public void UpdateWithDifferentTargetOrDefaultReturnsNewLabel()
{
LabelTarget target = Expression.Label(typeof(int));
ConstantExpression defaultVal = Expression.Constant(42);
LabelExpression label = Expression.Label(target, defaultVal);
Assert.NotSame(label, label.Update(Expression.Label(typeof(int)), defaultVal));
Assert.NotSame(label, label.Update(target, Expression.Constant(42)));
}
public void UpdateWithSameTargetAndDefaultReturnsSameLabel()
{
LabelTarget target = Expression.Label(typeof(int));
ConstantExpression defaultVal = Expression.Constant(42);
LabelExpression label = Expression.Label(target, defaultVal);
Assert.Same(label, label.Update(target, defaultVal));
}
public T?Simplify <T>(T?expression) where T : Expression
{
if (expression is null)
{
return(null);
}
Expression expr = expression.Reduce() switch
{
UnaryExpression unaryExpr => unaryExpr.Update(Simplify(unaryExpr.Operand)),
BinaryExpression binaryExpr => binaryExpr.Update(Simplify(binaryExpr.Left), binaryExpr.Conversion, Simplify(binaryExpr.Right)),
LambdaExpression lambdaExpr => Expression.Lambda(Simplify(lambdaExpr.Body), lambdaExpr.Name, lambdaExpr.TailCall, Simplify(lambdaExpr.Parameters)),
TryExpression tryExpr => tryExpr.Update(Simplify(tryExpr.Body), Simplify(tryExpr.Handlers), Simplify(tryExpr.Finally), Simplify(tryExpr.Fault)),
NewExpression newExpr => newExpr.Update(Simplify(newExpr.Arguments)),
GotoExpression gotoExpr => gotoExpr.Update(gotoExpr.Target, Simplify(gotoExpr.Value)),
LoopExpression loopExpr => loopExpr.Update(loopExpr.BreakLabel, loopExpr.ContinueLabel, Simplify(loopExpr.Body)),
BlockExpression blockExpr => blockExpr.Update(Simplify(blockExpr.Variables), Simplify(blockExpr.Expressions)),
IndexExpression indexExpr => indexExpr.Update(Simplify(indexExpr.Object) !, Simplify(indexExpr.Arguments)),
LabelExpression labelExpr => labelExpr.Update(labelExpr.Target, Simplify(labelExpr.DefaultValue)),
MemberExpression memberExpr => memberExpr.Update(Simplify(memberExpr.Expression)),
SwitchExpression switchExpr => switchExpr.Update(Simplify(switchExpr.SwitchValue), Simplify(switchExpr.Cases), Simplify(switchExpr.DefaultBody)),
DynamicExpression dynamicExpr => dynamicExpr.Update(Simplify(dynamicExpr.Arguments)),
ListInitExpression listInitExpr => listInitExpr.Update(Simplify(listInitExpr.NewExpression), Simplify(listInitExpr.Initializers)),
NewArrayExpression newArrayExpr => newArrayExpr.Update(Simplify(newArrayExpr.Expressions)),
InvocationExpression invokeExpr => invokeExpr.Update(Simplify(invokeExpr.Expression), Simplify(invokeExpr.Arguments)),
MemberInitExpression memberInitExpr => memberInitExpr.Update(Simplify(memberInitExpr.NewExpression), memberInitExpr.Bindings),
MethodCallExpression methodCallExpr => methodCallExpr.Update(Simplify(methodCallExpr.Object), Simplify(methodCallExpr.Arguments)),
TypeBinaryExpression typeBinaryExpr => typeBinaryExpr.Update(Simplify(typeBinaryExpr.Expression)),
ConditionalExpression condExpr => condExpr.Update(Simplify(condExpr.Test), Simplify(condExpr.IfTrue), Simplify(condExpr.IfFalse)),
RuntimeVariablesExpression runtimeVarExpr => runtimeVarExpr.Update(Simplify(runtimeVarExpr.Variables)),
_ => expression
};
foreach (var transform in transformers)
{
expr = transform.Transform(expr, this);
}
return((T)expr);
}
private static Expression SetChildren(ReadOnlySpan <Expression> newChildren, LabelExpression l) => l.DefaultValue == null ? l : l.Update(l.Target, newChildren[0]);
/// <summary>
/// Visits the children of the <see cref="LabelExpression" />.
/// </summary>
/// <param name="node">The expression to visit.</param>
/// <returns>The modified expression, if it or any subexpression was modified;
/// otherwise, returns the original expression.</returns>
protected internal virtual Expression VisitLabel(LabelExpression node)
{
return(node.Update(VisitLabelTarget(node.Target), Visit(node.DefaultValue)));
}
protected override Expression VisitLabel(LabelExpression node)
{
return(node.Update(this.VisitLabelTarget(node.Target), _defaultValue));
}
protected virtual Expression VisitLabel(LabelExpression node, Type expectedType) => node.Update(VisitLabelTarget(node.Target, expectedType), Visit(node.DefaultValue, expectedType));
