This commit generalises parsing of associative operators from left-associative
only (with some ugly hacks to support right-associative assignment) to properly
left/right-associative operators.
Parsing still is not general enough to handle non-associative,
non-highest-precedence prefix or non-highest-precedence postfix operators (e.g.
`..` range syntax), though. That should be fixed in the future.
Lastly, this commit adds support for parsing right-associative `<-` (left arrow)
operator with precedence higher than assignment as the operator for placement-in
feature.
This PR switches the implemented ordering from `unsafe const fn` (as was in the original RFC) to `const unsafe fn` (which is what the lang team decided on)
Previously, if you copied a signature from a trait definition such as:
```rust
fn foo<'a>(&'a Bar) -> bool {}
```
and moved it into an `impl`, there would be an error message:
"unexpected token `'a`"
Adding to the error message that a pattern is expected should help
users to find the actual problem with using a lifetime here.
This commit stabilizes and deprecates library APIs whose FCP has closed in the
last cycle, specifically:
Stabilized APIs:
* `fs::canonicalize`
* `Path::{metadata, symlink_metadata, canonicalize, read_link, read_dir, exists,
is_file, is_dir}` - all moved to inherent methods from the `PathExt` trait.
* `Formatter::fill`
* `Formatter::width`
* `Formatter::precision`
* `Formatter::sign_plus`
* `Formatter::sign_minus`
* `Formatter::alternate`
* `Formatter::sign_aware_zero_pad`
* `string::ParseError`
* `Utf8Error::valid_up_to`
* `Iterator::{cmp, partial_cmp, eq, ne, lt, le, gt, ge}`
* `<[T]>::split_{first,last}{,_mut}`
* `Condvar::wait_timeout` - note that `wait_timeout_ms` is not yet deprecated
but will be once 1.5 is released.
* `str::{R,}MatchIndices`
* `str::{r,}match_indices`
* `char::from_u32_unchecked`
* `VecDeque::insert`
* `VecDeque::shrink_to_fit`
* `VecDeque::as_slices`
* `VecDeque::as_mut_slices`
* `VecDeque::swap_remove_front` - (renamed from `swap_front_remove`)
* `VecDeque::swap_remove_back` - (renamed from `swap_back_remove`)
* `Vec::resize`
* `str::slice_mut_unchecked`
* `FileTypeExt`
* `FileTypeExt::{is_block_device, is_char_device, is_fifo, is_socket}`
* `BinaryHeap::from` - `from_vec` deprecated in favor of this
* `BinaryHeap::into_vec` - plus a `Into` impl
* `BinaryHeap::into_sorted_vec`
Deprecated APIs
* `slice::ref_slice`
* `slice::mut_ref_slice`
* `iter::{range_inclusive, RangeInclusive}`
* `std::dynamic_lib`
Closes#27706Closes#27725
cc #27726 (align not stabilized yet)
Closes#27734Closes#27737Closes#27742Closes#27743Closes#27772Closes#27774Closes#27777Closes#27781
cc #27788 (a few remaining methods though)
Closes#27790Closes#27793Closes#27796Closes#27810
cc #28147 (not all parts stabilized)
Previously, if you copied a signature from a trait definition such as:
```
fn foo<'a>(&'a Bar) -> bool {}
```
and moved it into an `impl`, there would be an error message:
"unexpected token `'a`"
Adding to the error message that a pattern is expected should help
users to find the actual problem with using a lifetime here.
Qualified paths allow full path after the `>::`. For example
```rust
<T as Foo>::U::generic_method::<f64>()
```
The example is taken from `test/run-pass/associated-item-long-paths.rs`.
This PR removes random remaining `Ident`s outside of libsyntax and performs general cleanup
In particular, interfaces of `Name` and `Ident` are tidied up, `Name`s and `Ident`s being small `Copy` aggregates are always passed to functions by value, and `Ident`s are never used as keys in maps, because `Ident` comparisons are tricky.
Although this PR closes https://github.com/rust-lang/rust/issues/6993 there's still work related to it:
- `Name` can be made `NonZero` to compress numerous `Option<Name>`s and `Option<Ident>`s but it requires const unsafe functions.
- Implementation of `PartialEq` on `Ident` should be eliminated and replaced with explicit hygienic, non-hygienic or member-wise comparisons.
- Finally, large parts of AST can potentially be converted to `Name`s in the same way as HIR to clearly separate identifiers used in hygienic and non-hygienic contexts.
r? @nrc
Make sure Name, SyntaxContext and Ident are passed by value
Make sure Idents don't serve as keys (or parts of keys) in maps, Ident comparison is not well defined
There is a dead code in libsyntax/parser/parse.rs, when parsing structs.
Two functions are involved:
* [parse_item_struct](cd9c9f048f/src/libsyntax/parse/parser.rs (L4691))
* [parse_tuple_struct_body](cd9c9f048f/src/libsyntax/parse/parser.rs (L4769))
The problem is that both functions handle the case with unit structs. But because
`parse_tuple_struct_body` is called from `parse_item_struct`, it never faces
this case.
This PR removes unit struct case from `parse_tuple_struct_body` function. I tested with `make -j8 check-statge1`.
