Programming in D: Tutorial and Reference

https://ddili.org/ders/d.en/

by teleforce • 1 year ago

147 122 1 year ago

ddili.org

Daunk• 1 year ago

I feel like D is such an underrated language.

WalterBright6• 1 year ago

We're not good at marketing! But we're very good at language ergonomics.

jadbox2• 1 year ago

Just to add, I learned D in a day and finished most of project euler without needing to look up the manual. D is more "python" than python in that it makes coding very.

IMHO, Zig is the closest thing to being D-esk (like with comptime), but it's still not a mainstream option yet.

jadbox2• 1 year ago

* makes coding very straight forward. Most of the time I find what I needed in the language just using intuition.

kingbob0002• 1 year ago

Love D! I used it a bit in college when it was required for a programming language class. It's hard to justify using it nowadays though.

bsdooby6• 1 year ago

Utah Valley University? Or Romania, or Turkey? And why is D's usage hard to justify (because of Rust and/or contemporary C++)?

acehreli5• 1 year ago

Mike Shah has been using D for teaching software engineering at Northeastern University and Yale. Here is his DLang playlist: https://www.youtube.com/playlist?list=PLvv0ScY6vfd9Fso-3cB4C...

kingbob0002• 1 year ago

Yes, UVU. And also yes. If I find myself needing something low-level and performant, I have a hard time justifying the ramp-up time required to use D since there is a near zero chance I would use it in my current or future employment. While that isn't always how I decide what technologies to use in my personal time, it definitely is a factor that tips the scales towards a more mainstream language

jpecar• 1 year ago

Is D runtime still crashing when host has more than 128 cpu cores? I learned this the hard way ...

alphaglosined• 1 year ago

Are you talking about "Issue 24254 - LDC crash on Epyc Bergamo"?

That was fixed within the week, with a notification given that it had been sent to the reporter.

bsdooby6• 1 year ago

One of the best language reference manuals out there...

bsdooby6• 1 year ago

...could need an update, though.

acehreli5• 1 year ago

Author here... AMA.

bsdooby6• 1 year ago

Planning on an update? Some new features made it into the language (I think).

acehreli5• 1 year ago

All I need is another wave of motivation. I'm searching. :)

usrbinenv3• 1 year ago

I recently read almost the whole book in a week or so. It's excellent and I feel like I can write in D pretty well after reading it. Too bad that I most likely won't be writing in D, but, at least, I'm confident I can come back to it anytime and be up to speed if I ever need to. This book should be the goto for anyone who wishes to quickly learn the language.

bachmeier• 1 year ago

Been a heavy user of the language since 2013. This book was very helpful at the time. I don't think it was a book at that time, though, more a lengthy collection of notes as I recall.

acehreli5• 1 year ago

Exactly. It really was a happy accident. I talked about it here: https://dlang.org/blog/2016/06/29/programming-in-d-a-happy-a...

WalterBright6• 1 year ago

Currently I'm working on adding an AArch64 code generator to the venerable dmd D compiler. It's fun as it's completely differernt from the X86_64. In some ways very clever and in some ways completely wacky.

nerdralph• 1 year ago

I tried D several years ago, and liked the language. I didn't stick with it because of the lack of libraries compared to perl, python, C++, etc.

croemer2• 1 year ago

Anything compiled with LDC2 >=1.29 (3y old) will immediately crash/segfault on macOS >=15.4

A fix is on master/beta but will still take some time to be released.

https://github.com/dlang/dmd/issues/21126

Doxin• 1 year ago

Good thing there's the DMD and GDC compilers too then

croemer2• 1 year ago

DMD is also affected

shoozza• 1 year ago

Slightly off topic: Is D a good language for creating tiny windows or Linux executables? There is an upcoming game jam (4mb jam 2025) which gives extra points for game submissions <= 8KB. With c you can fit a window with graphics update in an executable of less than 900 bytes[0]. Granted it's using crinkler for linking which does some compression.

0: https://gist.github.com/ske2004/336d8cce8cd9db59d61ceb13c1ed...

monkeyelite5• 1 year ago

Yes. Just use the “better C” mode

mariusor5• 1 year ago

... which is not D any more though.

zascrash• 1 year ago

D deserves more recognition. It's a cool language under the radar for too long. I wish a major corporation backed it. I had a great time learning D. Also I admire Walter Bright If I could achieve even a fraction of his productivity, that would be awesome.

creata9• 1 year ago

Sincere question, not meant to be a shallow dismissal: Where is D a better choice than C++? In what aspects is it enough of an improvement over C++ to justify using a niche language?

acehreli5• 1 year ago

D is technically better than C++ in most features. (It has always lead C++. For example, among about 100 new feauters that C++11 brought, only 2 were not already in D. No C++ designer will ever admit this fact.)

