--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/memo.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,22 @@
+"""Provide a decorator that caches expensive functions
+"""
+import logging
+_logger = logging.getLogger(__file__)
+info = _logger.info
+def infop(*args):
+    info(' '.join(str(a) for a in args))
+
+def memo(f):
+    #TODO: support kwargs to rval.  This requires looking up the names of f's parameters to 
+    #      construct a proper key.
+
+    #TODO: use weak references instead of a normal dict so that the cache doesn't prevent
+    #      garbage collection
+    cache = {}
+    def rval(*args):
+        if args not in cache:
+            cache[args] = f(*args)
+        return cache[args]
+    rval.__name__ = 'memo@%s'%f.__name__
+    return rval
+