CODEWITHSUNDEEP
swiftundefined
Sasha Sewerow
Sasha Sewerow

Reputation: 117

Swift error. Used undeclared type String

if we insert line "case let dictionary as [String : AnyObject]:" inside struct's method everything works fine. But if use inside nested enums we get error "Used undefined type String"

public struct JSON {

    public enum Type : Int {

        case Number
        case String
        case Bool
        case Array
        case Dictionary
        case Null
        case Unknown

        public static func evaluate(object: AnyObject) -> Type {

            switch object {
            case let dictionary as [String : AnyObject]: // this lines supply error. Use of undefined type String
                return .Dictionary
            default:
                return .Unknown
            }
        }

    } // enum Type

Could some one explain why I have the error with String type?

Upvotes: 3

Views: 5449

Answers (3)

codebaboon
codebaboon

Reputation: 67

If you want to fix this without renaming the enum case, you can change the argument type to Swift.String, i.e.:

case let dictionary as [Swift.String : AnyObject]:

That should work (I had a similar problem and this solved it).

Upvotes: 0

Wonjung Kim
Wonjung Kim

Reputation: 1933

It seems enum Type contains case String, and it hides the String what you want. I tried the code in Playground and there is no more error after change String to another name.

EDIT How about reading the project SwiftyJSON (only single file)

https://github.com/SwiftyJSON/SwiftyJSON/blob/master/Source/SwiftyJSON.swift

I does very similar job.(JSON Handling)

It also contains the code looks like this:

public enum Type :Int {

    case Number
    case String
    case Bool
    case Array
    case Dictionary
    case Null
    case Unknown
}

I think this project will be very helpful for you. (and I guess you may end up using this project)

Upvotes: 9

Martin R
Martin R

Reputation: 540075

As already said in the other answer, String inside enum Type refers to the enumeration value. The same problem would occur with

let a : Array<Int> = []
let b : Bool = false

inside methods of enum Type. Renaming the enumeration values is probably the best solution.

But for the sake of completeness: You can solve the problem by prepending the "Swift" module name explicitly to refer to the String type:

case let dictionary as [Swift.String : AnyObject]:

Upvotes: 1

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