Re: Implementing typestate

[Ola Fosheim Grostad via Digitalmars-d]

On Wednesday, 16 September 2015 at 06:25:59 UTC, Ola Fosheim 
Grostad wrote:
On Wednesday, 16 September 2015 at 05:51:50 UTC, Tobias Müller 
wrote:
Ola Fosheim Grøstad  
wrote:

But you need non-copyable move-only types for it to work.


Yes... But will it prevent you from doing two open() in a row 
at compiletime?


Nevermind, it needs linear typing, not only move semantics...

Re: Implementing typestate

[Ola Fosheim Grostad via Digitalmars-d]

On Wednesday, 16 September 2015 at 05:51:50 UTC, Tobias Müller 
wrote:

Ola Fosheim Grøstad  wrote:
On Tuesday, 15 September 2015 at 20:34:43 UTC, Tobias Müller 
wrote:

There's a Blog post somewhere but I can't find it atm.


Ok found it: > 
http://pcwalton.github.io/blog/2012/12/26/typestate-is-dead/


But that is for runtime detection, not compile time?


Not as far as I understand it.
The marker is a type, not a value. And it's used as template 
param.

But you need non-copyable move-only types for it to work.


Yes... But will it prevent you from doing two open() in a row at 
compiletime?

Why do abstract class functions require definitions?

[FiveNights via Digitalmars-d-learn]

Every so often I'll get a compiler error that isn't particularly 
clear on what's wrong and eventually I'll figure out that what's 
causing it is having a function in an abstract class somewhere 
that isn't defined:


abstract class SomeClass {
int someVariable;
void someFunction();
}
the solution is usually:
void someFunction(){}

Usually the abstract class is a converted interface, but it 
turned out that I needed to include a variable for it to work out 
and I just wasn't keen on remembering to put a mixin in each 
derived class.


I'm just wondering why I can't have an undefined function in an 
abstract class? I'd the compiler to say, "Hey, you forgot to put 
'someFunction()' in 'SomeDerrivedClass', go do something about 
that." when I end a function with a semi-colon in the base class 
and don't have it in the derrived. Everything just seems to break 
in cryptic ways unless I curly brace the function ending.

[Issue 15069] nonsense struct template instantiations still compile

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15069

Sobirari Muhomori  changed:

   What|Removed |Added

 CC||dfj1es...@sneakemail.com

--- Comment #1 from Sobirari Muhomori  ---
*** Issue 15070 has been marked as a duplicate of this issue. ***

--

[Issue 15060] Can't load a D shared library first, then load a C shared library

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15060

--- Comment #1 from ponce  ---
Suggestion from David Nadlinger

"
This is OS X only, right? In this case, it is hard to judge where exactly it
sits and what needs to be done to fix it, as no work has been done on dylib
support recently in either compiler. A wild guess is that there might still be
an image change handler, etc. registered that dyld tries to call when loading
the new library, but which no longer exists in the program. Searching druntime
for "_dyld" might reveal something of this sort."

--

Re: Why do abstract class functions require definitions?

[Jacob Carlborg via Digitalmars-d-learn]

On 2015-09-16 10:49, FiveNights wrote:

Every so often I'll get a compiler error that isn't particularly clear
on what's wrong and eventually I'll figure out that what's causing it is
having a function in an abstract class somewhere that isn't defined:

abstract class SomeClass {
 int someVariable;
 void someFunction();
}
the solution is usually:
void someFunction(){}

Usually the abstract class is a converted interface, but it turned out
that I needed to include a variable for it to work out and I just wasn't
keen on remembering to put a mixin in each derived class.

I'm just wondering why I can't have an undefined function in an abstract
class? I'd the compiler to say, "Hey, you forgot to put 'someFunction()'
in 'SomeDerrivedClass', go do something about that." when I end a
function with a semi-colon in the base class and don't have it in the
derrived. Everything just seems to break in cryptic ways unless I curly
brace the function ending.


I'm guessing you see a link error. The reason you see that instead of a 
compile error is because D supports separate compilation. Meaning that 
the method could be implemented in a different library that are resolved 
during link time.


As already answered in another post, the solution is to prefix the 
method declaration with "abstract".


--
/Jacob Carlborg

Re: running code on the homepage

[ixid via Digitalmars-d]

On Wednesday, 16 September 2015 at 06:44:30 UTC, nazriel wrote:
On Wednesday, 16 September 2015 at 05:54:03 UTC, Andrei Amatuni 
wrote:
maybe I'm doing something wrong...but the output of running 
the default code snippet on the dlang.org homepage is:


"unable to fork: Cannot allocate memory"

not a good look


Thank you for letting us know,

This issue will be fixed very soon.

Best regards,
Damian Ziemba


Would it be possible to set things up so ones that fail are 
retired until they can be fixed? Non-working examples look awful 
for the language.

Re: Initalizing complex array types or some other problem ;/

[Andrea Fontana via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 01:46:09 UTC, Prudence wrote:
In any case, Maybe you are not as smart as you think you are if 
you can't understand it? Maybe next time you shouldn't assume 
you are the oracle of all knowledge and if you can't understand 
it then it's bad/wrong.


In fact, it's quite simple to understand for anyone with half a 
brain.


Seriously. Don't guess. It's not that complex and it would take 
you 5 mins to understand if you wanted. No reason to try and 
through your ego in it.


"Prudence" seems not to fit well as nickname.

[Issue 15069] New: nonsense struct template instantiations still compile

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15069

  Issue ID: 15069
   Summary: nonsense struct template instantiations still compile
   Product: D
   Version: D2
  Hardware: All
OS: All
Status: NEW
  Severity: major
  Priority: P1
 Component: dmd
  Assignee: nob...@puremagic.com
  Reporter: john.loughran.col...@gmail.com

void main()
{
Stuff!(Thing!float) s;
}
struct Stuff(T)
{
T!int var;
}
struct Thing(T)
{
T varling;
}

This compiles and makes no sense.

--

Re: running code on the homepage

[nazriel via Digitalmars-d]

On Wednesday, 16 September 2015 at 05:54:03 UTC, Andrei Amatuni 
wrote:
maybe I'm doing something wrong...but the output of running the 
default code snippet on the dlang.org homepage is:


"unable to fork: Cannot allocate memory"

not a good look


Thank you for letting us know,

This issue will be fixed very soon.

Best regards,
Damian Ziemba

Re: dpaste web site

[Ola Fosheim Grøstad via Digitalmars-d]

How about just using a single click recaptcha:

https://www.google.com/recaptcha/intro/index.html

Re: Implement the "unum" representation in D ?

[Don via Digitalmars-d]

On Tuesday, 15 September 2015 at 11:13:59 UTC, Ola Fosheim 
Grøstad wrote:

On Tuesday, 15 September 2015 at 10:38:23 UTC, ponce wrote:
On Tuesday, 15 September 2015 at 09:35:36 UTC, Ola Fosheim 
Grøstad wrote:

http://sites.ieee.org/scv-cs/files/2013/03/Right-SizingPrecision1.pdf


That's a pretty convincing case. Who does it :)?


I'm not convinced. I think they are downplaying the hardware 
difficulties. Slide 34:


Disadvantages of the Unum Format
* Non-power-of-two alignment. Needs packing and unpacking, 
garbage collection.


I think that disadvantage is so enormous that it negates most of 
the advantages. Note that in the x86 world, unaligned memory 
loads of SSE values still take longer than aligned loads. And 
that's a trivial case!


The energy savings are achieved by using a primitive form of 
compression. Sure, you can reduce the memory bandwidth required 
by compressing the data. You could do that for *any* form of 
data, not just floating point. But I don't think anyone thinks 
that's worthwhile.


The energy comparisons are plain dishonest. The power required 
for accessing from DRAM is the energy consumption of a *cache 
miss* !! What's the energy consumption of a load from cache? That 
would show you what the real gains are, and my guess is they are 
tiny.


So:
* I don't believe the energy savings are real.
* There is no guarantee that it would be possible to implement it 
in hardware without a speed penalty, regardless of how many 
transistors you throw at it (hardware analogue of Amdahl's Law)

* but the error bound stuff is cool.

[Issue 15068] New: wrong error message on attempting to use type as template

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15068

  Issue ID: 15068
   Summary: wrong error message on attempting to use type as
template
   Product: D
   Version: D2
  Hardware: All
OS: All
Status: NEW
  Severity: major
  Priority: P1
 Component: dmd
  Assignee: nob...@puremagic.com
  Reporter: john.loughran.col...@gmail.com

void main()
{
Stuff!int s;
}
struct Stuff(T)
{
T!int var;
}

leads to the error:
test.d(8): Error: template instance T!int T is not a template declaration, it
is a alias

T is not an alias, it's a type.

--

[Issue 15071] New: filenames and module names with case-insensitive HFS+

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15071

  Issue ID: 15071
   Summary: filenames and module names with case-insensitive HFS+
   Product: D
   Version: D2
  Hardware: All
OS: Mac OS X
Status: NEW
  Severity: major
  Priority: P1
 Component: dmd
  Assignee: nob...@puremagic.com
  Reporter: john.loughran.col...@gmail.com

by default, OS X uses case-insensitive-but-case-preserving HFS+ and this is
what almost all OS X users will have.

consider the following (incorrect) code:

% cat chirplet.d 
import mathutil;

auto chirplet()
{
exp(0);
}

% cat mathUtil.d 
auto expi(double )
{
}

auto exp(T)(T c)
{
expi(c);
}
% dmd chirplet.d mathUtil.d -main
Undefined symbols for architecture x86_64:
  "_D8mathutil4expiFNaNbNiNfdZv", referenced from:
  _D8mathutil10__T3expTiZ3expFNaNbNiNfiZv in chirplet.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
--- errorlevel 1


What I think is happening:
While compiling chirplet.d, dmd sees `import mathutil;` and asks the filesystem
for a file called `mathutil.d` in the current directory. HFS+ provides
`mathUtil.d` because it doesn't know any better. dmd continues compiling and
emits references to `mathutil` symbols. dmd compiles `mathUtil.d` and emits
`mathUtil` symbols. Linker sees the case mismatch and fails.

