Either+Decodable.swift

extension Either : Decodable where Right: Decodable, Left == Error {
    public init(from decoder: Decoder) throws {
        do {
            let container = try decoder.singleValueContainer()
            let value = try container.decode(Right.self)
            self = .right(value)
        } catch {
            self = .left(error) 
        }
    }
    
    
}