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digitalmars.D - Compare boost::hana to D

reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
I'm brushing up on my C++ to prepare for my C++Now 2017 presentation[1]. 
boost::hana is an impressive library that overlaps with many D features:

   http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

Have you used boost::hana? What are your thoughts on it?

And please share your ideas for the presentation. There has been threads 
here about C++ closing the gap. Does D still bring competitive advantage 
or is it becoming irrelevant? (Obviously, some think its irrelevant 
already.) I'm trying to collect opinions... :)

Thank you,
Ali

[1] 
http://cppnow.org/2017-conference/announcements/2017/04/09/d-keynote.html
Apr 19 2017
next sibling parent Nicholas Wilson <iamthewilsonator hotmail.com> writes:
On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017 
 presentation[1]. boost::hana is an impressive library that 
 overlaps with many D features:

   
 http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?

 And please share your ideas for the presentation. There has 
 been threads here about C++ closing the gap. Does D still bring 
 competitive advantage or is it becoming irrelevant? (Obviously, 
 some think its irrelevant already.) I'm trying to collect 
 opinions... :)

 Thank you,
 Ali

 [1] 
 http://cppnow.org/2017-conference/announcements/2017/04/09/d-keynote.html


Even if it offers comparable features I would show the code it 
takes to do something (probably slightly non-trivial), the error 
message you get if you do something wrong and the compile time 
taken, which I suspect D should win significantly in.
Apr 19 2017
prev sibling next sibling parent reply Sebastiaan Koppe <mail skoppe.eu> writes:
On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 Have you used boost::hana? What are your thoughts on it?

 And please share your ideas for the presentation. There has 
 been threads here about C++ closing the gap. Does D still bring 
 competitive advantage or is it becoming irrelevant? (Obviously, 
 some think its irrelevant already.) I'm trying to collect 
 opinions... :)


Haven't used C++ for a while actually. And seeing it after some 
time, makes me tremble convulsively.

While hana is indeed an awesome library it adds another set of 
things to learn, and it just doesn't compare favourably to D 
where most is buildin and a lot less ugly.
Apr 19 2017
parent reply Kagamin <spam here.lot> writes:
On Wednesday, 19 April 2017 at 09:01:25 UTC, Sebastiaan Koppe 
wrote:

 Haven't used C++ for a while actually. And seeing it after some 
 time, makes me tremble convulsively.


_STD_BEGIN
         // basic_string INSERTERS AND EXTRACTORS
template<class _Elem,
     class _Traits,
     class _Alloc> inline
     basic_istream<_Elem, _Traits>& operator>>(
         basic_istream<_Elem, _Traits>&& _Istr,
         basic_string<_Elem, _Traits, _Alloc>& _Str)
     {	// extract a string
     typedef ctype<_Elem> _Ctype;
     typedef basic_istream<_Elem, _Traits> _Myis;
     typedef basic_string<_Elem, _Traits, _Alloc> _Mystr;
     typedef typename _Mystr::size_type _Mysizt;

     ios_base::iostate _State = ios_base::goodbit;
     bool _Changed = false;
     const typename _Myis::sentry _Ok(_Istr);

     if (_Ok)
         {	// state okay, extract characters
         const _Ctype& _Ctype_fac = _USE(_Istr.getloc(), _Ctype);
         _Str.erase();

         _TRY_IO_BEGIN
         _Mysizt _Size = 0 < _Istr.width()
             && (_Mysizt)_Istr.width() < _Str.max_size()
                 ? (_Mysizt)_Istr.width() : _Str.max_size();
         typename _Traits::int_type _Meta = _Istr.rdbuf()->sgetc();

         for (; 0 < _Size; --_Size, _Meta = 
_Istr.rdbuf()->snextc())
             if(_Traits::eq_int_type(_Traits::eof(), _Meta))
                 {	// end of file, quit
                 _State |= ios_base::eofbit;
                 break;
                 }
             else if (_Ctype_fac.is(_Ctype::space,
                 _Traits::to_char_type(_Meta)))
                 break;	// whitespace, quit
             else
                 {	// add character to string
                 _Str.append(1, _Traits::to_char_type(_Meta));
                 _Changed = true;
                 }
         _CATCH_IO_(_Istr)
         }

     _Istr.width(0);
     if (!_Changed)
         _State |= ios_base::failbit;
     _Istr.setstate(_State);
     return (_Istr);
     }

:)
Apr 19 2017
parent Nicholas Wilson <iamthewilsonator hotmail.com> writes:
On Wednesday, 19 April 2017 at 11:58:07 UTC, Kagamin wrote:

 On Wednesday, 19 April 2017 at 09:01:25 UTC, Sebastiaan Koppe 
 wrote:

 Haven't used C++ for a while actually. And seeing it after 
 some time, makes me tremble convulsively.


 // basic_string INSERTERS AND EXTRACTORS
 [...]
 :)


Ah yes C++ standard implementations. It took me a good 30s to 
find what function was being declared (operator >>). Used to have 
nightmares of those flying past at high speed  when getting 
template errors.
Apr 19 2017
prev sibling next sibling parent reply Laeeth Isharc <laeethnospam nospamlaeeth.com> writes:
On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017 
 presentation[1]. boost::hana is an impressive library that 
 overlaps with many D features:

   
 http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?

 And please share your ideas for the presentation. There has 
 been threads here about C++ closing the gap. Does D still bring 
 competitive advantage or is it becoming irrelevant? (Obviously, 
 some think its irrelevant already.) I'm trying to collect 
 opinions... :)

 Thank you,
 Ali

 [1] 
 http://cppnow.org/2017-conference/announcements/2017/04/09/d-keynote.html


Hi Ali.

Hope you're well.

I think not enough has been written on D's plasticity - Andrei 
and Walter talk about it in passing a couple of times.  But I 
have the impression that it's maybe quite important for merits of 
D's real world commercial value. Compare using refactoring  tools 
with not really needing them to same extent.

Something related to that.  I can go back and read my D code from 
early 2014 when I was learning D and it's all perfectly clear to 
me.  My python code not so much.  And two of the people working 
with me on D side have no professional experience in finance, but 
it didn't take long for them to get up to speed on my project 
which is maybe 120k SLOC plus some wrapping code.  I didn't have 
time or bandwidth to write comments or tests yet it was quite 
feasible to understand code without them.

On the other hand I was reading some object oriented C++ code of 
20k lines split between 200 files.  I just about read C++ so 
ceteris non paribus.  But the fragmentation and artificial 
abstraction makes it much harder to see what's going on and it's 
scarier to change it.  Plus template errors in C++! And that 20k 
lines is maybe 6k lines in 10 files in D.

I haven't always been super happy about using dub on Windows and 
like Manu said there is an energy gap introducing Windows 

isn't worse than cmake - porting some windows C++ code to build 
on linux.

The keynote by the embedded device guy at last years c++ conf was 
spot on - if you're arguing you're losing.  Why should I use D? 
Well probably you shouldn't if you don't want to.  In fact in 
these cases you definitely shouldn't, whether you want to or not. 
  However some people find its brought them some benefits and here 
are some if the commonalities.

Some concrete examples that are true and essentially real might 
be a nice counterpart to the "quicksort in two lines" language 
evangelism that Andrei rightly complains about.

Maybe you have some from Weka.  Please ask Atila Neves if some 
finance examples might be helpful.  (Eg excel-d, which I started 
and Stefan and Atila finished).

