[Bug] Solidity `hex` and `unicode` prefixes cause an error

[makcandrov]

Component

sol! macro

What version of Alloy are you on?

0.7.0

Operating System

None

Describe the bug

• hex:

  alloy_sol_types::sol! {
  contract Contract {
      function foo() external {
          bytes memory b = hex"ab";
      }
  }
  }

  error: prefix `hex` is unknown
  --> src\main.rs:4:30
  |
  4 |             bytes memory b = hex"ab";
  |                              ^^^ unknown prefix
  |
  = note: prefixed identifiers and literals are reserved since Rust 2021
  help: consider inserting whitespace here
  |
  4 |             bytes memory b = hex "ab";
  |                                 +

• unicode:

alloy_sol_types::sol! {
    contract Contract {
        function foo() external {
            string memory s = unicode"a";
        }
    }
}

error: prefix `unicode` is unknown
 --> src\main.rs:4:31
  |
4 |             string memory s = unicode"a";
  |                               ^^^^^^^ unknown prefix
  |
  = note: prefixed identifiers and literals are reserved since Rust 2021
help: consider inserting whitespace here
  |
4 |             string memory s = unicode "a";
  |                                      +

[DaniPopes]

This is a known limitation, rust fails lexing the code before even passing it to the macro.

https://github.com/alloy-rs/core/tree/main/crates/syn-solidity#known-limitations