--

[Issue 15070] New: Template is silently extracted from type and reinstantiated

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15070

  Issue ID: 15070
   Summary: Template is silently extracted from type and
reinstantiated
   Product: D
   Version: D2
  Hardware: All
   URL: http://forum.dlang.org/post/puelgpxgijdxvejsxwzy@forum
.dlang.org
OS: All
Status: NEW
  Keywords: accepts-invalid
  Severity: normal
  Priority: P1
 Component: dmd
  Assignee: nob...@puremagic.com
  Reporter: dfj1es...@sneakemail.com

import std.stdio;
void main()
{
Stuff!(Thing!float) s;
writeln(typeid(s.var));
writeln(typeid(s.var.varling));
writeln(typeid(s));
alias F=Thing!float;
//F!int i; //doesn't compile
}
struct Stuff(T)
{
T!int var;
}
struct Thing(T)
{
T varling;
}

--

Re: Implement the "unum" representation in D ?

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 08:17:59 UTC, Don wrote:
I'm not convinced. I think they are downplaying the hardware 
difficulties. Slide 34:


I don't think he is downplaying it. He has said that it will 
probably take at least 10 years before it is available in 
hardware. There is also a company called Rex Computing that are 
looking at unum:


http://www.theplatform.net/2015/07/22/supercomputer-chip-startup-scores-funding-darpa-contract/

He assumes that you use a scratchpad (a big register file), not 
caching, for intermediate calculations.


His basic reasoning is that brute force ubox methods makes for 
highly parallel calculations. It might be possible to design ALUs 
that can work with various unum bit widths efficiently (many 
small or a few large)... who knows. You'll have to try first.


Let's not forget that there is a _lot_ of legacy constraints and 
architectural assumptions in both x86 architecture.


The energy comparisons are plain dishonest. The power required 
for accessing from DRAM is the energy consumption of a *cache 
miss* !! What's the energy consumption of a load from cache?


I think this argument is aiming at HPC where you can find funding 
for ASICs. They push a lot of data over the memory bus.

[Issue 15070] Template is silently extracted from type and reinstantiated

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15070

Sobirari Muhomori  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution|--- |DUPLICATE

--- Comment #1 from Sobirari Muhomori  ---


*** This issue has been marked as a duplicate of issue 15069 ***

--

[Issue 15069] nonsense struct template instantiations still compile

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15069

Sobirari Muhomori  changed:

   What|Removed |Added

 CC|dfj1es...@sneakemail.com|

--

Re: Re-named & Selective Imports

[Kagamin via Digitalmars-d-learn]

Well, arguably disjunctive combination doesn't make much sense 
here, because renamed import disambiguates it all enough, but 
makes it impossible to merge arbitrary namespaces ad hoc, a 
feature I missed several times.

What kind of sorcery is that?

[NX via Digitalmars-d-learn]

import std.stdio;
void main()
{
Stuff!(Thing!float) s;
writeln(typeid(s.var));
writeln(typeid(s.var.varling));
writeln(typeid(s));
}
class Stuff(T)
{
T!int var;
}
class Thing(T)
{
T varling;
}

Re: Implement the "unum" representation in D ?

[deadalnix via Digitalmars-d]

On Wednesday, 16 September 2015 at 08:17:59 UTC, Don wrote:
On Tuesday, 15 September 2015 at 11:13:59 UTC, Ola Fosheim 
Grøstad wrote:

On Tuesday, 15 September 2015 at 10:38:23 UTC, ponce wrote:
On Tuesday, 15 September 2015 at 09:35:36 UTC, Ola Fosheim 
Grøstad wrote:

http://sites.ieee.org/scv-cs/files/2013/03/Right-SizingPrecision1.pdf


That's a pretty convincing case. Who does it :)?


I'm not convinced. I think they are downplaying the hardware 
difficulties. Slide 34:


Disadvantages of the Unum Format
* Non-power-of-two alignment. Needs packing and unpacking, 
garbage collection.


I think that disadvantage is so enormous that it negates most 
of the advantages. Note that in the x86 world, unaligned memory 
loads of SSE values still take longer than aligned loads. And 
that's a trivial case!


The energy savings are achieved by using a primitive form of 
compression. Sure, you can reduce the memory bandwidth required 
by compressing the data. You could do that for *any* form of 
data, not just floating point. But I don't think anyone thinks 
that's worthwhile.




GPU do it a lot. Especially, but not exclusively on mobile. Not 
to reduce the misses (a miss is pretty much guaranteed, you load 
32 thread at once in a shader core, each of them will require at 
least 8 pixel for a bilinear texture with mipmap, that's the bare 
minimum. That means 256 memory access at once. One of these pixel 
WILL miss, and it is going to stall the 32 threads). It is not a 
latency issue, but a bandwidth and energy one.


But yeah, in the general case, random access is preferable, 
memory alignment, and the fact you don't need to do as much 
bookeeping are very significants.


Also, predictable size mean you can split your dataset and 
process it in parallel, which is impossible if sizes are random.


The energy comparisons are plain dishonest. The power required 
for accessing from DRAM is the energy consumption of a *cache 
miss* !! What's the energy consumption of a load from cache? 
That would show you what the real gains are, and my guess is 
they are tiny.




The energy comparison is bullshit. As long as you haven't loaded 
the data, you don't know how wide they are. Meaning you need 
either to go pessimistic and load for the worst case scenario or 
do 2 round trip to memory.


The author also use a lot the wire vs transistor cost, and how it 
evolved? He is right. Except that you won't cram more wire at 
runtime into the CPU. The CPU need the wiring for the worst case 
scenario, always.


The hardware is likely to be slower as you'll need way more 
wiring than for regular floats, and wire is not only cost, but 
also time.


That being said, even a hit in L1 is very energy hungry. Think 
about it, you need to go a 8 - way fetch (so you'll end up 
loading 4k of data from the cache) in parallel with address 
translation (usually 16 ways) in parallel with snooping into the 
load and the store buffer.


If the load is not aligned, you pretty much have to multiply this 
by 2 if it cross a cache line boundary.


I'm not sure what his number represent, but hitting L1 is quite 
power hungry. He is right on that one.



So:
* I don't believe the energy savings are real.
* There is no guarantee that it would be possible to implement 
it in hardware without a speed penalty, regardless of how many 
transistors you throw at it (hardware analogue of Amdahl's Law)

* but the error bound stuff is cool.


Yup, that's pretty much what I get out of it as well.

Re: What kind of sorcery is that?

[John Colvin via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 08:28:24 UTC, NX wrote:

import std.stdio;
void main()
{
Stuff!(Thing!float) s;
writeln(typeid(s.var));
writeln(typeid(s.var.varling));
writeln(typeid(s));
}
class Stuff(T)
{
T!int var;
}
class Thing(T)
{
T varling;
}


Filed a bug: https://issues.dlang.org/show_bug.cgi?id=15069

Re: Implement the "unum" representation in D ?

[deadalnix via Digitalmars-d]

On Saturday, 11 July 2015 at 18:16:22 UTC, Timon Gehr wrote:

On 07/11/2015 05:07 PM, Andrei Alexandrescu wrote:

On 7/10/15 11:02 PM, Nick B wrote:

John Gustafson book is now out:

It can be found here:

http://www.amazon.com/End-Error-Computing-Chapman-Computational/dp/1482239868/ref=sr_1_1?s=books=UTF8=1436582956=1-1=John+Gustafson=1436583212284=093TDC82KFP9Y4S5PXPY



Very interesting, I'll read it. Thanks! -- Andrei



I think Walter should read chapter 5.


What is this chapter about ?

Re: Best Direction on Spawning Process Async

[Ali Çehreli via Digitalmars-d-learn]

On 09/15/2015 09:21 PM, Mike McKee wrote:

What's the best direction from...

http://dlang.org/phobos/std_process.html

...on spawning an async process and then peeking at it occasionally as
it runs, and then get notified when it finishes? In other words, what
std.process functions would you recommend I use? What I want to avoid is
a blocking state where the GUI freezes because it's waiting for the
process to complete.

For instance, imagine you are building a front end GUI (like GtkD) to a
command-line based antivirus scanner. You'll want to spawn the process,
show a progress bar, and as the command line returns status information,
you peek at it asynchronously and then update the progress bar (or
perhaps store virus detected info in a table), and then stop the
progress bar at 100% when the command process has finished.



Sounds like an easy task for std.concurrency:

import std.stdio;
import std.concurrency;
import core.thread;

struct Progress {
int percent;
}

struct Done {
}


void doWork() {
foreach (percent; 0 .. 100) {
Thread.sleep(100.msecs);
if (!(percent % 10)) {
ownerTid.send(Progress(percent));
}
}

ownerTid.send(Done());
}

void main() {
auto worker = spawn();

bool done = false;
while (!done) {
bool received = false;

while (!received) {
received = receiveTimeout(
// Zero timeout is a non-blocking message check
0.msecs,
(Progress message) {
writefln("%s%%", message.percent);
},

(Done message) {
writeln("Woohoo!");
done = true;
});

if (!received) {
// This is where we can do more work
Thread.sleep(42.msecs);
write(". ");
stdout.flush();
}
}
}
}

Ali

Re: Runtime error when calling a callback in a parallel Task

[BBasile via Digitalmars-d-learn]

On Tuesday, 15 September 2015 at 23:49:23 UTC, BBasile wrote:
Under Windows this works fine but under Linux I got a runtime 
error.


this could be reduced to :
[...]
If it can help to understand the problem, here is the unreducted 
case:


https://github.com/BBasile/Coedit/blob/master/cedast/src/ast.d#L343

Re: Why do abstract class functions require definitions?

