Revision as of 19:21, 12 May 2006 editHarmil (talk | contribs)8,207 edits →Benchmark comparison← Previous edit | Revision as of 20:50, 12 May 2006 edit undo-Barry- (talk | contribs)1,472 edits →Benchmark comparison: I want to put it back. Hopefully I won't have to do that Misplaced Pages arbitration thing and bring in people not involved with this article.Next edit → | ||
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:::I gave you the link to the modification above, and no, we cannot assert that it "probably balances out". Can we please, just stick to facts. This benchmark, like almost any cross-language benchmark is horribly flawed, and should not be referenced. -] 19:21, 12 May 2006 (UTC) | :::I gave you the link to the modification above, and no, we cannot assert that it "probably balances out". Can we please, just stick to facts. This benchmark, like almost any cross-language benchmark is horribly flawed, and should not be referenced. -] 19:21, 12 May 2006 (UTC) | ||
::::Sorry, I didn't know that was the link to the diff. Unfortunately, I'm not sure how to read that and I don't want to learn. I like the added context of surrounding code anyway. I'd prefer if you use my web application and link to the results. But it probably won't make a whole lot of difference in my opinion of whether to add the Benchmark Comparisons section. In fact, I wouldn't even be able to cite your improved version of that benchmark because of the no original research rule. On the other hand, I wouldn't object to a stronger disclaimer, especially if you've actually managed to legally improve the speed, and you may be able to , which would allow it to be used in this article. | |||
::::Also, even if you did speed the script as fast as you claim without breaking it, that doesn't mean Perl would have won any more tests, and if it did win one more, that's only a small fraction of the 16 or so speed tests (32 now that I doubled the data). Using one improved test to discount the validity of the entire data set is itself flawed. | |||
::::I noticed that part of your modification goes against best programming practices. You replaced descriptive variables like $item with Perl's default variables like $_. I guess that's technically allowed, but I wouldn't want to maintain your code. | |||
::::I think we need more input on this, because I really think the Benchmark Comparisons section improves this article and I'll probably put it back. I don't think there's anything like it in other programming language articles and it could help make this article a featured page. | |||
::::Again, I wouldn't mind disclaimers and references that show that the results should be considered with caution. In fact, the section can concentrate on the flaws in cross-language benchmarks, but some people would figure it balances out and may put some value on the data. How <i>DO</i> you choose a programming language if you want speed, or something else that can be benchmarked, but don't have different versions of the exact program you'll be using that are written in multiple languages? If you do have some important snippets written in multiple languages, how do you know you wrote them each optimally so the comparison lives up to Harmil's standards? People need to make those language choices sometimes, and most probably base it on less accurate information than is contained in these benchmarks. | |||
::::It's probably more accurate to use the references to learn how to create a benchmark specific to your machine and program (I included that link in the Benchmark Comparisons section), but if you don't want to go through all that, what do you do? Ask some guy on a message board? Questions like "what language should I use for..." are asked all the time, and when it comes to needing speed or fewer lines or less memory, the data Benchmark Comparisons article is probably better. ] 20:50, 12 May 2006 (UTC) |
Revision as of 20:50, 12 May 2006
Perl has been listed as one of the good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it. Review: No date specified. To provide a date use: {{GA|insert date in any format here}}. |
- Archive 1- Leaking; Book Reviews, Xah Lee, would-be perl critic?; Perl programming language?; Regular Expressions with Perl Examples; Logo suggestion; Merits and demerits of Perl as a programming language; Propagandistic errors; Web hosting advertisements; Obfuscation example; History; Copyedits; TOCleft and indented paragraphs; Perl 6; Section ordering; Pathologically Eclectic Rubbish Lister.
A sample Perl program
- A sample Perl program
$message = "Hello, world! The magic number is 234542354."; print $message; $message =~ s/d+/-1/; print $message; exit 0
- The above program can be written as:
$_ = "The magic number is 150\n"; print; s/\d+/-1/; print;
- which demonstrates the idea of topic (
$_
) in Perl. Also, theexit 0
at the end is completely redundant. (See: pl:Perl) --Rafał Pocztarski 07:01, 7 Aug 2004 (UTC)
- A version showing slightly more powerful regex, err, power in Perl:
$_ = "The magic number is 150\n"; print; s/ (\d+) / $1 * 2 /ex; print;
- Quite a nice example. --Rafał Pocztarski 07:11, 7 Aug 2004 (UTC)
- You're saying that it shows "high use of meaningful punctuation characters"?
- You've never seen any REAL perl code :). What about using this (uppercase input) as an example:
while(<>) { $_=~y/a-z/A-Z/; print; }
- --Taw
- Even better would be a line noise winner from one of the obfuscated perl contests, if that code is public domain. :-)
- But that would miss the point - we want to show real Perl code, not one that was deliberately obfuscated. --Taw
- I feel this entry should shy away from obfuscated code entirely! It just helps encourage the FUD that Perl is unreadable/write only/whatever, and that's a biased opinion. I can write incredibly obfuscated Java, but no-one feels the need to be posting that on the Java page. It tarnishes the neutral tone of the entry. I'd go as far as to remove the example (it's a bit pointless anyhow, what exactly is it demonstrating? I could come up with far more interesting examples of punctuation character usage, so that can't be it).
- Anway, as an aside, you do realize you can get rid of the $_ in your code?:
while(<>) { tr/a-z/A-Z/; print; }
- Any books that tell you otherwise, burn 'em!
- Finally there's the succinct:
print uc while (<>);
- ...and I'll be surprised if there's anything more readable for the same task in any other popular language, assuming you've bothered to learn at least the rudiments of Perl, that is. --Derek
- Or better yet:
print uc while <>;
- Even more clean and readable. One only has to say: uc is upper-case and the diamond is input. Great example. --Rafał Pocztarski 07:04, 7 Aug 2004 (UTC)
erl
See http://www.perldoc.com/perl5.8.0/pod/perlfaq1.html, under "What's the difference between Perl and perl?". erl is not and has never been an acronym. --nknight 23:36 Mar 6, 2003 (UTC)
- It would seem, though, that the Perl documentation is self-contradictory in this regard, since http://www.perldoc.com/perl5.8.0/pod/perl.html#NAME says "perl - Practical Extraction and Report Language," which is how Larry Wall is supposed to have gotten the name for the language in the first place. --James Munroe 04:53 Aug 31, 2003 (UTC)
- But if it was Practical Extraction and Report Language, the language name should be PEARL, not Perl. (Note: All caps, an `A'.) In fact, that was its original name until Larry found another language named PEARL (or Pearl). So it went to Perl, and the acronym no longer makes sense.
- Like what anon user (above) says, pearl (now perl) started off as an acronym and Larry Wall had to change the name in order to avoid clash with another language with the same name.
