Today the formatter still uses some private APIs
and this commit aims to expose some of them.
In particular, Macro.classify_atom/1 was added to
expose if an atom is an alias, an identifier, quoted,
or unquoted.
Note that the API does not say anything about
operators, since they can fall within three distinct
categories:
* unquoted and callable, such as, `+`, `-`, and
most operators
* unquoted and not callable, such as, `.`, `..`,
and `..//`, which would be ambiguous when used
as `Module.OP()`
* quoted but callable, such as `::`, which is
ambiguous in the atom syntax but not as calls
This information still remains private, especially
because most times operators are used, we often still
want to learn about their precedence too.
We also exposed `inspect_atom/2` with three
distinct clauses to cover the different scenarios
atoms can be inspected at runtime and in source
code.
José Valim
c4527b3ff4