One last thing.  D is a pretty good language for getting stuff 
done quickly in for a prototype that can be cleaned up quickly. 
That's a point Andy Smith made, and that Liran made in his talk 
also.  I am having to deal with that increasingly now.  I would 
certainly much rather turn a D prototype written by a trader into 
production than a python one - lets not speak of Matlab! This 
aspect is mentioned on website but should be hammered home - it's 
a practical language for getting started stuff done fast  without 
leaving a mess.
Apr 19 2017
next sibling parent Joakim <dlang joakim.fea.st> writes:
On Wednesday, 19 April 2017 at 10:58:06 UTC, Laeeth Isharc wrote:

 One last thing.  D is a pretty good language for getting stuff 
 done quickly in for a prototype that can be cleaned up quickly. 
 That's a point Andy Smith made, and that Liran made in his talk 
 also.  I am having to deal with that increasingly now.  I would 
 certainly much rather turn a D prototype written by a trader 
 into production than a python one - lets not speak of Matlab! 
 This aspect is mentioned on website but should be hammered home 
 - it's a practical language for getting started stuff done fast
  without leaving a mess.


This is a point that keeps coming up, but it is hard to market 
without people either trying the language or user testimonials.  
Would you be able to write up a blog post about this, perhaps 
along with your D collaborators to fish out some concrete 
examples from your collective experience, maybe for the D blog?

We tend to focus more on the technical side for the D blog, would 
be nice to have a post from this development perspective.
Apr 19 2017
prev sibling next sibling parent =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 04/19/2017 03:58 AM, Laeeth Isharc wrote:


 Hope you're well.


I'm doing very well. Hoping to see you at DConf. :)

Here's another reminder to all: The registration deadline is this Sunday!


 On the other hand I was reading some object oriented C++ code of 20k
 lines split between 200 files.  I just about read C++ so ceteris non
 paribus.  But the fragmentation and artificial abstraction makes it much
 harder to see what's going on and it's scarier to change it.


That's a good point that comes up regularly. I wonder why C++ code seems 
to use OOP more than e.g. D does? Is it the reverberation of that old 
"everything is an object" style? Otherwise, it's quite possible to do 
compile-time polymorphism in C++ as well.


 However dub isn't worse than cmake


OT: I've used CMake in an unrelated project. I had failed to learn how 
to write a custom rule in it. It was super easy to make comman targets 
like an executable or library, but not custom stuff that we had needed. 
Anyway... There are smarter people who can use it. :)


 Some concrete examples that are true and essentially real might be a
 nice counterpart to the "quicksort in two lines" language evangelism
 that Andrei rightly complains about.


OT: Is there something new in Haskell that makes Sieve of Eratosthenes 
easier than the following entertaining paper shows?

   https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf


 Maybe you have some from Weka.


Yes, Weka is a great user of D. They take full advantage of the 
compile-time features of D for profit. :)

OT: Unfortunately, I'm not with Weka anymore. :/ Now I know that it 
takes way more focus to work through the 10 hour and the 1 day 
differences. Their weekends are Friday and Saturday, so by the time I 
started my Thursday morning, Israel was already off to their weekends.


 D is a pretty good language for getting stuff done quickly in
 for a prototype that can be cleaned up quickly. That's a point
 Andy Smith made, and that Liran made in his talk also.


Joakim is right when saying "it is hard to market without people either 
trying the language or user testimonials". I'm dealing with the same 
issue at my current job: Despite my attempts, there may be separate 
non-D languages for prototyping and actual implementation.

Ali
Apr 19 2017
prev sibling parent Walter Bright <newshound2 digitalmars.com> writes:
On 4/19/2017 3:58 AM, Laeeth Isharc wrote:

 I think not enough has been written on D's plasticity - Andrei and Walter talk
 about it in passing a couple of times.  But I have the impression that it's
 maybe quite important for merits of D's real world commercial value. Compare
 using refactoring  tools with not really needing them to same extent.


It's a really hard idea to get across.

Back when I wrote in C and C++, usually the first algorithm and data structure
I 
picked persisted through to the end of life of the program. I'd optimize the 
hell out of it, but I didn't change it.

But with D, I find I redo the algorithms and data structures, trying to find
one 
that works better. The Warp project is a particular example of that.

In C/C++, changing the algorithm/data structure meant rewriting the program. D 
makes it easy to change that without major rewrites, so it's much more likely 
that I'll be willing to change it.

