I was just playing around with eval, trying to figure out if you can define an
operator overload at runtime (seems you can't, good) and noticed this in the
spec... [1]
"Returns whatever $code returns, or fails."
How does one get the compile error from an eval? What's the equivalent to $@?
I
So, the concrete use-case I'm thinking of here is currency.
Darren Duncan wrote:
>> [2] "Num" should have an optional limit on the number of decimal places
>> it remembers, like NUMERIC in SQL, but that's a simple truncation.
>
> I disagree.
>
> For starters, any "limit" built into a type d
TSa (Thomas Sandlaß) wrote:
> I want to stress this last point. We have the three types Int, Rat and Num.
> What exactly is the purpose of Num? The IEEE formats will be handled
> by num64 and the like. Is it just there for holding properties? Or does
> it do some more advanced numeric stuff?
"Int"
TSa (Thomas Sandlaß) wrote:
> Can't we have that as a general feature of all operators?
> That is:
>
>my ($x, $y);
>
>say $x * $y; # prints 1
>say $x + $y; # prints 0
>
> It is a cleaver idea to make the operator choose an appropriate
> value for a Nothing value. Why having that only
Darren Duncan wrote:
> Patrick R. Michaud wrote:
>> Correct. I suspect that eventually the Rakudo developers will have
>> to develop a custom set of PMCs for Perl 6 behaviors rather than
>> relying on the Parrot ones.
>
> I think it would be better for things like unlimited-precision integers
> a
Larry Wall wrote:
> On Fri, Oct 03, 2008 at 11:57:30PM -0400, Michael G Schwern wrote:
> : What's the status of numeric upgrades in Perl 6? Is see the docs say "Perl
> 6
> : intrinsically supports big integers and rationals through its system of type
> : declarations. I
What's the status of numeric upgrades in Perl 6? Is see the docs say "Perl 6
intrinsically supports big integers and rationals through its system of type
declarations. Int automatically supports promotion to arbitrary precision" but
it looks like it's doing the same thing as Perl 5.
$ ./perl6 -e
David Green wrote:
> I bet we actually don't disagree much; I'm not really against "ro" --
> I'm just not against "readonly" because of its length. If I were
> writing casually, I'd use "rw" and "ro"; formally, I'd use "read only"
> and "read/write" (or even "readable and writable"). At an in-bet
David Green wrote:
> On 2008-Sep-23, at 2:32 pm, Michael G Schwern wrote:
>> My other thought is that since parameters are read-only by default
>> it's not
>> thought you'd have to write it much so clarity wins out over brevity,
>> the flip
>> side of H
John M. Dlugosz wrote:
> I'm not opposed to having it be "ro", but wonder why he didn't call it that
> in the first place, so there must be a reason.
Nobody's perfect?
My other thought is that since parameters are read-only by default it's not
thought you'd have to write it much so clarity wins o
Patrick R. Michaud wrote:
> On Sun, Sep 21, 2008 at 07:02:37PM -0700, Michael G Schwern wrote:
>> I'm pondering what the proper syntax is for a subroutine parameter with both
>> a
>> trait and a default. That is...
>> sub foo ($arg = 42)
>> and
>>
I'm pondering what the proper syntax is for a subroutine parameter with both a
trait and a default. That is...
sub foo ($arg = 42)
and
sub foo ($arg is readonly)
together in one parameter. Would that be
sub foo ($arg = 42 is readonly)
or
sub foo ($arg is rea
Eric Wilhelm asked me to chime in here.
is_deeply() is about checking that two structures contain the same values.
This is different from checking that they're the same *things*, that they are
in fact the same object or reference.
You need both.
Reading eqv() it seems that yes, it is doing like
Larry Wall wrote:
> But I will make one general remark at the start, which is that we
> want Perl 6 programmer to look at curlies differently than Perl 5
> programmers do. In Perl 5, curlies were overloaded many different
> ways, and rarely did they mean a closure by themselves. In Perl 6,
> it's
John Siracusa wrote:
> On 12/21/07 5:54 AM, Larry Wall wrote:
>> To you and me, the fact that there are single quotes means there's
>> something there to hide. But other people think the other way and
>> see double quotes as indicating there's something to interpolate.
