How to make switch statement in SwiftUI

Issue #656

Lately I’ve been challenging myself to declare switch statement in SwiftUI, or in a more generalized way, execute any anonymous function that can return a View

Use Switch and Case views

Note that this approach does not work yet, as TupeView should support variadic number of contents, and also T.RawValue needs to conform to Equatable in order to check the cases.

Also in Switch statement, Content can’t be inferred

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struct Case<T: RawRepresentable, Content: View>: View {
let value: T
let content: Content

init(_ value: T, @ViewBuilder content: () -> Content) {
self.value = value
self.content = content()
}

var body: some View {
content
}
}

struct Switch<T: RawRepresentable, Content: View>: View {
let value: T
let cases: TupleView<Case<T, Content>>

init(_ value: T, @ViewBuilder cases: () -> TupleView<Case<T, Content>>) {
self.value = value
self.cases = cases()
}

var body: some View {
makeBody()
}

private func makeBody() -> some View {
// TODO: Logic here
cases
}
}

struct UseSwitchStatement {
let animal: Animal = .cat

var body: some View {
VStack {
Switch(animal) {
Case(Animal.cat) {
Text("cat")
}
Case(Animal.dog) {
Text("dog")
}
Case(Animal.mouse) {
Text("mouse")
}
}
}
}
}

Use MakeView

Another solution is to use a MakeView view, this is more generic as it can execute any functions

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enum Animal: String {
case cat
case dog
case mouse
}

struct MakeView: View {
let make: () -> AnyView

var body: some View {
make()
}
}

struct UseMakeView: View {
let animal: Animal = .cat

var body: some View {
MakeView {
switch self.animal {
case .cat:
return Text("cat").erase()
case .dog:
return Text("dog").erase()
case .mouse:
return Text("mouse").erase()
}
}
}
}

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