public override Expression Visit(Expression node)
{
if (node == null || !IsNullable(node.Type))
{
return base.Visit(node);
}
var oldPropagationPoint = _propagationPoint;
_propagationPoint = new PropagationPoint();
var transformedExpression = base.Visit(node);
if (_propagationPoint.IsActive)
{
var result = Expression.Variable(node.Type);
transformedExpression = Expression.Block(
new[] { result },
Expression.Assign(result, Expression.Constant(null, node.Type)),
Expression.Assign(result, transformedExpression),
Expression.Label(_propagationPoint.Label),
result);
}
_propagationPoint = oldPropagationPoint;
return transformedExpression;
}
public override Expression Visit(Expression node)
{
if (node == null || node.NodeType == ExpressionType.Lambda)
{
return(node);
}
if (!IsNullable(node.Type))
{
return(base.Visit(node));
}
var oldPropagationPoint = _propagationPoint;
_propagationPoint = new PropagationPoint();
var transformedExpression = base.Visit(node);
if (_propagationPoint.IsActive)
{
var result = Expression.Variable(node.Type);
transformedExpression = Expression.Block(
new[] { result },
Expression.Assign(result, Expression.Constant(null, node.Type)),
Expression.Assign(result, transformedExpression),
Expression.Label(_propagationPoint.Label),
result);
}
_propagationPoint = oldPropagationPoint;
return(transformedExpression);
}