StructField -> FieldDef ("field definition")
Field -> ExprField ("expression field", not "field expression")
FieldPat -> PatField ("pattern field", not "field pattern")
Also rename visiting and other methods working on them.
Improve suggestion for tuple struct pattern matching errors.
Closes#80174
This change allows numbers to be parsed as field names when pattern matching on structs, which allows us to provide better error messages when tuple structs are matched using a struct pattern.
r? ``@estebank``
Along the way, we also implement a handful of diagnostics improvements
and fixes, particularly with respect to the special handling of `||` in
place of `|` and when there are leading verts in function params, which
don't allow top-level or-patterns anyway.
This is a pure refactoring split out from #80689.
It represents the most invasive part of that PR, requiring changes in
every caller of `parse_outer_attributes`
In order to eagerly expand `#[cfg]` attributes while preserving the
original `TokenStream`, we need to know the range of tokens that
corresponds to every attribute target. This is accomplished by making
`parse_outer_attributes` return an opaque `AttrWrapper` struct. An
`AttrWrapper` must be converted to a plain `AttrVec` by passing it to
`collect_tokens_trailing_token`. This makes it difficult to accidentally
construct an AST node with attributes without calling `collect_tokens_trailing_token`,
since AST nodes store an `AttrVec`, not an `AttrWrapper`.
As a result, we now call `collect_tokens_trailing_token` for attribute
targets which only support inert attributes, such as generic arguments
and struct fields. Currently, the constructed `LazyTokenStream` is
simply discarded. Future PRs will record the token range corresponding
to the attribute target, allowing those tokens to be removed from an
enclosing `collect_tokens_trailing_token` call if necessary.
Currently, when a user uses a struct pattern to pattern match on
a tuple struct, the errors we emit generally suggest adding fields
using their field names, which are numbers. However, numbers are
not valid identifiers, so the suggestions, which use the shorthand
notation, are not valid syntax. This commit changes those errors
to suggest using the actual tuple struct pattern syntax instead,
which is a more actionable suggestion.
