Created
August 27, 2018 07:13
-
-
Save marhoily/3a7461c4b7bfb55499351f866fd60791 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| using System.Collections.Generic; | |
| using FluentAssertions; | |
| using Xunit; | |
| namespace DesignPatters | |
| { | |
| public sealed class Pattern4 | |
| { | |
| public class Computer | |
| { | |
| public int Value { get; private set; } | |
| public void Calc(char @operator, int operand) | |
| { | |
| switch (@operator) | |
| { | |
| case '+': Value += operand; break; | |
| case '-': Value -= operand; break; | |
| case '*': Value *= operand; break; | |
| case '/': Value /= operand; break; | |
| } | |
| } | |
| } | |
| public class Operation | |
| { | |
| public char Operator { get; } | |
| public int Operand { get; } | |
| private readonly Computer _computer; | |
| public Operation(Computer computer, char @operator, int operand) | |
| { | |
| _computer = computer; | |
| Operator = @operator; | |
| Operand = operand; | |
| } | |
| public virtual void Apply() => _computer.Calc(Operator, Operand); | |
| public virtual void UnApply() => _computer.Calc(Opposite(Operator), Operand); | |
| private static char Opposite(char @operator) | |
| { | |
| switch (@operator) | |
| { | |
| case '+': return '-'; | |
| case '-': return '+'; | |
| case '*': return '/'; | |
| default: return '*'; | |
| } | |
| } | |
| } | |
| sealed class Calculator | |
| { | |
| private readonly Computer _computer = new Computer(); | |
| private readonly Stack<Operation> _memory = new Stack<Operation>(); | |
| public int Push(char @operator, int operand) | |
| { | |
| var operation = new Operation(_computer, @operator, operand); | |
| operation.Apply(); | |
| _memory.Push(operation); | |
| return _computer.Value; | |
| } | |
| public int Pop() | |
| { | |
| var operation = _memory.Pop(); | |
| operation.UnApply(); | |
| return _computer.Value; | |
| } | |
| } | |
| private readonly Calculator _calculator = new Calculator(); | |
| [Fact] | |
| public void Test() | |
| { | |
| _calculator.Push('+', 3).Should().Be(3); | |
| _calculator.Push('*', 2).Should().Be(6); | |
| _calculator.Pop().Should().Be(3); | |
| _calculator.Pop().Should().Be(0); | |
| } | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment