- for hackers, refactored the "visitor" system of ClauseElement and

SchemaItem so that the traversal of items is controlled by the
ClauseVisitor itself, using the method visitor.traverse(item).
accept_visitor() methods can still be called directly but will
not do any traversal of child items.  ClauseElement/SchemaItem now
have a configurable get_children() method to return the collection
of child elements for each parent object. This allows the full
traversal of items to be clear and unambiguous (as well as loggable),
with an easy method of limiting a traversal (just pass flags which
are picked up by appropriate get_children() methods). [ticket:501]
- accept_schema_visitor() methods removed, replaced with
get_children(schema_visitor=True)
- various docstring/changelog cleanup/reformatting

1 files changed, 23 insertions, 21 deletions

diff --git a/lib/sqlalchemy/ansisql.py b/lib/sqlalchemy/ansisql.py
index 5d5c42208..ebaedca54 100644
--- a/lib/sqlalchemy/ansisql.py
+++ b/lib/sqlalchemy/ansisql.py
@@ -75,6 +75,8 @@ class ANSICompiler(sql.Compiled):
     Compiles ClauseElements into ANSI-compliant SQL strings.
     """
 
+    __traverse_options__ = {'column_collections':False}
+
     def __init__(self, dialect, statement, parameters=None, **kwargs):
         """Construct a new ``ANSICompiler`` object.
 
@@ -388,13 +390,13 @@ class ANSICompiler(sql.Compiled):
         self.select_stack.append(select)
         for c in select._raw_columns:
             if isinstance(c, sql.Select) and c.is_scalar:
-                c.accept_visitor(self)
+                self.traverse(c)
                 inner_columns[self.get_str(c)] = c
                 continue
             if hasattr(c, '_selectable'):
                 s = c._selectable()
             else:
-                c.accept_visitor(self)
+                self.traverse(c)
                 inner_columns[self.get_str(c)] = c
                 continue
             for co in s.columns:
@@ -402,10 +404,10 @@ class ANSICompiler(sql.Compiled):
                     labelname = co._label
                     if labelname is not None:
                         l = co.label(labelname)
-                        l.accept_visitor(self)
+                        self.traverse(l)
                         inner_columns[labelname] = l
                     else:
-                        co.accept_visitor(self)
+                        self.traverse(co)
                         inner_columns[self.get_str(co)] = co
                 # TODO: figure this out, a ColumnClause with a select as a parent
                 # is different from any other kind of parent
@@ -414,10 +416,10 @@ class ANSICompiler(sql.Compiled):
                     # names look like table.colname, so add a label synonomous with
                     # the column name
                     l = co.label(co.name)
-                    l.accept_visitor(self)
+                    self.traverse(l)
                     inner_columns[self.get_str(l.obj)] = l
                 else:
-                    co.accept_visitor(self)
+                    self.traverse(co)
                     inner_columns[self.get_str(co)] = co
         self.select_stack.pop(-1)
 
@@ -443,7 +445,7 @@ class ANSICompiler(sql.Compiled):
                     else:
                         continue
                     clause = c==value
-                    clause.accept_visitor(self)
+                    self.traverse(clause)
                     whereclause = sql.and_(clause, whereclause)
                     self.visit_compound(whereclause)
 
@@ -596,7 +598,7 @@ class ANSICompiler(sql.Compiled):
         vis = DefaultVisitor()
         for c in insert_stmt.table.c:
             if (isinstance(c, schema.SchemaItem) and (self.parameters is None or self.parameters.get(c.key, None) is None)):
-                c.accept_schema_visitor(vis)
+                vis.traverse(c)
 
         self.isinsert = True
         colparams = self._get_colparams(insert_stmt, default_params)
@@ -610,7 +612,7 @@ class ANSICompiler(sql.Compiled):
                 return self.bindparam_string(p.key)
             else:
                 self.inline_params.add(col)
-                p.accept_visitor(self)
+                self.traverse(p)
                 if isinstance(p, sql.ClauseElement) and not isinstance(p, sql.ColumnElement):
                     return "(" + self.get_str(p) + ")"
                 else:
@@ -631,7 +633,7 @@ class ANSICompiler(sql.Compiled):
         vis = OnUpdateVisitor()
         for c in update_stmt.table.c:
             if (isinstance(c, schema.SchemaItem) and (self.parameters is None or self.parameters.get(c.key, None) is None)):
-                c.accept_schema_visitor(vis)
+                vis.traverse(c)
 
