Let blocks View as Markdown

Hi again!

Now that namespaces seem to be on their way into PHP 6 I wonder if
let-blocks, as in JavaScript 1.7+, ever has been considered for PHP, to
hide global variables from each other?

If so, can someone point me to the discussion?

For those that might have missed JS 1.7:
http://developer.mozilla.org/en/docs/New_in_JavaScript_1.7#Block_scope_with_let

Lars Gunther

The reason I posted my suggestions on this list was that a while ago I
had a few ideas as to how PHP could be improved. A seasoned PHP
developer suggested that I'd take my suggestions to this list.

Thanks a lot for your suggestions, but (as you can see from the list) we have a lot of other things to do
and adding new pretty looking features from other languages is the last thing in my personal TODO list.

There are two ways to add a new feature I know of:

1. to convince the developers that it's terribly critical to have this feature (which I doubt is possible)
   or rouse their interest in some other way;
2. to do it yourself, probably with some help from the developers.

I believe the second way is and will stay the best ever.
And it's not about your CVS karma, this is how Open Source works.

Also, every time you suggest a new feature, you should remember that it would
appear on shared hostings in no less than 3-5 years.
This is quite critical issue for most of the people, but they tend to forget about it.

--
Wbr,
Antony Dovgal

2. Block scope is part of quite a few languages. Does it serve any
   purpose in C, C# or Java? Does "my" and "local" serve any purpose in
   PERL? [1]

Funny that you ask, because Perl docs you linked specifically say
"local" does not serve any real purpose, is extremely confusing and they
have it only for BC reasons. "my" does serve a purpose, but in Perl
scopes are a bit different from PHP (anonymous functions, etc.) so
per-scope local variables make more sense.

I am not saying that PHP must have it just because it exists in other
languages - far from it! But it can not be that hard to imagine use
cases.

If it isn't so hard to imagine them, it shouldn't be hard to post them,
right? ;)

My main contact with PHP nowadays is teaching it. And my students are
usually newbies to web development. Real namespaces is quite a long way
away from their understanding. Not everyone is a Bill Joy, a Linus
Torvalds or a Rasmus Leerdorf!

That's one reason why we work hard to keep the language simple, while on
the other hand trying to make it powerful enough to be useful. These are
contradicting goals, so finding a balance between them is not easy.
That's why new features must be carefully weighted - how much
complication does it add? How much power? Is is worth it?
Naturally, if one proposes something, it is expected that he'd make the
first argument towards proving the worthiness - which may or may not be
supported by the community.

Many students - and other newbies - will cut and paste as a part of
their learning process. So even for more simple procedural code there is
a point in being able to hide variables from one snippet to another.

function? :)

I consider block scope a sort of "namespaces light", an easy to
understand first step. As JS 2 will have the "let" keyword - and to most
newbies JS will be the principal "other" language besides PHP - a
similar construct would be easy to grasp.

I seriously doubt that many newbies need Javascript features that
appeared only in 1.7 - such as let blocks with advanced scoping rules -
or really understand them. Javascript is rather complicated (and
powerful) language - definitely more complicated than PHP, IMHO.

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com