Update Like method

Update Like method
Issue: #30

Author: JonathanMagnan

Main/Source/NMemory.Lab/Form1.cs

@@ -20,7 +20,7 @@ public Form1()
             MyDatabase myDatabase = new MyDatabase();
 
             myDatabase.Members.Insert(new Member() {Id = "1", Name = "abc"});
-            var list = myDatabase.Members.Where(x => x.Name == "Abc").ToList();
+            var list = myDatabase.Members.Where(x => Functions.Like(x.Name, "%e%")).ToList();
 
         }
 

Main/Source/NMemory.Net45/NMemory.Net45.csproj

@@ -33,7 +33,7 @@
     <DocumentationFile>bin\Release\NMemory.xml</DocumentationFile>
   </PropertyGroup>
   <PropertyGroup>
-    <SignAssembly>true</SignAssembly>
+    <SignAssembly>false</SignAssembly>
   </PropertyGroup>
   <PropertyGroup>
     <AssemblyOriginatorKeyFile>Key.snk</AssemblyOriginatorKeyFile>

Main/Source/NMemory.Net45/Properties/AssemblyVisibility.cs

@@ -24,5 +24,5 @@
 
 using System.Runtime.CompilerServices;
 
-//[assembly: InternalsVisibleTo("NMemory.Test")]
-[assembly: InternalsVisibleTo("NMemory.Test, PublicKey=002400000480000094000000060200000024000052534131000400000100010007D1FA57C4AED9F0A32E84AA0FAEFD0DE9E8FD6AEC8F87FB03766C834C99921EB23BE79AD9D5DCC1DD9AD236132102900B723CF980957FC4E177108FC607774F29E8320E92EA05ECE4E821C0A5EFE8F1645C4C0C93C1AB99285D622CAA652C1DFAD63D745D6F2DE5F17E5EAF0FC4963D261C8A12436518206DC093344D5AD293")]
+[assembly: InternalsVisibleTo("NMemory.Test")]
+//[assembly: InternalsVisibleTo("NMemory.Test, PublicKey=002400000480000094000000060200000024000052534131000400000100010007D1FA57C4AED9F0A32E84AA0FAEFD0DE9E8FD6AEC8F87FB03766C834C99921EB23BE79AD9D5DCC1DD9AD236132102900B723CF980957FC4E177108FC607774F29E8320E92EA05ECE4E821C0A5EFE8F1645C4C0C93C1AB99285D622CAA652C1DFAD63D745D6F2DE5F17E5EAF0FC4963D261C8A12436518206DC093344D5AD293")]

Main/Source/NMemory.Shared/Functions.cs

@@ -22,6 +22,8 @@
 // </copyright>
 // ----------------------------------------------------------------------------------
 
+using System.Text;
+
 namespace NMemory
 {
     using System.Text.RegularExpressions;
@@ -30,20 +32,42 @@ public static class Functions
     {
         public static bool Like(string input, string pattern)
         {
-            // http://stackoverflow.com/questions/5663655/like-operator-in-linq-to-objects
+            // https://stackoverflow.com/a/5663768/5619143
+
+            var regex = new Regex(ConvertLikeToRegex(pattern), RegexOptions.IgnoreCase);
+            return IsRegexMatch(input, regex);
+        }
+
+        internal static bool IsRegexMatch(string input, Regex regex)
+        {
+            if (input == null)
+                return false;
+
+            return regex.IsMatch(input);
+        }
+
+        internal static string ConvertLikeToRegex(string pattern)
+        {
+            StringBuilder builder = new StringBuilder();
+            // Turn "off" all regular expression related syntax in the pattern string
+            // and add regex begining of and end of line tokens so '%abc' and 'abc%' work as expected
+            builder.Append("^").Append(Regex.Escape(pattern)).Append("$");
 
-            // Turn "off" all regular expression related syntax in the pattern string.
-            pattern = Regex.Escape(pattern);
+            /* Replace the SQL LIKE wildcard metacharacters with the
+            * equivalent regular expression metacharacters. */
+            builder.Replace("%", ".*").Replace("_", ".");
 
-            // Replace the SQL LIKE wildcard metacharacters with the equivalent regular expression metacharacters.
-            pattern = pattern.Replace("%", ".*?").Replace("_", ".");
+            /* The previous call to Regex.Escape actually turned off
+            * too many metacharacters, i.e. those which are recognized by
+            * both the regular expression engine and the SQL LIKE
+            * statement ([...] and [^...]). Those metacharacters have
+            * to be manually unescaped here. */
+            builder.Replace(@"\[", "[").Replace(@"\]", "]").Replace(@"\^", "^");
 
-            // The previous call to Regex.Escape actually turned off too many metacharacters, i.e. those which 
-            // are recognized by both the regular expression engine and the SQL LIKE statement ([...] and [^...]). 
-            // Those metacharacters have to be manually unescaped here.
-            pattern = pattern.Replace(@"\[", "[").Replace(@"\]", "]").Replace(@"\^", "^");
+            // put SQL LIKE wildcard literals back
+            builder.Replace("[.*]", "[%]").Replace("[.]", "[_]");
 
-            return Regex.IsMatch(input, pattern, RegexOptions.IgnoreCase); 
+            return builder.ToString();
         }
     }
 }

Main/Source/NMemory.Test/NMemory.Test.csproj

@@ -37,7 +37,7 @@
     <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup>
-    <SignAssembly>true</SignAssembly>
+    <SignAssembly>false</SignAssembly>
   </PropertyGroup>
   <PropertyGroup>
     <AssemblyOriginatorKeyFile>FinalPublicKey.snk</AssemblyOriginatorKeyFile>