Function extract_subject_before_arrow

src/completion/named_args.rs:321–348

Extract the subject before `->` for method calls. `arrow_pos` points to the `-` of `->`. Handles `$this`, `$var`, and simple variable names.

(chars: &[char], arrow_pos: usize)

/// `arrow_pos` points to the `-` of `->`.
/// Handles `$this`, `$var`, and simple variable names.
pub fn extract_subject_before_arrow(chars: &[char], arrow_pos: usize) -> String {
    let mut i = arrow_pos;
    // Skip whitespace
    while i > 0 && chars[i - 1] == ' ' {
        i -= 1;
    }

    // Check for `)` — chained call, skip for now
    if i > 0 && chars[i - 1] == ')' {
        return String::new();
    }

    // Read identifier (property or variable name without `$`)
    let end = i;
    while i > 0 && (chars[i - 1].is_alphanumeric() || chars[i - 1] == '_') {
        i -= 1;
    }

    // Check for `$` prefix (variable)
    if i > 0 && chars[i - 1] == '$' {
        i -= 1;
        return chars[i..end].iter().collect();
    }

    // Could be a chained property: `$this->prop->method(` — just return
    // the identifier; resolution in server.rs will handle it.
    chars[i..end].iter().collect()
}

/// Extract a class name (possibly namespace-qualified) before `::`.
///