[Kagamin via Digitalmars-d-learn]

declare as
abstract void someFunction();

Re: Implementing typestate

[Idan Arye via Digitalmars-d]

On Wednesday, 16 September 2015 at 06:25:59 UTC, Ola Fosheim 
Grostad wrote:
On Wednesday, 16 September 2015 at 05:51:50 UTC, Tobias Müller 
wrote:
Ola Fosheim Grøstad  
wrote:
On Tuesday, 15 September 2015 at 20:34:43 UTC, Tobias Müller 
wrote:

There's a Blog post somewhere but I can't find it atm.


Ok found it: > 
http://pcwalton.github.io/blog/2012/12/26/typestate-is-dead/


But that is for runtime detection, not compile time?


Not as far as I understand it.
The marker is a type, not a value. And it's used as template 
param.

But you need non-copyable move-only types for it to work.


Yes... But will it prevent you from doing two open() in a row 
at compiletime?


What's wrong with two `open()`s in a row? Each will return a new 
file handle.

How do I change debug mode with dub?

[Alex_Freeman via Digitalmars-d-learn]

Hey all! I'm just wondering how to run dub with different debug 
versions, or running it with different versions generally? Is 
there also a way to have code behind multiple debug versions, or 
run more than one debug version at once?


Thanks!

Re: Why do abstract class functions require definitions?

[Marc Schütz via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 09:31:25 UTC, Jacob Carlborg 
wrote:

On 2015-09-16 10:49, FiveNights wrote:
Every so often I'll get a compiler error that isn't 
particularly clear
on what's wrong and eventually I'll figure out that what's 
causing it is
having a function in an abstract class somewhere that isn't 
defined:


abstract class SomeClass {
 int someVariable;
 void someFunction();
}
the solution is usually:
void someFunction(){}

Usually the abstract class is a converted interface, but it 
turned out
that I needed to include a variable for it to work out and I 
just wasn't

keen on remembering to put a mixin in each derived class.

I'm just wondering why I can't have an undefined function in 
an abstract
class? I'd the compiler to say, "Hey, you forgot to put 
'someFunction()'
in 'SomeDerrivedClass', go do something about that." when I 
end a
function with a semi-colon in the base class and don't have it 
in the
derrived. Everything just seems to break in cryptic ways 
unless I curly

brace the function ending.


I'm guessing you see a link error. The reason you see that 
instead of a compile error is because D supports separate 
compilation. Meaning that the method could be implemented in a 
different library that are resolved during link time.


As already answered in another post, the solution is to prefix 
the method declaration with "abstract".


Wouldn't the following behaviour be more useful as a default?

abstract class Foo {
void bar1() { } // non-abstract, obviously
void bar2();// abstract, because it's in an 
abstract class

// (different from now)
extern void bar3(); // non-abstract, but defined 
externally

}

Re: Type helpers instead of UFCS

[Per Nordlöw via Digitalmars-d]

On Saturday, 12 September 2015 at 20:37:37 UTC, BBasile wrote:

UFCS is good but there are two huge problems:
- code completion in IDE. It'will never work.


Is is possible.

DCD plans to support it:

https://github.com/Hackerpilot/DCD/issues/13

I agree that this is a big issue, though, and is one of the most 
important things to work on.

[Issue 15072] New: [REG2.069-devel] Re-introducing codegen performance regression 14805

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15072

  Issue ID: 15072
   Summary: [REG2.069-devel] Re-introducing codegen performance
regression 14805
   Product: D
   Version: D2
  Hardware: All
OS: All
Status: NEW
  Keywords: performance
  Severity: regression
  Priority: P1
 Component: dmd
  Assignee: nob...@puremagic.com
  Reporter: k.hara...@gmail.com

Code snippet from test/runnable/todt.d in dmd test suite:

module test;

struct S14805
{
ushort one;
}
auto a14805 = new S14805[513*513];

void main() {}

Command line:
dmd -c test.d

Will consume cpu time.

Introduced in: https://github.com/D-Programming-Language/dmd/pull/5050

--

Re: How do I change debug mode with dub?

[Gary Willoughby via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 10:42:13 UTC, Alex_Freeman 
wrote:
Hey all! I'm just wondering how to run dub with different debug 
versions, or running it with different versions generally? Is 
there also a way to have code behind multiple debug versions, 
or run more than one debug version at once?


Thanks!


There's lots of useful information here:
http://code.dlang.org/package-format?lang=json

Re: FancyPars

[Bastiaan Veelo via Digitalmars-d-announce]

On Thursday, 2 July 2015 at 14:25:09 UTC, Stefan Koch wrote:


I hope that it will be suitable to beginners.


Sounds like you want to share this, but I can't find a licence. 
In case this turns out to be useful, we would need one :-)


If you want I can prepare a PR for that, just let me know which 
licence to pick.


Best,
Bastiaan.

Re: Final templated interface method not found

[Andre via Digitalmars-d-learn]

Thanks, it works like a charme.

Kind regards
André

Re: running code on the homepage

[Dmitry Olshansky via Digitalmars-d]

On 16-Sep-2015 09:44, nazriel wrote:

On Wednesday, 16 September 2015 at 05:54:03 UTC, Andrei Amatuni wrote:

maybe I'm doing something wrong...but the output of running the
default code snippet on the dlang.org homepage is:

"unable to fork: Cannot allocate memory"

not a good look


Thank you for letting us know,

This issue will be fixed very soon.

Best regards,
Damian Ziemba


May I suggest you to record such conditions with automatic notification 
e.g. by e-mail.


Only 1 in 10 of visitors will consider reporting an issue, of these only 
1 in 10 will get to dlang forum to post a message.


--
Dmitry Olshansky

Re: Another, is it a bug?

[Meta via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 03:48:59 UTC, Random D user 
wrote:
Yeah... I guess I was expecting it to overload across class 
boundaries. I mean there's already a member eat in base class 
and sub class can't override that since it's got different 
parameters, and it's a function (can't be variable), so the 
reasonable thing would be to overload it (which is why I tried 
override to see if it forces/hints overriding/overloading).
Instead it creates two ambiguous names of which only one has to 
be disambiguated to use which seems super error prone. IMO it 
should just be error/warning.


Given that, normally properties are just overloaded methods in 
D, it's pretty sad classes break this behavior/convention.


It's the exact same as in Java, and probably C# as well. I don't 
know if there's any OOP language that overloads methods between 
the base and super class.


https://ideone.com/En5JEc

[Issue 15073] New: SIGRTMIN is an alias to a private function

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15073

  Issue ID: 15073
   Summary: SIGRTMIN is an alias to a private function
   Product: D
   Version: D2
  Hardware: x86_64
OS: Linux
Status: NEW
  Severity: major
  Priority: P1
 Component: druntime
  Assignee: nob...@puremagic.com
  Reporter: tomerfil...@gmail.com

a simple program such as

import core.sys.posix.signal;

void main() {
int rtmin = SIGRTMIN;
}

fails to compile with

Error: function core.sys.posix.signal.__libc_current_sigrtmin is not
accessible from module main

Due to the functions being marked private in core.sys.posix.signal

--

[Issue 15072] [REG2.069-devel] Re-introducing codegen performance regression 14805

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15072

Kenji Hara  changed:

   What|Removed |Added

   Keywords||pull

--- Comment #1 from Kenji Hara  ---
https://github.com/D-Programming-Language/dmd/pull/5083

--

Re: Release D 2.068.1

[Marco Leise via Digitalmars-d-announce]

Am Tue, 15 Sep 2015 08:39:41 +
schrieb John Colvin :

> On Monday, 14 September 2015 at 23:53:16 UTC, Martin Nowak wrote:
> > On Monday, 14 September 2015 at 20:14:45 UTC, Jack Stouffer 
> > wrote:
> >> On Monday, 14 September 2015 at 17:51:59 UTC, Martin Nowak 
> >> wrote:
> >>> What platform are you on?
> >>
> >> I'm on OS X, using the homebrew version of DMD. And homebrew 
> >> is telling me that I have 2.068.1 installed
> >
> > Well I guess it's a bug in the homebrew script then.
> > Nobody is setting the VERSION file and there is no git repo to 
> > query.
> > https://github.com/Homebrew/homebrew/blob/f8b0ff3ef63e60a1da17ec8d8e68d949b1cebc27/Library/Formula/dmd.rb#L50
> 
> Where is the VERSION file documented? Why does it need manual 
> intervention only for patch releases and pre-releases?

I noticed this as well. There are different VERSION files
depending on where you download DMD source code from: The
releases on GitHub have 2.068 while the releases on dlang.org
have 2.068.1 in VERSION. That's easy to miss when you build
from source.
(Also the dlang.org downloads add to the DMD download
statistics, which is why I use those even though they
include extra binaries for all OSs.)

-- 
Marco

[Issue 15071] filenames and module names with case-insensitive HFS+

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15071

--- Comment #1 from Sobirari Muhomori  ---
>From spec:
---
By convention, package and module names are all lower case. This is because
those names can have a one-to-one correspondence with the operating system's
directory and file names, and many file systems are not case sensitive. All
lower case package and module names will minimize problems moving projects
between dissimilar file systems.
---

Also D is case sensitive, so you can't change identifier case and expect it to
work.