>> I think PBP comes down on
oreach syntax, for instance.
> (Though I disagree with the conflation of numeric and associative
> arrays, a flaw shared by JavaScript.)
>
>
> On 12/20/07, Michael G Schwern <[EMAIL PROTECTED]> wrote:
>> Patrick R. Michaud wrote:
>>> Just to add another persp
Jonathan Scott Duff wrote:
> On Thu, Dec 20, 2007 at 07:58:51AM -0500, Mark J. Reed wrote:
>> I think the issue is that bare vars don't interpolate anymore, but
>> they still have sigils of their own, so adding to the default interp
>> syntax is too noisy: ${$var} is not really much improvement ov
Patrick R. Michaud wrote:
> Just to add another perspective, PHP uses curlies inside of
> double-quoted strings to indicate various forms of
> interpolation, and it doesn't seem to cause major issues
> there.
PHP has 8000 built in functions and it doesn't seem to cause issues there.
I'll not be t
I was reading an article about Perl 6, I forget which one, and it happened to
mention that code can be interpolated inside double quoted strings. That's
one thing, my concern is with the selected syntax.
say "foo { 1+1 }"; # "foo 2"
The {...} construct seems far too common one in norma
orted due to compilation errors.
$ perl1 -e 'no 4; print "Happy New Year, 1988!\n"'
syntax error in file /tmp/perl-eE52cHQ at line 1, next token "string"
Execution aborted due to compilation errors.
--
Michael G Schwern [EMAIL PROTECTED] http://www.pobo
On Fri, Apr 15, 2005 at 09:32:23PM -0400, Chip Salzenberg wrote:
> > Perl 6 is going to have to decide on some sort of standard internal getcwd
> > technique, $CWD or not.
>
> I don't think Perl 6 "has" to do anything of the kind. It would
> be a mistake to try.
Sorry, I had assumed that having
On Fri, Apr 15, 2005 at 08:31:57PM -0400, Chip Salzenberg wrote:
> According to Michael G Schwern:
> > And this is exactly what File::chdir does. $CWD is a tied scalar.
>
> I don't think current directory maps well on a variable. That won't
> stop peo
On Fri, Apr 15, 2005 at 11:52:38PM +0200, Juerd wrote:
> > becomes an unverifiable operation. You have to use chdir() if you want to
> > error check and $CWD is reduced to a "scripting" feature.
>
> Well, after failure it can be cwd() but false without breaking any real
> code, because normally,
Thus spake Larry Wall:
> Offhand, I guess my main semantic problem with it is that if a chdir
> fails, you aren't in an undefined location, which the new value of $CWD
> would seem to indicate. You're just where you were. Then the user
> either has to remember that, or there still has to be some
I was doing some work on Parrot::Test today and was replacing this code
with something more cross platform.
# Run the command in a different directory
my $command = 'some command';
$command= "cd $dir && $command" if $dir;
system($command);
I replaced it with th
[ Sorry if my replies to this thread have seemed a little disjoint. I just
realized I'd unsubscribed myself from p6l last year when I started a $job$
and never resubscribed. So I'd only been seeing fragments of the
conversation. Catching up from the archives...
]
Larry's idea of making $
This drifed off list but I don't think that was intentional.
- Forwarded message from Yuval Kogman <[EMAIL PROTECTED]> -
From: Yuval Kogman <[EMAIL PROTECTED]>
Date: Fri, 18 Mar 2005 01:12:42 +0200
To: Michael G Schwern <[EMAIL PROTECTED]>
Subject: Re: .me
On Thu, Mar 17, 2005 at 11:46:52PM +0200, Yuval Kogman wrote:
> I think this should mean $_, and if the user really really really
> wants to do .foo on the invocant, then why not just say:
>
> method bar ($_:) {
> .foo;
> }
Because $_ can change.
method bar ($_:) {
On Thu, Mar 17, 2005 at 07:00:08PM +1100, Adam Kennedy wrote:
> The only minor thing I
> can see would be that you will end up with a slight asymmetry question
> of "if we use $:attribute for a private attribute, do we call :method
> for a private method?"
