HaloO,
Larry Wall wrote:
On Wed, Apr 16, 2008 at 04:29:23PM +, [EMAIL PROTECTED] wrote:
: my Dog $spot = .new();
:
: to
:
: my $Spot = Dog.new();
:
: when you remove the declaration.
You'd also break multiple dispatch rather badly...
Sorry, why that? Isn't the dispatch on the dynamic
HaloO,
John M. Dlugosz wrote:
Any strong feeling about order-of-evaluation issues?
And short-circuiting of the implicit and. I think
f() g() h() is re-written by the compiler as
f() ($temp = g()) $temp h(). Note that C#
defines the order of evaluation as strictly left to
right. And I
sub GetType (--Type) { ... }
my ::RunTimeType := GetType;
This is clearly permitted by the prose, that ::x may be bound to any object
that does the Abstraction role, such as a typename, package, module, class,
role, grammar, or any other protoobject with .HOW hooks.
But the syntax might
HaloO,
John M. Dlugosz wrote:
Variance?
Yeah, the standard set of co-, contra-, in- and bivariance ;)
Assume A : B being subtypes. Then how should Foo[A]
and Foo[B] relate?
Foo[A] : Foo[B] # covariance
Foo[B] : Foo[A] # contravariance
Invariance means there's no relation at all.
HaloO,
John M. Dlugosz wrote:
sub GetType (--Type) { ... }
my ::RunTimeType := GetType;
I think my declares value variables which means you need
a sigil:
my ::RunTimeType $ := GetType;
and of course you capture the runtime type of the
return value of GetType. If you write that as
Is there something for perl analogous to the sort of formal presentation
seen in e.g., Robin Milner's Definition of Standard ML ?
Is there any confluence between things perl and things found in the
literature on partial evaluation (e.g., John Launchbury's thesis, papers
etc.) ?
Thanks!
-
Hugh
On Wed, Apr 16, 2008 at 11:19:33PM -0400, Bob Rogers wrote:
Pardon a lurker, but I'm not sure I understand the point of this. In:
if $x $y $z { ... }
I would expect a sensible compiler short-circuit the $x $y part, and
indeed the Chained comparisons section of S03 (version 135)
HaloO,
John M. Dlugosz wrote:
First, consider the stated examples for Generic type parameters, from
the passage which defines the terminology in S02:
I fear we need a rigorous definition of generic first.
sub max (Num ::X @array)
{
push @array, X.new();
}
Here you have a nice
HaloO,
Mark J. Reed wrote:
Type checking in both js2/ecma4 and p6 is not merely documentation.
It is enforced, but only if present. This is a tricky thing to
achieve, which is why I suggested reading the js stuff to see how they
went about it.
I like the 'like' operator that does a
HaloO,
[EMAIL PROTECTED] wrote:
You should look at Common Lisp. it's definition of optional typing
is that if you take a correct program and remove all the type
declarations, then it still works correctly, although it may be
significantly less efficient. Larry and i have discussed this and
On Thu, Apr 17, 2008 at 09:24:47AM +0200, TSa wrote:
HaloO,
Larry Wall wrote:
On Wed, Apr 16, 2008 at 04:29:23PM +, [EMAIL PROTECTED] wrote:
: my Dog $spot = .new();
: : to
: : my $Spot = Dog.new();
: : when you remove the declaration.
You'd also break multiple dispatch rather
On Sun, Apr 13, 2008 at 09:00:08PM -, John M. Dlugosz wrote:
:
: :(:who($name), :why($reason)) := (why = $because, who = me);
:
: What do the symbols $name and $reason refer to? Are they names already in
scope?
That would be the intent, yes. Mind you, it seems like something only a
crazy
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
Why the complicated sig? Note that the left sequential definition
enforces that ($a + $b) + $c dispatches to a version of + with the
return type of the lhs addition. That is you need lots of overloaded
versions of listfix +. Nonetheless I would
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
HaloO,
John M. Dlugosz wrote:
Variance?
Yeah, the standard set of co-, contra-, in- and bivariance ;)
Assume A : B being subtypes. Then how should Foo[A]
and Foo[B] relate?
Foo[A] : Foo[B] # covariance
Foo[B] : Foo[A] #
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
I guess not. But
::Newname ::= OldTypeName;
should work. The type system is a runtime overlay to
the value system. This is reflected in the source by
putting types and values into different syntactic slots.
You cannot mix these!
But
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
Which is no problem if ::T defines it in the lexical scope. Any
outer definition is hidden. I guess re-using ::T in the same scope
again for capturing a new type is an error. Just like redeclaring
a value variable. BTW is
You appear to be saying
From: Patrick R. Michaud [EMAIL PROTECTED]
Date: Thu, 17 Apr 2008 07:22:20 -0500
On Wed, Apr 16, 2008 at 11:19:33PM -0400, Bob Rogers wrote:
. . . but IIUC and is not short-circuiting.
and is short-circuiting.
Aha. I was misled by the presence of andthen, and was too sure of
On Thu, Apr 17, 2008 at 03:41:06PM -0500, John M. Dlugosz wrote:
The multi-dictionary search didn't show this usage of covariance and
contravariance. But the series of articles on Type Theory in JOT uses
it to mean in the same direction and in the opposite direction but
doesn't define
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