Define a class with mutable variable

• Category: Defining Types
• Description: Define a class with mutable variable
• Code:

using System;
using System.Console;

enum BuilderState
{
  | None
  | Active
  | Completed
}

// opens BuilderState enumeration to implicitly access it's internal structure
using BuilderState;

class Builder
{
  // a current state mutable auto property with private setter
  public CurrentState : BuilderState { get; private set; }

  public Begin() : void { CurrentState = Active }

  public End() : void
  {
    // complete the build process...
    CurrentState = Completed
  }
}

def print_state(b) { WriteLine($"current state = $(b.CurrentState)") }

def b = Builder();
print_state(b);
b.Begin();
print_state(b);
b.End();
print_state(b);

• Execution Result:

current state = None
current state = Active
current state = Completed