D is safer and more productive. It's a joy to write in D because most of the time it feels like whatever you think, you code. This is unlike C++ where you fight the language all the time. C++ is not a productive programming language. I say this with experience: I coded in C++ as an "expert" for many many years, including these last couple of years. It's not fun to write in C++, which translates to another kind of loss of productivity.

C++ is a burden and liability for companies but no CTO will be blamed for chosing it because it's popular. I can list so many popular things and persons that worth nothing but I will refrain from getting political.

Yes, on paper, there are way more C++ programmers out there than D programmers. But I interview these C++ programmers occasionally. Most of them don't even have an inkling that they don't know C++ at all.

How about engineering with C++? That is such a difficult task. I went over header file hygiene with a colleague a couple of months ago. The number of points that you should pay attention to is mind boggling: Don't #include unnecessarily, do forward declare as much as possible (but what can be forward declared is hard to understand even for experienced programmers), #include your own API header first to prove that it's complete (and good luck!), don't forget header guards, don't reuse header guards, etc. etc. This is just efficient header file usage! We haven't started coding yet!

My friends, the emperor doesn't have clothes. C++ simply is not a tool that is designed well. People who choose it do so because they have to or they are masochists. (True story: I asked a relatively young Google meetup presenter once why he was using C++ instead of a modern language and he said "because it is hard".) C++ separates the elite from the masses; I used to strive to be a C++ elite; I am not interested a bit anymore; I want to write useful programs with D; and I do.

D is niche only because humans are populists. We are not encouraged to use tools (or products) that are designed better. We follow popular leaders. It takes one some time to find his or her own voice to reject bad products and use only good ones. I am extremely lucky to work for a company that allows me to use D to write useful products.

I still take the same joy from programming that I did when I first learned it.

Then there is the human aspect of it: I want to be associated with real people isntead of snobby elites. (Remember how C++ was marketed at around 2000? "Yes, C++ is hard but it was never meant to be for normal programmers anyway." Ha ha ha! I am old enough now to reject that mentality. Bad design is bad design my friends; you can't defend it by blaming the user for not being elite.)

I can go on and on...

Now it's my turn to ask: Why would anyone choose C++ for their projects despite the production costs that it brings? None of your programmers really know it; they introduce hidden liabilities in the projects, their source code become non-refactorable monsters. Why waste that money on C++ when you can produce products easily. Products that just work...

Neku42• 1 year ago

Programming in D after C++ is like the opposite of death by 1000 cuts - its just a constant stream of finding nice little things that simplify your life or avoid footguns. You become accustomed to all the niceties very fast and its hard to justify going back haha.

D is by no means perfect (and over the years it has accumulated lots of warts) but if you know what you are doing it enables amazing productivity and almost never gets in your way. If you have an idea about solving a problem in a particular way there's almost always a path available to do just that without running into "computer says no" situations (stares at Go).

usrbinenv3• 1 year ago

I constantly feel like inferior languages are picked up, while superior languages are discarded. It's almost as if the universe had a law: "inferior technology is always preferred no matter how hard you seethe".

Examples:

  * Python preferred over Ruby
  * TypeScript preferred over Dart or even JavaScript (which is fine and, as a bonus, doesn't require compilation step like TS)
  * Go is preferred over Crystal and D.

While Python, TypeScript and Go are quite alright, there is no doubt in my mind that their alternatives are absolutely superior as languages. Yes, in case of Dart, Crystal and D the ecosystem doesn't have the abundance of well-tested libraries, but as languages they are simply better. The Go argument that it's popular because it's simpler is absurd in the sense that no one really forces you to write complex code and use classes or other advanced OOP features in D.

esafak2• 1 year ago

https://en.wikipedia.org/wiki/Worse_is_better

old-gregg• 1 year ago

Languages do not matter as much as you think. Ecosystems are everything. Twice in my life I started companies (the first one took all my life savings) and in both cases the right call was what you called an "inferior language".

I actually liked D very much, and WB had been a personal hero of mine when I was in college. But I am not betting my career on an ecosystem built around by a single brilliant guy. For high-stakes projects, a wise decision is building on a platform with several deep-pocketed backers.

