[Python-Dev] Re: [ python-Patches-876206 ] scary frame speed hacks (original) (raw)

Phillip J. Eby pje at telecommunity.com
Tue Mar 2 15:03:40 EST 2004

At 02:37 PM 3/2/04 -0500, Terry Reedy wrote:

"Armin Rigo" <arigo at tunes.org> wrote in message news:20040301161215.GA3963 at vicky.ecs.soton.ac.uk... > Hello, > > Takes 3.26s instead of just 2.64s. This is a major speed hit (20%).

Yes. People will notice. I feel safe in predicting that an avoidable 20% slowdown will generate 'strong' objections, especially from devotees of the functional/recursive style. > On the other hand, recursive functions are not so common in Python, I think the frequency varies considerably depending on the problem domain and the inductional persuasion of the programmer: iterationist vs. recursionist vs. inbetweenist. While Python, with its 'for' statements, encourages the iterative form of linear induction, branching recursion is usually much clearer that the iterative equivalent, and Python is meant to encourage readable code. Since branching recursion usually generates a wide but shallow (virtual) tree of argument structures, the depth limit is usually not a problem for such cases.

It's not just recursive functions at issue. It's also:

ALL of these scenarios involve multiple, simultaneously-active frames for a given code object, and most are non-obvious at the point of inspection.

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