Merge pull request #32 from rvhuang/wip-debug-helper-2

Improve algorithm observation APIs
rvhuang · Jan 14, 2019 · 29000d7 · 29000d7
2 parents e5fe133 + 127d302
commit 29000d7
Show file tree

Hide file tree

Showing 11 changed files with 91 additions and 63 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -7,7 +7,9 @@ dotnet: 2.2
 
 install:
 - dotnet restore src/Heuristic.Linq.sln
+- dotnet restore src/Heuristic.Linq.Example.sln
 
 script:
 - dotnet build src/Heuristic.Linq.sln
+- dotnet build src/Heuristic.Linq.Example.sln
 - dotnet test src/Heuristic.Linq.Test/Heuristic.Linq.Test.csproj -c Release
diff --git a/src/Heuristic.Linq.Example.EightPuzzle/Heuristic.Linq.Example.EightPuzzle.csproj b/src/Heuristic.Linq.Example.EightPuzzle/Heuristic.Linq.Example.EightPuzzle.csproj
@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Heuristic.Linq\Heuristic.Linq.csproj" />
+    <PackageReference Include="linq-to-astar" Version="1.1.0" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Heuristic.Linq.Example.PathFinding/Heuristic.Linq.Example.PathFinding.csproj b/src/Heuristic.Linq.Example.PathFinding/Heuristic.Linq.Example.PathFinding.csproj
@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Heuristic.Linq\Heuristic.Linq.csproj" />
+    <PackageReference Include="linq-to-astar" Version="1.1.0" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/src/Heuristic.Linq.Example.sln b/src/Heuristic.Linq.Example.sln
@@ -0,0 +1,64 @@
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.27428.2015
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Example", "Heuristic.Linq.Example\Heuristic.Linq.Example.csproj", "{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Example.PathFinding", "Heuristic.Linq.Example.PathFinding\Heuristic.Linq.Example.PathFinding.csproj", "{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Example.EightPuzzle", "Heuristic.Linq.Example.EightPuzzle\Heuristic.Linq.Example.EightPuzzle.csproj", "{16307EF6-A7BB-4E54-8496-9F39CAE78D90}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x64.Build.0 = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x86.Build.0 = Debug|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x64.ActiveCfg = Release|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x64.Build.0 = Release|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x86.ActiveCfg = Release|Any CPU
+		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x86.Build.0 = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x64.Build.0 = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x86.Build.0 = Debug|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x64.ActiveCfg = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x64.Build.0 = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x86.ActiveCfg = Release|Any CPU
+		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x86.Build.0 = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x64.Build.0 = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x86.Build.0 = Debug|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|Any CPU.Build.0 = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x64.ActiveCfg = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x64.Build.0 = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x86.ActiveCfg = Release|Any CPU
+		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {C5E73D1C-3461-42FF-817B-0EF9965EFCAE}
+	EndGlobalSection
+EndGlobal
diff --git a/src/Heuristic.Linq.Example/Heuristic.Linq.Example.csproj b/src/Heuristic.Linq.Example/Heuristic.Linq.Example.csproj
@@ -6,6 +6,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Heuristic.Linq\Heuristic.Linq.csproj" />
+    <PackageReference Include="linq-to-astar" Version="1.1.0" />
   </ItemGroup>
 </Project>
diff --git a/src/Heuristic.Linq.Test/ObserverTest.cs b/src/Heuristic.Linq.Test/ObserverTest.cs
@@ -1,5 +1,6 @@
 using Moq;
 using System;
+using System.Diagnostics;
 using System.Drawing;
 using System.Linq;
 using Xunit;
@@ -22,9 +23,11 @@ public class ObserverTest
         [InlineData(nameof(RecursiveBestFirstSearch))]
         public void TestIProgressOnlyCreatedOnce(string algorithmName)
         {
-            var factory = new Mock<IAlgorithmObserverFactory>();
+            var factory = new Mock<IAlgorithmObserverFactory<Point>>();
+            var progress = new Progress<AlgorithmState<Point, Point>>();
 
