private static Expression MakeLocal(Expression e)
{
if (e.NodeType == ExpressionType.Constant)
{
return(e);
}
else if (e.NodeType == ExpressionType.Convert || e.NodeType == ExpressionType.ConvertChecked)
{
UnaryExpression ue = (UnaryExpression)e;
if (ue.Type == typeof(object))
{
Expression local = MakeLocal(ue.Operand);
return((e.NodeType == ExpressionType.Convert) ? Expression.Convert(local, e.Type) : Expression.ConvertChecked(local, e.Type));
}
// convert a const null
if (ue.Operand.NodeType == ExpressionType.Constant)
{
ConstantExpression c = (ConstantExpression)ue.Operand;
if (c.Value == null)
{
return(Expression.Constant(null, ue.Type));
}
}
}
var useExpressionFunctions = Mindbox.Data.Linq.Configuration.UseExpressionFunctions();
var function = useExpressionFunctions
? ExpressionFunctionFactory.Create(e)
: Expression.Lambda(e).Compile();
return(Expression.Invoke(Expression.Constant(function)));
}
private static object EvaluateViaExpressionFunction(Expression expression)
{
var evaluator = ExpressionFunctionFactory.Create(expression);
return(evaluator.DynamicInvoke());
}
