Added newer_pairwise_group() convenience function.

1 files changed, 23 insertions, 0 deletions

diff --git a/setuptools/dep_util.py b/setuptools/dep_util.py
new file mode 100644
index 00000000..2931c13e
--- /dev/null
+++ b/setuptools/dep_util.py
@@ -0,0 +1,23 @@
+from distutils.dep_util import newer_group
+
+# yes, this is was almost entirely copy-pasted from
+# 'newer_pairwise()', this is just another convenience
+# function.
+def newer_pairwise_group(sources_groups, targets):
+    """Walk both arguments in parallel, testing if each source group is newer
+    than its corresponding target. Returns a pair of lists (sources_groups,
+    targets) where sources is newer than target, according to the semantics
+    of 'newer_group()'.
+    """
+    if len(sources_groups) != len(targets):
+        raise ValueError("'sources_group' and 'targets' must be the same length")
+
+    # build a pair of lists (sources_groups, targets) where source is newer
+    n_sources = []
+    n_targets = []
+    for i in range(len(sources_groups)):
+        if newer_group(sources_groups[i], targets[i]):
+            n_sources.append(sources_groups[i])
+            n_targets.append(targets[i])
+
+    return n_sources, n_targets