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Re: Style: buried variables or double referencing?

by gryphon (Abbot)
on Aug 20, 2005 at 15:41 UTC ( #485390=note: print w/ replies, xml ) Need Help??


in reply to Style: buried variables or double referencing?

Greetings punch_card_don,

Each of your suggested styles has merit depending on the particulars of the situation. Context is everything. There's nothing in your code examples that would make me shiver if I had to maintain it. (Although, "...many lines of code later..." does cause some pause, I have to admit.) A couple key things to consider:

  • Use very clear nouns for variable names that are short and accurately describe the data
  • Keep relevant code together; don't pre-define variables too early; in other words, don't my a scalar on line 4 then use it for the first time on line 100

I tend to write really compact code, but I understand that it can be more difficult for someone else to maintain. Here's what I'd be tempted to do:

for (0 .. (($some_variable eq 'x') ? 14 : 9 )) { print $_, "\n"; # or whatever goes on in here... }

TMTOWTDI, and you've already posted a few good ways.

gryphon
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Re^2: Style: buried variables or double referencing?
by punch_card_don (Curate) on Aug 20, 2005 at 16:21 UTC
    Although, "...many lines of code later..." does cause some pause, I have to admit.

    "many lines of code" = about 1,500

    and that's another style question. It's that big because it performs four phases of a multi-phase user inquiry to a database. That is, offer some options in a form, receive user selections, search database for more options that follow loically from the user's selections, and repeat total of four times. All phases use a large collection of identical constants, many identical sub-routines, but do a lot of crunching that's unique to that phase. So Having all four phases in one script with a phase-sorter at the beginning means:

    • reduced total code lines because common elements are not rerpoduced in separate scripts
    • during development, a change to any common element only has to be made once instad of four times.
    At the same time, I've sometimes wondered - is this considered a large script? Unweildy? Does it impact peformance to have to load one large script?

    Forget that fear of gravity,
    Get a little savagery in your life.

      "many lines of code" = about 1,500
      How do you create your html? If it is generated with print and heredocs within the script, you probably can reduce its size by using a templating mechanism and moving the html to separate files.

      Also, if you have such a big number of constants in your script, I would put them in some kind of configuration file, so you can change them without having to edit the script.
      • reduced total code lines because common elements are not rerpoduced in separate scripts
      • during development, a change to any common element only has to be made once instad of four times.
      There is another way to achieve this. Put your common code into modules.


      holli, /regexed monk/
      So Having all four phases in one script
      All in one script? How do you test that? I would have broken it into modules the moment I hit 500 lines. Especially since there is common code, and a large amount of it, that receives varying parameters: perfect thing to want to test that formally so that I can isolate a problem between called subroutines and calling code.
      reduced total code lines because common elements are not rerpoduced in separate scripts
      Uh, that's what a module is for. If you have cut-n-paste worry, then you aren't using modules right
      a change to any common element only has to be made once instad of four times
      Again, a sign that you don't understand modular development.

      I'm betting I would cringe looking at your "script". Mostly because I've seen far too many already in my life, and I think I've nearly used up my quota. {grin}

      -- Randal L. Schwartz, Perl hacker
      Be sure to read my standard disclaimer if this is a reply.

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