Precise error typing in Swift

[toph42 (Topher Hickman)]

This looks like what you’re talking about, and you don’t need typed Errors for that:

[Pitch] Typed throws

IMHO, there are two kinds of responses to errors - a specific response, and a general one. Only the calling code knows how it will deal with errors, so a “typed throws” is the function guessing possible calling code behavior. The problem is, that gives four possible combinations - two where the function guesses correctly, and two where it doesn’t. The most damaging is when it suspects a caller doesn’t care about the error, when the caller actually does. This is unwanted wrapping. To provide a…