Other explanations for this are:

1. I'm better at encapsulating algorithms and data structures

2. D's unit test feature makes me much more confident in making changes.

I can't help but think it is more than that. In D my programs just go together 
faster, and have fewer bugs. The code tends to look more like a solution to the 
problem rather than a mass of ->::<> and other syntax.

But these things are hard to get across in a presentation, so instead I talk 
about features, and the audience goes "well I can do that in C++/Rust/Go" even 
if it is awkward or requires a 3rd party tool or whatever.
Apr 21 2017
prev sibling next sibling parent reply Adrian Matoga <dlang.spam matoga.info> writes:
On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017 
 presentation[1]. boost::hana is an impressive library that 
 overlaps with many D features:

   
 http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?

 And please share your ideas for the presentation. There has 
 been threads here about C++ closing the gap. Does D still bring 
 competitive advantage or is it becoming irrelevant? (Obviously, 
 some think its irrelevant already.) I'm trying to collect 
 opinions... :)

 Thank you,
 Ali

 [1] 
 http://cppnow.org/2017-conference/announcements/2017/04/09/d-keynote.html


I was at C++ Meeting 2016 in Berlin, where Louis Dionne talked 
about hana in his keynote [1]. I've summarized my feelings in a 
blog post [2]. In short, you can do the same tricks in D, but 
frequently there's an idiomatic way to express the same thing 
just as concisely without them.
And of course, feel free to use any part of my post in your talk. 
:)

[1] https://www.youtube.com/watch?v=X_p9X5RzBJE
[2] https://epi.github.io/2017/03/18/less_fun.html
Apr 19 2017
next sibling parent reply Sebastiaan Koppe <mail skoppe.eu> writes:
On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


Great article!
Apr 19 2017
parent reply Adrian Matoga <dlang.spam matoga.info> writes:
On Wednesday, 19 April 2017 at 18:26:20 UTC, Sebastiaan Koppe 
wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga 
 wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 Great article!


Thanks! I should mention I've also got somewhat positive feedback 
from Louis [1].

[1] https://twitter.com/LouisDionne/status/843227582803849216
Apr 19 2017
next sibling parent reply David Gileadi <gileadisNOSPM gmail.com> writes:
On 4/19/17 11:30 AM, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 18:26:20 UTC, Sebastiaan Koppe wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 Great article!


 
 Thanks! I should mention I've also got somewhat positive feedback from 
 Louis [1].
 
 [1] https://twitter.com/LouisDionne/status/843227582803849216


Minor nit in the article--in the following paragraph "runtime" should 
probably be replaced with "compile time":

"Note the enum in place where C++ version used auto. The type is also 
inferred automatically, but using enum forces index to be computed at 
runtime and only then it can be used in static assert."
Apr 19 2017
parent reply Adrian Matoga <dlang.spam matoga.info> writes:
On Wednesday, 19 April 2017 at 18:57:19 UTC, David Gileadi wrote:

 On 4/19/17 11:30 AM, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 18:26:20 UTC, Sebastiaan Koppe 
 wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga 
 wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html









 Minor nit in the article--in the following paragraph "runtime" 
 should probably be replaced with "compile time":

 "Note the enum in place where C++ version used auto. The type 
 is also inferred automatically, but using enum forces index to 
 be computed at runtime and only then it can be used in static 
 assert."


Fixed, thanks a lot!
It seems impossible to spot all mistakes without someone else's 
eyes even if I read it a thousand times... :|
Apr 19 2017
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 04/19/2017 12:12 PM, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 18:57:19 UTC, David Gileadi wrote:

 On 4/19/17 11:30 AM, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 18:26:20 UTC, Sebastiaan Koppe wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html









 Minor nit in the article--in the following paragraph "runtime" should
 probably be replaced with "compile time":

 "Note the enum in place where C++ version used auto. The type is also
 inferred automatically, but using enum forces index to be computed at
 runtime and only then it can be used in static assert."


