- improved support for complex queries embedded into "where" criterion

 for query.select() [ticket:449]
- contains_eager('foo') automatically implies eagerload('foo')
- query.options() can take a combiantion MapperOptions and tuples of MapperOptions,
so that functions can return groups
- refactoring to Aliasizer and ClauseAdapter so that they share a common base methodology,
which addresses all sql.ColumnElements instead of just schema.Column.  common list-processing
methods added.
- query.compile and eagerloader._aliasize_orderby make usage of improved list processing on
above.
- query.compile, within the "nested select generate" step processes the order_by clause using
the ClauseAdapter instead of Aliasizer since there is only one "target"

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/sqlalchemy/util.py b/lib/sqlalchemy/util.py
index 54b1afa9f..c2e0dbc45 100644
--- a/lib/sqlalchemy/util.py
+++ b/lib/sqlalchemy/util.py
@@ -35,6 +35,16 @@ def to_set(x):
     else:
         return x
 
+def flatten_iterator(x):
+    """given an iterator of which further sub-elements may also be iterators,
+    flatten the sub-elements into a single iterator."""
+    for elem in x:
+        if hasattr(elem, '__iter__'):
+            for y in flatten_iterator(elem):
+                yield y
+        else:
+            yield elem
+            
 def reversed(seq):
     try:
         return __builtin__.reversed(seq)