Paul Hodges wrote:
--- Jonadab the Unsightly One <[EMAIL PROTECTED]> wrote:
Consider this test in Perl:
if "\0" {...}
Its equivalent in C is this:
if ("") ...
That can't be right. If anything it's got the two languages
flipped, but that's still not quite right either. Apples and
o
--- Brent 'Dax' Royal-Gordon <[EMAIL PROTECTED]> wrote:
> Paul Hodges wrote:
> > --- Spider Boardman <[EMAIL PROTECTED]> wrote:
> >>You need ord() for character/grapheme/byte/whatever testing that's
> >>equivalent to what C does. Since C doesn't really have strings,
> >>and Perl does, this is just
--- Jonadab the Unsightly One <[EMAIL PROTECTED]> wrote:
> Paul Hodges wrote:
>
> > Do note that I realize I can check it. It's just that for no reason
> > I can quite define, my C background wants a null byte to be FALSE
> > without any special chicanery on my part when checking. I can live
> > w
--- Simon Cozens <[EMAIL PROTECTED]> wrote:
> [EMAIL PROTECTED] (Paul Hodges) writes:
> > Do note that I realize I can check it. It's just that for no reason
> > I can quite define, my C background wants a null byte to be FALSE
> > without any special chicanery on my part when checking. I can live
Paul Hodges wrote:
--- Spider Boardman <[EMAIL PROTECTED]> wrote:
You need ord() for character/grapheme/byte/whatever testing that's
equivalent to what C does. Since C doesn't really have strings, and
Perl does, this is just one of those differences between the
languages where (essentially, and pe
Paul Hodges wrote:
Do note that I realize I can check it. It's just that for no reason I
can quite define, my C background wants a null byte to be FALSE without
any special chicanery on my part when checking. I can live with the
fact it isn't going to be, it just seems odd to me.
If that seems odd
[EMAIL PROTECTED] (Paul Hodges) writes:
> Do note that I realize I can check it. It's just that for no reason I
> can quite define, my C background wants a null byte to be FALSE without
> any special chicanery on my part when checking. I can live with the
> fact it isn't going to be, it just seems
--- Spider Boardman <[EMAIL PROTECTED]> wrote:
> At some point in history, Paul Hodges wrote (in part):
> ph> So a null byte is still Boolean true. Ugh, yarf, ack, etc.
>
> No. And it never has been (at least in my world view).
A valid point, though I reply:
my $x = "\0";
print "true" i
On Thu, 2004-06-24 at 21:45, Brent 'Dax' Royal-Gordon wrote:
> Perhaps not as happy as you think:
>
> my $foo = '0';
> my String $bar = '0';
> if $foo { say 'foo true' }
> if $bar { say 'bar true' }
>
> Would print 'bar true', but not 'foo true'.
Frankly, I love it. Since I plan
At some point in history, Paul Hodges wrote (in part):
ph> So a null byte is still Boolean true. Ugh, yarf, ack, etc.
No. And it never has been (at least in my world view). However, asking
that question explains some things. See below for more.
ph> But as long as I know -- easy enough to che
Paul Hodges wrote:
So a null byte is still Boolean true.
But just tell me thisam I the only guy who thinks this *feels*
wierd? Understanding the reason doesn't make it any more ~comfortable~.
I think you are. Perl considers null to be data--it's that simple.
Remember, while Perl can work with
Paul Hodges wrote:
So a null byte is still Boolean true.
Ugh, yarf, ack, etc.
But as long as I know -- easy enough to check explicitly.
But just tell me thisam I the only guy who thinks this *feels*
wierd?
It doesn't feel weird to me, but my previous languages of choice
were fairly high-level (
On Thu, Jun 24, 2004 at 08:23:39PM -0700, Paul Hodges wrote:
> --- Luke Palmer <[EMAIL PROTECTED]> wrote:
> So a null byte is still Boolean true.
> Ugh, yarf, ack, etc.
>
> But as long as I know -- easy enough to check explicitly.
