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Re^13: can't import using exporter

by Corion (Pope)
on Mar 16, 2012 at 10:15 UTC ( #959955=note: print w/replies, xml ) Need Help??

in reply to Re^12: can't import using exporter
in thread can't import using exporter

As Anonymous Monk already pointed out, your are misreading/mistyping the Module::Runtime documentation and trying to import a function that does not exist. Instead of looking for errors with Perl, maybe consider actually reading the error message and comparing it to the documentation. But as you seem to have a penchant for ignoring replies or not reading them, I will repeat it again:

Module::Runtime does not export a function named module_notational_filename. It is only documented to export a function named module_notional_filename.

As for your other "evidence", again, you don't show any code, you still do not seem to have a grasp as to how to debug things. I am not joking about the maximum of 10 lines for a program to demonstrate your extraordinary findings. Please put in the effort to reduce your programs, and consider splitting up the large program of over 800 lines into more manageable modules in separate files. This will not only help you in finding the errors, it will also limit the damage you can do by editing a single file to exactly that file, and keep lots of red herrings out of your mind. Also, this will likely limit the side effects of ill-advised changes or misunderstood documentation to a short and manageable file instead of showing error message in an 800 lines file.

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Re^14: can't import using exporter
by perl-diddler (Chaplain) on Mar 16, 2012 at 22:20 UTC
    You actually replied? For what purpose?

    Penchant for beating dead cows much?

    p.s. the documented spelling for 'the word after 800 in your last paragraph is 'line', no 's', please make a note of it. If it wasn't used as an adjective phrase for the next word, then the 's' would be appropriate. Guess we all can make spelling mistakes -- though as I stated earlier and you ignored, the word in the dictionary is spelled notational. The fact that the author misspelled it is a "UI" bug (i.e. the user-interface to the function causes confusion due to word misspelling or non-standard word usage).

      I'm sorry - English is not my first language, nor my second or third, so I'm not necessarily familiar with all the colloquialisms. I know of the phrase "flogging a dead horse", but I'm unaware of the meaning of "beating a dead cow". Is this cockney slang for some sexual activity? It is maybe a bit telling, but my knowledge of the English language is mostly restricted to phrases that occur in polite conversation. I'm happy that you try to contribute back by helping me widen my vocabulary, but maybe you can explain in simple words what this phrase is supposed to express.

      As for the parts more closely related to Perl - it might not have been an explicit lesson by either merlyn or brian d foy, but neither Perl nor the authors of Perl modules are restricted to using only words in your dictionary. This fact might have come to your attention already as Perl let you use variable names such as $Filename2Fields instead of $File_name_to_fields. If the author of a module you use documents the name of a function, it is conventional to use that documented name to access that function instead of another name you'd have chosen instead. Perl supports you to modify your code to use the cromulent function names chosen by others, as it advises you when you use a different name for a function that the module author did not name in the same way.

      Of course, you are free to lament these literary disagreements and claim them as "bugs". You can of course write copy-edited Perl-code, but to expect that Perl and Perl authors adhere to your seemingly limited dictionary strikes me as a quite surprising stance, especially as there are quite a lot of Perl module authors who do not share your upbringing nor a copy of your dictionary. If you think that your vocabulary is the be-all end-all epitome of literacy, I recommend you start an initiative to convince all Perl programmers to only use words you approve of in function names and variable names. Until then though, I recommend that you start reading and understanding the error messages Perl so helpfully tries to provide you with, instead of claiming bugs in Perl. Especially reading the documentation of modules, and if in doubt, reading the source code of modules usually brings great enlightenmend as towards the vocabulary that other module authors use and offer to you to use as well.

        Can I assert that computer science is not your primary background as well?

        Your instructions on narrowing down the source of a problem are true for simplistic programs in simplistic environments, but those are not the environments of today's computer systems. An update introduced either because I installed an update for an unrelated product like photoshop or such, or because of some permitted OS update, (manual or automatic), can easily change the behavior of installed programs.

