konsti 730e6b2b4c Refactor StmtIf: Formatter and Linter (#5459) ... ## Summary Previously, `StmtIf` was defined recursively as ```rust pub struct StmtIf { pub range: TextRange, pub test: Box<Expr>, pub body: Vec<Stmt>, pub orelse: Vec<Stmt>, } ``` Every `elif` was represented as an `orelse` with a single `StmtIf`. This means that this representation couldn't differentiate between ```python if cond1: x = 1 else: if cond2: x = 2 ``` and ```python if cond1: x = 1 elif cond2: x = 2 ``` It also makes many checks harder than they need to be because we have to recurse just to iterate over an entire if-elif-else and because we're lacking nodes and ranges on the `elif` and `else` branches. We change the representation to a flat ```rust pub struct StmtIf { pub range: TextRange, pub test: Box<Expr>, pub body: Vec<Stmt>, pub elif_else_clauses: Vec<ElifElseClause>, } pub struct ElifElseClause { pub range: TextRange, pub test: Option<Expr>, pub body: Vec<Stmt>, } ``` where `test: Some(_)` represents an `elif` and `test: None` an else. This representation is different tradeoff, e.g. we need to allocate the `Vec<ElifElseClause>`, the `elif`s are now different than the `if`s (which matters in rules where want to check both `if`s and `elif`s) and the type system doesn't guarantee that the `test: None` else is actually last. We're also now a bit more inconsistent since all other `else`, those from `for`, `while` and `try`, still don't have nodes. With the new representation some things became easier, e.g. finding the `elif` token (we can use the start of the `ElifElseClause`) and formatting comments for if-elif-else (no more dangling comments splitting, we only have to insert the dangling comment after the colon manually and set `leading_alternate_branch_comments`, everything else is taken of by having nodes for each branch and the usual placement.rs fixups). ## Merge Plan This PR requires coordination between the parser repo and the main ruff repo. I've split the ruff part, into two stacked PRs which have to be merged together (only the second one fixes all tests), the first for the formatter to be reviewed by @michareiser and the second for the linter to be reviewed by @charliermarsh. * MH: Review and merge https://github.com/astral-sh/RustPython-Parser/pull/20 * MH: Review and merge or move later in stack https://github.com/astral-sh/RustPython-Parser/pull/21 * MH: Review and approve https://github.com/astral-sh/RustPython-Parser/pull/22 * MH: Review and approve formatter PR https://github.com/astral-sh/ruff/pull/5459 * CM: Review and approve linter PR https://github.com/astral-sh/ruff/pull/5460 * Merge linter PR in formatter PR, fix ecosystem checks (ecosystem checks can't run on the formatter PR and won't run on the linter PR, so we need to merge them first) * Merge https://github.com/astral-sh/RustPython-Parser/pull/22 * Create tag in the parser, update linter+formatter PR * Merge linter+formatter PR https://github.com/astral-sh/ruff/pull/5459 --------- Co-authored-by: Micha Reiser <micha@reiser.io>		2023-07-18 13:40:15 +02:00
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snapshots	Refactor StmtIf: Formatter and Linter (#5459)	2023-07-18 13:40:15 +02:00
fixtures.rs	Format target: annotation = value? expressions (#5661)	2023-07-11 16:40:28 +02:00