RFC #19: Errors

[ProCode-Software]

• My goal is for error objects to have codes attached. My preferred way is one defined by the module creating the error, which may be an enum.

// Module myMod
public type ErrorCode {
    .notFound(path: String)
    .accessDenied
}
// A user of 'myMod' could check like:
when err.code {
    .notFound(path) -> ...
    .accessDenied -> ...
}

• a. Make Error an interface, similar to Go, with the message as a String field, and a code (Any type). Also, should they be fields, or methods (so structs can compute messages; but that could also be done by an initializer)?
• b. Make Error a struct

  type Error {
      message: String
      code: Any
  }