[27388] in Perl-Users-Digest
Perl-Users Digest, Issue: 9063 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Sat Mar 18 09:06:01 2006
Date: Sat, 18 Mar 2006 06:05:04 -0800 (PST)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Sat, 18 Mar 2006 Volume: 10 Number: 9063
Today's topics:
Re: A Problem With GD <abigail@abigail.nl>
Code that makes you say hmmm! <someone@example.com>
Re: Code that makes you say hmmm! <1usa@llenroc.ude.invalid>
Re: debugging perl program with Tk mainloop <ngoc@yahoo.com>
Re: deferred module loading ? <tadmc@augustmail.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: 17 Mar 2006 21:52:10 GMT
From: Abigail <abigail@abigail.nl>
Subject: Re: A Problem With GD
Message-Id: <slrne1mbsa.46n.abigail@alexandra.abigail.nl>
Mark Manning (markem@airmail.net) wrote on MMMMDLXXXI September MCMXCIII
in <URL:news:121krm9gd07bh97@corp.supernews.com>:
== Abigail wrote:
== > Mark Manning (markem@airmail.net) wrote on MMMMDLXXVIII September
== > MCMXCIII in <URL:news:121e4203g00m77f@corp.supernews.com>:
== > ?? Abigail wrote:
== > ?? <code snipped for space>
== > ??
== > ?? I added in a new line which reads "$v = ++$v % 2" and the results are:
== >
== > But since '$v = ++$v % 2' modifies $v twice in the same statement, the
== > fact it toggles $v is just happistance, and there's no garantee it will
== > work on every platform, or on a next version of Perl.
== >
== >
== >
== > Abigail
==
== Well that's strange. I thought one of the strong points of Perl was that it
== guaranteed to always do the pre-increment command before doing anything else
It doesn't. And this fact is documented.
== Unlike C/C++ where you are not guaranteed to be able to do this.
Pre/post increment/decrement works "as in C". With the same benefits.
And the same flexibility for the implementation.
== Would you say that "$v = (++$v) % 2" would always work due to the parenthesi
That still modifies $v twice in the same expression.
== Or just in general the ++$v may not work?
In general '++ $v' works. Just don't modify the same thing twice in
the same expression.
Abigail
--
:$:=~s:$":Just$&another$&:;$:=~s:
:Perl$"Hacker$&:;chop$:;print$:#:
------------------------------
Date: Sat, 18 Mar 2006 11:21:32 GMT
From: "John W. Krahn" <someone@example.com>
Subject: Code that makes you say hmmm!
Message-Id: <03SSf.2749$nQ6.1906@clgrps13>
I downloaded a Perl program recently and encountered this line:
if(exists $_[0]->{"name"} and scalar($_[0]->{"name"}) eq $_[0]->{"name"}){
Comments? Jokes?
John
--
use Perl;
program
fulfillment
------------------------------
Date: Sat, 18 Mar 2006 12:15:57 GMT
From: "A. Sinan Unur" <1usa@llenroc.ude.invalid>
Subject: Re: Code that makes you say hmmm!
Message-Id: <Xns978A4A077CC82asu1cornelledu@127.0.0.1>
"John W. Krahn" <someone@example.com> wrote in
news:03SSf.2749$nQ6.1906@clgrps13:
> I downloaded a Perl program recently and encountered this line:
>
>
> if(exists $_[0]->{"name"} and scalar($_[0]->{"name"}) eq
> $_[0]->{"name"}){
>
Sartre must be communicating with the rest of us through the life-form who
put together those lines.
I am speechless.
Sinan
--
A. Sinan Unur <1usa@llenroc.ude.invalid>
(remove .invalid and reverse each component for email address)
comp.lang.perl.misc guidelines on the WWW:
http://mail.augustmail.com/~tadmc/clpmisc/clpmisc_guidelines.html
------------------------------
Date: Sat, 18 Mar 2006 09:55:33 +0100
From: ngoc <ngoc@yahoo.com>
Subject: Re: debugging perl program with Tk mainloop
Message-Id: <2v-dnf_I_ZpqV4bZRVnzvA@telenor.com>
Thank you very much. You solve my problem. Now I can debugg without
using print command in the code -> better quality of software -> my boss
will be happy.
> main::(foo:7): my $mw = MainWindow->new;
> DB<1> l 1-18
> 1 #!/usr/local/bin/perl
> 2: use strict;
> 3: use warnings;
> 4
> 5: use Tk;
> 6
> 7==> my $mw = MainWindow->new;
> 8: $mw->Label(-text => 'Hello, world!')->pack;
> 9: $mw->Button(
> 10 -text => 'Quit',
> 11 -command => \&quit,
> 12 )->pack;
> 13: MainLoop;
> 14
> 15 sub quit {
> 16: my $variable = 42;
> 17: exit;
> 18 }
> DB<2> b 17
> DB<3> c
> # << Press Quit button on GUI >>
> main::quit(foo:17): exit;
> DB<3> p $variable
> 42
> DB<4> q
>
------------------------------
Date: Fri, 17 Mar 2006 16:54:41 -0600
From: Tad McClellan <tadmc@augustmail.com>
Subject: Re: deferred module loading ?
Message-Id: <slrne1mfhh.2c7.tadmc@magna.augustmail.com>
bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
> Is there any way to avoid loading a module
> until it is (in fact) needed?
perldoc AutoLoader
AutoLoader - load subroutines only on demand
> And, yes, I have searched the documentation
See also perlsub.pod.
> and the web
> but haven't found information that I can use. I do not
> know wether this reflects a lack of information, or a lack
> of understanding on my part :-|
Merely the lack of the proper search term, I expect.
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
From: Perl-Users-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Digest Administrivia (Last modified: 6 Apr 01)
Message-Id: <null>
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End of Perl-Users Digest V10 Issue 9063
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