         self.isupdate = True
         colparams = self._get_colparams(update_stmt, default_params)
@@ -643,7 +645,7 @@ class ANSICompiler(sql.Compiled):
                 self.binds[p.shortname] = p
                 return self.bindparam_string(p.key)
             else:
-                p.accept_visitor(self)
+                self.traverse(p)
                 self.inline_params.add(col)
                 if isinstance(p, sql.ClauseElement) and not isinstance(p, sql.ColumnElement):
                     return "(" + self.get_str(p) + ")"
@@ -734,7 +736,7 @@ class ANSISchemaBase(engine.SchemaIterator):
         findalterables = FindAlterables()
         for table in tables:
             for c in table.constraints:
-                c.accept_schema_visitor(findalterables)
+                findalterables.traverse(c)
         return alterables
 
 class ANSISchemaGenerator(ANSISchemaBase):
@@ -752,7 +754,7 @@ class ANSISchemaGenerator(ANSISchemaBase):
     def visit_metadata(self, metadata):
         collection = [t for t in metadata.table_iterator(reverse=False, tables=self.tables) if (not self.checkfirst or not self.dialect.has_table(self.connection, t.name, schema=t.schema))]
         for table in collection:
-            table.accept_schema_visitor(self, traverse=False)
+            table.accept_visitor(self)
         if self.supports_alter():
             for alterable in self.find_alterables(collection):
                 self.add_foreignkey(alterable)
@@ -760,9 +762,9 @@ class ANSISchemaGenerator(ANSISchemaBase):
     def visit_table(self, table):
         for column in table.columns:
             if column.default is not None:
-                column.default.accept_schema_visitor(self, traverse=False)
+                column.default.accept_visitor(self)
             #if column.onupdate is not None:
-            #    column.onupdate.accept_schema_visitor(visitor, traverse=False)
+            #    column.onupdate.accept_visitor(visitor)
 
         self.append("\nCREATE TABLE " + self.preparer.format_table(table) + " (")
 
@@ -777,20 +779,20 @@ class ANSISchemaGenerator(ANSISchemaBase):
             if column.primary_key:
                 first_pk = True
             for constraint in column.constraints:
-                constraint.accept_schema_visitor(self, traverse=False)
+                constraint.accept_visitor(self)
 
         # On some DB order is significant: visit PK first, then the
         # other constraints (engine.ReflectionTest.testbasic failed on FB2)
         if len(table.primary_key):
-            table.primary_key.accept_schema_visitor(self, traverse=False)
+            table.primary_key.accept_visitor(self)
         for constraint in [c for c in table.constraints if c is not table.primary_key]:
-            constraint.accept_schema_visitor(self, traverse=False)
+            constraint.accept_visitor(self)
 
         self.append("\n)%s\n\n" % self.post_create_table(table))
         self.execute()
         if hasattr(table, 'indexes'):
             for index in table.indexes:
-                index.accept_schema_visitor(self, traverse=False)
+                index.accept_visitor(self)
 
     def post_create_table(self, table):
         return ''
@@ -890,7 +892,7 @@ class ANSISchemaDropper(ANSISchemaBase):
             for alterable in self.find_alterables(collection):
                 self.drop_foreignkey(alterable)
         for table in collection:
-            table.accept_schema_visitor(self, traverse=False)
+            table.accept_visitor(self)
 
     def supports_alter(self):
         return True
@@ -906,7 +908,7 @@ class ANSISchemaDropper(ANSISchemaBase):
     def visit_table(self, table):
         for column in table.columns:
             if column.default is not None:
-                column.default.accept_schema_visitor(self, traverse=False)
+                column.default.accept_visitor(self)
 
         self.append("\nDROP TABLE " + self.preparer.format_table(table))
         self.execute()