On Wed, Apr 16, 2008 at 07:51:03PM -0500, John M. Dlugosz wrote:
> No, *@ is the slurpy array parameter. I was thinking of
>
> (*,*,$x) = @array; # skips first two elements
>
> to suppose that @* might mean "no name" if the syntax would not allow for
> bare @ there without an identifier.
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 d
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] # contravar
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
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
HaloO,
John M. Dlugosz wrote:
I seem to recall seeing sigils in a signature without names,
but now I can't remember where.
E.g. in S06 und section "The want function".
Regards, TSa.
Somewhere else, I think it discussed unnamed parameters to fu
TSa Thomas.Sandlass-at-barco.com |Perl 6| wrote:
HaloO,
John M. Dlugosz wrote:
How do you declare a function that returns an array? Something like
sub foo (blah) is Array of X { ... }
I meant "of", not "is".
In general the of keyword instanciates parametric types just like
the direct
HaloO,
John M. Dlugosz wrote:
I seem to recall seeing sigils in a signature without names,
but now I can't remember where.
E.g. in S06 und section "The want function".
Regards, TSa.
--
"The unavoidable price of reliability is simplicity"
-- C.A.R. Hoare
HaloO,
John M. Dlugosz wrote:
How do you declare a function that returns an array? Something like
sub foo (blah) is Array of X { ... }
The 'is' there is your invention, isn't it? The synopsis
require 'of' or 'returns' depending if you want to specify
the outer and/or inner type. The 'is'
How do you declare a function that returns an array? Something like
sub foo (blah) is Array of X { ... }
seems right, but it has two problems. First is a real problem, and is a
mistake seen a lot in C# and the .NET framework. A concrete type is
used when it should be an interface. What
