Nick Coghlan wrote: > Python, however, uses a dynamic name binding system and scopes are expensive > because they require setting up all of the machinery to support nested > visibility.
Scopes within a function needn't be anywhere near as expensive as scopes for nested functions are. The compiler can just allocate all the locals that are going to be needed on entry to the function, and keep track of which ones are visible. The only runtime overhead would be unbinding locals as they go out of scope, if that were considered necessary or desirable. The main problem is Python's lack of declarations, which means that nested locals could only be used in places where it's clear that a new variable is being introduced, such as for loops, LCs, etc. Greg _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