-            factory.Setup(f => f.Create(It.IsAny<HeuristicSearchBase<Point, Point>>())).Returns(() => new Progress<AlgorithmState<Point, Point>>());
+            progress.ProgressChanged += (o, e) => Debug.WriteLine("{0}\t{1} ({2})", e.Node.Step, e.Node.Level, nameof(progress.ProgressChanged));
+            factory.Setup(f => f.Create(It.IsAny<HeuristicSearchBase<Point, Point>>())).Returns(() => progress);
 
             var queryable = HeuristicSearch.Use(algorithmName, start, goal, (step, lv) => step.GetFourDirections(unit), null, factory.Object);
             var obstacles = new[] { new Point(5, 5), new Point(6, 6), new Point(7, 7), new Point(8, 8), new Point(9, 9) };
@@ -44,7 +47,7 @@ orderby step.GetManhattanDistance(goal)
         [InlineData(nameof(RecursiveBestFirstSearch))]
         public void TestLastFlagFound(string algorithmName)
         {
-            var factory = new Mock<IAlgorithmObserverFactory>();
+            var factory = new Mock<IAlgorithmObserverFactory<Point>>();
             var progress = new Mock<IProgress<AlgorithmState<Point, Point>>>();
             var actual = default(AlgorithmFlag?);
             var expected = (AlgorithmFlag?)AlgorithmFlag.Found;
@@ -73,7 +76,7 @@ orderby step.GetManhattanDistance(goal)
         [InlineData(nameof(RecursiveBestFirstSearch))]
         public void TestLastFlagNotFound(string algorithmName)
         {
-            var factory = new Mock<IAlgorithmObserverFactory>();
+            var factory = new Mock<IAlgorithmObserverFactory<Point>>();
             var progress = new Mock<IProgress<AlgorithmState<Point, Point>>>();
             var actual = default(AlgorithmFlag?);
             var expected = (AlgorithmFlag?)AlgorithmFlag.NotFound;

diff --git a/src/Heuristic.Linq.sln b/src/Heuristic.Linq.sln
@@ -4,14 +4,8 @@ VisualStudioVersion = 15.0.27428.2015
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq", "Heuristic.Linq\Heuristic.Linq.csproj", "{3CBF214D-8F76-4EA2-8B52-F517C4C44D5E}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Example", "Heuristic.Linq.Example\Heuristic.Linq.Example.csproj", "{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Test", "Heuristic.Linq.Test\Heuristic.Linq.Test.csproj", "{E13EDB71-C5DB-40B0-A097-94ACB803347B}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Heuristic.Linq.Example.PathFinding", "Heuristic.Linq.Example.PathFinding\Heuristic.Linq.Example.PathFinding.csproj", "{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Heuristic.Linq.Example.EightPuzzle", "Heuristic.Linq.Example.EightPuzzle\Heuristic.Linq.Example.EightPuzzle.csproj", "{16307EF6-A7BB-4E54-8496-9F39CAE78D90}"
-EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -34,18 +28,6 @@ Global
 		{3CBF214D-8F76-4EA2-8B52-F517C4C44D5E}.Release|x64.Build.0 = Release|Any CPU
 		{3CBF214D-8F76-4EA2-8B52-F517C4C44D5E}.Release|x86.ActiveCfg = Release|Any CPU
 		{3CBF214D-8F76-4EA2-8B52-F517C4C44D5E}.Release|x86.Build.0 = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x64.Build.0 = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Debug|x86.Build.0 = Debug|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x64.ActiveCfg = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x64.Build.0 = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x86.ActiveCfg = Release|Any CPU
-		{2A7970EB-AFC3-476E-83B4-EB2175AA26ED}.Release|x86.Build.0 = Release|Any CPU
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Debug|x64.ActiveCfg = Debug|Any CPU
@@ -58,30 +40,6 @@ Global
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Release|x64.Build.0 = Release|Any CPU
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Release|x86.ActiveCfg = Release|Any CPU
 		{E13EDB71-C5DB-40B0-A097-94ACB803347B}.Release|x86.Build.0 = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x64.Build.0 = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Debug|x86.Build.0 = Debug|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x64.ActiveCfg = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x64.Build.0 = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x86.ActiveCfg = Release|Any CPU
-		{4A5F4997-8FCC-4DE0-8954-DC69F7AC499E}.Release|x86.Build.0 = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x64.Build.0 = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Debug|x86.Build.0 = Debug|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|Any CPU.Build.0 = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x64.ActiveCfg = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x64.Build.0 = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x86.ActiveCfg = Release|Any CPU
-		{16307EF6-A7BB-4E54-8496-9F39CAE78D90}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

