Add percentage and scripted heuristics to significant terms

src/Nest/DSL/Aggregations/SignificantTermsAggregationDescriptor.cs

@@ -40,6 +40,12 @@ public interface ISignificantTermsAggregator : IBucketAggregator
 		[JsonProperty("gnd")]
 		GoogleNormalizedDistanceHeuristic GoogleNormalizedDistance { get; set; }
 
+		[JsonProperty("percentage")]
+		PercentageScoreHeuristic PercentageScore { get; set; }
+
+		[JsonProperty("script_heuristic")]
+		ScriptedHeuristic Script { get; set; }
+
 		[JsonProperty("background_filter")]
 		IFilterContainer BackgroundFilter { get; set; }
 
@@ -57,6 +63,8 @@ public class SignificantTermsAggregator : BucketAggregator, ISignificantTermsAgg
 		public MutualInformationHeuristic MutualInformation { get; set; }
 		public ChiSquareHeuristic ChiSquare { get; set; }
 		public GoogleNormalizedDistanceHeuristic GoogleNormalizedDistance { get; set; }
+		public PercentageScoreHeuristic PercentageScore { get; set; }
+		public ScriptedHeuristic Script { get; set; }
 		public IFilterContainer BackgroundFilter { get; set; }
 	}
 
@@ -84,6 +92,10 @@ public class SignificantTermsAggregationDescriptor<T> : BucketAggregationBaseDes
 
 		GoogleNormalizedDistanceHeuristic ISignificantTermsAggregator.GoogleNormalizedDistance { get; set; }
 
+		PercentageScoreHeuristic ISignificantTermsAggregator.PercentageScore { get; set; }
+
+		ScriptedHeuristic ISignificantTermsAggregator.Script { get; set; }
+
 		IFilterContainer ISignificantTermsAggregator.BackgroundFilter { get; set; }
 
 		public SignificantTermsAggregationDescriptor<T> Field(string field)
@@ -167,6 +179,18 @@ public SignificantTermsAggregationDescriptor<T> GoogleNormalizedDistance(bool? b
 			return this;
 		}
 
+		public SignificantTermsAggregationDescriptor<T> PercentageScore()
+		{
+			this.Self.PercentageScore = new PercentageScoreHeuristic();
+			return this;
+		}
+
+		public SignificantTermsAggregationDescriptor<T> Script(Func<ScriptedHeuristicDescriptor, ScriptedHeuristicDescriptor> scriptSelector)
+		{
+			this.Self.Script = scriptSelector(new ScriptedHeuristicDescriptor()).ScriptedHeuristic;
+			return this;
+		}
+
 		public SignificantTermsAggregationDescriptor<T> BackgroundFilter(Func<FilterDescriptor<T>, FilterContainer> selector)
 		{
 			this.Self.BackgroundFilter = selector(new FilterDescriptor<T>());

src/Nest/Domain/Aggregations/ISignificantTermsHeuristic.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using Newtonsoft.Json;
+using System;
 
 namespace Nest
 {
@@ -25,4 +26,39 @@ public class GoogleNormalizedDistanceHeuristic
 		public bool? BackgroundIsSuperSet { get; set; }
 	}
 
+	public class PercentageScoreHeuristic
+	{
+	}
+
+	public class ScriptedHeuristic
+	{
+		[JsonProperty("script")]
+		public string Script { get; set; }
+		[JsonProperty("lang")]
+		public string Lang { get; set; }
+		[JsonProperty("params")]
+		public IDictionary<string, object> Params { get; set; }
+	}
+
+	public class ScriptedHeuristicDescriptor
+	{
+		internal ScriptedHeuristic ScriptedHeuristic = new ScriptedHeuristic();
+		public ScriptedHeuristicDescriptor Script(string script)
+		{
+			this.ScriptedHeuristic.Script = script;
+			return this;
+		}
+
+		public ScriptedHeuristicDescriptor Lang(string lang)
+		{
+			this.ScriptedHeuristic.Lang = lang;
+			return this;
+		}
+
+		public ScriptedHeuristicDescriptor Params(Func<FluentDictionary<string, object>, FluentDictionary<string, object>> paramsSelector)
+		{
+			this.ScriptedHeuristic.Params = paramsSelector(new FluentDictionary<string, object>());
+			return this;
+		}
+	}
 }