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Comment by igouy | Hacker News Reader

> That's like…

No it is not. Program X may not have measured less than Program Y.

> … meaningful comparisons…

Earlier you complained there was "code that's very unidiomatic" but now you say "writing all the Lisp programs as if they were being written in Java" would be exactly right?

1) You seem to be contradicting your own argument.

2) Your desire for "rigorous" comparison is in-conflict with your desire for inter-language comparison.

> … different programs use different algorithms…

For some programs, for some definition of "algorithm".

> … the comparison tells me nothing about the relative speed of those languages.

What is the speed of a programming language?

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> Earlier you complained there was "code that's very unidiomatic" but now you say "writing all the Lisp programs as if they were being written in Java" would be exactly right?

I may have misinterpreted your comment. By "as if they were written in Java" I meant using a similar algorithm. Alternatively, there could be a rule about idiomatic code (enforced by experts), which would compare very different things, but would also be at least somewhat meaningful.

> For some programs

I don't know. Whenever someone refers me to a result on that site that looks weird, I see very different algorithms.

> for some definition of "algorithm".

For a very well-accepted definition of an algorithm in the context of real performance comparisons.

> What is the speed of a programming language?

I'm not sure (although perhaps I could come up with some definition given enough thought), but I didn't make a website that compares languages based on performance. In fact, I said that the website is totally meaningless. But the people behind it may have something in mind, and if they do, they're not telling us. All I can do is think of ways to use the site's data in ways that can at least be meaningful.

> … a similar algorithm.

Will someone else look at those similar algorithms and "see very different algorithms"?

> … a result on that site that looks weird, I see very different algorithms.

Do regex libraries for different languages in-fact always implement the same algorithms?

> What is the speed of a programming language? I'm not sure…

You did say "Java outperforms SBCL by a very wide margin -- 1.25-4x faster".

Saying "… so the comparison tells me nothing about the relative speed of those languages" suggests you are looking for something that tells us about "the relative speed" of those languages?

> Will someone else look at those similar algorithms and "see very different algorithms"?

I would think so.

> Do regex libraries for different languages in-fact always implement the same algorithms?

I don't know. But I do know that when something is presented as an answer, it's good to know what the question is.

> suggests you are looking for something that tells us about "the relative speed" of those languages?

I can think of a couple of ways the two can compare. One is the relative speeds (and other metrics) of programs of a similar nature, written simple idiomatic code. This gives a general "feel" for what kind of workloads different languages may be suitable for. Another is comparing the performance of the compiler/interpreter on some microbenchmark of the same algorithms, preferably written by people who coordinate, and preferably without mixing too many variables (e.g. measuring parallel scheduling separately and regex separately). Either one of these is of some interest.

The benchmark game does neither. If there is some idea behind the site's comparisons, it's certainly keeping it a mystery.

> … relative speeds (and other metrics) of programs…

So when you say "the relative speed of those languages" you actually mean the relative speed of programs?

> … programs of a similar nature … preferably without mixing too many variables…

Seems vague, no-longer rigorous.

We can make mystery for ourselves — no one can force us to understand.

> So when you say "the relative speed of those languages" you actually mean the relative speed of programs?

No, I mean the relative speed of programs with some carefully chosen relation between them. For example, there is a big difference between "relative income of individuals" and "relative income of social groups," even though the latter could be reduced to the former. Whether a comparison of individuals is meaningful as a comparison of groups depends on how the individuals are chosen and aggregated. Clearly not every choice of individuals would make for a meaningful comparison of groups and not every choice of programs makes for a meaningful comparison of languages. The choices made by the game do not seem at all meaningful for the comparison of languages, but if there is some rhyme or reason to the choice, the website doesn't say what it is.

> We can make mystery for ourselves — no one can force us to understand.

True, but when a website chooses to present data in some aggregate way that seems to defy any familiar forms of aggregation and reasoning without so much as stating what the meaning of the presentation is, it is itself mysterious. I agree that it is possible that the comparisons are not worthless, but without any statement of a hypothesis, it is the most reasonable conclusion. I am sure that the authors of the website would agree that if they don't even attempt to say what the meaning of the comparisons is, even in their own minds, it is reasonable to assume it means nothing.

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