renaming to src/neco to src/nepi

[nepi.git] / src / nepi / util / rmatcher.py

diff --git a/src/nepi/util/rmatcher.py b/src/nepi/util/rmatcher.py
new file mode 100644 (file)
index 0000000..08563f6
--- /dev/null
+++ b/src/nepi/util/rmatcher.py
@@ -0,0 +1,46 @@
+
+def match_tags(box, all_tags, exact_tags):
+    """ returns True if box has required tags """
+    tall = set(all_tags)
+    texact = set(exact_tags)
+
+    if texact and box.connections == texact:
+        return True
+
+    if tall and tall.issubset(box.connections):
+        return True
+
+    return False
+
+def find_boxes(box, all_tags = None, exact_tags = None, max_depth = 1):
+    """ Look for the connected boxes with the required tags, doing breath-first
+    search, until max_depth ( max_depth = None will traverse the entire graph ).
+    """
+    if not all_tags and not exact_tags:
+        msg = "No matching criteria for resources."
+        raise RuntimeError(msg)
+
+    queue = set()
+    # enqueue (depth, box) 
+    queue.add((0, box))
+    
+    traversed = set()
+    traversed.add(box)
+
+    depth = 0
+
+    result = set()
+
+    while len(q) > 0: 
+        (depth, a) = queue.pop()
+        if match_tags(a, all_tags, exact_tags):
+            result.add(a)
+
+        if not max_depth or depth <= max_depth:
+            depth += 1
+            for b in sorted(a.connections):
+                if b not in traversed:
+                    traversed.add(b)
+                    queue.add((depth, b))
+    
+    return result