in reply to Re: Re: Re: Recursive map Design Questions
in thread Recursive map Design Questions

I don't think I forgot anything.

I was genuinely asking whether Abigail thought that this was something that I should be testing for in my programs or just another of those many perl quirks that it's good to be aware of but probably pointless actually coding tests for.

Abigail tends to have a very dry sense of humour and I couldn't tell if this was a serious concern for everyday use or not from his post, so I asked.

We could put checks in our code to make sure that someone hasn't re-defined our defined constants, but that would render them pretty pointless.

So, my question remains -- should I be checking the return from ref for definedness every time I call it, or is the possibility of a reference blessed into package 0 (zero) or package '' sufficiently rare and unlikely that I can reasonably ignore the possibility?

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
If I understand your problem, I can solve it! Of course, the same can be said for you.
  • Comment on Re: Re: Re: Re: Recursive map Design Questions

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Re: Re: Re: Re: Re: Recursive map Design Questions
by demerphq (Chancellor) on Oct 03, 2003 at 23:27 UTC

    I don't think I forgot anything.

    Well, it seemed to me that you forgot that its somewhat traditional in Perl to leave as much rope as people need to hang themselves. Personally I dont see it as too much of a problem. *shrugs*

    is the possibility of a reference blessed into package 0 (zero) or package '' sufficiently rare and unlikely that I can reasonably ignore the possibility?

    In general I would say that you can ignore the possibility. If you happen to decide to write something is supposed to walk any data structrue correctly then I would say that you should consider the whole slew of possibilities in this area.

    BTW, I didnt mean to imply that you should be worried about redefining constants. Just that its a useful feature in some respects and the side effect of when it is needed for useful things is that it allows some very dangerous things. As does blessing.

    Anyway, cheers.


    ---
    demerphq

      First they ignore you, then they laugh at you, then they fight you, then you win.
      -- Gandhi

[reply]
[d/l]

      I understand the philosophy of perl in this respect, and in many cases I am in favour of it, but only when the rope has a useful purpose beside hanging me:)

      I don't yet have enough long-term experience of Perl or the internals to know if there is a useful (if obscure) purpose in allowing blessing into these weird package spaces, and thought to utilise Abigails greater experience to short-circuit that learning curve.

      I cannot think of one and felt, as I implied in the original post, that there was "nothing to worry about", but I've been bitten by that feeling before only to be shown the errors of my limited vision (usually by Abigail!).

      It's my opinion that if this particular piece of rope has no useful purpose, then I can see no particular reason for leaving it lying around. It doesn't seem (from my cursory inspections of the source) that it wouldn't be a difficult task to coil this particular loose end. I'd even be prepared to have a go at doing it, once I was convinced that there was no such useful purpose. I think tyes earlier reply to you indicates that he feels the same, but that is an interpretation.

      Examine what is said, not who speaks.
      "Efficiency is intelligent laziness." -David Dunham
      "When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
      If I understand your problem, I can solve it! Of course, the same can be said for you.
[reply]

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