Tokens that are not enums

[ccleve]

Similar to #803, I have an existing Token type (widely used throughout the system) that looks like this:

pub struct Token {
    pub token_type: TokenType,
    // other stuff
}

Token is not an enum, but it contains one.

I'm trying to figure out how to use this with lalrpop. I have a TokenIterator that produces tokens, and I've gotten it working with my grammar. My grammar looks like this:

extern {
  type Location = usize;
  type Error = LexicalError;

  enum Token {
    "Word" => TokenType::Word,
    "(" => TokenType::OpenParen,
    ...
  }
}

The problem is hooking things up so the generated code matches on token.token_type instead of token.

When I generate the code, I get this compiler error:

error[E0308]: mismatched types
   --> src/query/lalrpop/query_parser.rs:222:13
    |
221 |         match *__token {
    |               -------- this expression has type `tokens::Token`
222 |             TokenType::OpenParen if true => Some(0),
    |             ^^^^^^^^^^^^^^^^^^^^ expected `Token`, found `TokenType`

If I hand-edit the generated code to change this:

match *__token {

to this:

match __token.token_type {

everything works beautifully.

How do I get the system to generate the code appropriately?

@ethindp It look like you got this working. What is your secret?