- The old expansion would still apply to perl as words like "and" are usually excluded from an acronym. However, Wall, the jovial person that he is, came up with the new acronym "Pathologically Eclectic Rubbish Lister" to match the new name. However I feel that these events and the link given by Nknight above should not be interpreted to mean that perl is no longer an acronym but a backronym. (refer interview with Larry Wall and the question ".. How'd you come up with that name?" http://www.linuxjournal.com/article.php?sid=339 ) --Jay 08:32, 3 Mar 2004 (UTC)
- Hi, folks; perl never was an acronym. If it was, then Larry himself is lying. Anyone who's been in perl long enough to read the FAQ knows the story, and I've never heard anyone who's actually read the story claim that it's not true. Most everyone who claims perl was originally an acronym is much further removed than those who know the truth.
- Incidentally, I corrected the famous quip, "Nothing but perl can parse Perl," from Tom Christiansen. The source on this is the FAQ. --Jdavidb 15:55, 8 Mar 2004 (UTC)
- Full Ack regarding the Perl FAQ. According to it, Perl is only backronymed to Practical Extraction and Report Language.
- But (and I noticed this just in this moment) if you look at http://history.perl.org/PerlTimeline.html under 1987, the (said to be) first man page shows exactly that acronym. Perl History also talks about 18th of December 1987, release date of Perl 1.000.
- But in fact the first occurence of Perl at all was in May 1987, see http://use.perl.org/articles/03/12/15/0326207.shtml?tid=1. The therein mentioned Usenet posting can be found at http://groups.google.com/groups?selm=4628%40sdcrdcf.UUCP. The posting mentions that at that date, Perl is already 3 months old.
- I'll put the Usenet posting and the Perl History Timeline into the article as external links, so the details of what is true and what is not can be discussed before any decisions regarding the article's content are made. :-) --XTaran 23:07, 11 Mar 2004 (UTC)
- Blame me for the initial-cap spelling of Perl for the language. When we were writing the first Camel book, the lowercase
version of "perl" kept disappearing into the text. So I discussed with Larry, and we decided together that "perl" would represent the interpreter (and be in constant-width font as a result), and "Perl" would represent the language. And no, "PERL" was never valid. --Randal Schwartz
Name
- ""Perl" was originally named "pearl", after the "pearl of great price" of Matthew 13:46"
What is the reference to this information? --Jay 14:44, 6 Mar 2004 (UTC)
- This seems to be the source, with a little bit of this thrown in for seasoning. --chocolateboy 17:38, 6 Mar 2004 (UTC)
For a little detail on why "Perl" and not "Pearl", in Larry's (paraphrased) words from State of the Onion 2005 "I went through every single three and four letter word in the dictionary but couldn't find anything good. I don't know how I missed 'Ruby'". He wanted the name either 3 or 4 letters, hence the convenient shortening when he heard about the PEARL language.
Perl - Practical Extraction and Report Language
The manpage for Perl begins with:
NAME perl - Practical Extraction and Report Language
This article suggests that "Practical Extraction and Report Language" is deprecated and "was intended humorously". I see no evidence that this is the case. I intend to move "Practical Extraction and Report Language" into the intro and remove the presumably false statement if there are no objections. --Eloquence* 02:24, Apr 13, 2004 (UTC)
- I have strong objections, because Perl is not an acronym. The etymology of the name is very clear and would be widely known if people weren't so desirous of ignorance. All one has to do is read chapter 27 of the 3rd edition of the camel book, or google around a bit. The name of the language was originally to be "Pearl", before Larry heard of another language known as "PEARL". He removed a letter and all was well in the world. "Practical Extraction and Report Language" is a post-facto rationalization. Perl is not an acronym. --nknight 06:53, 13 Apr 2004 (UTC)
- It doesn't matter if it is a "post-facto rationalization". We are not an etymological guide and the history of the name is only of marginal interest to most readers. If this is the way the word Perl is resolved in manuals today, then it should be prominently mentioned, not falsely claimed to be "intended humorously". I can agree to include the fact that Perl was technically not intended to be an acronym, but it is also a fact that it is today widely used as one, including by the makers of Perl. --Eloquence* 06:57, Apr 13, 2004 (UTC)
- Feel free to remove any discussion about the name itself, but I will strongly oppose any attempt to define Perl as an acronym of "Practical Extraction and Report Language", as it is simply false, as anyone that has done substantive research on the subject will tell you. --nknight 07:06, 13 Apr 2004 (UTC)
Backronym in intro
I've been meaning to bring this up for a while. The backronym, "practical extraction and reporting language", is in fact rarely used to describe the language. Its main claim to fame is that it is found at the beginning of the man page, where it almost comically serves to fulfil the custom whereby man pages begin with an excruciatingly concise summary. Other than that and a couple of appearances in O'Reilly books, it's not very widespread. Furthermore, it is better applied to very early versions of the language, given that Perl is a general-purpose language and not just for report generation (there are, in fact languages dedicated to reports, which bear little resemblance to Perl). For the above reasons I recommend removing it from the intro. Thoughts? --Yath 23:39, 4 October 2005 (UTC)
Explanation of for/foreach Syntax
I understand that this isn't supposed to be an exhaustive explanation of Perl syntax, but for/foreach are much more flexible and useful than this suggests. At the very least, I suggest replacing the "foreach ( array )" with "foreach ( LIST )", which is more accurate. (fish_at_uc_org)
- Technically, ARRAY is more accurate. If you give a literal list, its first copied/aliased into an array, then the array is walked. --Randal Schwartz
- After I read your post, I immediately reverted my change (thus replacing list with array). But I'm not sure that was the right thing to do, and I don't believe you were even suggesting such a reversion. (Namely because foreach( array ) would disallow useful constructs like foreach( qw/foo bar baz/ ) and even foreach( foo() ), which Perl obviously allows.) So I've reverted my original reversion; the article now uses foreach( list ). --Diberri | Talk 06:40, Aug 23, 2004 (UTC)
- Yeah, list is more appropriate and I believe Perl does copy the contents of the list given in a foreach context. --Sundar 10:06, Aug 23, 2004 (UTC)
- As I understand it, that part of the article is trying to explain the syntax of for, so the internals of the implementation, and the copying to a temporary array, are irrelevant. Syntactically, the target of the for is a list, not an array. Compare this with the target of pop or tie, which is syntactically an array. --Dominus 13:44, 23 Aug 2004 (UTC)
- I agree. The array copy is an implementation detail. --PhilHibbs 09:03, 24 Aug 2004 (UTC)
- It is undoubtedly an implementation detail, but nevertheless quite an important one affecting the code meaning, so the list-like syntax notwithstanding, maybe it should be stated that in fact
for
iterates over an array, not a list:
- It is undoubtedly an implementation detail, but nevertheless quite an important one affecting the code meaning, so the list-like syntax notwithstanding, maybe it should be stated that in fact
@a=(1..10); for (@a) {@a=(); print} # prints only 1
- Rafał Pocztarski 18:07, 24 Aug 2004 (UTC)
- Saying that perl expects a LIST at that point doesn't imply that an array is being flattened into a LIST, does it? An array is still a LIST. (fish_at_uc_org)
- You make a good point, but I'm not sure this article (or any article on a programming language) should get into such minutiae. Since arrays are lists, but not vice versa, foreach( list ) should be used because 1) it's correct, even considering minute details, and 2) it's simpler than saying foreach( array ) and then having to qualify it. --Diberri | Talk 00:55, Sep 15, 2004 (UTC)
Sample code formatting
Regarding Ævar Arnfjörð Bjarmason's changes to the code formatting (using <tt> instead of <pre>), I think I prefer the look that the stylesheet imparts to <pre> blocks. --Yath 23:26, 15 Aug 2004 (UTC)
Merits and demerits of Perl as a programming language
Here's some text I removed, from a section named "Merits and demerits of Perl as a programming language":
- "Like all programming languages, perl does some things well, and other things, well, less than efficiently. Many programmers have come to terms with this and use a judicious mix of shell-script and perl to get around the more obvious deficiencies (date manipulation can be slow in terms of relative processing time, for example). On the upside, perl is very useful for low level file manipulation at which, in many respects, its performance is often comparable with e.g. sed."
