How can I call a function with a dictionary?

I try to create a Dictionary to call some functions.

Dictionary

My array takes a key Int, a String and a function, like this:

let list_weapons: [Int: [Any]] = [1: ["Sword", attack_sword],
2: ["Magic wand", heal_magic_wand],
3: ["Hammer", attack_hammer],
4: ["Axe", attack_axe]]


These functions take a Class as a parameter, like this:

Class

func attack_sword(character: Character)


I try to call my function like that but it doesn't work.

list_weapons[1]![1](character: Character)


Cannot call value of non-function type 'Any'

If you have some ideas or advise me with another container

Thank you

4 Answers
4

Using an array of Any to store a string and a closure (function) with a specific signature is a poor choice. It would be better to declare a struct with two properties of the correct type. Then store those structures in your dictionary.

Any

struct

struct Action
let name: String
let function: (Character) -> ()


let list_weapons: [Int: Action] = [
1: Action(name: "Sword", function: attack_sword),
// and the rest
]

list_weapons[1]!.function(someCharacter)


You don't need to store methods in a dictionary to solve your problem. In my opinion, an architecture solution would be better here. You can play with selectors if you like, but I guess things will be much easier if you just do something like that

// Here you can specify all common thing about your weapons
protocol Weapon: class
var name: String get
func attack(character: Character)


// Each weapon has its own class which can contain eveything you need
class Sword: Weapon
class MagicWand: Weapon
class Hammer: Weapon
class Axe: Weapon

// That's how you can store you weapons list
// You can use a dictionary if you like
let weaponsArray: [Weapon] = [Sword(),
MagicWand(),
Hammer(),
Axe()]

// And that's how you can use them
weaponsArray[0].attack(character: character)


You have to cast Any to the Function before using it.

cast

let f = (list_weapons[1]![1] as! (Character) -> Void)
f("a") //it will invoke attack_sword("a")


And without temp variable,

(list_weapons[1]![1] as! (Character) -> Void)("a")


You can cast the element to a function type:

if let attack = list_weapons[1]![1] as? ((Character) -> Void)
attack(...)
else
print("Cannot attack")



But you better rework your data model. Using dictionaries can get confusing very quickly. Here's one way to do it:

protocol Weapon
var name: String get
func attack(character: Character)


struct Sword: Weapon
let name = "Sword"
func attack(character: Character) ...


struct MagicWand: Weapon
let name = "Magic Wand"
func attack(character: Character) ...


struct Hammer: Weapon
let name = "Hammer"
func attack(character: Character) ...


struct Axe: Weapon
let name = "Axe"
func attack(character: Character) ...


let weapons: [Weapon] = [Sword(), MagicWand(), Hammer(), Axe()]
weapons[1].attack(character: ...)


You extend each weapon with different damages, unique features, levels, etc.

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