Returns the first identifier token, if any.
fn parsePtrIndexPayload(p: *Parse) Error!OptionalTokenIndex
fn parsePtrIndexPayload(p: *Parse) Error!OptionalTokenIndex {
_ = p.eatToken(.pipe) orelse return .none;
_ = p.eatToken(.asterisk);
const identifier = try p.expectToken(.identifier);
if (p.eatToken(.comma) != null) {
_ = try p.expectToken(.identifier);
}
_ = try p.expectToken(.pipe);
return .fromToken(identifier);
}