Enum inferred raw value

[Amzd]

Previously we could already get the raw value of a case with EnumCase.value and now that can also return a new case called inferredRawValue.

enum Foo: String {
  case bar // implicit raw value of "bar"
}

enum Foo: Int {
  case bar = 3
  case baz // implicit raw value of 4
}

EnumCaseValue.rawValue and EnumCaseValue.inferredRawValue have the same associated value type so you can do:

switch value {
  case .rawValue(let initializer), .inferredRawValue(let initializer): 
    // ..
  default: break
}

This PR only adds raw representable checking when it is the first inherited type, which is the simplest case. It does not check eg typealias RawValue = String.

[stackotter]

Thanks for the PR! Just a few small requested changes, but looks good for the most part

[Amzd]

Requires #31

[stackotter]

Thanks for addressing those changes. Looking pretty good now, just got a few more requests. Thanks for catching and fixing the floating point issue too 🙏

[stackotter]

Move this helper function to the top of the function to make things read a bit nicer.

[stackotter]

Move the values (after the colons) onto new lines to reduce line length and make things a bit easier to skim

[stackotter]

I feel like this should be renamed to make it clear that it's the types of the associated values and not actual values.

[Amzd]

To what?

[stackotter]

Maybe associatedValueParameters? (given that they include labels as well)

[stackotter]

Is this essentially equivalent to rawValue?.description with a bit of added normalisation? I feel like in situations where you'd use this, you don't need the normalisation anyway, so rawValue?.description would suffice (in which case this property shouldn't be necessary).

[Amzd]

I had no idea that was possible so just my inexperience with swift syntax showing.

[stackotter]

Every case has the same associated value, so I feel it may be better to turn this enum into a struct with a nested Kind enum (containing these cases but without associated values) alongside kind and identifier fields.