As of [this cpython PR](https://github.com/python/cpython/pull/135996),
it is not allowed to concatenate t-strings with non-t-strings,
implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now
syntax errors.
This PR updates some AST nodes and parsing to reflect this change.
The structural change is that `TStringPart` is no longer needed, since,
as in the case of `BytesStringLiteral`, the only possibilities are that
we have a single `TString` or a vector of such (representing an implicit
concatenation of t-strings). This removes a level of nesting from many
AST expressions (which is what all the snapshot changes reflect), and
simplifies some logic in the implementation of visitors, for example.
The other change of note is in the parser. When we meet an implicit
concatenation of string-like literals, we now count the number of
t-string literals. If these do not exhaust the total number of
implicitly concatenated pieces, then we emit a syntax error. To recover
from this syntax error, we encode any t-string pieces as _invalid_
string literals (which means we flag them as invalid, record their
range, and record the value as `""`). Note that if at least one of the
pieces is an f-string we prefer to parse the entire string as an
f-string; otherwise we parse it as a string.
This logic is exactly the same as how we currently treat
`BytesStringLiteral` parsing and error recovery - and carries with it
the same pros and cons.
Finally, note that I have not implemented any changes in the
implementation of the formatter. As far as I can tell, none are needed.
I did change a few of the fixtures so that we are always concatenating
t-strings with t-strings.
This PR implements template strings (t-strings) in the parser and
formatter for Ruff.
Minimal changes necessary to compile were made in other parts of the code (e.g. ty, the linter, etc.). These will be covered properly in follow-up PRs.
## Summary
I don't remember exactly when we made `Identifier` a node but it is now
considered a node (it implements `AnyNodeRef`, it has a range). However,
we never updated
the `SourceOrderVisitor` to visit identifiers because we never had a use
case for it and visiting new nodes can change how the formatter
associates comments (breaking change!).
This PR updates the `SourceOrderVisitor` to visit identifiers and
changes the formatter comment visitor to skip identifiers (updating the
visitor might be desired because it could help simplifying some comment
placement logic but this is out of scope for this PR).
## Test Plan
Tests, updated snapshot tests
## Summary
This PR removes the cyclic dev dependency some of the crates had with
the parser crate.
The cyclic dependencies are:
* `ruff_python_ast` has a **dev dependency** on `ruff_python_parser` and
`ruff_python_parser` directly depends on `ruff_python_ast`
* `ruff_python_trivia` has a **dev dependency** on `ruff_python_parser`
and `ruff_python_parser` has an indirect dependency on
`ruff_python_trivia` (`ruff_python_parser` - `ruff_python_ast` -
`ruff_python_trivia`)
Specifically, this PR does the following:
* Introduce two new crates
* `ruff_python_ast_integration_tests` and move the tests from the
`ruff_python_ast` crate which uses the parser in this crate
* `ruff_python_trivia_integration_tests` and move the tests from the
`ruff_python_trivia` crate which uses the parser in this crate
### Motivation
The main motivation for this PR is to help development. Before this PR,
`rust-analyzer` wouldn't provide any intellisense in the
`ruff_python_parser` crate regarding the symbols in `ruff_python_ast`
crate.
```
[ERROR][2024-05-03 13:47:06] .../vim/lsp/rpc.lua:770 "rpc" "/Users/dhruv/.cargo/bin/rust-analyzer" "stderr" "[ERROR project_model::workspace] cyclic deps: ruff_python_parser(Idx::<CrateData>(50)) -> ruff_python_ast(Idx::<CrateData>(37)), alternative path: ruff_python_ast(Idx::<CrateData>(37)) -> ruff_python_parser(Idx::<CrateData>(50))\n"
```
## Test Plan
Check the logs of `rust-analyzer` to not see any signs of cyclic
dependency.