I'm sure a section like ==Tasks for which Perl is unsuited== could be useful and informative, but the above paragraph has no redeeming qualities. Allow me to nitpick.
- "a judicious mix of shell-script and perl to get around the more obvious deficiencies" -- Perl replaces and exceeds sh in nearly every capacity. When perl falls short, you either switch languages or call a utility, but the instances in which that utility would be sh are vanishingly rare.
- "date manipulation can be slow in terms of relative processing time, for example"- perhaps this is a rare example of when sh is better than Perl? If you can demonstrate this, I won't object to it being reinserted into the article.
- "perl is very useful for low level file manipulation"- This is too vague. By "low level file manipulation", do you mean manipulating links and permissions, or something even lower? Perl is ok for fiddling with links and permissions, I guess, but as a strength, it's no big deal. For lower-level operations... well, you'll have to clarify if that's what you meant.
- "at which, in many respects, its performance is often comparable with e.g. sed." sed? Perhaps you meant data manipulation. This is one of the foundations of Perl and is well covered elsewhere in the article.
--Yath 08:01, 14 Sep 2004 (UTC)
- I also agree. There's a lot of be said about Perl's failings and deficiencies (see Sins of Perl Revisited, for example) but I don't think this is it. --Dominus 13:14, 14 Sep 2004 (UTC)
But after you realize that language switch could be too costly you learn to use external sub routines and gain access to all the codebase that evolved in the C world and C library calls interface world. That's the point you become several times more productive. How many times and how fast depends on your C/C++/libs experience.—The preceding unsigned comment was added by 194.149.124.54 (talk • contribs) .
Data types and Variables
With all the Perl hackers around, we have an article on Perl that does not explain, or even do more than mention in passing, Perl data types and variables. The word data only appears as part of "database", "type" doesn't appear at all, and "variable" only appears in a misdescription of function parameters. I've half a mind to submit this article for deletion, if this is all there is to show after three years. --Tony Sidaway 11:30, 26 Nov 2004 (UTC)
- Are you kidding? If incompleteness was grounds for deletion, Misplaced Pages would dissolve. :-) Sure, the article needs work. So be bold! For now, I've added a brief bit on built-in data types ($scalars, @arrays, and %hashes), but there's lots of room for improvement. Why don't you take a stab at it? --David Iberri | Talk 09:18, Nov 27, 2004 (UTC)
- I don't think adding yet more of the same is going to make this into an encyclopedia article. I think it would probably make more sense to wikify the perldoc files (see User:Tony_Sidaway/Projects/man_perl/man_perl for an example based on Perl 5.6.1, with an example of a link to man perlbook) and reserve the main Perl article for a brief language summary as is the case with languages like Fortran, lisp and so on. --] 17:27, 27 Nov 2004 (UTC)
- I'm not sure I understand what you mean bo "adding yet more of the same". If you mean that the existing article is a bit too low-level (e.g. the regular expression section needs more commentary and fewer examples, IMO) and that the built-in data types section I added is similarly too low-level, then I might agree. But I'm not sure that a brief summary would suffice. Wiki is not paper, so I don't think we need to be overly concise. Examples are good, as demonstrated by Lisp programming language. --David Iberri | Talk 19:44, Nov 27, 2004 (UTC)
- Someone coming to Perl should be able to find out what he or she needs to know. The type of language it is, what people use it for, what it looks like, in general terms the kinds of facilities it provides to the user, the design considerations of the language, and its history.
- What is there would probably be all right if it were more concise and (above all) accurate. The section on subroutines, for instance, erroneously refers to "Variables passed to a subroutine"--an error that could be forgiven in a first year Computer Science student, but is not to be expected in an encyclopedia.
- I think I'll continue with my efforts to wikify man perl and, once I have completed that task to my satisfaction (I'll be using scripting to do the translation to wiki), I'll compose a rewrite of Perl that refers the interested reader to the appropriate sections of that copious and very readable electronic manual of the Perl language. This should provide the best of both worlds. --] 21:21, 27 Nov 2004 (UTC)
Time to split the page?
The Perl page is at 30K. It's long to read and big to edit. Would it make sense to split some of the big sections, e.g.
off into separate pages? --Swmcd 16:19, 2005 Mar 1 (UTC)
- Yep :-) --chocolateboy 19:34, 1 Mar 2005 (UTC)
- Only 30K? You slackers. My talk page is longer than that! :) --Maru (talk) Contribs 20:27, 12 November 2005 (UTC)
Language Design Philosophy
I recently restored the following deleted paragraph from the "language design" section of the article:
- "The design of Perl can be understood as a natural response to three broad trends in the computer industry: falling hardware costs, rising labor costs, and advancing compiler technology. Earlier computer languages, such as Fortran and C, were designed to make efficient use of expensive computer hardware. In contrast, Perl is designed to make efficient use of expensive computer programmers."
The user who deleted this paragraph said in the edit comment that it was "unencyclopedic". The paragraph is factual, and I believe it is correct. Moreover, I think that it is a good capsule summary of the major overarching principle of Perl's language design. Accordingly, I believe that the criticism of this paragraph as "unencyclopedic" is mistaken. --Dominus 5 July 2005 14:17 (UTC)
- I agree with you, and your revert beat out my revert by a short period of time. I see Fredrik has since offered up some "compromise language", but I still think the original language made the point better, so I've reverted back to that. In my opinion, the 'graph speaking of computer productivity versus programmer productivity is the heart of the matter and should certainly stay. --Atlant 5 July 2005 14:23 (UTC)
- I agree, "unencyclopedic" was a bad choice of word (it only referred to a small part of the paragraph). The main problem is:
- "The design of Perl can be understood as a natural response to three broad trends in the computer industry."
