"Myers, Dirk" wrote:
>
> Karl Glazebrook wrote:
>
> > But what is $x[3] ?
>
> > It could be a scalar.
>
> > BUT it could be a reference to a list.
>
> > It could be a reference to a 2D PDL image.
>
> ... but references are scalar. So, $x[3] *is* a scalar.
>
> That scalar could be a reference to a list. It could be a reference to a 2D
> PDL image. It could also contain a tar of the perl source distribution. We
> can *never* tell what a scalar contains just by looking at it.
exactly.
> I don't think this is a problem with the line-noise markers themselves -- I
> think this ambiguity is inherent in the idea of scalars, and the idea that
> references are scalar. On the surface this seems reasonable: a reference is
> a single thing. The implications of that idea lead to ugly code, though.
yes.
> So maybe the idea of scalars isn't useful for references, and maybe it's
> worth suggesting that references shouldn't really be scalars...
Yes, I guess what I am arguing is because we are now using references for
most things the concept of @lists as such as of little use.
> > @{$x->{$$fred{Blah}}}[1..3]
>
> Ugh. I hope no one's arguing that this is pretty. (In fact, I think anyone
> who believes this is pretty or elegant should probably not be allowed near
> sharp objects...)
>
> On the other hand, I'm not convinced that just cutting the line noise helps.
> It seems to me that the concept of really only having three first-class data
> types (scalar, hash, array), the fact that these types are intimately tied
> to context, and the fact that perl will do some automagic context-dependent
> stuff limits the amount of change we can make without altering perl beyond
> recognition.
>
> In particular:
>
> @x[3] = grep &foo, @bar ;
>
> and
>
> $x[3] = grep &foo, @bar ;
>
> have very different results because of context. Changing this is a big deal
> for the way perl works (at least from my point of view).
It depends on whether we are after a radical redefinition of the language
or not.
> Further, it really looks to me like the basic complaint isn't with the
> markers themselves, but rather that dereferencing complicated things is not
> just complicated, but *really* complicated.
And confusing.
> I think some of these comments have been meant as "go away and use Python",
> but I think some of them were meant as "what can Perl learn from Python"?
That's where I am coming from.
>
> Personally, I want to know what Perl should learn from Python. (I've kind
> of liked Python when I've used it, but it doesn't run reliably on some of
> the platforms I need to have my stuff work on. Because of this, I seldom use
> Python, and I'm not familiar enough with it to know what the good points
> are.)
I think it's the cleaner object syntax and the was you can pass everything
around by reference without a lot of $@{} - which IS confusing.
> Back to line noise: do I support removing line noise? Nope. Do I support
> the current dereferencing syntax? I'm not fond of it for complicated
> expressions. I don't have a better suggestion, though.
I am glad my suggestion has at least triggered some debate.
> I'm glad this is getting discussed, because I'd like to see it improved, but
> I don't have any answers. I just wanted to throw in my $0.02, though, and
> say thanks very much for bringing up what I think is the *real* question
> here... which is "can we improve the syntax for dereferencing thingys? "
Indeed.
Karl