 Fixed, thanks a lot!
 It seems impossible to spot all mistakes without someone else's eyes
 even if I read it a thousand times... :|


(I saw that too. :) And one more.)

Thank you. Has this been on Reddit yet?

Two typos:

1) A missing underscore made me believe C++ gained a new keyword (make). :)

     auto events = make event_system("foo"_s, "bar"_s, "baz"_s});

2) Replace runtime with compile-time?

     "but using enum forces index to be computed at runtime"

Ali
Apr 19 2017
parent reply Adrian Matoga <dlang.spam matoga.info> writes:
On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli wrote:

 Thank you. Has this been on Reddit yet?


I haven't posted it there, I don't have an account.


 Two typos:

 1) A missing underscore made me believe C++ gained a new 
 keyword (make). :)

     auto events = make event_system("foo"_s, "bar"_s, "baz"_s});


Uhh, that underscore isn't the only problem in this line. ;)
Fixed both, thank you!
Apr 19 2017
parent reply Mike Parker <aldacron gmail.com> writes:
On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


I'll post it, but not today. It will get more attention if I wait 
until Friday afternoon GMT.
Apr 20 2017
parent reply Mike Parker <aldacron gmail.com> writes:
On Thursday, 20 April 2017 at 07:37:17 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


 I'll post it, but not today. It will get more attention if I 
 wait until Friday afternoon GMT.


https://www.reddit.com/r/programming/comments/66ovil/metaprogramming_is_less_fun_in_d/
Apr 21 2017
next sibling parent reply Mike Parker <aldacron gmail.com> writes:
On Friday, 21 April 2017 at 12:34:53 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 07:37:17 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga 
 wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli 
 wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


 I'll post it, but not today. It will get more attention if I 
 wait until Friday afternoon GMT.


 https://www.reddit.com/r/programming/comments/66ovil/metaprogramming_is_less_fun_in_d/


And I should add (for anyone paying attention), this is exactly 
the sort of thing I'm looking for more of on the D Blog. 
Submissions welcome :-)
Apr 21 2017
parent reply Adrian Matoga <dlang.spam matoga.info> writes:
On Friday, 21 April 2017 at 12:37:03 UTC, Mike Parker wrote:

 On Friday, 21 April 2017 at 12:34:53 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 07:37:17 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga 
 wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli 
 wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


 I'll post it, but not today. It will get more attention if I 
 wait until Friday afternoon GMT.


 https://www.reddit.com/r/programming/comments/66ovil/metaprogramming_is_less_fun_in_d/


 And I should add (for anyone paying attention), this is exactly 
 the sort of thing I'm looking for more of on the D Blog. 
 Submissions welcome :-)


This, and the generally positive feedback on r and HN are quite 
motivating. :)
I have some ideas for more articles but being a non-native 
English speaker I need a lot of time to make the text look at 
least understandable, so I usually give up quickly and move on to 
play with code instead. :)
Apr 21 2017
parent Nicholas Wilson <iamthewilsonator hotmail.com> writes:
On Friday, 21 April 2017 at 19:48:53 UTC, Adrian Matoga wrote:

 On Friday, 21 April 2017 at 12:37:03 UTC, Mike Parker wrote:

 And I should add (for anyone paying attention), this is 
 exactly the sort of thing I'm looking for more of on the D 
 Blog. Submissions welcome :-)


 This, and the generally positive feedback on r and HN are quite 
 motivating. :)
 I have some ideas for more articles but being a non-native 
 English speaker I need a lot of time to make the text look at 
 least understandable, so I usually give up quickly and move on 
 to play with code instead. :)


I'm a native speaker, but I hate writing with a passion, but I 
found the D community are very forthcoming with suggestions and 
improvements w.r.t both code and language typos and structure 
issues.
Apr 22 2017
prev sibling next sibling parent Joakim <dlang joakim.fea.st> writes:
On Friday, 21 April 2017 at 12:34:53 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 07:37:17 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga 
 wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli 
 wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


