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src/Nest/Analysis/TokenFilters/PredicateTokenFilter .cs

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+using System;
+using Newtonsoft.Json;
+
+namespace Nest
+{
+	/// <summary>
+	/// The predicate_token_filter token filter takes a predicate script, and removes tokens that do
+	/// not match the predicate.
+	/// </summary>
+	public interface IPredicateTokenFilter : ITokenFilter
+	{
+		/// <summary>
+		/// a predicate script that determines whether or not the current token will
+		/// be emitted.  Note that only inline scripts are supported.
+		/// </summary>
+		[JsonProperty("script")]
+		IScript Script { get; set; }
+	}
+
+	public class PredicateTokenFilter : TokenFilterBase, IPredicateTokenFilter
+	{
+		public PredicateTokenFilter() : base("predicate_token_filter") { }
+
+		public IScript Script { get; set; }
+	}
+
+	/// <inheritdoc cref="IPredicateTokenFilter" />
+	public class PredicateTokenFilterDescriptor
+		: TokenFilterDescriptorBase<PredicateTokenFilterDescriptor, IPredicateTokenFilter>, IPredicateTokenFilter
+	{
+		protected override string Type => "predicate_token_filter";
+
+		IScript IPredicateTokenFilter.Script { get; set; }
+
+		/// <inheritdoc cref="IPredicateTokenFilter.Script" />
+		public PredicateTokenFilterDescriptor Script(Func<ScriptDescriptor, IScript> scriptSelector) =>
+			Assign(a => a.Script = scriptSelector?.Invoke(new ScriptDescriptor()));
+
+		/// <inheritdoc cref="IPredicateTokenFilter.Script" />
+		public PredicateTokenFilterDescriptor Script(string predicate) =>
+			Assign(a => a.Script = new InlineScript(predicate));
+	}
+}