convert dictionary

DictionaryConverter.swift

import Foundation

typealias Parameters = [AnyHashable: Any]

protocol Converter {
    func convert(_ input: Any) -> Any
}

struct BoolConverter: Converter {
    func convert(_ input: Any) -> Any {
        if let bool = input as? Bool {
            return bool.description
        } else {
            return input
        }
    }
}

struct StringConverter: Converter {
    func convert(_ input: Any) -> Any {
        if let str = input as? String {
            return str.capitalized
        } else {
            return input
        }
    }
}

protocol CompositeConverter: Converter {
    /// order in which the converters are applied
    var converters: [Converter] { get }
}

extension CompositeConverter {
    func convert(_ input: Any) -> Any {
        return converters.reduce(input) { (acc, converter) in
            converter.convert(acc)
        }
    }

    func convert(_ input: Parameters) -> Parameters {
        return input.mapValues { value -> Any in convert(value) }
    }
}

struct ParametersConverter: CompositeConverter {
    let converters: [Converter] = [BoolConverter(), StringConverter()]
}

// MARK: - exec

let dic: Parameters = [
    "string": "string",
    "int": 0,
    "bool": true
]
let converter = ParametersConverter()
converter.convert(dic) // ["string": "String", "int": 0, "bool": "True"]