That occurs no matter if .method means
On Thu, Mar 17, 2005 at 06:04:56PM +1100, Adam Kennedy wrote:
> I should add that Darren and I, who both have similar tendencies towards
> larger scale coding where consistency is far preferred to compactness,
> both ended up concluding that our style policies will be to _always_ use
> explicit
There's a discussion going on #perl6/irc.freenode.org right now wondering
about what .method means. We'd all assumed it meant $self.method (where
$self is always the method invocant) but then had a look at Synopsis 12
which states
Dot notation can omit the invocant if it's in $_:
.doit(1
not be the right thing. Consider
delegation instead.
--
Michael G Schwern[EMAIL PROTECTED] http://www.pobox.com/~schwern/
You're more radiant than a memory of breathtaking ecstasy.
will be MUCH easier to install. :)
--
Michael G Schwern[EMAIL PROTECTED] http://www.pobox.com/~schwern/
Cottleston, Cottleston, Cottleston Pie.
A fly can't bird, but a bird can fly.
Ask me a riddle and I reply:
"Cottleston, Cottleston, Cottleston Pie."
t; in their heads.
I'm one of them. Its not a previous syntax thing, its a translation to
English thing.
This may be a consequence of the example used
while $n++ then $foo > $bar
which I immediately associated with.
if $n++ then $foo > $bar
I didn't say it makes s
"if/then" which is confusing. Its exactly
the opposite from what you're trying to convey.
It also doesn't convey anything about "evaluate the left hand side, ignore
the results and evaluate the right". Unfortunately, I don't have a better
name.
--
Michael G Schwern[EMAIL PROTECTED] http://www.pobox.com/~schwern/
Now we come to that part of the email you've all been waiting for--the end.
?
Its scheduled to occur shortly following Hell. ;)
--
Michael G Schwern[EMAIL PROTECTED] http://www.pobox.com/~schwern/
WOOHOO! I'm going to Disneyland!
http://www.goats.com/archive/980805.html
On Sat, Aug 02, 2003 at 08:16:19PM -0700, Larry Wall wrote:
> On Sat, Aug 02, 2003 at 04:33:19PM -0700, Michael G Schwern wrote:
> : I'm not making an argument against %_, just noting that *_ is used
> : opportunisticly and you will break a few programs.
>
> Not necessarily
On Sun, Aug 03, 2003 at 01:37:16AM +0200, Abigail wrote:
> I am fond of doing
>
> local %_ = @_;
>
> as one of the first statements of a subroutine. That, or
>
> my %args = @_;
>
> I like the latter because it uses a lexical variable, but I like the
> former because %_ fits with @_ and
> Damian Conway <[EMAIL PROTECTED]> writes:
> >Hence, making C<%_> mean something different in core Perl 5 might possibly be
> >"forwards incompatible".
Representing the Backwards Compatiblity Police, I've had co-workers use
%_ as the globalist of all global hashes. %_ transends all packages and
On Mon, Mar 31, 2003 at 08:13:09PM +0200, Matthijs van Duin wrote:
> I think we should consider cooperative threading, implemented using
> continuations. Yielding to another thread would automatically happen when
> a thread blocks, or upon explicit request by the programmer.
>
> It has many adv
/www.php.net/manual/en/language.types.array.php
So that makes a nice case study to investigate.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
On Thu, Jan 09, 2003 at 11:15:49PM -0500, John Siracusa wrote:
> On 1/9/03 10:10 PM, Michael G Schwern wrote:
> > I would assume it to be a compiler hint via subroutine attribute.
> >
> > sub debug ($msg) is off {
> > print STDERR $msg;
> > }
> >
&g
e.
sub debug ($msg) is off {
print STDERR $msg;
}
some "this subroutine is a no-op if a flag is set" attribute.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
0
(For this example I put the top level "ps:" back into the YAML so it would
translate better into XML)
xyx is just a really thin wrapper around YAML.pm and XML::Simple.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance
ing a lot of code. Am I missing something?
I think your external format (XML which is a tree) is not mapping well to
your internal format (Perl which uses hashes,arrays and scalars) causing you
to have to shuffle your awkward XML->tree structure into something more
Perlish. By pic
On Tue, Dec 17, 2002 at 09:48:56AM -0500, Dan Sugalski wrote:
> >Simon Cozens wrote:
> >> Once again we're getting steadily closer to inventing Ruby.
