call count pinata party

2 files changed, 53 insertions, 24 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 51664d64e..ac46d5768 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -109,6 +109,22 @@ FUNCTIONS = {
     functions.user: 'USER'
 }
 
+
+class _CompileLabel(object):
+    """lightweight label object which acts as an expression._Label."""
+
+    __metaclass__ = sql._FigureVisitName
+    __visit_name__ = 'label'
+    __slots__ = 'element', 'name'
+    
+    def __init__(self, col, name):
+        self.element = col
+        self.name = name
+        
+    @property
+    def quote(self):
+        return self.element.quote
+
 class DefaultCompiler(engine.Compiled):
     """Default implementation of Compiled.
 
@@ -175,9 +191,7 @@ class DefaultCompiler(engine.Compiled):
         self.string = self.process(self.statement)
 
     def process(self, obj, **kwargs):
-        meth = getattr(self, "visit_%s" % obj.__visit_name__, None)
-        if meth:
-            return meth(obj, **kwargs)
+        return obj._compiler_dispatch(self, **kwargs)
 
     def is_subquery(self):
         return self.stack and len(self.stack) > 1 and self.stack[-1].get('from')
@@ -243,8 +257,8 @@ class DefaultCompiler(engine.Compiled):
 
         if result_map is not None:
             result_map[name.lower()] = (name, (column, ), column.type)
-
-        if getattr(column, "is_literal", False):
+        
+        if column.is_literal:
             name = self.escape_literal_column(name)
         else:
             name = self.preparer.quote(name, column.quote)
@@ -252,7 +266,7 @@ class DefaultCompiler(engine.Compiled):
         if column.table is None or not column.table.named_with_column:
             return name
         else:
-            if getattr(column.table, 'schema', None):
+            if column.table.schema:
                 schema_prefix = self.preparer.quote(column.table.schema, column.table.quote_schema) + '.'
             else:
                 schema_prefix = ''
@@ -432,8 +446,8 @@ class DefaultCompiler(engine.Compiled):
         if isinstance(column, sql._Label):
             return column
 
-        if select.use_labels and getattr(column, '_label', None):
-            return column.label(column._label)
+        if select.use_labels and column._label:
+            return _CompileLabel(column, column._label)
 
         if \
             asfrom and \
@@ -441,9 +455,9 @@ class DefaultCompiler(engine.Compiled):
             not column.is_literal and \
             column.table is not None and \
             not isinstance(column.table, sql.Select):
-            return column.label(column.name)
+            return _CompileLabel(column, column.name)
         elif not isinstance(column, (sql._UnaryExpression, sql._TextClause, sql._BindParamClause)) and (not hasattr(column, 'name') or isinstance(column, sql._Function)):
-            return column.label(column.anon_label)
+            return _CompileLabel(column, column.anon_label)
         else:
             return column
 
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index cb2bcd6d6..39c31c8cb 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -944,7 +944,6 @@ def is_column(col):
     """True if ``col`` is an instance of ``ColumnElement``."""
     return isinstance(col, ColumnElement)
 
-
 class _FigureVisitName(type):
     def __init__(cls, clsname, bases, dict):
         if not '__visit_name__' in cls.__dict__:
@@ -952,6 +951,21 @@ class _FigureVisitName(type):
             x = m.group(1)
             x = re.sub(r'(?!^)[A-Z]', lambda m:'_'+m.group(0).lower(), x)
             cls.__visit_name__ = x.lower()
+        
+        # set up an optimized visit dispatch function
+        # for use by the compiler
+        visit_name = cls.__dict__["__visit_name__"]
+        if isinstance(visit_name, str):
+            func_text = "def _compiler_dispatch(self, visitor, **kw):\n"\
+            "    return visitor.visit_%s(self, **kw)" % visit_name
+        else:
+            func_text = "def _compiler_dispatch(self, visitor, **kw):\n"\
+            "    return getattr(visitor, 'visit_%s' % self.__visit_name__)(self, **kw)"
+    
+        env = locals().copy()
+        exec func_text in env
+        cls._compiler_dispatch = env['_compiler_dispatch']
+        
         super(_FigureVisitName, cls).__init__(clsname, bases, dict)
 
 class ClauseElement(object):
@@ -1682,6 +1696,7 @@ class FromClause(Selectable):
     named_with_column = False
     _hide_froms = []
     quote = None
+    schema = None
 
     def _get_from_objects(self, **modifiers):
         return []
@@ -2553,19 +2568,19 @@ class _Label(ColumnElement):
     def __init__(self, name, element, type_=None):
         while isinstance(element, _Label):
             element = element.element
-        self.name = name or "{ANON %d %s}" % (id(self), getattr(element, 'name', 'anon'))
-        self.element = element.self_group(against=operators.as_)
-        self.type = sqltypes.to_instance(type_ or getattr(element, 'type', None))
+        self.name = self.key = self._label = name or "{ANON %d %s}" % (id(self), getattr(element, 'name', 'anon'))
+        self._element = element
+        self._type = type_
         self.quote = element.quote
-
-    @property
-    def key(self):
-        return self.name
-
-    @property
-    def _label(self):
-        return self.name
-
+    
+    @util.memoized_property
+    def type(self):
+        return sqltypes.to_instance(self._type or getattr(element, 'type', None))
+        
+    @util.memoized_property
+    def element(self):
+        return self._element.self_group(against=operators.as_)
+        
     def _proxy_attr(name):
         get = attrgetter(name)
         def attr(self):
@@ -2693,7 +2708,7 @@ class TableClause(_Immutable, FromClause):
     """
 
     named_with_column = True
-
+    
     def __init__(self, name, *columns):
         super(TableClause, self).__init__()
         self.name = self.fullname = name