On Sun, 6 Feb 2005 10:49:05 -0600, Skip Montanaro <[EMAIL PROTECTED]> wrote: > > In a python-checkins message, Raymond stated: > > Raymond> Replace list of constants with tuples of constants. > > I understand the motivation here (the peephole optimizer can convert a tuple > of constants into a single constant that need not be constructed over and > over), but is the effort worth the cost of changing the logical nature of > the data structures used? If lists are conceptually like vectors or arrays > in other languages and tuples are like C structs or Pascal records, then by > converting from list to tuple form you've somehow muddied the data structure > water just to take advantage of tuples' immutability. > > Wouldn't it be better to have the peephole optimizer recognize the throwaway > nature of lists in these contexts: > > for elt in [1, 2, 4, 8, 16]: > ... > > if foo in [list, tuple]: > ... > > (anywhere a list of constants immediately follows the "in" or "not in" > keywords) and convert them into constants? The cases you converted all > matched that usage.
I'm with Skip, *unless* the change is in a PROVEN TIME-CRITICAL PIECE OF CODE. Let's not hand-micro-optimize code just because we can. -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ 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