- Saying that it is a "natural response" is pretty biased. Also, the contrast with "earlier computer languages" is wrong, because although many earlier languages were designed for speed, others were certainly not. The text makes it sound like Perl invented the concept of abstracting things away from the hardware. The third sentence is at least partially redundant. Btw, Atlant, my third edit was not a revert, but rather an "unrevert"; I wrote it before Dominus did his second revert, after reconsidering deleting the entire paragraph. --Fredrik | talk 5 July 2005 14:29 (UTC)
- I agree, "unencyclopedic" was a bad choice of word (it only referred to a small part of the paragraph). The main problem is:
- I agree with you that the word "natural" should be removed.
- I don't think the text makes it sound like Perl invented the concept of abstracting things away from the hardware. There is nothing in the paragraph as written that suggests that Perl was the first or only language to do that.
- I also don't think the third sentence is redundant. It establishes a general principle, which is then elaborated upon by the following paragraph. I think the two paragraphs complement each other. --Dominus 5 July 2005 14:35 (UTC)
- What if it said something like "Many earlier languages, such as..." instead? --Dominus 5 July 2005 14:44 (UTC)
Intro paragraph
The intro paragraph says:
Perl borrows features from C, shell scripting ...
200.150.42.62 changed it to:
Perl has a unique set of features partly borrowed from C, shell scripting ...
I reverted it. I think the point of the phrase "a unique set of features" is to emphasize that Perl does have its own feature set, independently of all the other languages that it has borrowed from. But that is presumably true of any programming language. If we really need to make this point, I'd rather move it down to the Language features paragraph. The intro paragraph should stay very short, for the benefit of readers who just want capsule summary of the subject. OTOH, if "unique set of features" means something else, then it needs to say so with precision. --Swmcd 2005 July 6 18:43 (UTC)
Perl is not (really) an interpreted language
I noticed the intro said that Perl is an interpreted language, so I went to edit it to change "intepreted" to "byte-compiled". But then, in the interest of consistency, I read further down. The entire article whipsaws between "interpret(er|ed|s)" and "compile(r|d|s|-time)" with little rhyme or reason (except it doesn't say "interpret-time" anyway, thankfully!). I can't imagine that the lay reader is going to have any luck understanding Perl's execution. Was there some prior discussion that decided that it's better to pretend Perl's interpreted? Or is a byte-compiled language which immediately executes the bytecode considered "interpreted" these days since actual line-by-line interpreters seem to be getting more and more rare? --TreyHarris 17:39, 24 August 2005 (UTC)
- If I were doing the editing, I'd say make it clear that modern Perl is a compiled langauge. (I honestly don't know if it's fair or not to call the compiled representation of the code "byte code"; I've never looked closely at exactly what data structures come out of the compiler but I'll bet they're more complex than just byte-code that is then interpreted by a runtime engine.) But there's no doubt that everything is compiled, even any eval(...) stuff. --Atlant 17:51, 24 August 2005 (UTC)
- I put "interpreted" back in. Section 1.3 Implementaion describes Perl's execution architecture. We could argue the semantics of words like "compiled" and "interpreted". However, people who read in an encyclopedia article that Perl is interpreted will draw correct conclusions about its available features and CPU requirements. --Swmcd 15:55, 2005 September 2 (UTC)
Pro vs. Con
These sections are POV, unsourced and not well written. I also think the idea of an "advantages/pro" section in a programming language article is silly, as you're required to compare it to every other language in existence, which isn't help. Criticism can be done independently of other languages though. The pro section includes those two "perl is fun!" quotes which really shouldn't be there. The con section does contain common criticisms, but it needs to be sourced. And this last "rule of thumb" I've never even heard of: "A rule of thumb is that if resources to run Java are available, then Perl can certainly be used." Java programs run considerably faster than Perl programs due to being JITed, so I'm not even sure who would say such a thing. --Nathan J. Yoder 05:49, 19 October 2005 (UTC)
- I think that there are some pros/cons that are held by a wide number of experienced people. For instance, nobody would write a ray-tracer in pure Perl. And non-experienced people often have very similar initial responses when learning the language. Though I do think some care does need to be taken to make sure the pros/cons actually represent consensus of a majority of some community, and not just the thoughts of one person who just learned the language, or otherwise similar to overboard rants that some people have posted on the internet. --Interiot 20:08, 19 October 2005 (UTC)
- Yes, that's why there needs to be some sourcing to confirm these aren't just every random complaint being inserted. I think "advantages" shouldn't be given their own section, they should be interwoven into the article and just listed as features to let the reader decide. Criticisms tend to be a bit harder to integrate like that without sounding hackneyed, plus I think people generally like them condensed into one section. --Nathan J. Yoder 01:11, 20 October 2005 (UTC)
- All pros and con for Perl, with Perl it's just more visible, from the contributors view depned on the depth of insight into Perl and it's facilities and ability to use them where they fit. The JITcalim could be made parially invalid example using mixed approach of not only Perl. The argumentation would be offtopic here and would resemble trolling or flamewar because we are not benchamrking "the one task" in Java/Perl/mixed enviroment. The trick and truth is not to list pros as it can't be compared to everything and still be usable wiki page but provide information that educates the reader enough to be able to decide what tasks is Perl good for and what other facilites may be used to bind it with other specialized tool while the result remains effective in some way. On the other hand it's good idea to list mistakes under con to speed up the rejection during language selection for some task. It will help prevent the reader from using Perl where the gain will not be significant and in this way will reduce the FUD like "write only language" and other negative generalized attitude to reappear.
Regarding the cons added this morning, I would like to see the business one removed or significantly reworded. I work at a Fortune 100 business that uses Perl quite a bit. We don't base our business on it, but we have TONS of worker scripts that do perform little useful tasks. Also, the Symbian OS development environment is heavily based on Perl, so that's someone else who doesn't find substantive problems with it. Also, the perl/C integration, is that a valid criticism? Are there other interpretted languages which integrate significantly easier with C (other than with .NET, which is much different than any other interpretted language out there). --Interiot 20:16, 19 October 2005 (UTC)
- Yes, some languages are designed to be easy to integrate like Lua and Tcl. Boost also provides some nice bindings to Python. --Nathan J. Yoder 01:11, 20 October 2005 (UTC)
A warning on adding content
The title of the section is Opinion, not Pro vs. Con. I have observed that people have strong opinions about Perl. I think that these opinions are somewhat relevant to understanding the language itself, and very relevant to understanding the culture and—occasionally—controversy that surround it. The section is divided into two sub-heads: Pro and Con. However, the purpose of the sub-heads is not to advocate for their respective opinions; rather, it is to summarize and present them. There is a natural tendency for people reading this section to add material responding to opinions with which they disagree. However, doing so is not appropriate for this section. It obscures the point of the section and risks becoming POV. --Swmcd 21:28, 20 October 2005 (UTC)
Use of $a, $b in examples
The variables $a and $b have special behavior in Perl because of their use in the sort function. They are the only non-magic variables in Perl that will not cause an error if they are not declared under "use strict". Because of this, their use should be avoided in examples as doing so could lead beginners to encounter subtle problems with their code due to the lack of strict declaration checking for those variable names.