 I'll post it, but not today. It will get more attention if I 
 wait until Friday afternoon GMT.


 https://www.reddit.com/r/programming/comments/66ovil/metaprogramming_is_less_fun_in_d/


Nice work, already made the top 20 upvoted proggit links this 
week:

https://www.reddit.com/r/programming/top/?time=week

Active discussion going on, liked this Q&A:

https://www.reddit.com/r/programming/comments/66ovil/comment/dgkjnh6
Apr 21 2017
prev sibling parent Adrian Matoga <dlang.spam matoga.info> writes:
On Friday, 21 April 2017 at 12:34:53 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 07:37:17 UTC, Mike Parker wrote:

 On Thursday, 20 April 2017 at 05:01:17 UTC, Adrian Matoga 
 wrote:

 On Wednesday, 19 April 2017 at 19:22:11 UTC, Ali Çehreli 
 wrote:

 Thank you. Has this been on Reddit yet?


 I haven't posted it there, I don't have an account.


 I'll post it, but not today. It will get more attention if I 
 wait until Friday afternoon GMT.


 https://www.reddit.com/r/programming/comments/66ovil/metaprogramming_is_less_fun_in_d/


Thanks!

Maaan, reddit takes ages to load on mobile and doesn't let me 
read anything until I close all these annoying popups. Yet the 
comments are mostly in the same tone I saw a few times in the 
past when links were posted here ("D sucks" and so on) and made 
me think of reddit as a complete waste of time. It looks like 
it's all the time the same topic – bad, bad GC, D1 vs. D2, oh, 
and Rust and Go are better.

OTOH, I saw it posted also on HN 
(https://news.ycombinator.com/item?id=14165198)
and there, the discussion seems to be slightly more interesting.
Apr 21 2017
prev sibling parent Joakim <dlang joakim.fea.st> writes:
On Wednesday, 19 April 2017 at 18:30:49 UTC, Adrian Matoga wrote:

 On Wednesday, 19 April 2017 at 18:26:20 UTC, Sebastiaan Koppe 
 wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga 
 wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 Great article!


 Thanks! I should mention I've also got somewhat positive 
 feedback from Louis [1].

 [1] https://twitter.com/LouisDionne/status/843227582803849216


Interesting exchange.

Your tweet announcing that post 
(https://twitter.com/C012294/status/843216981566349312) doesn't 
show up for me in twitter's hashtag search:

https://twitter.com/hashtag/dlang

Can't say I'm surprised that they're incompetent at searching 
their own tweets though.
Apr 19 2017
prev sibling next sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


BTW in your D foreach, you could also have done `switch`

   void trigger(string event) {
     switch(event) {
       foreach (i, e; events) {
         case e:
           foreach (c; callbacks_[i])
             c();
           return;
       }
       default:
            assert(false, "trying to trigger an unknown event: " ~ 
event);
     }
   }


And the compiler+runtime can optimize that into a binary search 
when it gets larger automatically.
Apr 21 2017
next sibling parent Adrian Matoga <dlang.spam matoga.info> writes:
On Friday, 21 April 2017 at 13:10:43 UTC, Adam D. Ruppe wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga 
 wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 BTW in your D foreach, you could also have done `switch`

   void trigger(string event) {
     switch(event) {
       foreach (i, e; events) {
         case e:
           foreach (c; callbacks_[i])
             c();
           return;
       }
       default:
            assert(false, "trying to trigger an unknown event: " 
 ~ event);
     }
   }


 And the compiler+runtime can optimize that into a binary search 
 when it gets larger automatically.


