Used by various Parser methods such as check_keyword and eat_keyword.
The first field is always used by those methods. The second field is only
used when the first field doesn’t match.
Used by various Parser methods such as check and eat. The first field
is always by used those methods. The second field is only used when the
first field doesn’t match.
A bitset type designed specifically for Parser::expected_token_types,
which is very hot. u128 is the smallest integer that will fit every
TokenType value.
Used in “expected”/“expected one of” error messages. Tokens are added here
as necessary. Tokens with values (e.g. literals, identifiers) are
represented by a single variant (e.g. Literal, Ident).