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Using D to Create the World’s Fastest File System

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Re: Using D to Create the World’s Fastest File System

#61

Post by torstenvl »

WalterBright wrote: post #11
hardwaresofton wrote: post #8

I would have liked to hear more about what exactly made D so great -- reading through it it's kind of vague. He mentions generics and finally getting LLVM support working as a target, and being able to use D at a high and low-level but I don't see anything here that's groundbreaking. Could someone who uses D Hate to be that guy, but if you could compare it with rust that would be double A++ good... I know the targets…

My experience, which of course is anecdotal, is that the advantage is it's easy to change the algorithms and data structures. I've maintained C and C++ code bases for decades, and I've found that the first algorithm I tried has stayed there in the code. It gets tweaked, optimized, refactored, but it's the same algorithm and data structure. With D, when I developed the Warp preprocessor, https://github.com/facebookarc…

That would be nice. I wonder if C would ever consider adding that. Types are tracked by the compiler so it doesn't seem theoretically impossible.

Re: Using D to Create the World’s Fastest File System

#62

Post by skocznymroczny »

vthriller wrote: post #28
ileri62 wrote: post #15

Earlier quoted context omitted.

Here's the thing though: They wrote a new compiler and a new standard library to make the language work for them. How exactly is that good publicity for D? D itself looked and still looks very interesting to me, as it can be very performant, without having insanely ugly syntax such as c++ or rust (inb4 rUsT iS VeRy ReADaBlE).

> D itself looked and still looks very interesting to me, as it can be […] without having insanely ugly syntax such as c++ or rust (inb4 rUsT iS VeRy ReADaBlE). I did a quick dive into aforementioned stdlib only to stumble upon something I would rather prefer any Rust/C++ version over: https://github.com/weka-io/mecca/blob/f5dc6d9f71983ea7b852ad... Some might want to exempt standard library from the "readable code" a…

It has some additional. Because so much code is generated on the fly during compilation, and because of frequent use of auto, IDEs have a hard time understanding the syntax to provide proper autocompletion :(

Re: Using D to Create the World’s Fastest File System

#63

Post by jcelerier »

arunc wrote: post #32
yvdriess wrote: post #23

Earlier quoted context omitted.

D feels much more like a 'sane' C successor, dropped from a parallel dimension where C++ could evolve without caring much about breaking its legacy code running the world. It has a few warts, some D v1 leftovers, but overall feels much more coherent than modern C++; even as the latter has grown much closer to D by piling more on top of its templating system. What I personally found the stand out feature of D to be, i…

Not to forget, C++ template meta-programming was discovered by accident. That's probably the only feature (and C++ is the only language) that I can think of in any language that's discovered by accident and is of utmost essential for introspection capabilities.

> Not to forget, C++ template meta-programming was discovered by accident.

yep, in 1993 some graybeard working on GCC checked files by last modification date to do some refactoring and saw one that hadn't changed since july 7, 1926, aptly called "alexandrescu.c". When he opened it, his computer started glowing yellow and his BSD prompt suddenly changed from '$' to '>'. He executed the testcase associated and the horror happened... a 666 kilobyte dump of template error was uploaded right into comp.lang.c++, which blew the poor hacker's 486DX away. Since then templates roam free again in our universe.

OR

when people say that it was discovered, it's that it was discovered during the process of designing templates and they found it nice, so they kept it.

Re: Using D to Create the World’s Fastest File System

#64

Post by fsloth »

jpz wrote: post #12

Ah, just looking at this. When I was looking at D back around 2005 it was a closed shop run by one guy - I had the feeling it did not take off because it simply wasn't an open enough project. It is a shame, as since then we've had go, Swift, Rust all come along and it is a lot more competitive for mindshare in that space... not to forget the merits of modern C++ (it is a far better language post 2011)

"it was a closed shop run by one guy"

You do realize Walter Bright is a frequent HN resident :) ?

