Cis/EC.Helper/RabbitFunc/Expressions/ParameterExpression.cs

using EC.Helper.RabbitFunc.Runtime;
using MissingMemberException = EC.Helper.RabbitFunc.Runtime.MissingMemberException;

namespace EC.Helper.RabbitFunc.Expressions;

public class ParameterExpression : Expression
{
    internal ParameterExpression(ExpressionType nodeType, Type type, string name)
        : base(nodeType)
    {
        Type = type;
        Name = name;
    }

    public override Type Type { get; }

    public string Name { get; }

    internal static object Access(RuntimeContext context, string name)
    {
        var value = context.Access(name);
        if (value == null)
            throw new MissingMemberException(string.Format("missing member:{0}", name));

        return value.Value;
    }

    internal static T Access<T>(RuntimeContext context, string name)
    {
        return (T)Access(context, name);
    }

    public override object Eval(RuntimeContext context)
    {
        if (context == null)
            throw new ArgumentNullException(nameof(context));

        return Access(context, Name);
    }

    public override string ToString()
    {
        return Name;
    }
}