IronLanguages / IronLanguages/ironpython3
AST locations of f-string are incorrect
Nobody has claimed this yet.
- Dominant language
- C#
- Stars
- 2.8k
- Forks
- 316
- Avg merge
- 1d 9h
- Merged PRs (30d)
- 1
Description
For example, in the following example, col_offset of the FormattedValue.value is not correct:
import ast
ast.dump(ast.parse("f'{1}'"), include_attributes=True)
In multi-line expressions, lineno is also incorrect.
This is caused by the implementation in https://github.com/IronLanguages/ironpython3/pull/1334 which creates a parser to handle the f-string expression and the position of the f-string expression within the source is lost.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Review the f-string parser implementation introduced by pull request 1334 and trace how it creates a parser for embedded expressions. Preserve the source position when constructing the AST so FormattedValue locations, including multiline lineno values and col_offset, match the original source; verify with the ast.parse example in the issue.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- csharp, python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100