Add Search feature

AhoCorasick.Net.sln

@@ -14,8 +14,6 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = ".nuget", ".nuget", "{9EBF4F
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "build", "build", "{311D94BD-6DCE-46D8-862C-71AB38D19C14}"
-EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{389268B9-F389-4506-B79D-B2F4889F41D5}"
 	ProjectSection(SolutionItems) = preProject
 		build\AhoCorasick.Net.nuspec = build\AhoCorasick.Net.nuspec
 		build\AhoCorasick.Net.Source.nuspec = build\AhoCorasick.Net.Source.nuspec

src/AhoCorasick.Net/AhoCorasickTree.cs

@@ -58,6 +58,43 @@ public bool Contains(string text)
             return false;
         }
 
+        // todo copy paste from Contains method: Refactor!
+        // todo check performance 
+        public IEnumerable<KeyValuePair<string, int>> Search(string text)
+        {
+            var currentNode = _rootNode;
+
+            var length = text.Length;
+            for (var i = 0; i < length; i++)
+            {
+                while (true)
+                {
+                    var node = currentNode.GetNode(text[i]);
+                    if (node == null)
+                    {
+                        currentNode = currentNode.Failure;
+                        if (currentNode == _rootNode)
+                        {
+                            break;
+                        }
+                    }
+                    else
+                    {
+                        if (node.IsFinished)
+                        {
+                            foreach (var result in node.Results)
+                            {
+                                yield return new KeyValuePair<string, int>(result, i - result.Length + 1);
+                            }
+                        }
+
+                        currentNode = node;
+                        break;
+                    }
+                }
+            }
+        }
+
         private void AddPatternToTree(string pattern)
         {
             var latestNode = _rootNode;
@@ -69,6 +106,7 @@ private void AddPatternToTree(string pattern)
             }
 
             latestNode.IsFinished = true;
+            latestNode.Results.Add(pattern);
         }
 
         private void SetFailures()
@@ -107,8 +145,8 @@ private void SetFailures()
                 if (!currentNode.IsFinished)
                 {
                     currentNode.IsFinished = failure.IsFinished;
+                    currentNode.Results.AddRange(failure.Results);
                 }
-
             }
         }
 
@@ -117,6 +155,7 @@ private class AhoCorasickTreeNode
             public readonly AhoCorasickTreeNode Parent;
             public AhoCorasickTreeNode Failure;
             public bool IsFinished;
+            public List<string> Results;
             public readonly char Key;
 
             private int[] _buckets;
@@ -135,6 +174,7 @@ private AhoCorasickTreeNode(AhoCorasickTreeNode parent, char key)
 
                 _buckets = new int[0];
                 _entries = new Entry[0];
+                Results = new List<string>();
             }
 
             public AhoCorasickTreeNode[] Nodes

tests/AhoCorasick.Net.Tests/AhoCorasickTreeTests.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 
 using Xunit;
 using Xunit.Extensions;
@@ -32,6 +34,19 @@ public void InvalidKeywords(string[] keywords, Type exceptionType)
             Assert.Throws(exceptionType, () => new AhoCorasickTree(keywords));
         }
 
+        [Fact]
+        public void FindKeywordAndPosition()
+        {
+            var keywords = new AhoCorasickTree(new[] { "Mozilla", "6.3", "KHTML", "someKeyword" });
+            var userAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.99 Safari/537.36";
+            var keywordsPositions = keywords.Search(userAgent).ToList();
+
+            Assert.Equal(3, keywordsPositions.Count);
+            Assert.Contains(new KeyValuePair<string, int>("Mozilla", 0), keywordsPositions);
+            Assert.Contains(new KeyValuePair<string, int>("6.3", 24), keywordsPositions);
+            Assert.Contains(new KeyValuePair<string, int>("KHTML", 56), keywordsPositions);
+        }
+
         [Fact]
         public void Performance()
         {