[hyena] [Hyena] Add SubstringBetween method to StringUtil

[Gabriel Burt <gburt src gnome org>]

commit 81e8e6b096d7eedd4165d72e68695e0d26fd902a
Author: Gabriel Burt <gabriel burt gmail com>
Date:   Sun Aug 15 15:04:28 2010 -0700

    [Hyena] Add SubstringBetween method to StringUtil

 Hyena/Hyena/StringUtil.cs            |   15 +++++++++++++++
 Hyena/Hyena/Tests/StringUtilTests.cs |   10 ++++++++++
 2 files changed, 25 insertions(+), 0 deletions(-)
---
diff --git a/Hyena/Hyena/StringUtil.cs b/Hyena/Hyena/StringUtil.cs
index 8075a8c..99aaac5 100644
--- a/Hyena/Hyena/StringUtil.cs
+++ b/Hyena/Hyena/StringUtil.cs
@@ -329,6 +329,21 @@ namespace Hyena
             }
         }
 
+        public static string SubstringBetween (this string input, string start, string end)
+        {
+            int s = input.IndexOf (start);
+            if (s == -1)
+                return null;
+
+            s += start.Length;
+            int l = Math.Min (input.Length - 1, input.IndexOf (end, s)) - s;
+            if (l > 0 && s + l < input.Length) {
+                return input.Substring (s, l);
+            } else {
+                return null;
+            }
+        }
+
         private static readonly char[] escaped_like_chars = new char[] {'\\', '%', '_'};
         public static string EscapeLike (string s)
         {
diff --git a/Hyena/Hyena/Tests/StringUtilTests.cs b/Hyena/Hyena/Tests/StringUtilTests.cs
index e7c940c..637c027 100644
--- a/Hyena/Hyena/Tests/StringUtilTests.cs
+++ b/Hyena/Hyena/Tests/StringUtilTests.cs
@@ -159,6 +159,16 @@ href=http://lkjdflkjdflkjj>baz foo< /a> bar"));
             s = new string [] { "foo", "bar", "baz" };
             Assert.AreEqual ("foo -- bar -- baz", s.Join (" -- "));
         }
+
+        [Test]
+        public void TestSubstringBetween ()
+        {
+            Assert.AreEqual ("bar", "foobarbaz".SubstringBetween ("foo", "baz"));
+            Assert.AreEqual ("barfoobam", "erefoobarfoobambazabc".SubstringBetween ("foo", "baz"));
+            Assert.AreEqual (null, "foobar".SubstringBetween ("foo", "baz"));
+            Assert.AreEqual (null,  "bar".SubstringBetween ("foo", "baz"));
+            Assert.AreEqual (null,  "".SubstringBetween ("foo", "baz"));
+        }
     }
 
     [TestFixture]