http://docs.mir.dlang.io/latest/index.html
http://blog.mir.dlang.io/glas/benchmark/openblas/2016/09/23/...
That inflammatory wording doesn’t add anything to your comment. If you wanted to compare D with C++ it’d be a lot more useful to link to something which does that rather than just the documentation index.
C++ has for a long time embraced metaprogramming and given new tools for it (I think there's `static if` now? Or will be soon?), but it really all started out as an accident:
https://softwareengineering.stackexchange.com/questions/1253...
> If you wanted to compare D with C++
My second link does that, compares Mir to a bunch of other numeric libraries, most in C++.
Edit: (Replying to comment below by acdha because HN does not allow me to post new comments right now.)
I don't have that kind of example handy. I can point you to the D Gems section of the D tour to give you a taste of what is possible in D. Click on "Gems" in the navigation menu above to see them.
https://tour.dlang.org/tour/en/gems/uniform-function-call-sy...
If you want a detailed blog post comparing D and C++ metaprogramming, I don't have it ready yet. If you're curious to learn about it, look in more depth at the links I've provided. I'm sorry I don't have the resources to give you the detailed answer you require.
> My second link does that, compares Mir to a bunch of other numeric libraries, most in C++.
This is technically correct but not helpful because it just shows a bunch of benchmark results. If the point is to demonstrate how D is more powerful for this kind of programming what would be useful is something which shows the same function written in modern C++ and D so you could see how they differ.
Yet neither of them are as elegant as LISP macros.
I think D's metaprogramming is very close to lisp, possibly as close as possible without having sexps.
> it's not so bad
You can always use the C preprocessor in C++ if raw string manipulation is enough.
Seriously, though, constexpr means C++ also has static if, compile time loops, function eval, etc.
> constexpr means C++ also has static if, compile time loops, function eval, etc.
It's still not quite the same. I'm sorry to not bring examples, but if you look for them yourself, I think you'll find that D's metaprogramming looks nicer than C++'s constexpr.
Not even close. You can't conditionally insert a member.
(defmacro when (condition &rest body)
`(if ,condition (progn ,@body)))
I don't think you actually understand anything about the example code you posted. There is no special "complicated sublanguage" - the backquote[1] is an extension of the quote shorthand notation[2] for list literals. It is for building data structures and has nothing to do with "sublanguages" or macros. There is no special syntax for macros in Common Lisp. Common Lisp macros do not produce source code - they produce any type of Common Lisp objects directly. That is why they are simpler and strictly more powerful than D templates.
When it comes to templates, I wouldn't call anything from this list of D examples[3] elegant.
[1] http://www.lispworks.com/documentation/HyperSpec/Body/02_df.... [2] http://www.lispworks.com/documentation/HyperSpec/Body/s_quot... [3] https://dlang.org/templates-revisited.html
This doesn't add anything to the conversation. If you want to discuss my post, I'm happy to discuss. You're clearly upset that I didn't praise Common Lisp, but things like that don't lead to useful discussion.
> There is no special "complicated sublanguage" - the backquote[1] is an extension of the quote shorthand notation[2] for list literals. It is for building data structures and has nothing to do with "sublanguages" or macros. There is no special syntax for macros in Common Lisp.
I've never seen anyone write macros using only s-expressions. True, you don't need to learn any special syntax to do it, but that's not how anyone writes macros.
> When it comes to templates, I wouldn't call anything from this list of D examples[3] elegant.
How is that is relevant to my comment?
No, I am upset that you are posting misinformed comments about Common Lisp macros vs D templating while representing yourself as being knowledgeable about the subject. You clearly do not understand how the former works.
> I've never seen anyone write macros using only s-expressions. True, you don't need to learn any special syntax to do it, but that's not how anyone writes macros.
Please stop pretending that you have enough experience with Common Lisp to say things like "I've never seen anyone do X." Writing macros that call functions that return code is a basic technique - Graham's On Lisp is full of examples. Saying that quoting as a way of specifying list literals is a "complicated sublanguage" is on the level of "C++ templates have too many pointy brackets" of criticism.
I kind of fail to see how it is especially complicated. The macro uses a general mechanism to create lists. This mechanism isn't tied to macros and does not do anything special in macros.
It's also not really a sublanguage.
> then you think hard about where the leaks are
There are no leaks in the example.