Suggestion to add NotIn operator

[HowardHoulston]

Excellent code - thank you for sharing it.

I notice there is an In operator but unless I'm missing something, no NotIn operator.

I implemented as follows:

namespace ExpressionBuilder.Operations
{
    /// <summary>
    /// Operation representing a list "Contains" method call = false.
    /// </summary>
    public class NotIn : OperationBase
    {
        /// <inheritdoc />
        public NotIn()
            : base("NotIn", 1, TypeGroup.Default | TypeGroup.Boolean | TypeGroup.Date | TypeGroup.Number | TypeGroup.Text, true, true) { }

        /// <inheritdoc />
        public override Expression GetExpression(MemberExpression member, ConstantExpression constant1, ConstantExpression constant2)
        {
            if (!(constant1.Value is IList) || !constant1.Value.GetType().IsGenericType)
            {
                throw new ArgumentException("The 'NotIn' operation only supports lists as parameters.");
            }

            var type = constant1.Value.GetType();
            var inInfo = type.GetMethod("Contains", new[] { type.GetGenericArguments()[0] });
            var contains = Expression.Call(constant1, inInfo, member);
            return Expression.Not(contains);
        }
    }
}

And adding to the Operation class:

/// <summary>
/// Operation representing a list "Contains" method call = false.
/// </summary>
public static IOperation NotIn { get { return new NotIn(); } }

I hope this helps. Forgive me - I've never done a pull / submission so don't know the process.

Regards

[dbelmont]

Hi @HowardHoulston,
Many thanks for using the project and for your contribution! 😄 (and sorry for the late reply 😅)
I'll include this in the next release and make myself sure I mention your name in the commit message and the release notes to give you the due credit.
Many thanks.