[Feature Request] Encodable Default Value Handling

[tatewake]

• [x] I have read the documentation.

Is your feature request related to a problem? Please describe.

In my scenario, I need to assign default values during decoding if certain fields are missing (which is already supported), but I also want to avoid encoding a field if its value matches the same default.

Consider this Node struct:

@Codable
struct Node: Hashable {
    @Default("")
    var label: String = ""
    @Default(CGPoint.zero)
    var center: CGPoint = .zero
}

For example, if center isn't set, it should default to .zero during decoding. Similarly, for my use case, if it's already set to .zero, there's no need to encode it since it's the expected default.

Describe the solution you'd like Introduce a new tag, perhaps something like @IgnoreEncodingIfDefault when set alongside @Default(CGPoint.zero) or a standalone @IgnoreEncodingDefault(CGPoint.zero) for this purpose. (I'm not certain what the best naming convention would be, I'd imagine you'd have better ideas.)

I feel this feature would be particularly useful for user-editable configuration files where we would want to omit any "optional" fields, or just keeping human-readable configurations minimal for git diffing.

[soumyamahunt]

@tatewake have you looked into the the HelperCoder functionality provided to implement what you want?

[tatewake]

Ah, I have not, I'll look into it.