Suggest removing leading left angle brackets.
Fixes#57819.
This PR adds errors and accompanying suggestions as below:
```
bar::<<<<<T as Foo>::Output>();
^^^ help: remove extra angle brackets
```
r? @estebank
This commit extends existing suggestions to move lifetimes before types
in generic arguments to also suggest moving types behind associated type
bindings.
Add suggestion for incorrect field syntax.
Fixes#57684.
This commit adds a suggestion when a `=` character is used when
specifying the value of a field in a struct constructor incorrectly
instead of a `:` character.
r? @estebank
Remove quote_*! macros
This deletes a considerable amount of test cases, some of which we may want to keep. I'm not entirely certain what the primary intent of many of them was; if we should keep them I can attempt to edit each case to continue compiling without the quote_*! macros involved.
Fixes#46849.
Fixes#12265.
Fixes#12266.
Fixes#26994.
r? @Manishearth
Add error for trailing angle brackets.
Fixes#54521.
This PR adds a error (and accompanying machine applicable
suggestion) for trailing angle brackets on function calls with a
turbofish.
r? @estebank
This commit adds a suggestion when a `=` character is used when
specifying the value of a field in a struct constructor incorrectly
instead of a `:` character.
This commit implements a suggestion from @estebank that optimizes the
use of snapshots.
Instead of creating a snapshot for each recursion in `parse_path_segment`
and then replacing `self` with them until the first invocation where if
leading angle brackets are detected, `self` is not replaced and instead the
snapshot is used to inform how parsing should continue.
Now, a snapshot is created in the first invocation that acts as a backup
of the parser state before any generic arguments are parsed (and
therefore, before recursion starts). This backup replaces `self` if after
all parsing of generic arguments has concluded we can determine that
there are leading angle brackets. Parsing can then proceed from the
backup state making use of the now known number of unmatched leading
angle brackets to recover.
This commit extends the trailing `>` detection to also work for paths
such as `Foo::<Bar>>:Baz`.
This involves making the existing check take the token that is expected
to follow the path being checked as a parameter.
Care is taken to ensure that this only happens on the construction of a
whole path segment and not a partial path segment (during recursion).
Through this enhancement, it was also observed that the ordering of
right shift token and greater than tokens was overfitted to the examples
being tested.
In practice, given a sequence of `>` characters: `>>>>>>>>>`
..then they will be split into `>>` eagerly: `>> >> >> >> >`.
..but when a `<` is prepended, then the first `>>` is split:
`<T> > >> >> >> >`
..and then when another `<` is prepended, a right shift is first again:
`Vec<<T>> >> >> >> >`
In the previous commits, a example that had two `<<` characters was
always used and therefore it was incorrectly assumed that `>>` would
always be first - but when there is a single `<`, this is not the case.
Attempt to recover from parse errors while parsing a struct's literal fields
by skipping tokens until a comma or the closing brace is found. This allows
errors in other fields to be reported.
add applicability to remaining suggestions
Fixes#50723.
I noticed that the suggestion methods on `DiagnosticBuilder` weren't actually deprecated due to #57679. This PR deprecates them properly and fixes the remaining usages.
There's also a PR for clippy at rust-lang/rust-clippy#3667.
Simplify `TokenStream` some more
These commits simplify `TokenStream`, remove `ThinTokenStream`, and avoid some clones. The end result is simpler code and a slight perf win on some benchmarks.
r? @petrochenkov
Modify some parser diagnostics to continue evaluating beyond the parser
Continue evaluating further errors after parser errors on:
- trailing type argument attribute
- lifetime in incorrect location
- incorrect binary literal
- missing `for` in `impl Trait for Foo`
- type argument in `where` clause
- incorrect float literal
- incorrect `..` in pattern
- associated types
- incorrect discriminator value variant error
and others. All of these were found by making `continue-parse-after-error` `true` by default to identify errors that would need few changes. There are now only a handful of errors that have any change with `continue-parse-after-error` enabled.
These changes make it so `rust` _won't_ stop evaluation after finishing parsing, enabling type checking errors to be displayed on the existing code without having to fix the parse errors.
Each commit has an individual diagnostic change with their corresponding tests.
CC #48724.
Make `TokenStream` less recursive.
`TokenStream` is currently recursive in *two* ways:
- the `TokenTree` variant contains a `ThinTokenStream`, which can
contain a `TokenStream`;
- the `TokenStream` variant contains a `Vec<TokenStream>`.
The latter is not necessary and causes significant complexity. This
commit replaces it with the simpler `Vec<(TokenTree, IsJoint)>`.
This reduces complexity significantly. In particular, `StreamCursor` is
eliminated, and `Cursor` becomes much simpler, consisting now of just a
`TokenStream` and an index.
The commit also removes the `Extend` impl for `TokenStream`, because it
is only used in tests. (The commit also removes those tests.)
Overall, the commit reduces the number of lines of code by almost 200.
