LangMatches.cs

using System.Threading.Tasks;
using Waher.Script;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Content.Semantic.Functions
{
    public class LangMatches : FunctionTwoScalarVariables
    {
        public LangMatches(ScriptNode Value, ScriptNode Type, int Start, int Length, Expression Expression)
            : base(Value, Type, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(LangMatches);
 
        public override string[] DefaultArgumentNames => new string[] { "Language", "Pattern" };
 
        public override bool UpgradeScalarsToSameSet => true;
 
        public override IElement EvaluateScalar(string Argument1, string Argument2, Variables Variables)
        {
            if (string.IsNullOrEmpty(Argument1))
                return BooleanValue.False;
 
            if (Argument2 == "*")
                return BooleanValue.True;
 
            if (Argument2.IndexOf('-') >= 0)
                return string.Compare(Argument1, Argument2, true) == 0 ? BooleanValue.True : BooleanValue.False;
 
            int i = Argument1.IndexOf('-');
            if (i >= 0)
                Argument1 = Argument1.Substring(0, i);
 
            return string.Compare(Argument1, Argument2, true) == 0 ? BooleanValue.True : BooleanValue.False;
        }
 
        public override Task<IElement> EvaluateScalarAsync(string Argument1, string Argument2, Variables Variables)
        {
            return Task.FromResult(this.EvaluateScalar(Argument1, Argument2, Variables));
        }
    }
}