On 2010-09-17 11:50:51 -0400, Jacob Carlborg <d...@me.com> said:
Sounds good, I also once thought about adding extern (Objective-C) to
the language. About the selector syntax, wouldn't it be better to have
the same syntax as in Objective-C,
@selector(performSelector:withObject:). I mean D already has the
@annotation syntax for annotations/attributes I don't think we need yet
another one. I would also be nice to use
@selector(performSelector:withObject:) as an expression (or what is
called) to get the selector to a method just like in Objective-C.
I though about it, but decided against it. The @attribute syntax in D
isn't meant *at this time* to accept arguments. Nor is the DMD front
end ready to accept arguments for attributes. I don't want to inject my
code in the parsing of attributes and their propagation through the
frontend. Perhaps one day attributes will accept arguments and we could
reconsider. But in the meanwhile I try to avoid touching things which
are good candidates for possible future extensions to the regular D
language.
Also note that member functions of an extern (Objective-C) class or
interface always have implicitly a selector (made from the function's
name followed by as many colons as there are arguments). The special
selector syntax is only needed to specify a different selector than the
original. I'm not sure if this kind of implicit thing that you can
override fit very well with the notion of an attribute (certainly not
the current notion which is basically a binary flag).
For the same reason, I don't think reusing Objective-C's
"@selector(setObject:forKey:)" syntax for selector literals is a very
good idea. I'm not exactly sure what selector literals should look
like, but I'm currently leaning about simply making it a function
intrinsic:
import objc;
SEL s = objc.selector("setObject:forKey:");
Have you thought anything about the blocks that Apple added in Snow
Leopard, if those could be supported as well?
What about Objective-C categories?
Ideally blocks would be the same as delegates, but I hadn't given them
much thought yet.
I'm not sure whether I want to support creating new categories in D;
categories are quite "un-D-like" and despite their usefulness they're
clash-prone. But I sure want to be able to access categories from
existing Objective-C frameworks. So how exactly this would work? I
don't know.
In any case, I have much work to do before it's time to think about
categories and blocks. The most basic problem to solve in this all new
Objective-C "bridge" is the memory management. But I don't want to look
at this too much until I get the basics working.
--
Michel Fortin
michel.for...@michelf.com
http://michelf.com/
