Raymond Hettinger <rhettin...@users.sourceforge.net> added the comment:
FWIW, the new_child() and parents() part of the API was modeled after contexts in ANLTR where they are needed to overcome the limitations of Django's push/pop style which precludes a context from having multiple, independent children at the same time. The module docstring in the http://code.activestate.com/recipes/577434/ recipe shows how new_child() can be used to easily model both dynamic scoping and nested scoping. The other advantage of the new_child/parents API over the push/pop API is that it overcomes the occasional templating need to keep two copies of the context (before a push and after a push). In some ways, it is more difficult to keep track of a mutating chain that is being continuously pushed and popped. It is simpler to assign a chain to a variable and always know that it is associated with a given template and not have to worry about whether some utility function pushed a new context and failed to pop it when it was done. A push/pop style introduces the same problems as matching matching malloc() with free() in C. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11297> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
