A placeholder decodable type

AnyCodable.swift

// Reference: https://github.com/asensei/AnyCodable/blob/master/Sources/AnyCodable/AnyCodable.swift

import Foundation

public struct AnyCodable {
  
  // MARK: Initialization
  public init(_ value: Any?) {
    self.value = value
  }
  
  // MARK: Accessing Attributes
  public let value: Any?
}

extension AnyCodable: Decodable {
  
  public init(from decoder: Decoder) throws {
    let container = try decoder.singleValueContainer()
    
    if let value = try? container.decode(String.self) {
      self.value = value
    } else if let value = try? container.decode(Bool.self) {
      self.value = NSNumber(value: value)
    } else if container.decodeNil() {
      self.value = nil
    } else if let value = try? container.decode([String: AnyCodable].self) {
      self.value = value.mapValues { $0.value }
    } else if let value = try? container.decode([AnyCodable].self) {
      self.value = value.map { $0.value }
    } else if let value = try? container.decode(Int.self) {
      self.value = NSNumber(value: value)
    } else if let value = try? container.decode(Double.self) {
      self.value = NSNumber(value: value)
    } else {
      throw DecodingError.dataCorruptedError(
        in: container,
        debugDescription: "Invalid value cannot be decoded"
      )
    }
  }
}

extension AnyCodable: CustomStringConvertible {
  
  public var description: String {
    switch self.value {
    case let value as CustomStringConvertible:
      return value.description
    default:
      return String(describing: self.value)
    }
  }
}

extension AnyCodable: CustomDebugStringConvertible {
  
  public var debugDescription: String {
    switch self.value {
    case let value as CustomDebugStringConvertible:
      return value.debugDescription
    default:
      return self.description
    }
  }
}