> >
> >Agreed, but I don't think this is necessarily a Bad Thing.
>
> Disagreed--we're getting steadily closer to inventing Smalltalk. :)
Silly r
On Tue, Dec 17, 2002 at 03:12:09AM -0600, Josh Jore wrote:
> > This is just your friendly neighborhood curmudgeon reminding you that in
> > Perl 6, everything is an object. This is a concept that, as Perl
> > programmers, we're not familiar with.
>
> Are these objects class based or where do the
w style worth keeping.
@out = join "\n", map {...} grep {...} sort {...} @foo
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Pancakes is the better part of valor.
http://www.goats.com/archive/971202.html
g Ruby as a rough
guide, there aren't many of those.
http://www.rubycentral.com/book/ref_c_object.html
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
One disease, long life. No disease, short life.
go grammar happy.
In closing: Consider a method rather than a built-in or operator.
Everything is an object. Tattoo it on your forehead today.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]>
s @bar;
> > $obj1 eq $obj2;# [1] are their stringifications identical?
> > $obj1 == $obj2;# [2] are their numifications identical?
> > $obj1 === $obj2; # [3] are they in fact the same object?
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pob
e generally useful or not, which is why I asked here, for
> an increased sample size.
>
> And that increased sample size indicates "not", so I'll forget about it.
I dunno, my motto is "never hurts to put it in a library".
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
MERV GRIFFIN!
my $leap = $year % 4 == 0
&& ($year % 100 != 0 || $year % 400 == 0);
return $leap ? 29 : 28;
}
Of course there's nothing which says you can't just do *both*.
cache_and_return() is merely a function. Write it, stick it in a library,
distribute for fun and/or
...) in Perl 6 start at 0
will benefit most users. Do not invoke legacy. [1]
[1] ie. "because that's how most other languages do it" or "everyone is used
to it by now" are not valid arguments. Ask any Pascal programmer. :)
--
Michael G. Schwern <[EMAIL PROTE
{ /condition/ ? $i++ : () } @stuff;
Its so rare that you work by array index in Perl. Usually things flow
together element by element. Sort of like how you rarely handle strings
character by character which can severely confuse C programmers.
What was your friend trying to do?
--
Michael
dditional way to do it would be as an Array method.
@switches = @ARGV.cull /^-/;
Array.cull would remove and return a list of every element in @ARGV which
matched.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL P
hive.develooper.com/perl6-language@;perl.org/msg06639.html
"YAYAYA string concat proposal"
http://archive.develooper.com/perl6-language@;perl.org/msg06650.html
"a modest proposal Re: s/./~/g"
http://archive.develooper.com/perl6-language@;perl.org/msg06672.html
--
Michael G.
o?
In Perl 5 it stops at a sane point:
$ perl -wle 'print "bar" + "foo"'
Argument "foo" isn't numeric in addition (+) at -e line 1.
Argument "bar" isn't numeric in addition (+) at -e line 1.
0
Ok, so string + string does somet
sis of what happens when you try to
introduce infinity into the real number system, see:
http://mathforum.org/library/drmath/view/55764.html
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job O
oops ...
}
}
(putting aside that exception handlers stack).
Whatever you call it, exception or error, it will halt the program if left
unhandled.
[1] Less the few odd really hard core "the interpreter is having a bad trip"
sort of errors.
--
Michael G. Schwern <[EM
On Mon, Oct 14, 2002 at 08:25:43PM -0400, Mark J. Reed wrote:
> On 2002-10-14 at 20:15:33, Michael G Schwern wrote:
> > There are several verbal proofs why 1/0 is not +Infinity here:
> > http://mathforum.org/dr.math/faq/faq.divideby0.html
>
> Yeah, that would be why I sent
dr.math/faq/faq.divideby0.html
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Plus I remember being impressed with Ada because you could write an
infinite loop without a faked up con
ated will be a concept in Perl6.
What happens when NaN is used in an expression? Is NaN + 0 == NaN?
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
11. Every old idea will be
mething in the family of your original /T regex proposal would make more
sense. Attack the problem at its source.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Do you have a map? Because I keep getting lost in your armpits.
the denominators might be zero, you can just see if
the result is undef.
