refactored compiler and improved identifier handling for for-loops
--HG--
branch : trunk
diff --git a/jinja2/compiler.py b/jinja2/compiler.py
index 8fcb30f..9bf0044 100644
--- a/jinja2/compiler.py
+++ b/jinja2/compiler.py
@@ -533,6 +533,11 @@
self.writeline('%s = l_%s' % (ident, name))
return aliases
+ def restore_shadowed(self, aliases):
+ """Restore all aliases."""
+ for name, alias in aliases.iteritems():
+ self.writeline('l_%s = %s' % (name, alias))
+
def function_scoping(self, node, frame, children=None,
find_special=True):
"""In Jinja a few statements require the help of anonymous
@@ -870,8 +875,7 @@
def visit_For(self, node, frame):
# when calculating the nodes for the inner frame we have to exclude
# the iterator contents from it
- children = list(node.iter_child_nodes(exclude=('iter',)))
-
+ children = node.iter_child_nodes(exclude=('iter',))
if node.recursive:
loop_frame = self.function_scoping(node, frame, children,
find_special=False)
@@ -879,10 +883,20 @@
loop_frame = frame.inner()
loop_frame.inspect(children)
- undeclared = find_undeclared(children, ('loop',))
- extended_loop = node.recursive or node.else_ or 'loop' in undeclared
- if extended_loop:
- loop_frame.identifiers.add_special('loop')
+ # try to figure out if we have an extended loop. An extended loop
+ # is necessary if the loop is in recursive mode if the special loop
+ # variable is accessed in the body.
+ extended_loop = node.recursive or 'loop' in \
+ find_undeclared(node.iter_child_nodes(
+ only=('body',)), ('loop',))
+
+ # make sure the loop variable is a special one and raise a template
+ # assertion error if a loop tries to write to loop
+ loop_frame.identifiers.add_special('loop')
+ for name in node.find_all(nodes.Name):
+ if name.ctx == 'store' and name.name == 'loop':
+ self.fail('Can\'t assign to special loop variable '
+ 'in for-loop target', name.lineno)
# if we don't have an recursive loop we have to find the shadowed
# variables at that point
@@ -898,22 +912,24 @@
self.pull_locals(loop_frame)
if node.else_:
- self.writeline('l_loop = None')
+ iteration_indicator = self.temporary_identifier()
+ self.writeline('%s = 1' % iteration_indicator)
- self.newline(node)
- self.writeline('for ')
+ # Create a fake parent loop if the else or test section of a
+ # loop is accessing the special loop variable and no parent loop
+ # exists.
+ if 'loop' not in aliases and 'loop' in find_undeclared(
+ node.iter_child_nodes(only=('else_', 'test')), ('loop',)):
+ self.writeline("l_loop = environment.undefined(%r, name='loop')" %
+ "'loop' is undefined. the filter section of a loop as well " \
+ "as the else block doesn't have access to the special 'loop' "
+ "variable of the current loop. Because there is no parent "
+ "loop it's undefined.")
+
+ self.writeline('for ', node)
self.visit(node.target, loop_frame)
self.write(extended_loop and ', l_loop in LoopContext(' or ' in ')
- # the expression pointing to the parent loop. We make the
- # undefined a bit more debug friendly at the same time.
- parent_loop = 'loop' in aliases and aliases['loop'] \
- or "environment.undefined(%r, name='loop')" % "'loop' " \
- 'is undefined. "the filter section of a loop as well ' \
- 'as the else block doesn\'t have access to the ' \
- "special 'loop' variable of the current loop. " \
- "Because there is no parent loop it's undefined."
-
# if we have an extened loop and a node test, we filter in the
# "outer frame".
if extended_loop and node.test is not None:
@@ -928,7 +944,6 @@
self.visit(node.iter, loop_frame)
self.write(' if (')
test_frame = loop_frame.copy()
- self.writeline('l_loop = ' + parent_loop)
self.visit(node.test, test_frame)
self.write('))')
@@ -954,18 +969,18 @@
self.indent()
self.blockvisit(node.body, loop_frame, force_generator=True)
+ if node.else_:
+ self.writeline('%s = 0' % iteration_indicator)
self.outdent()
if node.else_:
- self.writeline('if l_loop is None:')
+ self.writeline('if %s:' % iteration_indicator)
self.indent()
- self.writeline('l_loop = ' + parent_loop)
self.blockvisit(node.else_, loop_frame, force_generator=False)
self.outdent()
# reset the aliases if there are any.
- for name, alias in aliases.iteritems():
- self.writeline('l_%s = %s' % (name, alias))
+ self.restore_shadowed(aliases)
# if the node was recursive we have to return the buffer contents
# and start the iteration code
@@ -1008,25 +1023,20 @@
self.writeline('caller = ')
self.macro_def(node, call_frame)
self.start_write(frame, node)
- self.visit_Call(node.call, call_frame,
- extra_kwargs={'caller': 'caller'})
+ self.visit_Call(node.call, call_frame, forward_caller=True)
self.end_write(frame)
def visit_FilterBlock(self, node, frame):
filter_frame = frame.inner()
filter_frame.inspect(node.iter_child_nodes())
-
aliases = self.collect_shadowed(filter_frame)
self.pull_locals(filter_frame)
self.buffer(filter_frame)
-
- for child in node.body:
- self.visit(child, filter_frame)
-
+ self.blockvisit(node.body, filter_frame, force_generator=False)
self.start_write(frame, node)
- self.visit_Filter(node.filter, filter_frame, 'concat(%s)'
- % filter_frame.buffer)
+ self.visit_Filter(node.filter, filter_frame)
self.end_write(frame)
+ self.restore_shadowed(aliases)
def visit_ExprStmt(self, node, frame):
self.newline(node)
@@ -1283,7 +1293,7 @@
self.write(':')
self.visit(node.step, frame)
- def visit_Filter(self, node, frame, initial=None):
+ def visit_Filter(self, node, frame):
self.write(self.filters[node.name] + '(')
func = self.environment.filters.get(node.name)
if func is None:
@@ -1292,10 +1302,15 @@
self.write('context, ')
elif getattr(func, 'environmentfilter', False):
self.write('environment, ')
- if isinstance(node.node, nodes.Filter):
- self.visit_Filter(node.node, frame, initial)
- elif node.node is None:
- self.write(initial)
+
+ # if the filter node is None we are inside a filter block
+ # and want to write to the current buffer
+ if node.node is None:
+ if self.environment.autoescape:
+ tmpl = 'Markup(concat(%s))'
+ else:
+ tmpl = 'concat(%s)'
+ self.write(tmpl % frame.buffer)
else:
self.visit(node.node, frame)
self.signature(node, frame)
@@ -1327,11 +1342,12 @@
self.visit(node.expr2, frame)
self.write(')')
- def visit_Call(self, node, frame, extra_kwargs=None):
+ def visit_Call(self, node, frame, forward_caller=False):
if self.environment.sandboxed:
self.write('environment.call(')
self.visit(node.node, frame)
self.write(self.environment.sandboxed and ', ' or '(')
+ extra_kwargs = forward_caller and {'caller': 'caller'} or None
self.signature(node, frame, False, extra_kwargs)
self.write(')')