--

Re: "if sting in string"

[smadus via Digitalmars-d-learn]

A lot of thanks... i choose the (line.canFind(term)).

No is not my first language, Python was my first, but i dont 
coding a long time...

Re: "if sting in string"

[John Colvin via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 12:55:13 UTC, smadus wrote:

Hello

Searching after hours, i give up and here is the question. ;)

I will make a programm, this searching all txt files on the 
system or the path from user and searching a user tiped term in 
this file.


http://dpaste.dzfl.pl/dec09a0f849c

The Problem is in the if() "line 17" i searching in 
std.algorithm, but i dont find a solution for my problem.


i hope, someone can help me.

I'm new on D and sorry for my bad english.

Happy Greetings

Shorty


line 17 should probably be:

if(canFind(line, term)){

you had your first closing bracket in the wrong place. Also, 
canFind looks for the second argument inside the first argument.


Other notes:

There is no need to pass the arguments by ref, the data is not 
copied.


File has a member function called byLine that can be used like 
this:

foreach(line; actually_file.byLine())
//do something with the line
see http://dlang.org/phobos/std_stdio.html#.File.byLine

No need to chomp a line before using canFind on it.

What are you trying to write on line 18? datei isn't defined 
anywhere

Re: running code on the homepage

[Andrei Amatuni via Digitalmars-d]

On Wednesday, 16 September 2015 at 10:17:21 UTC, Dmitry Olshansky 
wrote:

On 16-Sep-2015 09:44, nazriel wrote:
On Wednesday, 16 September 2015 at 05:54:03 UTC, Andrei 
Amatuni wrote:
maybe I'm doing something wrong...but the output of running 
the

default code snippet on the dlang.org homepage is:

"unable to fork: Cannot allocate memory"

not a good look


Thank you for letting us know,

This issue will be fixed very soon.

Best regards,
Damian Ziemba


May I suggest you to record such conditions with automatic 
notification e.g. by e-mail.


Only 1 in 10 of visitors will consider reporting an issue, of 
these only 1 in 10 will get to dlang forum to post a message.


well now I feel special :)

Re: running code on the homepage

[nazriel via Digitalmars-d]

On Wednesday, 16 September 2015 at 10:17:21 UTC, Dmitry Olshansky 
wrote:

On 16-Sep-2015 09:44, nazriel wrote:
On Wednesday, 16 September 2015 at 05:54:03 UTC, Andrei 
Amatuni wrote:
maybe I'm doing something wrong...but the output of running 
the

default code snippet on the dlang.org homepage is:

"unable to fork: Cannot allocate memory"

not a good look


Thank you for letting us know,

This issue will be fixed very soon.

Best regards,
Damian Ziemba


May I suggest you to record such conditions with automatic 
notification e.g. by e-mail.


Only 1 in 10 of visitors will consider reporting an issue, of 
these only 1 in 10 will get to dlang forum to post a message.


It is know for me issue.

At the time I was working on runable examples, samples on the 
main page were way simpler.
Not we are hitting some limitations of Container Dpaste's backend 
is running in.


I am working on new version of backend (and new container) as we 
speak so it will be solved once and for all.


1-2 days more and we will be done with it so IMHO no need take 
any additionals steps for it right now.

Re: Another, is it a bug?

[Kagamin via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 13:18:51 UTC, Meta wrote:
It's the exact same as in Java, and probably C# as well. I 
don't know if there's any OOP language that overloads methods 
between the base and super class.


https://ideone.com/En5JEc


https://ideone.com/aIIrKM No, there's nothing like that in Java 
and C#.

reggae v0.5.0: new features in the D meta-build system

[Atila Neves via Digitalmars-d-announce]

http://code.dlang.org/my_packages/reggae

What's new:
. API changes: main high-level rules are now called objectFiles, 
link, and scriptlike
. Optional top-level targets: aren't built by default but can be 
built on request

. Phony targets
. staticLibrary rule that does what it says
. unityBuild rule for C/C++ projects that builds a binary as one 
translation unit to speed up compilation
. Support for writing build descriptions in Python, Ruby, Lua and 
JavaScript


That last one might cause scratchy head syndrome. Why would I 
want to enable writing builds in a language other than D? Here's 
why:


1. Interpreting a build description is faster than compiling, 
linking and running it. Not a big deal since the build 
description isn't read often, but it's true
2. No confusion about when to use `enum` and when to use `alias`. 
Again, probably wasn't catching anybody unawares but also true
3. Not having to install a D compiler in order to generate builds 
- I ran into this issue at work the other day trying to use 
reggae on a weird VM with no root access

4. More importantly... to not limit reggae to only D developers

There are quite a few build systems / tools out there in which 
different languages are used. Almost all of them are only used by 
developers of their language niche: Ruby/Rake, Python/SCons/Waf, 
Groovy/Java/Gradle, Haskell/Shake, etc. This is my attempt to 
make reggae appeal to a wider audience.


I wanted to add a Lisp too but then I'd have to pick a dialect 
and an implemetation, only to annoy fans of other dialects. I 
might just do Emacs Lisp to annoy everyone equally! Also, for the 
lulz.


Atila

"if sting in string"

[smadus via Digitalmars-d-learn]

Hello

Searching after hours, i give up and here is the question. ;)

I will make a programm, this searching all txt files on the 
system or the path from user and searching a user tiped term in 
this file.


http://dpaste.dzfl.pl/dec09a0f849c

The Problem is in the if() "line 17" i searching in 
std.algorithm, but i dont find a solution for my problem.


i hope, someone can help me.

I'm new on D and sorry for my bad english.

Happy Greetings

Shorty

Re: "if sting in string"

[Rikki Cattermole via Digitalmars-d-learn]

On 17/09/15 12:55 AM, smadus wrote:

Hello

Searching after hours, i give up and here is the question. ;)

I will make a programm, this searching all txt files on the system or
the path from user and searching a user tiped term in this file.

http://dpaste.dzfl.pl/dec09a0f849c

The Problem is in the if() "line 17" i searching in std.algorithm, but i
dont find a solution for my problem.

i hope, someone can help me.

I'm new on D and sorry for my bad english.

Happy Greetings

Shorty


Highly inefficient design in code, but lets ignore that.

You want std.string : indexOf.

if (line.indexOf(term) >= 0) {

If I remember correctly.

[Issue 15071] filenames and module names with case-insensitive HFS+

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15071

--- Comment #2 from John Colvin  ---
(In reply to Sobirari Muhomori from comment #1)
> From spec:
> ---
> By convention, package and module names are all lower case. This is because
> those names can have a one-to-one correspondence with the operating system's
> directory and file names, and many file systems are not case sensitive. All
> lower case package and module names will minimize problems moving projects
> between dissimilar file systems.
> ---
> 
> Also D is case sensitive, so you can't change identifier case and expect it
> to work.

I don't expect it to work, but I do expect it to fail with a clear error
message before link-time.

--

Re: "if sting in string"

[cym13 via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 12:55:13 UTC, smadus wrote:

Hello

Searching after hours, i give up and here is the question. ;)

I will make a programm, this searching all txt files on the 
system or the path from user and searching a user tiped term in 
this file.


http://dpaste.dzfl.pl/dec09a0f849c

The Problem is in the if() "line 17" i searching in 
std.algorithm, but i dont find a solution for my problem.


i hope, someone can help me.

I'm new on D and sorry for my bad english.

Happy Greetings

Shorty


Turn it into either:

if (canFind(line, term)) {...

or

if (line.canFind(term)) {...

(they are equivalent)

This mistake seems odd, is D your first programming language?

[Issue 15073] SIGRTMIN is an alias to a private function

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15073

--- Comment #1 from Tomer Filiba  ---
Sent a pull request:
https://github.com/D-Programming-Language/druntime/pull/1386

--

Re: dpaste web site

[nazriel via Digitalmars-d]

On Wednesday, 16 September 2015 at 06:52:57 UTC, Ola Fosheim 
Grøstad wrote:

How about just using a single click recaptcha:

https://www.google.com/recaptcha/intro/index.html


Used that before - still was getting spam.

As Vladimir mentioned - it costs 0.001$ to get Captcha solved :)

Re: dpaste web site

[Andrea Fontana via Digitalmars-d]

On Wednesday, 16 September 2015 at 13:46:07 UTC, nazriel wrote:
On Wednesday, 16 September 2015 at 06:52:57 UTC, Ola Fosheim 
Grøstad wrote:

How about just using a single click recaptcha:

https://www.google.com/recaptcha/intro/index.html


Used that before - still was getting spam.

As Vladimir mentioned - it costs 0.001$ to get Captcha solved :)


Why don't you try to check some stats over post?

I mean: to check some frequencies of common d keywords/combo like 
"class", "struct", "int", "float", "if(" "while(", "(int ", 
"(float ", etc that are not common in plain english used by 
spammers...

Re: dmd codegen improvements

[Bruno Medeiros via Digitalmars-d]

On 28/08/2015 22:59, Walter Bright wrote:

People told me I couldn't write a C compiler, then told me I couldn't
write a C++ compiler. I'm still the only person who has ever implemented
a complete C++ compiler (C++98). Then they all (100%) laughed at me for
starting D, saying nobody would ever use it.

My whole career is built on stepping over people who told me I couldn't
do anything and wouldn't amount to anything.


So your whole career is fundamentally based not on bringing value to the 
software world, but rather merely proving people wrong? That amounts to 
living your professional life in thrall of other people's validation, 
and it's not commendable at all. It's a waste of your potential.


It is only worthwhile to prove people wrong when it brings you a 
considerable amount of either monetary resources or clout - and more so 
than you would have got doing something else with your time.


It's not clear to me that was always the case throughout your career... 
was it?


