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I think in the more newer languages, they have implemented true
booleans. Perl is kind of old school. Pascal defines them as a
grandfather of languages. Therefore as one migrates the languages to a
higher levels (e.g. Perl[n]), they all will end up with a boolean data
type. Therefore, I think the $true and $false is a more consistent
method in a multiple languages environments (particularly doing web
things [Java and Javascript] for a consistent set of rules across the
board. Thanks for your input.
jeremiah@[EMAIL PROTECTED]
wrote:
>
> On Oct 15, 2007, at 11:25 PM, Gary Blackburn wrote:
>
>>
>> On Oct 15, 2007, at 4:27 PM, Michael Barto wrote:
>>
>>> As both Java and Javascript both have a 'true' and 'false' or
>>> Boolean data type, is there any interest in evolution of Perl to
>>> have a true Boolean. Or what is the preferred method to do this in
>>> Perl. The "C" programmers want me to use "0"'s and "1"'s.
>>
>> In my experience the most common convention is to use undef and 1 as
>> your boolean values, as in:
>>
>> my $is_scared; # is_scared is initially set to undef, which
>> evaluates as "false"
>>
>> if ($monsters_under_my_bed) {
>> $is_scared = 1;
>> }
>>
>> Yeah, it's probably bad karma to use "undef" when you mean "0" but
>> this approach is very perl-ish, easy to read, and even recommended by
>> Damian Conway in his "Perl Best Practices" book (page 40... just
>> checked. :-D)
>
> You can, if you really want to, do this:
>
> my $true = 1;
> my $false;
>
> Still, it is not much of a substitute for knowing what exactly is
> _inside_ your variable and testing it to make sure. Plus, boolean
> values are un-perlish. Look at this for example:
>
> if ($var) {
> print "Yep!";
> } else {
> print "Nep!";
> }
>
> That is perlish, testing if $var is defined and doing some thing based
> on that. You can of course make it clearer with
>
> if ( defined ($var))
>
> But to be really perly and terse, this is the idiom:
>
> print "Yep" if ($var);
>
> Jeremiah
>
--
------------------------------------------------------------------------
*Michael Barto*
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LogiQwest Circle
LogiQwest Inc.
16458 Bolsa Chica Street, # 15
Huntington Beach, CA 92649
http://www.logiqwest.com/
mbarto@[EMAIL PROTECTED]
<mailto:mbarto@[EMAIL PROTECTED]
>
Tel: 714 377 3705
Fax: 714 840 3937
Cell: 714 883 1949
*'tis a gift to be simple*
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I think in the more newer languages, they have implemented true
booleans. Perl is kind of old school. Pascal defines them as a
grandfather of languages. Therefore as one migrates the languages to a
higher levels (e.g. Perl[n]), they all will end up with a boolean data
type. Therefore, I think the $true and $false is a more consistent
method in a multiple languages environments (particularly doing web
things [Java and Javascript] for a consistent set of rules across the
board. Thanks for your input.<br>
<br>
<a class="moz-txt-link-abbreviated"
href="mailto:jeremiah@[EMAIL PROTECTED]
">jeremiah@[EMAIL PROTECTED]
>
wrote:
<blockquote
cite="mid:6139CF9C-BD8F-4E50-A62D-97C2315BDECB@[EMAIL PROTECTED]
"
type="cite"><br>
On Oct 15, 2007, at 11:25 PM, Gary Blackburn wrote:
<br>
<br>
<blockquote type="cite"><br>
On Oct 15, 2007, at 4:27 PM, Michael Barto wrote:
<br>
<br>
<blockquote type="cite">As both Java and Javascript both have a
'true' and 'false' or Boolean data type, is there any interest in
evolution of Perl to have a true Boolean. Or what is the preferred
method to do this in Perl. The "C" programmers want me to use "0"'s and
"1"'s.
<br>
</blockquote>
<br>
In my experience the most common convention is to use undef and 1 as
your boolean values, as in:
<br>
<br>
my $is_scared; # is_scared is initially set to undef,
which
evaluates as "false"
<br>
<br>
if ($monsters_under_my_bed) {
<br>
$is_scared = 1;
<br>
}
<br>
<br>
Yeah, it's probably bad karma to use "undef" when you mean "0" but this
approach is very perl-ish, easy to read, and even recommended by Damian
Conway in his "Perl Best Practices" book (page 40... just checked. :-D)
<br>
</blockquote>
<br>
You can, if you really want to, do this:
<br>
<br>
my $true = 1;
<br>
my $false;
<br>
<br>
Still, it is not much of a substitute for knowing what exactly is
_inside_ your variable and testing it to make sure. Plus, boolean
values are un-perlish. Look at this for example:
<br>
<br>
if ($var) {
<br>
print "Yep!";
<br>
} else {
<br>
print "Nep!";
<br>
}
<br>
<br>
That is perlish, testing if $var is defined and doing some thing based
on that. You can of course make it clearer with
<br>
<br>
if ( defined ($var))
<br>
<br>
But to be really perly and terse, this is the idiom:
<br>
<br>
print "Yep" if ($var);
<br>
<br>
Jeremiah
<br>
<br>
</blockquote>
<br>
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16458 Bolsa Chica Street, # 15<br>
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