(&self, start: TextSize)
| 309 | } |
| 310 | |
| 311 | fn node_range(&self, start: TextSize) -> TextRange { |
| 312 | // It's possible during error recovery that the parsing didn't consume any tokens. In that |
| 313 | // case, `last_token_end` still points to the end of the previous token but `start` is the |
| 314 | // start of the current token. Calling `TextRange::new(start, self.last_token_end)` would |
| 315 | // panic in that case because `start > end`. This path "detects" this case and creates an |
| 316 | // empty range instead. |
| 317 | // |
| 318 | // The reason it's `<=` instead of just `==` is because there could be whitespaces between |
| 319 | // the two tokens. For example: |
| 320 | // |
| 321 | // ```python |
| 322 | // # last token end |
| 323 | // # | current token (newline) start |
| 324 | // # v v |
| 325 | // def foo \n |
| 326 | // # ^ |
| 327 | // # assume there's trailing whitespace here |
| 328 | // ``` |
| 329 | // |
| 330 | // Or, there could tokens that are considered "trivia" and thus aren't emitted by the token |
| 331 | // source. These are comments and non-logical newlines. For example: |
| 332 | // |
| 333 | // ```python |
| 334 | // # last token end |
| 335 | // # v |
| 336 | // def foo # comment\n |
| 337 | // # ^ current token (newline) start |
| 338 | // ``` |
| 339 | // |
| 340 | // In either of the above cases, there's a "gap" between the end of the last token and start |
| 341 | // of the current token. |
| 342 | if self.prev_token_end <= start { |
| 343 | // We need to create an empty range at the last token end instead of the start because |
| 344 | // otherwise this node range will fall outside the range of it's parent node. Taking |
| 345 | // the above example: |
| 346 | // |
| 347 | // ```python |
| 348 | // if True: |
| 349 | // # function start |
| 350 | // # | function end |
| 351 | // # v v |
| 352 | // def foo # comment |
| 353 | // # ^ current token start |
| 354 | // ``` |
| 355 | // |
| 356 | // Here, the current token start is the start of parameter range but the function ends |
| 357 | // at `foo`. Even if there's a function body, the range of parameters would still be |
| 358 | // before the comment. |
| 359 | |
| 360 | // test_err node_range_with_gaps |
| 361 | // def foo # comment |
| 362 | // def bar(): ... |
| 363 | // def baz |
| 364 | TextRange::empty(self.prev_token_end) |
| 365 | } else { |
| 366 | TextRange::new(start, self.prev_token_end) |
| 367 | } |
| 368 | } |
no test coverage detected