--
Bruno Medeiros
https://twitter.com/brunodomedeiros

Re: Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 10:31:58 UTC, Idan Arye wrote:
What's wrong with two `open()`s in a row? Each will return a 
new file handle.


Yes, but if you do it by mistake then you don't get the compiler 
to check that you call close() on both. I should have written 
"what if you forget close()". Will the compiler then complain at 
compile time?


You can't make that happen with just move semantics, you need 
linear typing so that every resource created are consumed exactly 
once.

Re: any way to initialize an array of structs to void?

[Meta via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 14:51:51 UTC, ref2401 wrote:

On Wednesday, 16 September 2015 at 14:48:59 UTC, Meta wrote:

Don't do this with a dynamic array, though, as they work a bit 
differently from static arrays.


Unfortunately I have to deal with dynamic arrays.


In that case, you can use std.array.uninitializedArray or 
std.array.minimallyInitializedArray as needed.


http://dlang.org/phobos/std_array.html#uninitializedArray
http://dlang.org/phobos/std_array.html#.minimallyInitializedArray

Re: Implement the "unum" representation in D ?

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 08:38:25 UTC, deadalnix wrote:
The energy comparison is bullshit. As long as you haven't 
loaded the data, you don't know how wide they are. Meaning you 
need either to go pessimistic and load for the worst case 
scenario or do 2 round trip to memory.


That really depends on memory layout and algorithm. A likely 
implementation would be a co-processor that would take a unum 
stream and then pipe it through a network of cores (tile based 
co-processor). The internal busses between cores are very very 
fast and with 256+ cores you get tremendous throughput. But you 
need a good compiler/libraries and software support.


The hardware is likely to be slower as you'll need way more 
wiring than for regular floats, and wire is not only cost, but 
also time.


You need more transistors per ALU, but slower does not matter if 
the algorithm needs bounded accuracy or if it converge more 
quickly with unums.  The key challenge for him is to create a 
market, meaning getting the semantics into scientific software 
and getting initial workable implementations out to scientists.


If there is a market demand, then there will be products. But you 
need to create the market first. Hence he wrote an easy to read 
book on the topic and support people who want to implement it.

Re: any way to initialize an array of structs to void?

[ref2401 via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 14:48:59 UTC, Meta wrote:

Don't do this with a dynamic array, though, as they work a bit 
differently from static arrays.


Unfortunately I have to deal with dynamic arrays.

Re: dmd codegen improvements

[Bruno Medeiros via Digitalmars-d]

On 02/09/2015 19:58, Walter Bright wrote:

On 8/29/2015 12:37 PM, Laeeth Isharc wrote:

In my experience you can deliver
everything people say they want, and then find it isn't that at all.


That's so true. My favorite anecdote on that was back in the 1990's. A
friend of mine said that what he and the world really needs was a Java
native compiler. It'd be worth a fortune!

I told him that I had that idea a while back, and had implemented one
for Symantec. I could get him a copy that day.

He changed the subject.

I have many, many similar stories.

I also have many complementary stories - implementing things that people
laugh at me for doing, that turn out to be crucial. We can start with
the laundry list of D features that C++ is rushing to adopt :-)



Yes, and this I think is demonstrative of a very important 
consideration: if someone says they want X (and they are not paying 
upfront for it), then it is crucial for *you* to be able to figure out 
if that person or group actually wants X or not.


If someone spends time building a product or feature that turns out 
people don't want... the failure is on that someone.



And on this aspect I think the development of D does very poorly. Often 
people clamored for a feature or change (whether people in the D 
community, or the C++ one), and Walter you went ahead and did it, 
regardless of whether it will actually increase D usage in the long run. 
You are prone to this, given your nature to please people who ask for 
things, or to prove people wrong (as you yourself admitted).


I apologize for not remembering any example at the moment, but I know 
there was quite a few, especially many years back. It usually went like 
this:


C++ community guy: "D is crap, it's not gonna be used without X"
*some time later*
Walter: "Ok, I've now implemented X in D!"
the same C++ community guy: either finds another feature or change to 
complain about (repeat), or goes silent, or goes "meh, D is still not good"
Me and other people from D community: "ok... now we have a new 
half-baked functionality in D, adding complexity for little value, and 
put here only to please people that are extremely unlikely to ever be 
using D whatever any case"...



--
Bruno Medeiros
https://twitter.com/brunodomedeiros

any way to initialize an array of structs to void?

[ref2401 via Digitalmars-d-learn]

struct MyStruct {
@disable this();

this(int a, string b) {
this.a = a;
this.b = b;
}

int a;
string b;
}

I know there is a way to create one instance of `MyStruct` and 
initialize it to void.

  MyStruct s = void;
  s = MyStruct(5, "abcdef");

How can initialize an array of `MyStruct` instances to void?
  auto arr = new MyStruct[10]; // compile-time Error: default 
construction is disabled for type MyStruct.

Re: any way to initialize an array of structs to void?

[ref2401 via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 14:57:49 UTC, Meta wrote:


In that case, you can use std.array.uninitializedArray or 
std.array.minimallyInitializedArray as needed.


http://dlang.org/phobos/std_array.html#uninitializedArray
http://dlang.org/phobos/std_array.html#.minimallyInitializedArray


Thanks)

Weird "circular initialization of isInputRange" error

[Alex Parrill via Digitalmars-d]

This piece of code (which I reduced with dustmite) gives me the 
following error when I try to compile it:


$ rdmd -main parser.d parser.d(28): Error: circular 
initialization of isInputRange
parser.d(31): Error: template instance 
std.meta.staticMap!(handler, ArrayReader*) error instantiating
parser.d(36):instantiated from here: 
unpacker!(RefRange!(immutable(ubyte)[]))
parser.d(40): Error: template instance 
std.range.primitives.isInputRange!(ArrayReader*) error 
instantiating
/usr/include/dmd/phobos/std/meta.d(546):instantiated 
from here: F!(ArrayReader*)
parser.d(43):instantiated from here: staticMap!(toTD, 
ArrayReader*)

Failed: ["dmd", "-main", "-v", "-o-", "parser.d", "-I."]


I'm not really sure what's causing the error; I'm not declaring 
`isInputRange` in my code. Commenting out the definition of `TD` 
(the very last line) removes the error. Am I doing something 
wrong here, or is this a compiler bug?


Tested with dmd v2.068.1 on Linux x64

Code:
-

import std.range;
import std.variant;
import std.typetuple;

///
template unpacker(Range)
{
/// Element data types. See `unpack` for usage.
alias MsgPackData = Algebraic!(
ArrayReader*,
);


/// Reader range for arrays.
struct ArrayReader {
MsgPackData _front;
void update() {
_front.drain;
}

void popFront() {
update;
}
}

void drain(MsgPackData d) {
static handler(T)(T t) {
static if(isInputRange!T)
data;
}
d.visit!(staticMap!(handler, MsgPackData.AllowedTypes));
}
}


alias TestUnpacker = unpacker!(RefRange!(immutable(ubyte)[]));
alias D = TestUnpacker.MsgPackData;

template toTD(T) {
static if(isInputRange!T)
alias toTD = This;
}
alias TD = Algebraic!(staticMap!(toTD, D.AllowedTypes)); // 
test data type

[Issue 15074] New: std.path.globMatch and escaping [/]/{/}

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15074

  Issue ID: 15074
   Summary: std.path.globMatch and escaping [/]/{/}
   Product: D
   Version: D2
  Hardware: All
OS: All
Status: NEW
  Severity: enhancement
  Priority: P1
 Component: phobos
  Assignee: nob...@puremagic.com
  Reporter: thecybersha...@gmail.com
CC: bugzi...@kyllingen.net

The documentation for std.path.globMatch says:

> Some characters of pattern have a special meaning (they are meta-characters)
> and *can't be escaped*.

In practice, this appears to be almost false. For * and ?, this can be done by
"escaping" them using [*] and [?]. '[' should be escape-able as "[[]", and ']'
shouldn't need to be escaped at all, except when in a [...] group, in which it
could be escaped as "{[...],]}". The only case where I don't see a solution is
escaping ']' in a [!...] group.

Anyway, attempting to escape either [/]/{/} results in:

core.exception.AssertError@std\path.d(3002): Assertion failure

The source of the unexplained assert is the function's contract:

in
{
// Verify that pattern[] is valid
import std.algorithm : balancedParens;
assert(balancedParens(pattern, '[', ']', 0));
assert(balancedParens(pattern, '{', '}', 0));
}

Two ways about this:

1) Remove this restriction, and instead improve the implementation to treat
unterminated groups during actual parsing as either an error, or implicitly
closed at the end of the pattern. Perhaps also add the above escaping tricks to
the documentation.

2) Declare that any use case complicated enough that you need to escape
meta-characters is a use case for std.regex, not std.path, and simply improve
the assert statement to produce a meaningful error message.

--

Re: Another, is it a bug?

[Meta via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 14:08:11 UTC, Kagamin wrote:

On Wednesday, 16 September 2015 at 13:18:51 UTC, Meta wrote:
It's the exact same as in Java, and probably C# as well. I 
don't know if there's any OOP language that overloads methods 
between the base and super class.


https://ideone.com/En5JEc


https://ideone.com/aIIrKM No, there's nothing like that in Java 
and C#.


Oh, whoops, you're right; I forgot to extend Test. My mistake.

Re: any way to initialize an array of structs to void?

[Meta via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 14:45:06 UTC, ref2401 wrote:

struct MyStruct {
@disable this();

this(int a, string b) {
this.a = a;
this.b = b;
}

int a;
string b;
}

I know there is a way to create one instance of `MyStruct` and 
initialize it to void.

