Added a new method for rolling a substring.

git-svn-id: https://humgenprojects.lumc.nl/svn/mutalyzer/trunk@475 eb6bd6ab-9ccd-42b9-aceb-e2899b4a52f1

mutalyzer/util.py

@@ -218,6 +218,24 @@ def format_range(first, last):
     return '%i_%i' % (first, last)
 #format_range
 
+def roll_(s, start, end) :
+    """
+    Different (and easier) way of finding the variability of a substring.
+    """
+    # TODO: Start counting at 1, testing, etc.
+
+    l = len(s)
+
+    i = 0
+    while end + i + 1 < l and s[start + i] == s[end + i + 1] :
+        i += 1
+
+    j = 0
+    while start - j and s[start - j - 1] == s[end - j] :
+        j += 1
+
+    return j, i
+#roll
 
 def roll(s, first, last):
     """