[1] I apologize for forgetting who.
[2] Discussion of divide by zero and why it's not infinity [3]
http://mathforum.org/dr.math/faq/faq.divideby0.html
[3] I was always taught it's infinity.
--
Michael G. Schwern
ne:
print defined? $foo;
This is a syntax error:
print defined? $foo : 42;
/home/schwern/tmp/foo.rb:1: parse error
print defined? $foo : 42;
^
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance
mmon and can be used
for Good or Evil.
[1] It would be less worse [2] as a compile-time exception.
[2] This is different than "better". ;)
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
I don't get it. Must be art.
e method implementations, just not with an interface
contract.
Unfortunately, Java doesn't ship with JUnit nor do Java libraries usually
ship with tests nor does a simple convention to run them nor an expectation
that the user will run the tests before installing. Score one for Perl. :)
ught to be one of those "sure you can do this, but please don't"
things.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
You see, in this world
ains(Object o)
Returns true if this collection contains the specified element.
I don't know basic Java syntax worth a damn, but I know its dirty little
secrets. ;)
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
It's Absinthe time!
example, but now I can't find it and I can't
remember what it was.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
It sure is fun masturbating.
http://www.unamerican.com/
ven above may be what many programmers expect, and may be more in
> line with perl's philosophy. It seems especially wonky to allow the
> cootie-infested "public" but not allow the more liberal interpretation
> of "private".
This sounds like "two wrongs make a right" to me.
--
Michael G Schwern <[EMAIL PROTECTED]> http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
t; > (OO Articles 6) Also considered drop-deads: interfaces, assertions (of
> > various sorts), multiple inheritance, complex delegation.
> >
> > Can we at least agree on these? Are there other basic tenets that
> > should be included?
>
> Bravo!
Me, too!
-
t technique, I think one was
already mentioned where subclasses can unintentionally weaken
preconditions to the point of eliminating them. I'm sort of casting
about looking for another way.
--
Michael G Schwern <[EMAIL PROTECTED]> http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
nor Java
background, so to me "interface" just means "how you use the thing"
and it happens to be inherited. I think you're reading more into it
than my deliberately simplistic definition.
The other part that's up in the air is if method signatures will be
enforced on
postconditions. In essence, you're not requiring any more of
> the client, but you can ensure more to them on completion, thus
> maintaining the parent's contract.
But what does it mean to be "stronger"? How does Eiffel figure out if
a given precondition is "stronger&q
be good
> here.
Delegation is a basic OO technique. We definately should have fast,
well-designed core support for it.
--
Michael G. Schwern <[EMAIL PROTECTED]> http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Is there an a
sarily require subclasses to do anything,
at least not in Perl.
So an interface is simply a class, maybe abstract, which requires its
subclasses to conform to its signature.
At least that's how I see it.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~sch
On Thu, Oct 03, 2002 at 07:23:14PM -0400, Michael G Schwern wrote:
>invar { .shoulders == .knees == .toes == 2 }
This may explain why I can only count to 12 with my shoes off.
As this is my 3rd reply to myself in the thread, I'll call it a night. :)
--
Michael G. Schwern
On Thu, Oct 03, 2002 at 03:54:09PM -0700, Michael Lazzaro wrote:
> I have no *good* syntax proposals for this, I don't think I've ever
> seen the problem solved with syntax that I really ever liked.
Class::Delegation?
--
Michael G. Schwern <[EMAIL
On Thu, Oct 03, 2002 at 06:46:14PM -0400, Michael G Schwern wrote:
> I see us already smashing too many things into the method signature as it
> is. It will rapidly get messy if you have a method with a complex signature
> and a handful of attributes and preconditions.
I think I ha
te check and not a
documented feature of the object. A clearer example might be something like
checking that an internal data structure used by the object is not circular.
A class invariant, yet not something I want to enforce on my children.
They're tools that when combined form an "inte
On Thu, Oct 03, 2002 at 05:30:49PM -0400, Trey Harris wrote:
> In a message dated Thu, 3 Oct 2002, Michael G Schwern writes:
>
> > On Thu, Oct 03, 2002 at 03:59:08PM -0400, Mike Lambert wrote:
> > > With pre/post conditions, a subclass is allowed to weaken the
> > &g
ould be pretty simple to teach and remember, "conditions and
invariants are inherited unless made private".
