public void Visit(FuncExpression <T> expression)
{
if (_random.NextDouble() < _mutationRate.GetValue())
{
MutateFuncExpression(expression);
}
}
public void Evaluate_WhenCalled_ReturnsExpected()
{
var expression = new FuncExpression <SomeClass>()
{
Left = new ValueExpression <SomeClass>(5.0),
Right = new ValueExpression <SomeClass>(9.0),
Operation = new Operation((a, b) => a + b, "+"),
};
var someClass = new SomeClass();
Assert.That(expression.Evaluate(someClass), Is.EqualTo(14.0));
}
private void MutateFuncExpression(FuncExpression <T> expression)
{
var rand = _random.NextDouble();
if (rand < 0.33)
{
expression.Left = _expressionGenerator.GetRandomExpression();
}
else if (rand < 0.67)
{
expression.Right = _expressionGenerator.GetRandomExpression();
}
else
{
expression.Operation = _expressionGenerator.GetRandomOperation();
}
}
public void Evaluate_WhenClonedAndCloneHasRightChanged_Unchanged()
{
var expression = new FuncExpression <SomeClass>()
{
Left = new ValueExpression <SomeClass>(5.0),
Right = new ValueExpression <SomeClass>(9.0),
Operation = new Operation((a, b) => a + b, "+"),
};
var clone = (FuncExpression <SomeClass>)expression.Clone();
clone.Right = new ValueExpression <SomeClass>(3.0);
var someClass = new SomeClass();
Assert.That(expression.Evaluate(someClass), Is.EqualTo(14.0));
Assert.That(clone.Evaluate(someClass), Is.EqualTo(8.0));
}
/// <summary> /// Creates an expression from a 2-argument function delegate /// </summary> /// <typeparam name="X1">The type of the delegate's first argument</typeparam> /// <typeparam name="X2">The type of the delegate's second argument</typeparam> /// <typeparam name="Y">The delegate return type</typeparam> /// <param name="f"></param> /// <returns></returns> public static Expression <Func <X1, X2, Y> > funcx <X1, X2, Y>(Func <X1, X2, Y> f) => FuncExpression.make(f);
//public static Converter converter(MethodInfo m)
//{
// var src = Expression.Parameter(typeof(object), "src");
// var convert = Expression.Convert(src, m.GetParameters()[0].ParameterType);
// var callResult = Expression.Call(null, m, convert);
// var result = Expression.Convert(callResult, typeof(object));
// return Expression.Lambda<Converter>(result, src).Compile();
//}
//public static Converter<TDst> converter<TDst>(MethodInfo m)
//{
// var src = Expression.Parameter(typeof(object), "src");
// var convert = Expression.Convert(src, m.GetParameters()[0].ParameterType);
// var callResult = Expression.Call(null, m, convert);
// return Expression.Lambda<Converter<TDst>>(callResult, src).Compile();
//}
/// <summary>
/// Creates an expression from a parameterless function delegate delegate
/// </summary>
/// <typeparam name="T">The delegate return type</typeparam>
/// <param name="f"></param>
/// <returns></returns>
public static Expression <Func <T> > funcx <T>(Func <T> f)
=> FuncExpression.make(f);
static FuncExpression <X, Y> Converter() => FuncExpression.make((X x) => (Y)Convert.ChangeType(x, typeof(Y)));
