Method new

crates/ruff_python_formatter/src/string/docstring.rs:881–896

Looks for a valid doctest PS1 prompt in the line given. If one was found, then state for a new doctest code example is returned, along with the code example line.

(original: InputDocstringLine<'src>)

    /// If one was found, then state for a new doctest code example is
    /// returned, along with the code example line.
    fn new(original: InputDocstringLine<'src>) -> Option<CodeExampleDoctest<'src>> {
        let trim_start = original.line.trim_start();
        // Prompts must be followed by an ASCII space character[1].
        //
        // [1]: https://github.com/python/cpython/blob/0ff6368519ed7542ad8b443de01108690102420a/Lib/doctest.py#L809-L812
        let code = trim_start.strip_prefix(">>> ")?;
        let indent_len = original
            .line
            .len()
            .checked_sub(trim_start.len())
            .expect("suffix is <= original");
        let lines = vec![CodeExampleLine { original, code }];
        let ps1_indent = &original.line[..indent_len];
        let doctest = CodeExampleDoctest { lines, ps1_indent };
        Some(doctest)
    }

    /// Looks for a valid doctest PS2 prompt in the line given. If one is
    /// found, it is added to this code example and ownership of the example is