diff --git a/src/Heuristic.Linq/Heuristic.Linq.csproj b/src/Heuristic.Linq/Heuristic.Linq.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
@@ -8,17 +8,17 @@
     <Authors>Robert Vandenberg Huang</Authors>
     <Product>Linq To A*</Product>
     <PackageLicenseUrl>https://raw.githubusercontent.com/rvhuang/linq-to-astar/master/LICENSE</PackageLicenseUrl>
-    <Version>1.2.0-beta</Version>
+    <Version>1.2.0-beta2</Version>
     <PackageId>linq-to-astar</PackageId>
     <PackageTags>linq;astar;heuristic</PackageTags>
     <Copyright>© 2019 Robert Vandenberg Huang</Copyright>
-    <Description>LINQ to A* is a POC aimed to incorporate LINQ into A* as well as other heuristic search algorithms. With the library, LINQ can now be used as query expression to state conditions and fetch shortest path found by the algorithm.</Description>
+    <Description>LINQ to A* is a POC aimed to bring LINQ to A* and other heuristic search algorithms. The library enables LINQ to be used as the query expression to the algorithm.</Description>
     <PackageIconUrl>https://raw.githubusercontent.com/rvhuang/linq-to-astar/master/favicon.ico</PackageIconUrl>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <SignAssembly>false</SignAssembly>
-    <PackageReleaseNotes>1. New interface IAlgorithmObserverFactory and a set of APIs have been added to support algorithm observation.
-2. All built-in algorithms now can be observed.
-3. Fix incorrect documentation comments.</PackageReleaseNotes>
+    <PackageReleaseNotes>1. The interface IAlgorithmObserverFactory has been redesigned for easier use.
+2. All APIs that accept IAlgorithmObserverFactory arguments have been changed.
+3. Fix grammatical errors in documentation comments.</PackageReleaseNotes>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">