And for toy/personal projects... do you even need a language anymore? Just ask your favorite LLM to generate you an executable which does what you want (partially joking here).

WalterBright6• 1 year ago

D's ImportC feature makes it super easy to access C libraries from D code. That means D fits right in with a C ecosystem, as it's no longer necessary to attempt to translate the .h files into D.

It's not perfect, as some people cannot resist using the C preprocessor for some bizarre constructions.

I used to write those bizarre things myself in C, and was proud of my work. But one day I decided to remove them all, and the code was better.

pjmlp6• 1 year ago

I belive asking the favorite LLM to generate an executable will be the future, just like high level languages drove Assembly development into a niche.

Yes it isn't here today, just like it took several decades for optimizing compiler backends to do a very good job.

In fact one of the reasons why Matt Goldbolt created Compiler Explorer was to have a way to settle arguments he was having in the games industry.

Demiurge2• 1 year ago

Python preferred over Ruby

... Perhaps what you're describing is having a niche opinion. If you had some opinions, like a preference for "Everything must be done in as many ways as possible with funky characters" or "I hate indentation", it would certainly seem that the world is against you. But, perhaps, you just really smart and can remember the intention of all the complicated code you wrote a year ago, so you don't even need to write comments, and thats great. However, being special does not mean that some technolgoy is objectively inferior, unless you can actually come up with a provably objective metric.

Overall, the technology that is there, solving most of the problems for most of the cases is the technology that is superior, by the law of the universe, not the other way around.

I don't agree with any of your examples, but I have my own, like Pascal is a better language than C, by many metrics. I can also accept that C, is what people who invented unix, also invented. And that makes Pascal inferior to C, now, as choice for any project that requires that you hire embedded software developers. That's what the universe decided.

kouteiheika2• 1 year ago

"Everything must be done in as many ways as possible with funky characters"

Are you sure you're not talking about Perl here? Because there are very few "funky characters" in Ruby and code written in it tends to be very readable, more so than Python in many cases.

I agree with OP. While Python is not a bad language, Ruby is a better language in general, and I'm reminded of it every time I have to work in Python (which is pretty often nowadays, due to Python's dominance in ML ).

I can give many examples as to why, but here's a quick toy example to show off the difference in philosophy between Ruby and Python. You have a list of numbers, you want to keep only odd numbers, sort them, and convert them to a string where each number is separated by comma. Here's the Ruby code:

    xs = [12, 3, 5, 8, 7, 10, 1, 4]
    ys = xs.filter { |x| x.odd? }.sort.join(", ")

Now let's do the same in Python:

    xs = [12, 3, 5, 8, 7, 10, 1, 4]
    ys = [x for x in xs if x % 2 != 0]
    ys.sort()
    ys = ", ".join(str(y) for y in ys)

Or alternatively in a single line (but in more complex cases this gets extremely unwieldy since, unlike Ruby, Python forces you to nest these, so you can't write nice pipelines that read top-to-bottom and left-to-right):

    xs = [12, 3, 5, 8, 7, 10, 1, 4]
    ys = ", ".join(str(y) for y in sorted(x for x in xs if x % 2 != 0))

And this matches my experience pretty well. Things I can do in Ruby in one line usually take two or three lines in Python, are more awkward to write and are less readable.

ofrzeta2• 1 year ago

It's quite subjective what you consider to be better. Is Ruby better than Python? Maybe so, but Ruby only ever had one killer app that is Rails while Python has a vast ecosystem. Is Crystal better than Go? Maybe so, but Go ist just so much more mature (plus the ecosystem argument).

zem2• 1 year ago

speaking of typescript and dart, the language i was really rooting for in that niche was haxe. wish it had gotten more mainstream.

phplovesong• 1 year ago

Haxe is still alive!

The devs are working on 5.0 as we speak!

Its really calming that Haxe is not moving as fast as the JS/TS ecosystem. You upgrade once every 3-4 years. Everything just usually "works"

We use Haxe for PHP and its really a secret hidden superpower, im amazed people dont know about / use.

Its mostly marketing, i guess. But i wish more devs tried it as an alternative to PHP or TypeScript, as the language is WAY better in almost every way.

GoblinSlayer2• 1 year ago

It's scary to not have type checks in JavaScript. I do them by eyeballing the code, but ugh.

