drieux, et al -- ...and then drieux said... % % On Saturday, July 13, 2002, at 07:11 , David T-G wrote: % % In the main I like where this is generally going.
Yay :-) % % A part of my argument with myself today has been about % % which is better? all 'teaching code' should be 'virgin clean'??? % or should we show the actual process by which ideas mutate from % a quick sketch to a 'completed' piece? I like the latter to a degree; a mix where we show just a couple of first ideas with their problems and then very quickly get to Really Good code would do well. % % Far too many times the 'way we learned' a coding language has little % to do with how we present the coding language. Heh :-) % % tell me what you think of % % http://www.wetware.com/drieux/pbl/perlTrick/CBO/jobBot/ % % where I am trying to do some of what I think you are asking about % in terms of 'if you do foo....' Yeah, I see. I like it, though I'll have to read in more depth when I have time. % % [..] % >I think this could be expanded to show use of "local" or "our" vars for % >those who *want* to expose $z but must still see the dangers in not using % >"my". Just a thought. % % This has me concerned - it could be the way that the phrase is turned. Certainly it could be :-) % % if one starts with the simple mandate of % % though shalt use '-w' and 'use strict' % % then the choices are limited Fair enough... % % any variable that one would 'local' with, % needed to have been declared with Right; AIUI 'local' allows a called subroutine to see a 'my' var when it would otherwise not descend into the new scope. I *think* I understand this. - 'my' defines a var for only this block and does not export to subroutines - 'our' defines a var that is basically a global - 'local' defines a var that is like a 'my' but is visible to children of the scope so that called subroutines can see it Of course, if I don't then some of this discussion may make a lot more sense in its nonsense :-) % % my or our % % remember that 'our' is a 5.6-ism if I recall correctly. Ah. Didn't know that. % % So i am not too sure i 'grok' your assertion % % 'see the dangers in not using "my"' % % as a contrast to 'our' or 'local'. Well, if you don't use 'my' then you're definitely in trouble. If you do use 'my', though, you can't see the variable in a subroutine. When you're recursing and don't want to step on $x again that's good, but when you're calling another routine and want to see $z then you'll be stuck. % % >This leads me to ruminating on global variables in general. Things like % >config vars -- %ENV % % these are essentially out of your control 'at start up' - if % by 'config' you mean the set that are 'built in' and accessible % with 'use Config'??? No, not 'use Config'. I mean the path or other passed-in vars (mebbe web page field vars) but also config stuff like $gzip='.gz' $verbose='on' $addr='[EMAIL PROTECTED]' as default settings for the code you're writing (maybe you'll turn $verbose off with a command-line flag, but you want it on by default). For that matter, what about a $verbose or $debug var that you use all over the place to see if you should print out extra stuff? % % >or a switch that says to do this one way or another % >or the like -- seem well suited to being global. % % the problem is that 'globals are' - there are bunches of % them that are defined all over the place - and one therefore % wants to 'manage' the problem as best as one can. Yeah. % % > Perhaps if declared with an "our" at the main scope level... % % one advantage of this is that you can establish a reasonable % habit of putting them where you know that you can find them... I like to do that, though I do admit that tight scoping can be good. % % The alternative habit of 'declare them where you need them' - has % the reverse 'bite you' problem. % % while($still_do_me) { % ..... % my @accumulator ; ... % cope_with_them($_) % for (@accumulator); ... Exactly. % % >Can one safely and sanely make % >the argument "thou shalt NEVER have an unadorned variable" or is that % >just pushing a little too hard? % % well.... think about it, the moment that you mandate % 'use strict' and '-w' - the code will run, but it % will whine without 'adorning' your variables as to % whom they belong to.... True. Perhaps I should have said "non-'my'", since the discussion is really about the times when you WANT globals. % % ciao % drieux Thanks & HAND :-D -- David T-G * It's easier to fight for one's principles (play) [EMAIL PROTECTED] * than to live up to them. -- fortune cookie (work) [EMAIL PROTECTED] http://www.justpickone.org/davidtg/ Shpx gur Pbzzhavpngvbaf Qrprapl Npg!
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