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
It's Flypaper Licking time!
r, etc...) use all cap names. At least I hope
not. Simply attaching an "is private" attribute to a pre condition block
seems the simplest way to go about it. Just like any other private thing,
it's not inherited and not visible outside the current class. "pre" vs
&
On Thu, Oct 03, 2002 at 04:54:13PM -0500, Garrett Goebel wrote:
> Garrett Goebel:
> > Michael G Schwern:
> > > But I don't want my subclasses to be constrained by that.
> > > It's just an implementation detail that I only wish to
> > > enforce upon
On Thu, Oct 03, 2002 at 03:59:08PM -0400, Mike Lambert wrote:
> With pre/post conditions, a subclass is allowed to weaken the
> preconditions or strengthen the postconditions.
How exactly does one "weaken" a precondition?
--
Michael G. Schwern <[EMAIL PROTECTED]>
On Thu, Oct 03, 2002 at 03:45:33PM -0500, Allison Randal wrote:
> On Thu, Oct 03, 2002 at 03:00:21PM -0400, Michael G Schwern wrote:
> > On Thu, Oct 03, 2002 at 02:46:38PM -0400, Michael G Schwern wrote:
> > > class ATV is Car, interface {
> >
> >
On Thu, Oct 03, 2002 at 02:46:38PM -0400, Michael G Schwern wrote:
> class ATV is Car, interface {
Hmmm. That should probably be
class ATV isa Car is interface {
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance
mentation detail that I only wish to enforce upon ATV and not it's
children. So they're private.
Makes sense, no?
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Remember, any tool can be the right tool.
-- Red Green
ions on a method would be treated,
> internally, as part of the overall signature/prototype of the method:
> i.e. if you override the method in a subclass, all original
> postconditions would still remain attached to it (though the new method
> might itself add additional postcondit
al solution much
better. When you use your MP3 Car as a Vehicle, the Vehicle methods win.
When you use it like an MP3_Player, the MP3_Player methods win. No need to
expose the underlying MP3_Player object to the user. YMMV.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobo
ubclasses by default, or
if you have to explicitly declare yourself to be an interface. That's up in
the air in my mind.
Orthoginal to that decision is if a subclass should be able to explicitly
ignore its parent's interface and conditions. I started by leaning towards
yes, now I'm
aliasing doesn't solve this?
Ahh, because Perl has to know that when $mover is used as a Vehicle it
uses Car.accel but when used as an MP3_Player it calls Car.mp3_drive.
Clever!
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance
e up with a practical case of adding parameters which
violates the interface, I'd say there's no problem, strict or no strict.
> My musing is that the behavior of a class in different contexts is
> itself an interface, in the sense of being a contract between a
> class/subclass and it
ls to really describe it well.
So since this list is a magnet for folks who know obscure programming
techniques, is there anyone out there familiar enough with SOP that they
could lay out some examples in pseudo-perl?
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~sc
of the method itself, or it's name? In other words, do aliases to the
same method carry the same signature and attributes?
> Oh yes, and we need to make sure DBC stuff is part of the interface, not
> the implementation.
Sensible.
--
Michael G. Schwern <[EMAIL PROTECTED]>
On Tue, Oct 01, 2002 at 01:36:19AM +0100, Simon Cozens wrote:
> [EMAIL PROTECTED] (Michael G Schwern) writes:
> > method _do_internal_init ($num) is private {
>
> Just thinking aloud, would
> sub foo is method is private is integer is fungible {
>
&
do we say the interface can
> only return object classes derived from that first object class?
Yes. The object class is simply a return type.
> And do we restrict the possible "flattenings" of the object class itself,
> using an interface, so subclasses of the returned ob
ill use for optional arguments,
so I'll just use the Perl 5 style.
--
Michael G. Schwern <[EMAIL PROTECTED]>http://www.pobox.com/~schwern/
Perl Quality Assurance <[EMAIL PROTECTED]> Kwalitee Is Job One
Do you have a map? Because I keep getting lost in your armpits.
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