>
> But just tell me thisam I the only guy who thinks this *fe
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Paul Hodges wrote:
| --- Luke Palmer <[EMAIL PROTECTED]> wrote:
|
|>Paul Hodges writes:
|>
|>>So, in P6:
|>>
|>> if 0 { print "0\n"; } # I assume this won't print.
|>> if '0' { print "'0'\n"; } # I assume this won't print.
|>> if ''{
On Thu, Jun 24, 2004 at 12:43:30PM -0700, Scott Bronson wrote:
>
> So, in summary, though "0"==false appears to work, it leads to a number
> of strange boundary conditions and, therefore, bugs. It's hard for new
> programmers to grasp and even old hacks are still sometimes tripped up
> by it. It
Jonadab the Unsightly One skribis 2004-06-24 22:11 (-0400):
> No, what's really special is the ability to return entirely
> different things in string versus numeric context, like the
> magic $! does in Perl5.
That too already works in Perl 5. See dualvar in Scalar::Util.
Perl 6 is very neat, but
Scott Bronson wrote:
That's the plan? Happy day! I was not aware of that. Because I didn't
see anything about this in Perl 6 Essentials, I just figured that
Perl5's '0'==undef was being brought forward into Perl6. The horror!
Sorry for the bad assumption. :)
Perhaps not as happy as you think:
--- Luke Palmer <[EMAIL PROTECTED]> wrote:
> Paul Hodges writes:
> > So, in P6:
> >
> > if 0 { print "0\n"; } # I assume this won't print.
> > if '0' { print "'0'\n"; } # I assume this won't print.
> > if ''{ print "''\n";} # I assume this won't print.
> > if undef { pr
Juerd wrote:
That we already have. "0 but true". (perldoc -f fcntl)
It's 1 but false that's really special :)
No, what's really special is the ability to return entirely
different things in string versus numeric context, like the
magic $! does in Perl5.
That, or interesting values of undef :-)
Paul Hodges writes:
> I seemed to have opened a can of worms, lol
> But did anybody see the one that had something to do with my question
> crawling around? (I've obviously missed a couple of messages. They're
> probably hanging out down at the router in the cyberspace equivelent of
> teenagers
I seemed to have opened a can of worms, lol
But did anybody see the one that had something to do with my question
crawling around? (I've obviously missed a couple of messages. They're
probably hanging out down at the router in the cyberspace equivelent of
teenagers ogling girls on the street c
On Thu, 2004-06-24 at 14:17, Smylers wrote:
> Because the above would've been insane: saying that C treats
> $x as a string would be pretending that C always treats its
> arguments as numbers, but something such as C doesn't
> have any numbers in it.
Doesn't it?
perl -e '$x = "frog"; print(($x
> -Original Message-
> From: Dave Whipp [mailto:[EMAIL PROTECTED]
> Sent: Thursday, June 24, 2004 5:22 PM
> To: [EMAIL PROTECTED]
> Subject: Re: definitions of truth
>
> "Larry Wall" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
&
On Thu, Jun 24, 2004 at 03:24:25PM -0700, Scott Walters wrote:
: I want an "okay". Routines should be able to "return okay" to indicate
: an ambivalent degree of success. "okay" would be defined as "true | false",
Some messages want to be simultaneously Warnocked and not Warnocked...
Larry
Austin Hastings skribis 2004-06-24 15:54 (-0700):
> I'd say yeah, it is. 0-but-true is pretty nice to have. (Finally the
> system calls can return something other than -1.)
That we already have. "0 but true". (perldoc -f fcntl)
It's 1 but false that's really special :)
Juerd
--- Juerd <[EMAIL PROTECTED]> wrote:
> Austin Hastings skribis 2004-06-24 14:29 (-0700):
> > > $foo as boolean
> > "This is Perl 6. Everything is an object, or at least pretends to
> > be one. Everything has a .boolean method that returns 0 or 1."
>
> If I understand the current design correctl
Austin Hastings skribis 2004-06-24 14:29 (-0700):
> > $foo as boolean
> "This is Perl 6. Everything is an object, or at least pretends to
> be one. Everything has a .boolean method that returns 0 or 1."
If I understand the current design correctly, having both .boolean and
casting via "as" woul
On 0, Juerd <[EMAIL PROTECTED]> wrote:
>
> However, is the name "boolean" final? I would prefer "true", perhaps
> with a corresponding "false".
I want an "okay". Routines should be able to "return okay" to indicate
an ambivalent degree of success. "okay" would be defined as "true | false",
so:
--- Dave Whipp <[EMAIL PROTECTED]> wrote:
> "Larry Wall" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> >
> > This is Perl 6. Everything is an object, or at least pretends to
> be one.
> > Everything has a .boolean method that returns 0 or 1. All
> conditionals
> > call the .bool
"Larry Wall" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
>
> This is Perl 6. Everything is an object, or at least pretends to be one.