For instance, someone not familiar with Perl's rules for variable scoping could inadvertently declare a local "$a" with "my $a" and then use it outside of the declaring block; in this case, "use strict" would not cause an error, but the implicitly global copy of "$a" would be used instead.
#!/usr/bin/perl use strict; use warnings; { my $a = ...; ... } print $a;
Mike Dillon 18:53, 22 November 2005 (UTC)
- I agree, and have changed the page to remove the references to $a and $b. Turnstep 19:50, 27 November 2005 (UTC)
- Cool. Good work on the other edits too. P.S. Greetings from Perl Monks... I'm mdillon there and I assume you're the same "turnstep". Mike Dillon 05:26, 28 November 2005 (UTC)
- Yep, how did you guess? :) Haven't really done much on there in years, however. Turnstep 06:39, 28 November 2005 (UTC)
- I haven't been active there in a couple years either, I just recognized the name. Mike Dillon 18:01, 28 November 2005 (UTC)
- Yep, how did you guess? :) Haven't really done much on there in years, however. Turnstep 06:39, 28 November 2005 (UTC)
- Cool. Good work on the other edits too. P.S. Greetings from Perl Monks... I'm mdillon there and I assume you're the same "turnstep". Mike Dillon 05:26, 28 November 2005 (UTC)
Context-free
- Perl has a context-free grammar; however, it cannot be parsed by a straight Lex/Yacc lexer/parser combination. Instead, it implements its own lexer, which coordinates with a modified GNU bison parser to resolve ambiguities in the language.
No it does not, in anything close to the strict definition of context-free. Actually, very few languages have context-free grammars (for example C doesn't, as a (b); may be either function call or variable declaration in some contexts).
Quick draft of a proof: function prototypes. Whether foo bar 1,2 parses as foo(bar(1,2)) or foo(bar(1),(2)) depends on earlier prototypes of foo and bar. Because of infinite numbers of possible functions, you can't encode this information in a context-free grammar. It's not the only Perl construct that's provably non-context-free. Taw 09:06, 3 December 2005 (UTC)
- You are right that Perl does not have a context-free grammar. The regex syntax isn't even context-free, since even backreferences introduce context-sensitivity. Besides the problem you pointed out, the function itself can behave differently if it is called in scalar v. list context. Your changes look good, although explicit reference to Lex and Yacc may not be the best thing; maybe it should just say "cannot be parsed by a standard lexer/parser combination" instead of "cannot be parsed by a straight Lex/Yacc lexer/parser combination". Mike Dillon 15:23, 3 December 2005 (UTC)
Hello world
Does the warning flag belong in the shebang line of the hello world program? It's never in my programs.
Maybe I'm Wassercrats, maybe I'm not. :P -Barry- 05:14, 11 December 2005 (UTC)
- I think Misplaced Pages should promote good coding practices, and it's good practice to get into the habit of writing
-w
in the shebang line of all Perl programs. --David Iberri (talk) 18:25, 12 December 2005 (UTC)
- Better yet, use warnings; Turnstep 18:46, 12 December 2005 (UTC)
- Add all the tips on good practice that you want, but the rule of the "Hello, world!" thing is just to print "Hello, world!" and a CR.
- I don't know who wrote the following, but it basically says that using -w isn't worth the trouble unless you need help developing your style:
- "...the code may be perfectly OK, but it will give you an error message so you have to go check. Let me warn you. It can be really annoying to be flooded with messages, especially if you know the code is OK, but my advice is to use -w anyway. If you learn to write code that doesn't generate warnings, you'll develop good style and be a better programmer."-Barry- 20:17, 12 December 2005 (UTC)
- - The "-w" switch should be included because it's canonical. It is included in the "hello world" examples in certain Perl books.
- - It is not Misplaced Pages's responsibility to promote good coding practices.
- - The "hello world" program is not just a program to print out "Hello, world!" and a CR. It is an idiomatic program.
- The Language features or Language structure section should cover things like -w and maybe debugging tools like strict, and common practices for using Perl would be appropriate for the article. I'm not saying that any particular matter of opinion should be promoted. I wouldn't object as much about the -w in the hello world script if it was explained somewhere that it's not essential.-Barry- 21:11, 12 December 2005 (UTC)
- Only good things happen when we promote coding practices that have been widely accepted as good ones. Why shouldn't this be Misplaced Pages's responsibility? --David Iberri (talk) 03:00, 13 December 2005 (UTC)
- In promoting something, there's often one-sidedness, which isn't appropriate for this quasi-encyclopedia thing we call Misplaced Pages, but the function of -w can be explained, as well as use warnings;. Mentioning that using -w is generally accepted to be a best-practice is fine too, I guess. -Barry- 03:17, 13 December 2005 (UTC)
Perlscript
no mention of perlscript? Gflores 05:58, 16 December 2005 (UTC)
The lead
I condensed the lead. The lead should be like a headline: very short, with just enough info to tell the reader what the article is about, and help them decide if they want to read further. Avoid adding anything to the lead that either is--or should be--somewhere else in the article. Swmcd 17:11, 16 December 2005 (UTC)
Perl is interpreted
There is a common distinction between intepreted and compiled languages. This distinction is not absolute. The text of most interpreted languages undergoes some kind of preliminary compliation—lexing or parsing—before it is passed to the execution engine. Conversely, every program is ultimately interpreted: CPUs interpret their own machine code.
When we say that a programming language is interpreted, that is generally understood to mean 2 things:
- programs in that langauge suffer a significant performance hit with respect to equivalent compiled programs
- the language offers strong introspection features, and—especially—an eval() function.
Both of these things are true of Perl, so we say that Perl is interpreted. Interested readers will find a more detailed description of Perl's execution architecture in the Implementation secion, while uninterested readers will draw correct conclusions about Perl's performance and language features even if they read no further than the statement Perl is interpreted.
Swmcd 05:18, 17 December 2005 (UTC)
- Sorry for editing the above post. I didn't notice that it was on the talk page.
- I thought the interpreted issue was settled months ago. Anyway, a significant performance hit won't be noticed with all Perl programs. This is covered on page 16 of Learning Perl, 3rd Edition. And eval() is nothing special to me, but maybe there's more meaning in what you're saying than I see. I'm not as into Perl as I used to be. -Barry- 08:33, 17 December 2005 (UTC)
The statement Perl programs are interpreted is gone, on the grounds that
"interpreted" implies "reparsed on every loop".
