Function extract_completion_target

src/completion/target.rs:22–40

Detect the access operator before the cursor position and extract both the `AccessKind` and the textual subject to its left. Returns `None` when no `->` or `::` is found (i.e. `AccessKind::Other`).

(content: &str, position: Position)

///
/// Returns `None` when no `->` or `::` is found (i.e. `AccessKind::Other`).
pub fn extract_completion_target(content: &str, position: Position) -> Option<CompletionTarget> {
    let lines: Vec<&str> = content.lines().collect();
    if position.line as usize >= lines.len() {
        return None;
    }

    // Collapse multi-line method chains so that continuation lines
    // (starting with `->` or `?->`) are joined with preceding lines.
    let (line, col) =
        collapse_continuation_lines(&lines, position.line as usize, position.character as usize);
    let chars: Vec<char> = line.chars().collect();

    let (subject, access_kind) = detect_access_operator(&chars, col)?;

    Some(CompletionTarget {
        access_kind,
        subject,
    })
}