Method parse_params

compiler/src/modules/parser/literals.rs:560–616

(&mut self)

    }

    pub(super) fn parse_params(&mut self) -> (Vec<String>, u16) {
        // No `(`: diagnostic, consume `:` so compile_body starts at Indent correctly.
        if !matches!(self.peek(), Some(TokenType::Lpar)) {
            self.diag_at_peek("expected '('");
            self.eat_if(TokenType::Colon);
            return (Vec::new(), 0);
        }
        self.advance();
        let mut params = Vec::new();
        let mut defaults = 0u16;
        // Lone `*` flips kw_only; subsequent params get `~` prefix.
        let mut kw_only = false;
        // Break on Rarrow: signals end of params (return type follows).
        while !matches!(self.peek(), Some(TokenType::Rpar | TokenType::Rarrow) | None) {
            if self.eat_if(TokenType::Slash) {
                self.eat_if(TokenType::Comma);
                continue;
            }
            if self.eat_if(TokenType::Star) {
                // Lone `*`: flip kw-only, no param emitted.
                if matches!(self.peek(), Some(TokenType::Comma | TokenType::Rpar)) {
                    self.eat_if(TokenType::Comma);
                    kw_only = true;
                    continue;
                }
                let nm = self.advance_text();
                params.push(s!("*", str &nm));
                self.drain_annotation();
                self.eat_if(TokenType::Comma);
                continue;
            }
            if self.eat_if(TokenType::DoubleStar) {
                let nm = self.advance_text();
                params.push(s!("**", str &nm));
                self.drain_annotation();
                self.eat_if(TokenType::Comma);
                continue;
            }
            let prefix = if kw_only { "~" } else { "" };
            let nm = self.advance_text();
            params.push(if prefix.is_empty() { nm } else { s!(str prefix, str &nm) });
            self.drain_annotation();
            if self.eat_if(TokenType::Equal) {
                self.expr();
                defaults += 1;
                // Trailing `=` marks this param as carrying a default value.
                if let Some(last) = params.last_mut() { last.push('='); }
            }
            self.eat_if(TokenType::Comma);
        }
        self.eat(TokenType::Rpar);
        if self.eat_if(TokenType::Rarrow) {
            while !matches!(self.peek(), Some(TokenType::Colon) | None) { self.advance(); }
        }
        self.eat(TokenType::Colon);
        (params, defaults)
    }