> Everything has a .boolean method that returns 0 or 1. All conditionals
> call the .boolean method, at least in the abstract.
My reading of A12 l
Scott Bronson writes:
> On Thu, 2004-06-24 at 11:34, Smylers wrote:
>
> > But you're fine with 0 being false? 0 and '0' are pretty much
> > interchangeable in Perl 5 -- wherever you can use one, you can use
> > the other and it gets coerced to it.
>
> Let's back up... Strings and numbers are m
On Thu, Jun 24, 2004 at 04:19:25PM -0400, Jonadab the Unsightly One wrote:
: Larry Wall wrote:
:
: >What do you mean by "length"?
:
: For a string, it obviously either means number of bytes or number
: of characters. Pick one, document it, and let people who want the
: other semantic use a pra
Larry Wall wrote:
What do you mean by "length"?
For a string, it obviously either means number of bytes or number
of characters. Pick one, document it, and let people who want the
other semantic use a pragma.
I don't think it matters which one you pick as default, as long
as it's clearly documen
Larry Wall skribis 2004-06-24 12:24 (-0700):
> Well, the type/property name doesn't have to be "boolean"--it could
> be "truth", instead.
I understand that 'true' and 'false' can't be used.
However, "truth" is in the same category as "definedness", and
$foo.definedness looks awful :)
Perhaps fo
On Thu, 2004-06-24 at 11:34, Smylers wrote:
> Scott Bronson writes:
> But you're fine with 0 being false? 0 and '0' are pretty much
> interchangeable in Perl 5 -- wherever you can use one, you can use the
> other and it gets coerced to it.
Let's back up... Strings and numbers are meant to be int
On Thu, Jun 24, 2004 at 08:44:45PM +0200, Juerd wrote:
: Larry Wall skribis 2004-06-24 11:29 (-0700):
: > This is Perl 6. Everything is an object, or at least pretends to be one.
: > Everything has a .boolean method that returns 0 or 1. All conditionals
: > call the .boolean method, at least in t
Larry Wall skribis 2004-06-24 11:29 (-0700):
> This is Perl 6. Everything is an object, or at least pretends to be one.
> Everything has a .boolean method that returns 0 or 1. All conditionals
> call the .boolean method, at least in the abstract. (The optimizer is
> free to optimize the method c
Scott Bronson writes:
> On Thu, 2004-06-24 at 08:04, Jonadab the Unsightly One wrote:
>
> > > In Perl5, the following values are FALSE: undef, '0', 0, and ''.
>
> > ... The really special case is '0', which is false for arcane (but
> > very sensible) reasons.
>
> I don't agree that '0' being fa
On Thu, Jun 24, 2004 at 08:04:10PM +0200, Juerd wrote:
: Scott Bronson skribis 2004-06-24 10:44 (-0700):
: > However, it seems that because Perl is finally getting a typing system,
: > this hack can be fixed in Perl itself! No programmer intervention
: > needed. Undef and '' can be false for stri
Scott Bronson skribis 2004-06-24 10:44 (-0700):
> However, it seems that because Perl is finally getting a typing system,
> this hack can be fixed in Perl itself! No programmer intervention
> needed. Undef and '' can be false for strings, undef and 0 can be false
> for integers, undef, 0, and 0.0
On Thu, 2004-06-24 at 10:44, Scott Bronson wrote:
> I don't agree that '0' being false is sensible...
I don't mean to imply that I think it's senseless. Just that, to me, it
smells suspiciously like a hack. :)
- Scott
On Thu, 2004-06-24 at 08:04, Jonadab the Unsightly One wrote:
> > In Perl5, the following values are FALSE: undef, '0', 0, and ''.
> ... The really special case is '0', which
> is false for arcane (but very sensible) reasons.
I don't agree that '0' being false is sensible. This, plus less than
vi
In Perl5, the following values are FALSE: undef, '0', 0, and ''.
What you fail to note is that each of these is false for a reason.
undef is false so that you can test an object for truth; if it
is undef it obviously contains no data, so it's false. 0 is false
so that you can test numbers for tru
Every now and then I have this discussion with people at work that involve Perl's
ideas of boolean truth. I usually break it down like this:
In Perl5, the following values are FALSE: undef, '0', 0, and ''.
Anything not in that list is considered TRUE in a boolean context. That means that
Perl
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