I've never drawn that inference, but if that's how the word is commonly understood, then we shouldn't use it. The word "interpreted" could be dropped from the lead. The word "interpreter" appears in 30 places in the article; I don't know what to do about that.
Swmcd 15:47, 17 December 2005 (UTC)
- Yeah, colloquially, we say "the Perl interpreter" (the standard /usr/bin/perl program), only to contrast it with "the Perl compiler" (various forms of perlcc and friends). --Randal L. Schwartz 20:02, 17 December 2005 (UTC)
Semicolons used inconsistently in one line scripts
I've seen one liners with and without semicolons in the article. For example, there's:
my $x = shift;
and there's:
$x =~ m/abc/
I suggest that semicolons be used consistently. The problem is that I encountered a line that I'm not sure can be a valid line of Perl code or whether it's a snippet of a line, so someone more advanced than me better take care of it. -Barry- 21:57, 17 December 2005 (UTC)
- You only need semicolons to separate statements. Most of the examples in the article aren't one-line scripts, they are just code fragments. The first example above would typically be a complete statement in a program, so it gets a semicolon. The second example is an expression that might be part of a larger statement, so it doesn't have a semicolon. Swmcd 13:43, 19 December 2005 (UTC)
Regex examples
Sorry, I don't understand what the following example is good for ( especially combined with 'This is more interesting for patterns that can match multiple strings', were the modifier //s should be in use ):
($matched) = $x =~ m/a(.)c/; # capture the character between 'a' and 'c'
$matched will print -1 on my machine, this should be a simple example and we should introduce $1 here Ulv 23:42, 18 December 2005 (UTC)
- The example worked as written
localhost:~/src/Perl>perl -le '$x="abc"; ($matched) = $x =~ m/a(.)c/; print $matched' b localhost:~/src/Perl>
- The term "multiple strings" doesn't mean that $x contains multiple lines; it means that the RE can match more than one string, e.g. 'abc', 'axc', a3c', etc. But the text should probably be more direct than that.
- We could describe either the return value or the $1, $2, ... variables; I'd rather not do both, in the interests of brevity. I think the return value is slightly simpler to illustrate:
($matched) = $x =~ m/a(.)c/; # capture the character between 'a' and 'c'
Page reorganization
User:Flash200 reorganized the page.
Previously, the top-level sections were
1 Overview 2 Language structure 3 Language design 4 Opinion 5 History 6 Future 7 CPAN 8 Name 9 Fun with Perl 10 See also 11 External links 12 References
Now, the top-level sections are
1 History 2 Philosophy 3 Usage 4 Syntax 5 Resources 6 Availability 7 Opinion 8 Fun with Perl 9 See also 10 References 11 External links
I think we should revert to the previous organization.
People tend to read encyclopedia articles the same way they read newspaper articles. They start at the top, and scan down until they find what they want to know, or get tired, or bored. Also encyclopedias are consulted by non-experts; experts have other resources.
So we should organize the article to quickly provide the information most commonly sought by people who don't know much about Perl. I think
1 Overview 2 Language structure ...
does this better than
1 History 2 Philosophy ...
Swmcd 14:54, 12 January 2006 (UTC)
Redraft 1
I created a subpage, User:Flash200/Programming-language_outline, for discussing the reorg. I removed most of my own comments from this page and added them there. --Flash 04:00, 18 January 2006 (UTC)
- I think you're putting the cart before the horse by making the assumption that programming language articles should all share a common structure. I'm not at all convinced of that. It seems to me that a CPAN section made a good deal of sense for the Perl article to have, and the fact that no other language has it seems like a silly reason to rule it an unnecessary section. On the other hand, a Criticism section makes sense for many languages that are or were in widespread use, but seems a bit odd for esoteric programming languages, say Emoticon or Befunge. I don't understand the need for consistency here. --TreyHarris 07:30, 17 January 2006 (UTC)
- Sorry, I wasn't being clear enough. The template above is a generic one, not specific to Perl. The Perl article would still have a CPAN section or subsection. And some articles wouldn't have a "Criticism" section. The template would be adapted as needed to fit each language.
- In the last several years, I've been adding encyclopedic content about programming languages to my website, and I'd like to migrate as much of that as possible to Misplaced Pages. Having more consistency and intuitiveness for the organization gives me a better frame of reference for deciding what content should be added where. And it may make it easier for others to work with multiple programming articles as well (reducing the incompatibility between the articles, and reducing the learning curve of going from one article to another). --Flash 18:56, 17 January 2006 (UTC)
I reverted most of the page reorganization. An historical presentation just doesn't give most readers the info they are looking for when they read a programming language page.
It is certainly possible that the page could benefit from some reorganization, but that should be discussed here first, and then applied to the existing structure of the page. Starting from a generic template and then trying to morph it into something appropriate to Perl is difficult and unnecessary.
Swmcd 04:20, 29 January 2006 (UTC)
- Swmcd, I'm not sure your two edits of April 1st are accurate, could you explain them, please? "Alternatively, the interpreter can be compiled to a linked library and embedded in other programs." -> "Alternately, the interpreter can be compiled to a link library and embedded in other programs.". This is an alternative (the other option of two) rather than something that alternates (first one, then the other, then the first). It's also a library that is linked, rather than a library of links. I didn't want to silently revert, even after double checking my own understanding of those words on the OED. SimonFr 14:30, 3 April 2006 (UTC)
- The term link librarary refers to a library of subroutines, suitable for linking with other code to create an executable. So it is a library that can be linked, not a library that is linked. The term linked library isn't generally used; someone hearing that term is liable to ask, "Linked with what?"
- I have to disagree, the term linked library is the one I've encountered more often, with shared library being the most common. I also disagree with your assertion of potential misunderstanding. Library (computer science) mentions the library is called a dynamically linked library. This term is sometimes shortened to "dynamic link library" It may be simpler to use shared library SimonFr 11:09, 13 April 2006 (UTC)
- I'm using alternately in sense 4 given at www.m-w.com
4 : constituting an alternative <took the alternate route home>
- Interesting, the OED doesn't mention this, it talks only about 'taking turns' definitions. Since they're effectively equivalent in US English, and have caused confusion to me, a British English speaker, could we use alternatively? SimonFr 11:09, 13 April 2006 (UTC)
- I always assumed that the term linked referred to the mechanism of referencing more than anything else. You cannot use a function within the library unless you link to it (Therefore the can/is issue is a moot point). Whether this is done statically (ie compile time) or dynamically (ie runtime) is irellevant. the concept of linking is for the library to be loaded into resident memory, providing a list of address pointers where each of the functions are now available to be called. Thus you are linking into this library in order to retrieve the code to run. I think you have the link around the wrong way... it isn't the library which is linked in but the program which is linked into the library. Enigmatical 23:20, 12 April 2006 (UTC)
Listed as a .Net Language?
