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New D programming language forum, written entirely in D (dlang.org)
97 points by rpeden 2163 days ago | hide | past | web | favorite | 26 comments

The site is amazingly fast (at least subjectively), even though there must be a higher traffic coming from HN. Has anyone inspected the code to see how it's done and if there's some kind of a web framework for D?

Funny that people notice this. I think this is how all pages on the internet should be! Lately I'm getting tired of all those fancy Javascript pages or pages build on bloated frameworks.

The speed of this forum has nothing to do with D. You can achieve this in a language like PHP as well.

Just skip the bloat (server and client side).

Here are some of the things that play a part in the forum's performance:

* Optimized and deflated static resources

* Deflated HTML output

* SQLite prepared statements

* Integrated HTTP server (although it's currently in front of an Apache proxy)

* An optimized string builder (https://github.com/CyberShadow/DAppenderResearch)

* RAM cache of frequent DB queries

While there are equivalents available for interpreted/CGI languages (e.g. opcode caches, memcached), there is still a significant performance advantage. With a warm cache, most pages can be written out in under 5ms, and the busiest in under 50.

For some perspective, the time needed to compose the busiest view (threaded or split-view) halved when I moved from naive string concatenation to an optimized appender.

Great work. I wonder if there is a way to turn this into a more general purpose framework then just serving up one specific forum.

Yes, there are way too many things hard-coded at the moment. I want to refactor all of it out into templates, config files and library code. There's apparently some interest of adopting some code into D's standard library, too.

s/some/a ton of/

What's the current state of D, in relation to compilers and libraries? Did one compiler/version and one standard library have won already?

Yes. D1 is pending deprecation at the end of this year. D2 uses a common runtime separated from the standard library, and you can use Phobos and Tango alongside each other.


It looks like web.d implements the response handler from scratch, so I doubt there's a framework. Maybe a framework will be extracted from this in the future.

It looks like there isn't even a template language -- it seems to build the html using the plain old string concatenation method.

   `<tr class="thread-post-row`, (post.info && post.id==selectedID ? ` thread-post-focused thread-post-selected` : ``), `">`
    `<div style="padding-left: `, format("%1.1f", OFFSET_INIT + level * offsetIncrement), OFFSET_UNITS, `">`
      `<div class="thread-post-time">`, summarizeTime(post.time, true), `</div>`,
      `<a class="postlink `, (user.isRead(post.rowid) ? "forum-read" : "forum-unread" ), `" href="`, encodeEntities(idToUrl(post.id)), `">`, truncateString(post.author, 20), `</a>`

I plan to move to HTML templates in a future version. It shouldn't affect performance.

It's probably not the deciding option, but the front-end code is only just over 20K because outside of a few images and a stylesheet there's very little going on.

A lot of Web Designers today tend to completely forget that page size matters, and that just because many of us have broadband connection it's no reason to throw JS and screen size images everywhere.

Hacker News is smaller, yet takes longer to serve: http://cl.ly/31360A1E2s2j031s0S2O

I didn't say that it was the underlying reason, but it's nice to note that even though the page looks nice it's also small and efficient, especially when you compare it to more established forums.

In browsing on an android device and its incredibly responsive for me. Much more than other sites ive browsed on this phone today.

The source is available on github:


Hell yes, that's what I'm talking about. We need good tools in nice, statically typed, native languages to make web applications!


   D's design goals attempt to combine the performance of 
   compiled languages with the safety and expressive power 
   of modern dynamic languages. Idiomatic D code is 
   commonly as fast as equivalent C++ code, while being 
   shorter and memory-safe.
D seems to have similar goals with Go (golang). Has anybody here used both?


For those interested, more info on the differences between D and Go: http://stackoverflow.com/questions/3554956/d-versus-go-compa...

More different than I thought.

I have always thought D was an interesting language. I never got into it because I thought it was pretty dormant. Has it been resurrected?

There's been an explosion of contributions to the compiler, runtime and standard library since their development was moved to GitHub about a year ago.

Cool! I may consider trying it again. Are the gcc or LLVM compilers up to date these days?

GDC is in really good shape (on *nix at least). LDC seems up-to-date, but not sure how stable it is.

The core team never went dormant. There was a point where the community seemed to have contracted sharply, back before 1.0. Is that what you mean? If so then yeah it seems to have turned itself around.

It looks site your main site is still linking to the old forum:

HN -> http://forum.dlang.org/ -> http://dlang.org/overview.html -> http://digitalmars.com/NewsGroup.html

Nicely done!

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