Merge pull request ReactiveX#1075 from radex/rx-examples-calculator

[RxExamples] Clean up the Calculator example
zsoltkiss · Jan 20, 2017 · 0de7e7e · 0de7e7e
2 parents 12e0ec1 + 7487e71
commit 0de7e7e
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Showing 3 changed files with 44 additions and 69 deletions.
diff --git a/RxExample/RxExample/Examples/Calculator/CalculatorState.swift b/RxExample/RxExample/Examples/Calculator/CalculatorState.swift
@@ -54,57 +54,28 @@ extension CalculatorState {
 
  if previousNumber == nil {
  return CalculatorState(previousNumber: currentNumber, action: .operation(o), currentNumber: nil, inScreen: currentNumber, replace: true)
- }
- else {
+ } else {
  let previous = Double(previousNumber)!
  let current = Double(inScreen)!
 
- switch action {
- case .operation(let op):
- switch op {
- case .addition:
- let result = "\(previous + current)"
- return CalculatorState(previousNumber: result, action: .operation(o), currentNumber: nil, inScreen: result, replace: true)
- case .subtraction:
- let result = "\(previous - current)"
- return CalculatorState(previousNumber: result, action: .operation(o), currentNumber: nil, inScreen: result, replace: true)
- case .multiplication:
- let result = "\(previous * current)"
- return CalculatorState(previousNumber: result, action: .operation(o), currentNumber: nil, inScreen: result, replace: true)
- case .division:
- let result = "\(previous / current)"
- return CalculatorState(previousNumber: result, action: .operation(o), currentNumber: nil, inScreen: result, replace: true)
- }
- default:
+ if case let .operation(op) = action {
+ let result = "\(op.perform(previous, current))"
+ return CalculatorState(previousNumber: result, action: .operation(o), currentNumber: nil, inScreen: result, replace: true)
+ } else {
  return CalculatorState(previousNumber: nil, action: .operation(o), currentNumber: currentNumber, inScreen: inScreen, replace: true)
  }
-
  }
-
  }
 
  func performEqual() -> CalculatorState {
- let previous = Double(previousNumber ?? "0")
+ let previous = Double(previousNumber ?? "0")!
  let current = Double(inScreen)!
 
- switch action {
- case .operation(let op):
- switch op {
- case .addition:
- let result = "\(previous! + current)"
- return CalculatorState(previousNumber: nil, action: .clear, currentNumber: result, inScreen: result, replace: true)
- case .subtraction:
- let result = "\(previous! - current)"
- return CalculatorState(previousNumber: nil, action: .clear, currentNumber: result, inScreen: result, replace: true)
- case .multiplication:
- let result = "\(previous! * current)"
- return CalculatorState(previousNumber: nil, action: .clear, currentNumber: result, inScreen: result, replace: true)
- case .division:
- let result = previous! / current
- let resultText = result == Double.infinity ? "0" : "\(result)"
- return CalculatorState(previousNumber: nil, action: .clear, currentNumber: resultText, inScreen: resultText, replace: true)
- }
- default:
+ if case let .operation(op) = action {
+ let result = op.perform(previous, current)
+ let resultText = (result == Double.infinity) ? "0" : "\(result)"
+ return CalculatorState(previousNumber: nil, action: .clear, currentNumber: resultText, inScreen: resultText, replace: true)
+ } else {
  return CalculatorState(previousNumber: nil, action: .clear, currentNumber: currentNumber, inScreen: inScreen, replace: true)
  }
  }

diff --git a/RxExample/RxExample/Examples/Calculator/CalculatorViewController.swift b/RxExample/RxExample/Examples/Calculator/CalculatorViewController.swift
@@ -12,7 +12,6 @@ import RxSwift
 import RxCocoa
 #endif
 
-
 class CalculatorViewController: ViewController {
 
  @IBOutlet weak var lastSignLabel: UILabel!
@@ -71,42 +70,27 @@ class CalculatorViewController: ViewController {
 
  Observable.from(commands)
  .merge()
- .scan(CalculatorState.CLEAR_STATE) { a, x in
- return a.tranformState(x)
+ .scan(CalculatorState.CLEAR_STATE) { previous, action in
+ previous.tranformState(action)
  }
- .debug("debugging")
+ .debug("calculator state")
  .subscribe(onNext: { [weak self] calState in
- self?.resultLabel.text = calState.inScreen
- switch calState.action {
- case .operation(let operation):
- switch operation {
- case .addition:
- self?.lastSignLabel.text = "+"
- case .subtraction:
- self?.lastSignLabel.text = "-"
- case .multiplication:
- self?.lastSignLabel.text = "x"
- case .division:
- self?.lastSignLabel.text = "/"
- }
- default:
+ self?.resultLabel.text = self?.formatResult(calState.inScreen)
+
+ if case let .operation(operation) = calState.action {
+ self?.lastSignLabel.text = operation.sign
+ } else {
  self?.lastSignLabel.text = ""
  }
  })
  .addDisposableTo(disposeBag)
  }
-
-//swifts string api sucks
 
- func prettyFormat(str: String) -> String {
- if str.hasSuffix(".0") {
-// return str[str.startIndex..<str.endIndex.pre]
+ func formatResult(_ result: String) -> String {
+ if result.hasSuffix(".0") {
+ return result.substring(to: result.index(result.endIndex, offsetBy: -2))
+ } else {
+ return result
  }
- return str
  }
 }
-
-
-
-
-
diff --git a/RxExample/RxExample/Examples/Calculator/Operation.swift b/RxExample/RxExample/Examples/Calculator/Operation.swift
@@ -14,3 +14,23 @@ enum Operator {
  case multiplication
  case division
 }
+
+extension Operator {
+ var sign: String {
+ switch self {
+ case .addition: return "+"
+ case .subtraction: return "-"
+ case .multiplication: return "×"
+ case .division: return "/"
+ }
+ }
+
+ var perform: (Double, Double) -> Double {
+ switch self {
+ case .addition: return (+)
+ case .subtraction: return (-)
+ case .multiplication: return (*)
+ case .division: return (/)
+ }
+ }
+}