Is there any reason why this is listed as a .Net language? I have heard rumours that Perl.Net may be on the cards but no mention is made of it in the article and so I am not sure why it is categorized as such. Enigmatical 01:51, 12 April 2006 (UTC)
processor-bound tasks???
From the article:
- Perl is not efficient at processor-bound tasks, and Perl data structures generally use more memory than comparable data structures in languages like C and C++.
This is true of any scripting language, so why is it nessesary to list it specifically as a criticism of Perl? Perl also isn't good for, say, creating an operating system like one would do with C and C++, but that's hardly worth mentioning. 209.92.136.131 20:53, 19 April 2006 (UTC)
Popular alternatives to Perl
Why make people click each link in the Major programming languages box on the bottom of the article when they're looking for alternatives? Perl, Python and PHP are known as the three Ps and should be mentioned as popular alternatives, either in an infobox or somewhere else.
On this page, O'Reilly's Editor In Chief, Frank Willison, says "You can use a number of languages with MySQL and PostgreSQL, but the most popular are the three "P's," the open source scripting languages Perl, Python, and PHP."
I suggest that languages listed in my proposed Popular Alternatives infobox (if a new section isn't created in an existing infobox) be limited to those in the top chart on this page. PHP and Python are in that chart.
Here's the infobox I'd like to add above the Major programming languages box at the bottom of the article:
Popular alternatives to Perl |
Alternative title: Some popular alternatives to Perl.
-Barry- 02:11, 1 May 2006 (UTC)
- See also Python's See also section. I figured an infobox is better for Perl's article since the See also section is full enough. -Barry- 02:19, 1 May 2006 (UTC)
- Sorry but this is just silly. An "infobox" presentation makes it seem like finding alternatives to Perl has some kind of prominence among programmers. Also, it's far too vague: alternatives in what particular purpose? Every possible purpose? You can't even argue that PHP fills that bill; it's a niche language that competes in a small slice of Perl's domain. My first reaction on seeing your box is that it's thinly-veiled, partisan Perl-bashing. So let's not do this. --Yath 03:09, 1 May 2006 (UTC)
- At the very least, I want to fit a "three Ps" reference in here. I wouldn't mind a short description of whatever alternative languages are included, which would mention that PHP isn't as powerful as Perl. I also wouldn't mind if Python was the only alternative listed.
- I'm surprised there's no programming language comparison on Misplaced Pages. Maybe I'm not looking in the right place. Maybe I'll ad an external link to one. If it's a good one, then an alternatives section wouldn't be as important.
- I think there's a place in this article for Perl bashing, but that would be in the cons section. I think alternatives should be mentioned in every programming language article. Python's article already mentions Perl.
- There are no veils here. I haven't been a fan of Perl for a while, and I'm even less of one lately, but I won't surpress anything good that anyone has to say about Perl unless it's untrue or clearly doesn't fit in the article. -Barry- 03:41, 1 May 2006 (UTC)
I have two main points. Firstly, it's a page-wide box containing just two lonely entries. It looks silly. If you want to mention "the three P's", then do so in the text. No need for a box.
Secondly, there's lots more alternatives as Yath alluded to. Off the top of my head: Bash and Csh for simple scripting, Sed and Awk for simple text manipulation, and lots of other domain-specific languages for web programming (ASP, JSP, SSI, etc...).
I just found Comparison of programming languages but it's pretty bare. You might want to bring it up to the standard of other comparison of... articles. Imroy 09:06, 1 May 2006 (UTC)
- Thanks for the link. I began fixing it up. When I fix it a little more, I'll remove some of those templates and link to it. -Barry- 00:58, 2 May 2006 (UTC)
The infor box is silly but if it were there you should add ruby Htaccess 14:23, 4 May 2006 (UTC)
At this point, the "three Ps" is an outdated concept. The application domain of Perl is shared primarily with (in alpha order): C#, Java, PHP, Python, Ruby, and shell -Harmil 19:05, 8 May 2006 (UTC)
- They're probably the languages most supported by web hosts, and probably the most used for websites, but feel free to add more detail to the article if you think the three Ps part is misleading. -Barry- 08:11, 9 May 2006 (UTC)
- The Web doesn't really have any bearing here (though I'm sure your average PHP programmer would be shocked to hear that). Perl pre-dates the Web by about 5 years and has always had strong usage in systems administration, scientific modeling, reporting, and a number of non-Web fields. As far as the Web goes, however, I think Ruby and Java have certainly made at least as much of a splash as Perl, Python and PHP. C# tends to be used more in the application programming world, but there's a fair amount of Web and data work that overlaps Perl and Python's domain. -Harmil 13:15, 9 May 2006 (UTC)
TCPI?
-Barry- just added a paragraph linking to the TCPI Long Term Trends chart and uses it to claim that Perl is rapidly losing in popularity. This index is nothing more than using Google and other search engines to search for:
+"<language> programming" -tv -channel
This has about as much credibility as the old Operating System Sucks-Rules-O-Meter and I'm just itching to remove or at least rewrite that section. What do other people think? Imroy 06:23, 10 May 2006 (UTC)
- I had this same discussion on Perlmonks and in Talk:Comparison of programming languages. Here's what I wrote in the latter:
- --------
- There's Misplaced Pages:Search engine test. Under idiosyncratic usage it says "A series of searches for different forms of a name reveals some approximation of their relative popularity."
- The TIOBE data has been around for a long time and is regularly updated. At , where it says "The definition of the TPC index can be found here" you can click "here" to see an explanation. I don't think it's a good explanation, especially for laymen, but it provides some details that might matter to some people.
- Here's a discussion that might be of interest.
- --------
- If necessary, I can do what I did in Comparison of programming languages and clarify that the data is gathered from search engine results. The numbers are actually more accurate than that sounds, so I may explain it a bit more than that, but I'd try leaving out the long footnote that I put in Comparison of programming languages. -Barry- 07:29, 10 May 2006 (UTC)
- The problem is that you have only one data point: the number of times Perl is mentioned on the Web. You don't have:
- Number of times it's mentioned in journal articles
- Number of times it's used in deployed systems
- Number of times it's mentioned on the Web (but not refered to as "programming").
- The other problem that I have with the idea of judging Perl "popularity" by Web hits is the idea of maturity. No one is running around saying, "hey look at this cool new language I just found," about a 20 year old programming language. On the other hand, 20 years worth of programmers continue to use it day in / day out as one of the primary tools in their toolbox.
- I'm also still a bit concerned about anyone who makes this edit summary comment: and then procedes to push for questionable language comparisons... Please review WP:POINT as soon as possible, and I will continue to attempt to assume good faith. -Harmil 18:28, 10 May 2006 (UTC)
- The problem is that you have only one data point: the number of times Perl is mentioned on the Web. You don't have:
- Thanks for pointing me to that badly written guideline. I fixed it.