        In Windows7 programs are sensitive to what order they are loaded in memory and what else is loaded at the same time. It's very rare that they interact -- as we both 'know', they are not "supposed" to interact. But I have seen it happen due to random memory allocation by windows. Such things are rarely repeatable once the offending programs are terminated or even the machine is rebooted and the same programs loaded. Something left over in memory caused a different behavior.

        In a perl program -- the larger the program, the more likely it will be that any memory corruption or leak in perl will later affect something else at random. Even the size of the file read in, could affect how it interprets things early on. There are tons of subtle bugs that might only. In real time testing, you don't just run a test once. You run it many times.. It may be the system only crashes after the 100, or 1000, or 10,000,000th execution.

        In my later career, with my time spent in writing linux kernel security functions, crashes would occur after some random time of execution -- a timing bug that only happened ever so rarely. How do you debug it? By adding debug lines to the code, you are likely to make it go away. By removing functionality from the code, you may eliminate evidence of the problem, but not the cause. You may have just made it 10,000 times less like to occur -- which for an OS that is to be running 24/7, is still unacceptable. The way I attacked one such problem was by making the code less readable by optimizing the hell outof it. Because initially, it forced the crash to occur more often -- until I found what was likely the cause -- but no one was SURE it was the cause, because you couldn't remove it and still have the program work but changing it might simply hide it more thoroughly. Eventually I felt good about the code executing 20x faster at near the physical limits of the machine, for ... well I wanted 6 days, but my boss wasn't willing to wait for more than 3 days. He still felt I was needlessly optimizing the code -- and resented taking almost an extra 2 weeks to find a code that a more senior engineer gave up on finding but code that needed to be run for hours to a day at a time when he gave up.

        Perl is no where near the complexity of a kernel, but it is easily approaching the level of a compiler where "at a distance" type bugs start being noticeable.

        Coverity released a study on open source code quality and compared it to proprietary source code products. The defects/line of code were about the same between projects of the same overall size. Defects grew/line proportional to the size of the project. They did mention that open source projects tended to be smaller for the same types of functionality than their commercial counterparts, thus overall, had fewer bugs for products of the same type.

        That means perl is not not immune to the same tendencies of having defects/line of code as any other project. And that as it grows, it will develop bugs similar to other projects of it's size. Programs do develop bugs where cause and effect don't happen together or due to only a few factors but sometime several and some random 'salt' thrown in on the random number generator for good measure.

        That's my recent, largest code experience -- where simplifying something to just headers, would never display the bugs.

        However, you are more like to end up with some seemingly innocuous change making huge, irrational changes in perl's error behavior (like in my response ^4, above). Indicating the problem is not one of 'simplicity', but one of complexity causing perl to misbehave. That doesn't mean complex is the problem -- if it is valid code, the parser should have handled OR if not, then should have given a more consistent and localized error message in both cases -- when clearly, it did not.

        That is indirect evidence of a bug in the program handling the parsing and producing the output.

        If you throw random garbage at the compiler -- it doesn't matter, that the program was wrong. The compiler shouldn't crash, and it should determine the point at which output was unacceptable, and if it couldn't make sense of it then gracefully retired, -- but at least point to the last place things made sense, and where things went wrong.

        perl 5.16 doesn't do that, if anything it reliably does not do that. That is bad design -- to the point most wouldn't consider it to be a design flaw or bug, requiring more more evidence that what we've come up this thread. To the point -- my claims of finding bugs in the compiler (supported by many bug reports some of which causes were found, and some not in past versions) would show that someone who strongly claims that my finding a bug is 'extraordinary', requiring extraordinary proof, is rather naive. I've had bugs that would reliable reduce the the perl compiler to a core dump after a random amount of runtime. I've had others that only required reading a very specific way through 4TB data files. Not something that is the subject of your every day testing.

        If I say I have multiple programs that have broke between versions, it's likely true and likely not entirely my fault if at all -- or so history has shown.

      the word in the dictionary is spelled notational

      The 500 year old word "notional" means "pertaining to or expressing the idea of". It may be a poor UI choice, but is a valid word.

        I was quite aware it was a word, but it doesn't have the same meaning as notational, which is the notation of X in some specified formation -- in this case module format of a module name.

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