  MyStruct s = void;
  s = MyStruct(5, "abcdef");

How can initialize an array of `MyStruct` instances to void?
  auto arr = new MyStruct[10]; // compile-time Error: default 
construction is disabled for type MyStruct.


MyStruct[10] arr = void;

Don't do this with a dynamic array, though, as they work a bit 
differently from static arrays.

Re: No -v or -deps for gdc?

[Atila Neves via Digitalmars-d-learn]

On Tuesday, 15 September 2015 at 18:12:56 UTC, Johannes Pfau 
wrote:

Am Tue, 15 Sep 2015 12:19:34 +
schrieb Atila Neves :

gdmd supports those options but gdc doesn't. Is that likely to 
always be the case?


Atila


gdmd is just a wrapper around gdc. If something is supported by 
gdmd it must also be supported by gdc (the exact switch names 
might differ).


See: 
https://github.com/D-Programming-GDC/GDMD/blob/master/dmd-script


Seems like -v maps to -fd-verbose and -deps to -fdeps.


Ah cool, thanks!

Atila

Re: reggae v0.5.0: new features in the D meta-build system

[Leandro Motta Barros via Digitalmars-d-announce]

This link should work for everyone: http://code.dlang.org/packages/reggae

(I never tried reggae. Maybe I should, it looks good.)

LMB


On Wed, Sep 16, 2015 at 11:07 AM, Atila Neves via Digitalmars-d-announce <
digitalmars-d-announce@puremagic.com> wrote:

> http://code.dlang.org/my_packages/reggae
>
> What's new:
> . API changes: main high-level rules are now called objectFiles, link, and
> scriptlike
> . Optional top-level targets: aren't built by default but can be built on
> request
> . Phony targets
> . staticLibrary rule that does what it says
> . unityBuild rule for C/C++ projects that builds a binary as one
> translation unit to speed up compilation
> . Support for writing build descriptions in Python, Ruby, Lua and
> JavaScript
>
> That last one might cause scratchy head syndrome. Why would I want to
> enable writing builds in a language other than D? Here's why:
>
> 1. Interpreting a build description is faster than compiling, linking and
> running it. Not a big deal since the build description isn't read often,
> but it's true
> 2. No confusion about when to use `enum` and when to use `alias`. Again,
> probably wasn't catching anybody unawares but also true
> 3. Not having to install a D compiler in order to generate builds - I ran
> into this issue at work the other day trying to use reggae on a weird VM
> with no root access
> 4. More importantly... to not limit reggae to only D developers
>
> There are quite a few build systems / tools out there in which different
> languages are used. Almost all of them are only used by developers of their
> language niche: Ruby/Rake, Python/SCons/Waf, Groovy/Java/Gradle,
> Haskell/Shake, etc. This is my attempt to make reggae appeal to a wider
> audience.
>
> I wanted to add a Lisp too but then I'd have to pick a dialect and an
> implemetation, only to annoy fans of other dialects. I might just do Emacs
> Lisp to annoy everyone equally! Also, for the lulz.
>
> Atila
>

Re: dmd codegen improvements

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 14:40:26 UTC, Bruno Medeiros 
wrote:
Me and other people from D community: "ok... now we have a new 
half-baked functionality in D, adding complexity for little 
value, and put here only to please people that are extremely 
unlikely to ever be using D whatever any case"...


D is fun for prototyping ideas, so yes half-baked and not stable, 
but still useful.


I'm waiting for Rust to head down the same lane of adding 
features and obfuscating the syntax (and their starting point is 
even more complex than D's was)...

Re: Implementing typestate

[Idan Arye via Digitalmars-d]

On Wednesday, 16 September 2015 at 14:34:05 UTC, Ola Fosheim 
Grøstad wrote:
On Wednesday, 16 September 2015 at 10:31:58 UTC, Idan Arye 
wrote:
What's wrong with two `open()`s in a row? Each will return a 
new file handle.


Yes, but if you do it by mistake then you don't get the 
compiler to check that you call close() on both. I should have 
written "what if you forget close()". Will the compiler then 
complain at compile time?


You can't make that happen with just move semantics, you need 
linear typing so that every resource created are consumed 
exactly once.


Move semantics should be enough. We can declare the destructor 
private, and then any code outside the module that implicitly 
calls the d'tor when the variable goes out of scope will raise a 
compilation error. In order to "get rid" of the variable, you'll 
have to pass ownership to the `close` function, so your code 
won't try to implicitly call the d'tor.

Re: How do I change debug mode with dub?

[Alex_Freeman via Digitalmars-d-learn]

On Wednesday, 16 September 2015 at 12:04:38 UTC, Gary Willoughby 
wrote:
On Wednesday, 16 September 2015 at 10:42:13 UTC, Alex_Freeman 
wrote:
Hey all! I'm just wondering how to run dub with different 
debug versions, or running it with different versions 
generally? Is there also a way to have code behind multiple 
debug versions, or run more than one debug version at once?


Thanks!


There's lots of useful information here:
http://code.dlang.org/package-format?lang=json


Thanks for the link!

I got it working with adding
"debugVersions": ["whatever","I","want"]
to my dub.json file :)

Thrift

[ddos via Digitalmars-d-learn]

Looking for a RPC library, thrift looked promising, but i can't 
even compile the simple example given here 
https://thrift.apache.org/tutorial/d


to compile i've
1. copied the thrift/lib/d/src/thrift folder to my source 
directory
2. copied the generated sources ( tutorial and share folder ) 
into my source directory
3. compiling with dub and dmd 66 ( ive also tried 68 before with 
the same result )


dub.json: http://pastebin.com/pQSsCUAd
compiling errors: http://pastebin.com/qp02S1EW

please help if you know how to get a simple example with d & 
thrift running

thx, dominik

Re: GC performance: collection frequency

[H. S. Teoh via Digitalmars-d]

On Tue, Sep 15, 2015 at 07:08:01AM +0200, Daniel Kozák via Digitalmars-d wrote:
> 
> http://dlang.org/changelog/2.067.0.html#gc-options
[...]

Wow that is obscure.  This really needs to go into the main docs so
that it can actually be found...


T

-- 
People demand freedom of speech to make up for the freedom of thought which 
they avoid. -- Soren Aabye Kierkegaard (1813-1855)

Re: Implementing typestate

[Marc Schütz via Digitalmars-d]

On Tuesday, 15 September 2015 at 21:44:25 UTC, Freddy wrote:

On Tuesday, 15 September 2015 at 17:45:45 UTC, Freddy wrote:

 Rust style memory management in a library


Wait nevermind about that part, it's harder than I thought.


Yeah, I thought about type-states as a way of implementing 
borrowing, too. I think the biggest difficulty is that the state 
of one object (the owner) can be affected by what happens in 
other objects (i.e., it becomes mutable again when those are 
destroyed).

Re: Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 15:34:40 UTC, Idan Arye wrote:
Move semantics should be enough. We can declare the destructor 
private, and then any code outside the module that implicitly 
calls the d'tor when the variable goes out of scope will raise 
a compilation error. In order to "get rid" of the variable, 
you'll have to pass ownership to the `close` function, so your 
code won't try to implicitly call the d'tor.


Sounds plausible, but does this work in C++ and D? I assume you 
mean that you "reinterpret_cast" to a different type in the 
close() function, which is cheating, but ok :).

Re: reggae v0.5.0: new features in the D meta-build system

[Kagamin via Digitalmars-d-announce]

Ruby link points to reggae-python.

Re: Creating a DLL with a ActiveX interface.

[Taylor Hillegeist via Digitalmars-d-learn]

On Monday, 14 September 2015 at 16:59:20 UTC, Adam D. Ruppe wrote:
On Monday, 14 September 2015 at 15:44:36 UTC, Taylor Hillegeist 
wrote:
So, Actually I am using NI LabVIEW to interact with my DLL. I 
imagine even getting hold of of that would troublesome or 
expensive.


Ah, all right. Here's a SO thing (followed up by email then


Fortunately I am working with Win7, And the below function seems 
to work beautifully.


export extern (Windows) void SayHello(Variant *Input_Variant)
{
string A = "HELLO WORLD!";
Input_Variant.CA_VariantSetCString(A.ptr);
}

My goal was to store variants in an associative array 
Variant[string] and use this as a portable interpreter returning 
the resulting Variant.


but that runs into some memory questions that I am not as savvy 
with.


1. Memory:
I need to manage memory from the dll. I can give the caller a 
pointer to manage, but I don't think that is visible from gc. 
There should be different associtive arrays for different objects 
in the caller. How do I manage this?


2. Threads:
I would like this to be as parallel as possible one objects call 
to its data should not hinder anothers.


I have seen on the Memory managment page 
http://wiki.dlang.org/Win32_DLLs_in_D  but I would like to know 
more.

Re: dpaste web site

[John Colvin via Digitalmars-d]

On Wednesday, 16 September 2015 at 16:12:03 UTC, Kagamin wrote:
On Wednesday, 16 September 2015 at 13:54:36 UTC, Andrea Fontana 
wrote:
I mean: to check some frequencies of common d keywords/combo 
like "class", "struct", "int", "float", "if(" "while(", "(int 
", "(float ", etc that are not common in plain english used by 
spammers...


Solving dcaptcha costs maybe 1$, so it should solve the problem 
of human spammers (too expensive).


I dunno, I reckon I could solve them in ~5 seconds each, 
especially with practice... At $1/solve it'd be one hell of an 
hourly rate!

Re: Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 16:24:49 UTC, Idan Arye wrote:
No need for `reinterpret_cast`. The `close` function is 
declared in the same module as the `File` struct, so it has 
access to it's private d'tor.


True, so it might work for D. Interesting.