diff --git a/src/Heuristic.Linq/HeuristicSearch.cs b/src/Heuristic.Linq/HeuristicSearch.cs
@@ -87,7 +87,7 @@ public static HeuristicSearchBase<TStep, TStep> AStar<TStep>(TStep from, TStep t
         /// <param name="observerFactory">The object that is able to create <see cref="IProgress{T}"/> instances.</param>
         /// <returns>The instance that is ready to be applied with LINQ expressions.</returns>
         /// <exception cref="ArgumentNullException"><paramref name="expander"/> is null.</exception>
-        public static HeuristicSearchBase<TStep, TStep> AStar<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory observerFactory)
+        public static HeuristicSearchBase<TStep, TStep> AStar<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory<TStep> observerFactory)
         {
             return new HeuristicSearchInitial<TStep>(nameof(AStar), from, to, comparer, expander) { AlgorithmObserverFactory = observerFactory };
         }
@@ -132,7 +132,7 @@ public static HeuristicSearchBase<TStep, TStep> BestFirstSearch<TStep>(TStep fro
         /// <param name="observerFactory">The object that is able to create <see cref="IProgress{T}"/> instances.</param>
         /// <returns>The instance that is ready to be applied with LINQ expressions.</returns>
         /// <exception cref="ArgumentNullException"><paramref name="expander"/> is null.</exception>
-        public static HeuristicSearchBase<TStep, TStep> BestFirstSearch<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory observerFactory)
+        public static HeuristicSearchBase<TStep, TStep> BestFirstSearch<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory<TStep> observerFactory)
         {
             return new HeuristicSearchInitial<TStep>(nameof(BestFirstSearch), from, to, comparer, expander) { AlgorithmObserverFactory = observerFactory };
         }
@@ -177,7 +177,7 @@ public static HeuristicSearchBase<TStep, TStep> RecursiveBestFirstSearch<TStep>(
         /// <param name="observerFactory">The object that is able to create <see cref="IProgress{T}"/> instances.</param>
         /// <returns>The instance that is ready to be applied with LINQ expressions.</returns>
         /// <exception cref="ArgumentNullException"><paramref name="expander"/> is null.</exception>
-        public static HeuristicSearchBase<TStep, TStep> RecursiveBestFirstSearch<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory observerFactory)
+        public static HeuristicSearchBase<TStep, TStep> RecursiveBestFirstSearch<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory<TStep> observerFactory)
         {
             return new HeuristicSearchInitial<TStep>(nameof(RecursiveBestFirstSearch), from, to, comparer, expander) { AlgorithmObserverFactory = observerFactory };
         }
@@ -222,7 +222,7 @@ public static HeuristicSearchBase<TStep, TStep> IterativeDeepeningAStar<TStep>(T
         /// <param name="observerFactory">The object that is able to create <see cref="IProgress{T}"/> instances.</param>
         /// <returns>The instance that is ready to be applied with LINQ expressions.</returns>
         /// <exception cref="ArgumentNullException"><paramref name="expander"/> is null.</exception>
-        public static HeuristicSearchBase<TStep, TStep> IterativeDeepeningAStar<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory observerFactory)
+        public static HeuristicSearchBase<TStep, TStep> IterativeDeepeningAStar<TStep>(TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory<TStep> observerFactory)
         {
             return new HeuristicSearchInitial<TStep>(nameof(IterativeDeepeningAStar), from, to, comparer, expander) { AlgorithmObserverFactory = observerFactory };
         }
@@ -320,7 +320,7 @@ public static HeuristicSearchBase<TStep, TStep> Use<TStep>(string algorithmName,
         /// <returns>The instance that is ready to be applied with LINQ expressions.</returns>
         /// <exception cref="ArgumentNullException"><paramref name="algorithmName"/> or <paramref name="expander"/> is null.</exception>
         /// <exception cref="ArgumentException"><paramref name="algorithmName"/> cannot be found.</exception>
-        public static HeuristicSearchBase<TStep, TStep> Use<TStep>(string algorithmName, TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory observerFactory)
+        public static HeuristicSearchBase<TStep, TStep> Use<TStep>(string algorithmName, TStep from, TStep to, Func<TStep, int, IEnumerable<TStep>> expander, IEqualityComparer<TStep> comparer, IAlgorithmObserverFactory<TStep> observerFactory)
         {
             try
             {

diff --git a/src/Heuristic.Linq/HeuristicSearchBase.cs b/src/Heuristic.Linq/HeuristicSearchBase.cs
@@ -53,7 +53,7 @@ public abstract class HeuristicSearchBase<TFactor, TStep> : IEnumerable<TFactor>
         /// </summary>
         public INodeComparer<TFactor, TStep> NodeComparer => _nc;
 
-        internal IAlgorithmObserverFactory AlgorithmObserverFactory { get; set; }
+        internal IAlgorithmObserverFactory<TStep> AlgorithmObserverFactory { get; set; }
 
         internal bool IsReversed { get; set; } // Consider exposing this.