Re: Using D to Create the World’s Fastest File System

#65

Post by nine_k »

hardwaresofton wrote: post #8

I would have liked to hear more about what exactly made D so great -- reading through it it's kind of vague. He mentions generics and finally getting LLVM support working as a target, and being able to use D at a high and low-level but I don't see anything here that's groundbreaking. Could someone who uses D Hate to be that guy, but if you could compare it with rust that would be double A++ good... I know the targets…

It would be great if someone knowledgeable compared these contenders for about the same space "close to metal":

  * Rust;
  * D;
  * Ada/Spark;
  * Zig;
using C and C++ as reference points.

(I also wonder if ATS-lang is used by anyone in practice; it seems to be targeted approximately at the same space.)

Re: Using D to Create the World’s Fastest File System

#66

Post by shiftoutbox »

So worlds fastest is a big claim. - How is it in comparison to a tmpfs on ram ? - How is it in in comparison to ufs/ffs or ext2 - Is it the fastest with some feature ? - Is it portable ? - Is it clusterable , on disk or over the network ? - What is it's target operating system ? - What is it's target market , SAN, NAS, Local Storage, etc ?

Re: Using D to Create the World’s Fastest File System

#67

Post by all2 »

chappar wrote: post #58
WalterBright wrote: post #26

Earlier quoted context omitted.

If I may be blunt, I could hardly believe SFINAE was a feature, and hated implementing it. But one thing I liked about C++ was the partial ordering scheme for template selection. I liked it so much D uses it for both templates and function overload selection (as opposed to the multi-level argument matching scheme C++ uses). Once I figured it out, I thought it was a beauty.

Do you mind giving an example for the specific use of "c++ partial ordering scheme for template selection"?

https://github.com/MicrosoftDocs/cpp-docs/blob/master/docs/c...

> Multiple function templates that match the argument list of a function call can be available. C++ defines a partial ordering of function templates to specify which function should be called. The ordering is partial because there can be some templates that are considered equally specialized.

> The compiler chooses the most specialized template function available from the possible matches.

And it goes on to give an example.

Re: Using D to Create the World’s Fastest File System

#68

Post by tombert »

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D.

I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer.

I suppose timing is everything for these kinds of things.

Re: Using D to Create the World’s Fastest File System

#69

Post by hardwaresofton »

WalterBright wrote: post #13
sargun wrote: post #10

Earlier quoted context omitted.

One of the nice aspects of D is that it interfaces with C++ really nicely. I'm not overly familiar with how Rust handles this, as the last time I tried to glue together Rust and C++ was more than a year ago, and the tooling was in evolution. From Go / CGo, it can be pretty scary to interface with native C++ code, and it requires lots of annoying boilerplate.

"C++ has a very complex ABI, and the Rust ABI is not frozen. However, both C++ and Rust support functions that use the C ABI. Therefore, interoperability between C++ and Rust involves writing things in such a way that C++ sees Rust code as C code and Rust sees C++ code as C code." https://hsivonen.fi/modern-cpp-in-rust/

Context: this poster is likely Walter Bright the creator and first implementer of D lang itself.

Cool to know you also read that article about C++ in rust (I personally read a little bit then left because trying to interface with C++ from rust wasn't a problem I had), but I guess it's obvious that you would.

Re: Using D to Create the World’s Fastest File System

#70

Post by nwah1 »

tombert wrote: post #68

I have wondered for awhile now why Rust is getting all this attention of being "Like C but safe and cool!", but no one would mention D. I personally don't do systems programming because I'm not smart enough but the little bit I have done, I found D to be the most-natural feeling (even over Rust), and D has been around a lot longer. I suppose timing is everything for these kinds of things.

D had a closed source reference compiler for a long time, and didn't have any major backers.

Rust had Mozilla backing early, and was fully open and transparent in terms of community feedback, and wasn't just making a language that had high level features, but was pioneering a new category of language that added tons of safety guarantees at compile time by default using a new paradigm of enforcing borrowing and ownership.

These safety guarantees are not just in regards to memory safety, but also in regards to data races.

D seems to allow memory safety guarantees, but not by default, and I believe it is enforced at runtime not compiletime.

So Rust was at once more accessible and more exciting.

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