Re: dpaste web site

[Kagamin via Digitalmars-d]

On Wednesday, 16 September 2015 at 13:54:36 UTC, Andrea Fontana 
wrote:
I mean: to check some frequencies of common d keywords/combo 
like "class", "struct", "int", "float", "if(" "while(", "(int 
", "(float ", etc that are not common in plain english used by 
spammers...


Solving dcaptcha costs maybe 1$, so it should solve the problem 
of human spammers (too expensive).

Re: Implementing typestate

[Idan Arye via Digitalmars-d]

On Wednesday, 16 September 2015 at 15:57:14 UTC, Ola Fosheim 
Grøstad wrote:
On Wednesday, 16 September 2015 at 15:34:40 UTC, Idan Arye 
wrote:
Move semantics should be enough. We can declare the destructor 
private, and then any code outside the module that implicitly 
calls the d'tor when the variable goes out of scope will raise 
a compilation error. In order to "get rid" of the variable, 
you'll have to pass ownership to the `close` function, so your 
code won't try to implicitly call the d'tor.


Sounds plausible, but does this work in C++ and D? I assume you 
mean that you "reinterpret_cast" to a different type in the 
close() function, which is cheating, but ok :).


No need for `reinterpret_cast`. The `close` function is declared 
in the same module as the `File` struct, so it has access to it's 
private d'tor.

Re: Best Direction on Spawning Process Async

[Mike McKee via Digitalmars-d-learn]

Beautiful, Ali. Took me a bit to read here...

http://dlang.org/phobos/std_concurrency.html

...but I realized that receiveTimeout() was a std.concurrency 
class method.

Re: Best Direction on Spawning Process Async

[Mike McKee via Digitalmars-d-learn]

This really shows the beauty and simplicity of the D language 
compared to C++. Check this out in Qt/C++:


http://stackoverflow.com/questions/32593463/spawn-async-qprocess-from-dynamic-library-peek-output-until-done

...see how much nicer the D version is here that Ali did, versus 
the Qt/C++ technique.

Re: Implement the "unum" representation in D ?

[Timon Gehr via Digitalmars-d]

On 09/16/2015 10:17 AM, Don wrote:


So:
...
* There is no guarantee that it would be possible to implement it in
hardware without a speed penalty, regardless of how many transistors you
throw at it (hardware analogue of Amdahl's Law)


https://en.wikipedia.org/wiki/Gustafson's_law :o)

Re: Overview of D User Groups?

[Ali Çehreli via Digitalmars-d]

On 09/16/2015 11:56 AM, qznc wrote:

Is there an overview of D user groups somewhere?

There is one in Berlin and one in the Valley, apparently. Walter
participates in the Cpp group in Seattle or something, if I remember
correctly.


If a Meetup group happens to list the right keywords (topics?) then it 
shows up on this map:


  http://dpl.meetup.com/

Ali

Re: Runtime error when calling a callback in a parallel Task

[Ali Çehreli via Digitalmars-d-learn]

On 09/15/2015 04:49 PM, BBasile wrote:

Under Windows this works fine but under Linux I got a runtime error.


Can it be because 'param' is invalid at the time clbck is called? The 
following program works under Linux. However, removing thread_joinAll() 
is a bug:


import std.parallelism;
import std.stdio;

alias CallBack = void function(void*);

class Foo
{
CallBack clbck;
void* param;
void dotask()
{
// some heavy processing
// tells the caller that some fresh data are available
if(clbck) clbck(param);  // debugger breaks HERE
}

void call()
{
task().executeInNewThread;
// returns directly but the caller will get a notif when finished
}
}

void handler(void* p)
{
writefln("Finishing with %s at %s", *(cast(int*)p), p);
}

void main()
{
auto foo = new Foo();
foo.clbck = 
int i = 42;
foo.param = 
foo.call();

import core.thread;
thread_joinAll();
}

Ali

Re: Implement the "unum" representation in D ?

[deadalnix via Digitalmars-d]

On Wednesday, 16 September 2015 at 14:11:04 UTC, Ola Fosheim 
Grøstad wrote:
On Wednesday, 16 September 2015 at 08:38:25 UTC, deadalnix 
wrote:
The energy comparison is bullshit. As long as you haven't 
loaded the data, you don't know how wide they are. Meaning you 
need either to go pessimistic and load for the worst case 
scenario or do 2 round trip to memory.


That really depends on memory layout and algorithm. A likely 
implementation would be a co-processor that would take a unum 
stream and then pipe it through a network of cores (tile based 
co-processor). The internal busses between cores are very very 
fast and with 256+ cores you get tremendous throughput. But you 
need a good compiler/libraries and software support.




No you don't. Because the streamer still need to load the unum 
one by one. Maybe 2 by 2 with a fair amount of hardware 
speculation (which means you are already trading energy for 
performances, so the energy argument is weak). There is no way 
you can feed 256+ cores that way.


To gives you a similar example, x86 decoding is often the 
bottleneck on an x86 CPU. The number of ALUs in x86 over the past 
decade decreased rather than increased, because you simply can't 
decode fast enough to feed them. Yet, x86 CPUs have a 64 ways 
speculative decoding as a first stage.


The hardware is likely to be slower as you'll need way more 
wiring than for regular floats, and wire is not only cost, but 
also time.


You need more transistors per ALU, but slower does not matter 
if the algorithm needs bounded accuracy or if it converge more 
quickly with unums.  The key challenge for him is to create a 
market, meaning getting the semantics into scientific software 
and getting initial workable implementations out to scientists.


If there is a market demand, then there will be products. But 
you need to create the market first. Hence he wrote an easy to 
read book on the topic and support people who want to implement 
it.


The problem is not transistor it is wire. Because the damn thing 
is variadic in every ways, pretty much every bit as input can end 
up anywhere in the functional unit. That is a LOT of wire.

LDC 0.16.0 alpha3 is out! Get it, test it, give feedback!

[Kai Nacke via Digitalmars-d-announce]

Hi everyone,

LDC 0.16.0 alpha3, the LLVM-based D compiler, is available for 
download!
This release is based on the 2.067.1 frontend and standard 
library and supports LLVM 3.1-3.7 (OS X: no support for 3.3).


Don't miss to check if your preferred system is supported by this 
release. There is even an alpha-quality Win64 version available!


As usual, you can find links to the changelog and the binary 
packages over at digitalmars.D.ldc:

http://forum.dlang.org/post/numjnaginhfmocbqg...@forum.dlang.org

Regards,
Kai

Re: Implement the "unum" representation in D ?

[deadalnix via Digitalmars-d]

On Wednesday, 16 September 2015 at 19:40:49 UTC, Ola Fosheim 
Grøstad wrote:
You can load continuously 64 bytes in a stream, decode to your 
internal format and push them into the scratchpad of other 
cores. You could even do this in hardware.




1/ If you load the worst case scenario, then your power advantage 
is gone.
2/ If you load these one by one, how do you expect to feed 256+ 
cores ?


Obviously you can make this in hardware. And obviously this is 
not going to be able to feed 256+ cores. Even with a chip at low 
frequency, let's say 800MHz or so, you have about 80 cycles to 
access memory. That mean you need to have 20 000+ cycles of work 
to do per core per unum.


That simple back of the envelope calculation. Your proposal is 
simply ludicrous. It's a complete non starter.


You can make this in hardware. Sure you can, no problem. But you 
won't because it is a stupid idea.


To gives you a similar example, x86 decoding is often the 
bottleneck on an x86 CPU. The number of ALUs in x86 over the 
past decade decreased rather than increased, because you 
simply can't decode fast enough to feed them. Yet, x86 CPUs 
have a 64 ways speculative decoding as a first stage.


That's because we use a dumb compiler that does not prefetch 
intelligently.


You know, when you have no idea what you are talking about, you 
can just move on to something you understand.


Prefetching would not change anything here. The problem come from 
variable size encoding, and the challenge it causes for hardware. 
You can have 100% L1 hit and still have the same problem.


No sufficiently smart compiler can fix that.

If you are writing for a tile based VLIW CPU you preload. These 
calculations are highly iterative so I'd rather think of it as 
a co-processor solving a single equation repeatedly than 
running the whole program. You can run the larger program on a 
regular CPU or a few cores.




That's irrelevant. The problem is not the kind of CPU, it is how 
do you feed it at a fast enough rate.


The problem is not transistor it is wire. Because the damn 
thing is variadic in every ways, pretty much every bit as 
input can end up anywhere in the functional unit. That is a 
LOT of wire.


I haven't seen a design, so I cannot comment. But keep in mind 
that the CPU does not have to work with the format, it can use 
a different format internally.


We'll probably see FPGA implementations that can be run on FPGU 
cards for PCs within a few years. I read somewhere that a group 
in Singapore was working on it.


That's hardware 101.

When you have a floating point unit, you get your 32 bits you get 
23 bits that go into the mantissa FU and 8 in the exponent FU. 
For instance, if you multiply floats, you send the 2 exponent 
into a adder, you send the 2 mantissa into a 24bits multiplier 
(you add a leading 1), you xor the bit signs.


You get the carry from the adder, and emit a multiply, or you 
count the leading 0 of the 48bit multiply result, shift by that 
amount and add the shit to the exponent.


If you get a carry in the exponent adder, you saturate and emit 
an inifinity.


Each bit goes into a given functional unit. That mean you need on 
wire from the input to the functional unit is goes to. Sale for 
these result.


Now, if the format is variadic, you need to wire all bits to all 
functional units, because they can potentially end up there. 
That's a lot of wire, in fact the number of wire is growing 
quadratically with that joke.


The author keep repeating that wire became the expensive thing 
and he is right. Meaning a solution with quadratic wiring is not 
going to cut it.

