public void GivenAnApplicationEvaluateTheApplicationCorrectly()
{
var application = @"(λx.(λy.x)) (λx.(λy.x))";
var lambdaExpression = _parser.Parse(application);
var interpreter = new InterpreterVisitor();
var events = new ReductionEventCollector();
ConnectEvents(interpreter, events);
lambdaExpression.Accept(interpreter);
var printVisitor = new NormalFormVisitor();
interpreter.Result.Accept(printVisitor);
Assert.Collection(events.Events,
e => Assert.Equal("α", e),
e => Assert.Equal("β", e));
Assert.Equal("λy.(λx0.(λx1.x0))", printVisitor.Result);
}
private static void ConnectEvents(InterpreterVisitor interpreter, ReductionEventCollector events)
{
interpreter.AlphaReductionEvent += events.OnAlphaReductionEvent;
interpreter.BetaReductionEvent += events.OnBetaReductionEvent;
interpreter.EtaReductionEvent += events.OnEtaReductionEvent;
}