Also all languages you mentioned support complex code and OOP.

vips7L• 1 year ago

Code can be complex in any language. TypeScript itself can produce some really complex types. OOP isn’t a bad thing either; it’s just a tool.

realharo• 1 year ago

Dart is much worse than TypeScript. The over-reliance on codegen for the most simple things (e.g. https://pub.dev/packages/freezed#primary-constructors), the lack of expressiveness of the type system (it only got sum types very recently), and a lot of other little annoyances are ever present when having to write Dart.

pjmlp6• 1 year ago

What pains me in Python adoption, beyond its use as Perl replacement, is that we have so much better dynamic languages with advanced JIT implementations, but have to reach out writing extensions in native languages instead.

At least Python as DSL for GPU JIT compilers is a thing now.

Yes, I know about PyPy in the corner looking for attention.

creata9• 1 year ago

we have so much better dynamic languages with advanced JIT implementations

What are some of these better languages that you're referring to? (The usual dynamic language JITs I hear people praise are LuaJIT and Chez. And V8. And the JVM?)

bnolsen2• 1 year ago

Regarding ruby and python I thought the 2 were in the same league, esp compared to perl. Over 20 years ago I evaluated both and went ruby because of the more consistent api and of course pythons forced whitespace is an easy tie breaker against it. At this point I'm not to pleased that many younger programmers that python as some sort of default and tend to end up writing far too fancy code in it when it ends up being the wrong tool.

Shorel2• 1 year ago

Performance matters (as long as most other things are the same).

Python won over Ruby because of performance. Ruby is easily the slowest of all mainstream languages.

bnolsen2• 1 year ago

Having coffee almost 30 years in c++ I really good tired of the complexity of it. Some of the newer complexity being workarounds for (in retrospect) poor decisions made decades ago. Build system situation never helped, and I still despise cmake. When D came out I was interested but garbage collection immediately turned me off, in my opinion the boost shared pointers (later adopted into the standard) solved and shut the door on memory leaks as a serious issue.

And then the d2 fiasco sort of blew it all up. Doesn't help that the language always felt very heavy to me. Likewise Rust feels heavy and cumbersome itself.

So it ends up that I'm another one of those who feels the itch getting scratched by zig.

WalterBright6• 1 year ago

When D came out I was interested but garbage collection immediately turned me off,

Only a small amount of D uses the garbage collector. It's quite easy to write D code that doesn't use it.

in my opinion the boost shared pointers (later adopted into the standard) solved and shut the door on memory leaks as a serious issue.

Reference counting is slow and memory intensive.

byteknight• 1 year ago

On what planet is JS better than TS. You ever work with JS?

nilslindemann• 1 year ago

Python preferred over Ruby

Python's syntax is closer to written human language, and it uses more obvious words.

TypeScript preferred over Dart or even JavaScript

Typescript is a strict superset of JavaScript.

Go is preferred over Crystal and D

Go is backed by a big Corp

Shorel2• 1 year ago

The Go argument that it's popular because it's simpler is absurd in the sense that no one really forces you to write complex code and use classes or other advanced OOP features in D.

The same argument applies to C++. No one is forcing you to create complex nested templates or other difficult features.

Yet many criticisms to the language are in the form: "But it is possible to write very complex code that no one understands!"

It is absurd.

chenzhekl• 1 year ago

The superior languages on your list just reflect your personal preferences. There are not perfect languages, just appropriate languages for given application.

Defletter7• 1 year ago

Really wanted to like Dlang but I just did not have a good time with it.

One of my projects has a really simple server written in nodejs that's basically (in terms of complexity) just an auth'd chatroom, and I wanted to switch it from using raw tcp sockets to websockets. And since the server is so simple, why not refactor it to another language and see if there's no some performance gains from that? I ended up doing something pretty similar to that "Comparing 10 programming languages. I built the same app in all of them." video from Tom Delalande (https://www.youtube.com/watch?v=-MbTj8DGOP0). I had several working versions of the server in:

- Bun, using Bun APIs (https://bun.sh/docs/api/websockets)

- Dart, using Dart APIs (https://api.dart.dev/stable/latest/dart-io/WebSocket-class.h...)

- Java, using Java-WebSocket (https://github.com/TooTallNate/Java-WebSocket)

- Kotlin, using Ktor (https://start.ktor.io/p/ktor-websockets)

- Rust, using tokio-tungstenite (https://docs.rs/tokio-tungstenite/latest/tokio_tungstenite/i...)