Thanks, I completely forgot about it. I should update the article 
soon.
Apr 21 2017
prev sibling parent reply Jesse Phillips <Jesse.K.Phillips+D gmail.com> writes:
On Friday, 21 April 2017 at 13:10:43 UTC, Adam D. Ruppe wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga 
 wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 BTW in your D foreach, you could also have done `switch`

   void trigger(string event) {
     switch(event) {
       foreach (i, e; events) {
         case e:
           foreach (c; callbacks_[i])
             c();
           return;
       }
       default:
            assert(false, "trying to trigger an unknown event: " 
 ~ event);
     }
   }


 And the compiler+runtime can optimize that into a binary search 
 when it gets larger automatically.


Doesn't the latest compiler complain with a depreciation that i/e 
initialization is being skipped?
Apr 22 2017
parent Steven Schveighoffer <schveiguy yahoo.com> writes:
On 4/23/17 12:22 AM, Jesse Phillips wrote:

 On Friday, 21 April 2017 at 13:10:43 UTC, Adam D. Ruppe wrote:

 On Wednesday, 19 April 2017 at 18:02:46 UTC, Adrian Matoga wrote:

 [2] https://epi.github.io/2017/03/18/less_fun.html


 BTW in your D foreach, you could also have done `switch`

   void trigger(string event) {
     switch(event) {
       foreach (i, e; events) {
         case e:
           foreach (c; callbacks_[i])
             c();
           return;
       }
       default:
            assert(false, "trying to trigger an unknown event: " ~ event);
     }
   }


 And the compiler+runtime can optimize that into a binary search when
 it gets larger automatically.


 Doesn't the latest compiler complain with a depreciation that i/e
 initialization is being skipped?


Yep, but it's just a warning. A really annoying warning. 
https://issues.dlang.org/show_bug.cgi?id=16521 has more details. static 
foreach + switch can be bad if you ref the elements of the tuple. The 
"correct" thing to do is:

foreach(i, _unused; someTuple)
{
     // use someTuple[i] instead of _unused
}

You will still get the warning though.

-Steve
Apr 23 2017
prev sibling parent reply Johannes Pfau <nospam example.com> writes:
Am Wed, 19 Apr 2017 18:02:46 +0000
schrieb Adrian Matoga <dlang.spam matoga.info>:


 On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali =C3=87ehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017=20
 presentation[1]. boost::hana is an impressive library that=20
 overlaps with many D features:

  =20
 http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?

 And please share your ideas for the presentation. There has=20
 been threads here about C++ closing the gap. Does D still bring=20
 competitive advantage or is it becoming irrelevant? (Obviously,=20
 some think its irrelevant already.) I'm trying to collect=20
 opinions... :)

 Thank you,
 Ali

 [1]=20
 http://cppnow.org/2017-conference/announcements/2017/04/09/d-keynote.ht=




ml =20

=20
 I was at C++ Meeting 2016 in Berlin, where Louis Dionne talked=20
 about hana in his keynote [1]. I've summarized my feelings in a=20
 blog post [2]. In short, you can do the same tricks in D, but=20
 frequently there's an idiomatic way to express the same thing=20
 just as concisely without them.
 And of course, feel free to use any part of my post in your talk.=20
 :)
=20
 [1] https://www.youtube.com/watch?v=3DX_p9X5RzBJE
 [2] https://epi.github.io/2017/03/18/less_fun.html
=20


OT but is there any benefit to identify events with strings? As long as
you use compile time only events I'd prefer a syntax as in
https://github.com/WebFreak001/EventSystem

(one benefit is that it's 100% IDE autocomplete compatible)

I guess if you want runtime registration of events identifying by name
is useful. But then you also somehow have to encode the parameter types
to make the whole thing safe...

-- Johannes
Apr 22 2017
next sibling parent Nicholas Wilson <iamthewilsonator hotmail.com> writes:
On Saturday, 22 April 2017 at 07:53:49 UTC, Johannes Pfau wrote:

 
 [1] https://www.youtube.com/watch?v=X_p9X5RzBJE
 [2] https://epi.github.io/2017/03/18/less_fun.html
 


 OT but is there any benefit to identify events with strings? As 
 long as you use compile time only events I'd prefer a syntax as 
 in https://github.com/WebFreak001/EventSystem

 (one benefit is that it's 100% IDE autocomplete compatible)

 I guess if you want runtime registration of events identifying 
 by name is useful. But then you also somehow have to encode the 
 parameter types to make the whole thing safe...

