Define and chain Closures with Inputs and Outputs
No Scoped State
let noStateCount = Closure<String, String> { text in
String(repeating: text, count: 4)
}
.then { string in
Int(string) ?? 0
}
XCTAssertEqual(noStateCount.method("5"), 5555)
XCTAssertEqual(noStateCount.method("5"), 5555)
XCTAssertEqual(noStateCount.method("5"), 5555)Scoped State
let stateCount: Closure<String, Int> = Closure<String, String> {
var count = 1
return { text in
defer {
count += 1
}
return String(repeating: text, count: count)
}
}
.then { string in
Int(string) ?? 0
}
XCTAssertEqual(stateCount.method("5"), 5)
XCTAssertEqual(stateCount.method("5"), 55)
XCTAssertEqual(stateCount.method("5"), 555)