Re: Implement the "unum" representation in D ?

[jmh530 via Digitalmars-d]

On Wednesday, 16 September 2015 at 08:38:25 UTC, deadalnix wrote:


Also, predictable size mean you can split your dataset and 
process it in parallel, which is impossible if sizes are random.


I don't recall how he would deal with something similar to cache 
misses when you have to promote or demote a unum. However, my 
recollection of the book is that there was quite a bit of focus 
on a unum representation that has the same size as a double. If 
you only did the computations with this format, I would expect 
the sizes would be more-or-less fixed. Promotion would be pretty 
rare, but still possible, I would think.


Compared to calculations with doubles there might not be a strong 
case for energy efficiency (but I don't really know for sure). My 
understanding was that the benefit for energy efficiency is only 
when you use a smaller sized unum instead of a float. I don't 
recall how he would resolve your point about cache misses.


Anyway, while I can see a benefit from using unum numbers 
(accuracy, avoiding overflow, etc.) rather than floating point 
numbers, I think that performance or energy efficiency would have 
to be within range of floating point numbers for it to have any 
meaningful adoption.

Silicon Valley D Meetup September 2015

[Ali Çehreli via Digitalmars-d-announce]

"Introducing ultraviolet-d, a web framework for REST-ful services"

  http://www.meetup.com/D-Lang-Silicon-Valley/events/224948581/

Ali

Re: Release D 2.068.1

[Martin Nowak via Digitalmars-d-announce]

On Tuesday, 15 September 2015 at 08:39:43 UTC, John Colvin wrote:
Where is the VERSION file documented? Why does it need manual 
intervention only for patch releases and pre-releases?


We should prolly remove the manually updated VERSION file.
The other build scripts update the file or pass VERSION=bla to 
make.

Overview of D User Groups?

[qznc via Digitalmars-d]

Is there an overview of D user groups somewhere?

There is one in Berlin and one in the Valley, apparently. Walter 
participates in the Cpp group in Seattle or something, if I 
remember correctly.

Re: Implement the "unum" representation in D ?

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 19:21:59 UTC, deadalnix wrote:
No you don't. Because the streamer still need to load the unum 
one by one. Maybe 2 by 2 with a fair amount of hardware 
speculation (which means you are already trading energy for 
performances, so the energy argument is weak). There is no way 
you can feed 256+ cores that way.


You can load continuously 64 bytes in a stream, decode to your 
internal format and push them into the scratchpad of other cores. 
You could even do this in hardware.


If you look at the ubox brute forcing method you compute many 
calculations over the same data, because you solve spatially, not 
by timesteps. So you can run many many parallell computations 
over the same data.


To gives you a similar example, x86 decoding is often the 
bottleneck on an x86 CPU. The number of ALUs in x86 over the 
past decade decreased rather than increased, because you simply 
can't decode fast enough to feed them. Yet, x86 CPUs have a 64 
ways speculative decoding as a first stage.


That's because we use a dumb compiler that does not prefetch 
intelligently. If you are writing for a tile based VLIW CPU you 
preload. These calculations are highly iterative so I'd rather 
think of it as a co-processor solving a single equation 
repeatedly than running the whole program. You can run the larger 
program on a regular CPU or a few cores.


The problem is not transistor it is wire. Because the damn 
thing is variadic in every ways, pretty much every bit as input 
can end up anywhere in the functional unit. That is a LOT of 
wire.


I haven't seen a design, so I cannot comment. But keep in mind 
that the CPU does not have to work with the format, it can use a 
different format internally.


We'll probably see FPGA implementations that can be run on FPGU 
cards for PCs within a few years. I read somewhere that a group 
in Singapore was working on it.

Re: Implement the "unum" representation in D ?

[Timon Gehr via Digitalmars-d]

On 09/16/2015 10:46 AM, deadalnix wrote:

On Saturday, 11 July 2015 at 18:16:22 UTC, Timon Gehr wrote:

On 07/11/2015 05:07 PM, Andrei Alexandrescu wrote:

On 7/10/15 11:02 PM, Nick B wrote:

John Gustafson book is now out:

It can be found here:

http://www.amazon.com/End-Error-Computing-Chapman-Computational/dp/1482239868/ref=sr_1_1?s=books=UTF8=1436582956=1-1=John+Gustafson=1436583212284=093TDC82KFP9Y4S5PXPY




Very interesting, I'll read it. Thanks! -- Andrei



I think Walter should read chapter 5.


What is this chapter about ?


Relevant quote: "Programmers and users were never given visibility or 
control of when a value was promoted to “double extended precision” 
(80-bit or higher) format, unless they wrote assembly language; it just 
happened automatically, opportunistically, and unpredictably. Confusion 
caused by different results outweighed the advantage of reduced 
rounding-overflow-underflow problems, and now coprocessors must dumb 
down their results to mimic systems that have no such extra scratchpad 
capability."

Re: Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 18:01:29 UTC, Marc Schütz 
wrote:

typestate(alias owner) {
this.owner := owner; // re-alias operator
this.owner.refcount++;
}


I don't think this is possible to establish in the general case. 
Wouldn't this require a full theorem prover? I think the only way 
for that to work is to fully unroll all loops and hope that a 
theorem prover can deal with it. Either that or painstakingly 
construct a proof manually (Hoare logic).


Like, how can you statically determine if borrowed references  
stuffed into a queue are all released? To do that you must prove 
when the queue is empty for borrowed references from a specific 
object, but it could be interleaved with references to other 
objects.

Re: Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 16 September 2015 at 18:41:33 UTC, Ola Fosheim 
Grøstad wrote:
I don't think this is possible to establish in the general 
case. Wouldn't this require a full theorem prover? I think the 
only way for that to work is to fully unroll all loops and hope 
that a theorem prover can deal with it.


For example:

Object obj = create();

for ... {
  (Object obj, Ref r) = obj.borrow();
  queue.push(r);
  dostuff(queue);
}


On the other hand if you have this:

  for i=0..2 {
(Object obj, Ref r[i]) = obj.borrow();
dostuff(r);
  }

then you can unwind it as (hopefully):

  (Object obj, Ref r[0]) = 
obj.borrow();
  (Object obj, Ref r[1]) = 
obj.borrow();
  (Object obj, Ref r[2]) = 
obj.borrow();


  x += somepurefunction(r[0]);
  x += somepurefunction(r[1]);
  x += somepurefunction(r[2]);

  r[0].~this();  // r[0] proven unmodified, type is 
Ref

  r[1].~this();  // r[1] proven to be Ref
  r[2].~this(); // r[2] proven to be Ref
  r.~this();

If the lend IDs always are unique then you sometimes can prove 
that all constructors have a matching destructor...  Or something 
like that...


?

Re: Load Qt UI XML File as GUI

[Ali Çehreli via Digitalmars-d-learn]

On 09/15/2015 09:36 PM, Steven Schveighoffer wrote:

On 9/16/15 12:03 AM, Mike McKee wrote:

Unfortunately, the http://dsource.org/forums/ doesn't appear to be
active -- I can't login after I registered. This is where the QtD
project has their forum. So, I'm asking this here.


Seems to have moved here, but it doesn't look fresh:

https://bitbucket.org/qtd/

dsource is dead (only there for archive reasons), don't use it.

-Steve


I wonder why this older one exists:

  https://github.com/qtd-developers/qtd

Ali

Re: Implement the "unum" representation in D ?

[deadalnix via Digitalmars-d]

On Wednesday, 16 September 2015 at 21:12:11 UTC, Ola Fosheim 
Grøstad wrote:
On Wednesday, 16 September 2015 at 20:53:37 UTC, deadalnix 
wrote:
On Wednesday, 16 September 2015 at 20:30:36 UTC, Ola Fosheim 
Grøstad wrote:
On Wednesday, 16 September 2015 at 20:06:43 UTC, deadalnix 
wrote:
You know, when you have no idea what you are talking about, 
you can just move on to something you understand.


Ah, nice move. Back to your usual habits?



Stop


OK. I stop. You are beyond reason.


True, how blind I was. It is fairly obvious now, thinking about 
it, that you can get 3 order of magnitude increase in sequential 
decoding in hardware by having a compiler with a vectorized SSA 
and a scratchpad !


Or maybe you have number to present us that show I'm wrong ?

Desperately looking for a work-around to load and unload D shared libraries from C on OSX

[ponce via Digitalmars-d]

Context: On OSX, a C program can load a D shared library but once 
unloaded the next dlopen will crash, jumping into a callback that 
doesn't exist anymore.


I've filed it here: https://issues.dlang.org/show_bug.cgi?id=15060


It looks like this was known and discussed several times already:
http://forum.dlang.org/post/vixoqmidlbizawbxm...@forum.dlang.org 
(2015)

https://github.com/D-Programming-Language/druntime/pull/228 (2012)


Any idea to work-around this problem would be awesome.

I'm not looking for something correct, future-proof, or pretty. 
Any shit that still stick to the wall will do. Anything!


The only case I need to support is: C host, D shared library, 
with runtime statically linked.


Please help!

Re: Implement the "unum" representation in D ?

[Wyatt via Digitalmars-d]

On Wednesday, 16 September 2015 at 08:53:24 UTC, Ola Fosheim 
Grøstad wrote:


I don't think he is downplaying it. He has said that it will 
probably take at least 10 years before it is available in 
hardware. There is also a company called Rex Computing that are 
looking at unum:


Oh hey, I remember these jokers.  They were trying to blow some 
smoke about moving 288 GB/s at 4W.  They're looking at unum?  Of 
course they are; care to guess who's advising them?  Yep.


I'll be shocked if they ever even get to tape out.

-Wyatt