Changeset 81

Timestamp:

05/03/07 13:08:27

Author:

fumanchu

Message:

New logic.combine(expr, kwargs) function (and sundry).

Files:

• trunk/geniusql/codewalk.py (modified) (1 diff)
• trunk/geniusql/logic.py (modified) (1 diff)
• trunk/geniusql/objects.py (modified) (2 diffs)
• trunk/geniusql/select.py (modified) (1 diff)
• trunk/geniusql/test/test_firebird.py (modified) (1 diff)

trunk/geniusql/codewalk.py

@@ -755 +755 @@
-                ip += 1
-        
+        # This is where we do folding of logical AND and OR operators.
+        # The Python code just writes "a AND b", but the VM (bytecode)
+        # acts more like assembly, using conditional JUMP instructions to
+        # implement logical operators. The map stored in self.targets is
+        # of the form:
+        #     {JUMP target: [(self.stack[-1], 'and'), ...]}
+        # where "JUMP target" is the instruction number of the bytecode
+        # which is the target of the JUMP, and each item in the value list
+        # is a tuple of (top of the calling stack, operation).
+        # It's a list because a single bytecode may be the target of
+        # multiple JUMP instructions.
+        # See visit_JUMP_IF_FALSE / TRUE.
-        terms = self.targets.get(ip)
-        if terms:

trunk/geniusql/logic.py

@@ -440 +440 @@
-    return Expression(func, earlybind=False)
-
+
+def combine(expr, kwargs):
+    """Return a single Expression (or None) for the given expr and kwargs.
+    
+    The supplied expr may be a lambda, an Expression, or None.
+    The kwargs may be an empty dict.
+    """
+    if expr is not None and not isinstance(expr, Expression):
+        expr = Expression(expr)
+    if kwargs:
+        f = filter(**kwargs)
+        if expr is None:
+            expr = f
+        else:
+            expr += f
+    return expr
+
+

trunk/geniusql/objects.py

@@ -437 +437 @@
-    def _select_lazy(self, restriction=None, **kwargs):
-        """Yield data dicts matching the given restriction."""
-
-
-
-
-
-
-
-
+
-        
-        attrs = self.keys()
@@ -697 +690 @@
-            pk = ""
-        
+        # Just to be sure...
+        try:
+            self.db.execute_ddl('DROP TABLE %s;' % table.qname)
+        except:
+            pass
-        self.db.execute_ddl('CREATE TABLE %s (%s%s);' %
-                            (table.qname, ", ".join(fields), pk))

trunk/geniusql/select.py

@@ -109 +109 @@
-        The order of sequences must match the order of tables given in the
-        relation (and therefore the restriction args, if applicable).
+        A final option is to pass a lambda (or Expression) which returns
+        the attributes as a tuple or list; e.g.:
+            lambda t1, t2: (t1.a, t1.b - now(), t1.c + t2.a)
+        This allows access to binary operations and builtin functions.
-    restriction: an Expression (or lambda) to restrict the rows returned;
-        if given, this will be used to construct a WHERE clause. The args

trunk/geniusql/test/test_firebird.py

@@ -32 +32 @@
-        # Isolate schema changes from one test to the next.
-        reload(zoo_fixture)
-
+
+
+
+
+
+
+
+
+
-
-if __name__ == "__main__":