Gather the declaration of errors

[clearloop]

Describe the feature

Error has not been implemented yet, ABIs are also required but considered in a separated PR

Solution

#[derive(Errors)]
enum Error {
  ERC20InvalidSender { sender: Address }
}

This solution could be similar as the events, see #281 (review)

[g4titanx]

hey @clearloop, assign me

[g4titanx]

@clearloop is there an existing error handling infrastructure?

[clearloop]

@clearloop is there an existing error handling infrastructure?

we currently just have revert!, if I'm not mistaken, solidity errors are using revert internally as well, you can check the proc-macro implementation by @malik672 in #298, the logic is the same

the main difference are:

1. logs need to call log1, log2, log3, log4, and we need to use revert!, revert1!...revert4! (maximum 4 parameters)
2. for errors, we need to append the variables to the memory as well, then we can revert (name + parameters) together

#[derive(Error)]
pub enum Error {
  Error0,
  Error1(Bytes32),
  Error2(Bytes32, Bytes32),
  Error3(Bytes32, Bytes32, Bytes32),
  Error4(Bytes32, Bytes32, Bytes32, Bytes32)
}

// which generates

impl Error {
  fn error0() {
    zink::revert!("Error");
  }

  fn error1(param: Bytes32) {
    zink::revert!("Error", param)
  }

  // ...
}

for the revert macro, see revert!, and for the example, feel free to ask anything in the telegram channel!

[g4titanx]

great! thanks

[clearloop]

great! thanks

see my implementation in a8a3eec, it's actually the same for this issue ^ ^