 -- Johannes


I don't know about events, but dcd uses things like token!"+=" 
instead of giving it a name, I think it is very readable, waaaaay 
better than php's T_pajamajama or whatever it is/was.
Apr 22 2017
prev sibling parent Adrian Matoga <dlang.spam matoga.info> writes:
On Saturday, 22 April 2017 at 07:53:49 UTC, Johannes Pfau wrote:

 OT but is there any benefit to identify events with strings? As 
 long as you use compile time only events I'd prefer a syntax as 
 in https://github.com/WebFreak001/EventSystem

 (one benefit is that it's 100% IDE autocomplete compatible)

 I guess if you want runtime registration of events identifying 
 by name is useful. But then you also somehow have to encode the 
 parameter types to make the whole thing safe...


I agree. Personally, I'd probably also start with something like 
WebFreak001's ES and only think about how to add run-time 
dispatch later if I absolutely need it.
Apr 24 2017
prev sibling parent reply Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= writes:
On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017 
 presentation[1]. boost::hana is an impressive library that 
 overlaps with many D features:

   
 http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?


I've looked at it and concluded that it didn't really offer 
anything substantial for me over what I can do with C++17 and my 
own minor extensions to the C++ standard lib.

But I'm not really keen on pulling in boost  in general as the 
best parts of it ends up in the C++ standard anyway when it is 
mature...

What specifically are you finding in boost::hana that justifies 
adding it as a dependency?
Apr 20 2017
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 04/20/2017 02:06 AM, Ola Fosheim Grøstad wrote:

 On Wednesday, 19 April 2017 at 08:19:52 UTC, Ali Çehreli wrote:

 I'm brushing up on my C++ to prepare for my C++Now 2017
 presentation[1]. boost::hana is an impressive library that overlaps
 with many D features:

   http://www.boost.org/doc/libs/1_64_0_b2/libs/hana/doc/html/index.html

 Have you used boost::hana? What are your thoughts on it?


 I've looked at it and concluded that it didn't really offer anything
 substantial for me over what I can do with C++17 and my own minor
 extensions to the C++ standard lib.

 But I'm not really keen on pulling in boost  in general as the best
 parts of it ends up in the C++ standard anyway when it is mature...


To their credit, according to their documentation, boost::hana is a 
header-only library.


 What specifically are you finding in boost::hana that justifies adding
 it as a dependency?


My motivation is learning enough about modern C++ to not make a fool of 
myself in front of an expert C++ crowd. :) If I hadn't known about 
boost::hana, I could have easily stressed D's compile-time features as 
if C++ did not have them. Now I see that although 
as-always-less-readable, C++ has lots of compile-time features through 
boost::hana. For example, boost::hana has the equivalent of AliasSeq, 
and it's not too inconvenient.

Ali
Apr 20 2017
parent Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= writes:
On Thursday, 20 April 2017 at 09:32:02 UTC, Ali Çehreli wrote:

 My motivation is learning enough about modern C++ to not make a 
 fool of myself in front of an expert C++ crowd. :) If I hadn't 
 known about boost::hana, I could have easily stressed D's 
 compile-time features as if C++ did not have them.


Good point. People going to C++ conferences are probably more 
likely to use (or play with) such libraries than the 
I-just-want-stuff-done-C++ programmers.

Besides if hana has it then several C++ programmers either use 
hana or have their own equivalent of it.


 Now I see that although as-always-less-readable, C++ has lots 
 of compile-time features through boost::hana. For example, 
 boost::hana has the equivalent of AliasSeq, and it's not too 
 inconvenient.


I have seen that boost::hana has received praise in the 
reddit.com/r/cpp group. You might ask there for examples of open 
source projects that use it in production?
Apr 20 2017