1 files changed, 32 insertions, 0 deletions
diff --git a/coverage/misc.py b/coverage/misc.py
index 15ddad08..a6d9f20b 100644
--- a/coverage/misc.py
+++ b/coverage/misc.py
@@ -14,5 +14,37 @@ def nice_pair(pair):
         return "%d-%d" % (start, end)
 
 
+def format_lines(statements, lines):
+    """Nicely format a list of line numbers.
+
+    Format a list of line numbers for printing by coalescing groups of lines as
+    long as the lines represent consecutive statements.  This will coalesce
+    even if there are gaps between statements.
+    
+    For example, if `statements` is [1,2,3,4,5,10,11,12,13,14] and
+    `lines` is [1,2,5,10,11,13,14] then the result will be "1-2, 5-11, 13-14".
+    
+    """
+    pairs = []
+    i = 0
+    j = 0
+    start = None
+    pairs = []
+    while i < len(statements) and j < len(lines):
+        if statements[i] == lines[j]:
+            if start == None:
+                start = lines[j]
+            end = lines[j]
+            j = j + 1
+        elif start:
+            pairs.append((start, end))
+            start = None
+        i = i + 1
+    if start:
+        pairs.append((start, end))
+    ret = ', '.join(map(nice_pair, pairs))
+    return ret
+
+
 class CoverageException(Exception):
     pass