Make nested dictionary flat again

FlattenNestedDictionary.swift

/*
BEFORE = ["id": 1, "sergio": ["yume": ["ssk": 999]], "product": ["name": "AAA", "description": ["banana": "yellow"]]]
AFTER = ["sergio/yume/ssk": 999, "id": 1, "product/name": "AAA", "product/description/banana": "yellow"]
*/

typealias JSON = [String : Any]

let nested: JSON = ["id": 1, "product": ["name": "AAA", "description": ["banana": "yellow"]], "sergio": ["yume": ["ssk": 999]]]

extension JSON where Key: ExpressibleByStringLiteral, Value: Any {
	
	/// Convert nested dictionary to flatten
	///
	/// - Returns: flat dictionary
	func toFlatten() -> JSON {
		var output: JSON = [:]
		
		func flattenDic(_ dic: JSON, parentPath: String = "", output: inout JSON) {
			for (key, val) in dic {
				let path = parentPath.isEmpty ? key : "\(parentPath)/\(key)"
				// Found dictionary ?
				if let childDic = val as? JSON {
					flattenDic(childDic, parentPath: path, output: &output)
				} else {
					output[path] = val
				}
			}
		}
		
		flattenDic(self, output: &output)
		
		return output
	}
	
}

print("BEFORE = \(nested)\n")
print("AFTER = \(nested.toFlatten())")