- Zig, using websocket.zig (https://zigistry.dev/packages/karlseguin/websocket.zig/)

- D, using serverino (https://code.dlang.org/packages/serverino)

And Dlang was, by far, the worst experience out of the lot. Firstly is the lack of adequate, comprehensive, and centralised tooling. I almost gave up when dmd could not even compile a freshly init'd project. The impression I got is that you're not really meant to use dmd directly, you're meant to use dub, like how you compile Java projects with Maven/Gradle, not javac. Except that there's also apparently three competing compilers (https://wiki.dlang.org/Compilers)? And good luck remembering the names of the tooling because they're all some random three-letter combination.

Serverino makes heavy use of mixins and attributes (think Java annotations), which is not ideal. But what really killed the deal was (despite using the recommended intellij plugin (https://wiki.dlang.org/IDEs) with the recommended tools installed and setup) not being able to inspect[1] serverino's mixin or its attributes. So I look at serverino's source code, except its source also has mixins... which I can't inspect. I'm not going to use something when I cannot easily ascertain its control flow. And while, yes, I probably should have gone with vibe-d (https://code.dlang.org/packages/vibe-d%3Ahttp) in the first place, mixins and attributes are nonetheless part of the language and the tooling should be able to tell me about them.

- [1] When I say "inspect" I mean requesting the IDE to show me the source/definition so I can see what it is, what it does, and where it's known to be used.

dimgl• 1 year ago

And Dlang was, by far, the worst experience out of the lot. Firstly is the lack of adequate, comprehensive, and centralised tooling. I almost gave up when dmd could not even compile a freshly init'd project.

Yep this also happened to me when I tried D. I love the idea of the language and the syntax is great, but I really don't want to fight my tools when I'm working on a project.

throwawee• 1 year ago

Tangential, but which of the 7 ended up being the best experience?

Defletter7• 1 year ago

It's a tossup between Dart and Bun: Dart has better language features but Bun has better APIs. Since Bun is first and foremost a Javascript runtime, it inherits its annoyances and issues, like the complete lack of pattern matching, or switch expressions at all, or decent enums, etc. That said, Bun includes SQLite support and encryption out of the box, whereas Dart is heavily compartmentalised (https://pub.dev/publishers/dart.dev/packages). Imagine if, in Bun, importing "node:crypto" meant needing a "node:crypto" npm dependency. Dart ekes out the win though, I think.

LugosFergus• 1 year ago

I found the lack of mature tooling to be hugely problematic. The Visual D extension always felt flimsy and unreliable when debugging D.

DUB also exhibits weird behavior. For example, I wanted it to produce separate debug and release binaries, which it won't do out of the box. Instead, it'll create the same binary for both configurations. Changing that behavior was more difficult than it needed to be. Maybe it's changed since then, but I didn't have a pleasurable experience.

GoblinSlayer2• 1 year ago

How did you build the rust project? The docs say:

Most Rust programmers don't invoke rustc directly, but instead do it through Cargo. It's all in service of rustc though! If you want to see how Cargo calls rustc, you can

$ cargo build --verbose

Defletter7• 1 year ago

Sure, but everything seems to point users towards using the compiler, not the package manager. For example:

- The tour guide first recommends dmd (https://tour.dlang.org/tour/en/welcome/run-d-program-locally), though it does mention dub at the bottom

- Clicking "Documentation -> Command-line Reference" takes you to dmd, with only the barest mention of dub

- Even this post, the "Programming in D" book, tells you to use dmd and doesn't mention dub at all.

trikko4• 1 year ago

Hi there. I'm the serverino's author.

Could you please explain better what's wrong with it?

It could be useful to improve newcomers experience.

How did you choose serverino over other frameworks?

Defletter7• 1 year ago

Oh the issue isn't with serverino itself but with the lack of tooling-support for the language features that serverino makes heavy use of. And while serverino is open source, so one can ultimately view its source code, not having access to modern IDE type inspection adds a lot of unnecessary friction.

pmags• 1 year ago

It's been about 10 years since I last dipped my toes in the D waters.

At the time (v 2.067) I stumbled across some surprisingly bad warts in the standard library that prevented me from using it for my intended purposes which writing software tools for bioinformatics.

As other posters have noted, language elegance is secondary to the ecosystem when you want to get things done.

For anyone who has been using D for an extended period, has the D ecosystem improved / expanded considerably in the last 5-10 years?

Alifatisk• 1 year ago

The Youtube channel Tsoding did a great overview of the D language, overall, he liked it!

Programming in D: Tutorial and Reference

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