- From various comments I've heard about TIOBE's data and my own data from a similar study, it seems there are people who think it's meaningful, even once they know where it comes from. It's just part of the information in that paragraph that makes the argument that Perl is losing popularity. I've read Perl has lost popularity elsewhere as well, and I'm sure I'm not the only one. If you must edit it, say something like "...based on advanced search engine queries." Maybe add a footnote with the exact query and list the search engines. Unfortunately, I don't think the page on TIOBE's website with the details is directly accessible with a link when Javascript is on. -Barry- 19:32, 10 May 2006 (UTC)
- Of course the data has meaning. Almost any statistic has some sort of 'meaning'. You just have to be careful to explain what it's measuring and what it's showing. And I don't feel you are doing that properly. Since it's using simple (NOT advanced) Google/Yahoo/MSN searches, it's probably picking up mostly forums, blogs, and corporate hype. It's not picking up on the number of actual projects using a particular language, or the number of programmers with experience in that language. A search involving job advertisements would be much more realistic, IMHO. This TIOBE index is extremely superficial. Imroy 23:57, 10 May 2006 (UTC)
- Not only that, but these statistics do not include any knowledge of what languages are used for intranets which can form a large part of commercial development. Enigmatical 00:07, 11 May 2006 (UTC)
TIOBE gives relative rankings. Perl needn't lose popularity in order to fall in the rankings. All that is necessary is that other langauges grow faster. I have one data point that bears on this. I host the Perl Module Mechanics page. Traffic to this page has been growing slowly, but steadily, over the last few years. Swmcd 23:24, 10 May 2006 (UTC)
- The word popularity still fits. I don't think saying something like "per capita" or "relative to..." is necessary. Citing the increased number of users (or web searchers) would be useless unless you cite it for of other languages too. But clarify whatever you want if you think it's necessary. -Barry- 23:36, 10 May 2006 (UTC)
Good grief! Has anyone looked at the TIOBE page? Between 2004 March and 2004 April, Java dropped from 24% to 19% in the rankings. At the bottom, they have this FAQ
# Q: What happened to Java in April 2004? Did you change your methodology?
A: No, we did not change our methodology at that time. Google changed its methodology. They performed a general sweep action to get rid of all kinds of web sites that had been pushed up. As a consequence, there was a huge drop for languages such as Java and C++. In order to minimize such fluctuations in the future, we added two more search engines (MSN and Yahoo) a few months after this incident.
With artifacts like that, how can we cite TOIBE as evidence of anything? Swmcd 23:45, 10 May 2006 (UTC)
The TIOBE paragraph also says
OSCON — the open source convention sponsored by book publisher O'Reilly — is much less Perl-oriented than it used to be. Randal L. Schwartz, author of several Perl books published by O'Reilly, has said that OSCON's organizers are openly hostile to Perl, and that Perl isn't interesting to O'Reilly anymore.
Could we get a direct quote here? Or a report from Randal himself?
A further question is whether this is relevant to Perl, or only relevant to people who publish books about Perl. Swmcd 23:54, 10 May 2006 (UTC)
- I gave the source of the quote in the edit summary. It's from a chat logged at . It comes from more than one sentence, and I figured it would look better not to make it a quote. -Barry- 02:48, 11 May 2006 (UTC)
Benchmark comparison
There's already a Comparison of programming languages article, but it wouldn't be practical to include a detailed comparison of every two languages. A detailed comparison between Perl and other languages might work for Perl's article, or maybe for a separate article titled Perl language comparison. I did that "be bold" thing and added it to this article.
I remembered this Perlmonks thread about a contest that I was thinking of mentioning here or in Comparison of programming languages, and that lead to me finding this page of links to various benchmarks. I clicked "Debian : AMD™ Sempron" then clicked "Perl" then selected the languages to compare Perl to, and that's what my tables are based on.
There are disclaimers on that website about the data not always applying, and there are other benchmarks for other operating systems. Maybe more information should be gathered for a separate page. -Barry- 08:24, 11 May 2006 (UTC)
- This benchmark is horribly, horribly flawed. In just 10 minutes of cursory analysis, I was able to modify the first benchmark so that it ran over 20% faster in Perl. I've removed the results, as it seems that no useful information can be extracted from such a flawed study. -Harmil 14:39, 11 May 2006 (UTC)
- That kind of thing works both ways and probably balances out. Could you post your modification somewhere? -Barry- 18:20, 11 May 2006 (UTC)
- I gave you the link to the modification above, and no, we cannot assert that it "probably balances out". Can we please, just stick to facts. This benchmark, like almost any cross-language benchmark is horribly flawed, and should not be referenced. -Harmil 19:21, 12 May 2006 (UTC)
- Sorry, I didn't know that was the link to the diff. Unfortunately, I'm not sure how to read that and I don't want to learn. I like the added context of surrounding code anyway. I'd prefer if you use my DiffNote web application and link to the results. But it probably won't make a whole lot of difference in my opinion of whether to add the Benchmark Comparisons section. In fact, I wouldn't even be able to cite your improved version of that benchmark because of the no original research rule. On the other hand, I wouldn't object to a stronger disclaimer, especially if you've actually managed to legally improve the speed, and you may be able to submit your benchmark, which would allow it to be used in this article.
- Also, even if you did speed the script as fast as you claim without breaking it, that doesn't mean Perl would have won any more tests, and if it did win one more, that's only a small fraction of the 16 or so speed tests (32 now that I doubled the data). Using one improved test to discount the validity of the entire data set is itself flawed.
- I noticed that part of your modification goes against best programming practices. You replaced descriptive variables like $item with Perl's default variables like $_. I guess that's technically allowed, but I wouldn't want to maintain your code.
- I think we need more input on this, because I really think the Benchmark Comparisons section improves this article and I'll probably put it back. I don't think there's anything like it in other programming language articles and it could help make this article a featured page.
- Again, I wouldn't mind disclaimers and references that show that the results should be considered with caution. In fact, the section can concentrate on the flaws in cross-language benchmarks, but some people would figure it balances out and may put some value on the data. How DO you choose a programming language if you want speed, or something else that can be benchmarked, but don't have different versions of the exact program you'll be using that are written in multiple languages? If you do have some important snippets written in multiple languages, how do you know you wrote them each optimally so the comparison lives up to Harmil's standards? People need to make those language choices sometimes, and most probably base it on less accurate information than is contained in these benchmarks.
- It's probably more accurate to use the references here to learn how to create a benchmark specific to your machine and program (I included that link in the Benchmark Comparisons section), but if you don't want to go through all that, what do you do? Ask some guy on a message board? Questions like "what language should I use for..." are asked all the time, and when it comes to needing speed or fewer lines or less memory, the data Benchmark Comparisons article is probably better. -Barry- 20:50, 12 May 2006 (UTC)