguments are not allowed to be a bare `_`.
Eric Huss
9a5aa90516