How to implement immutable ring buffer?
Could somebody share his thoughts on the subject? Would it be efficient? Is it possible to avoid memory copying to provide immutability? To avoid cache missing ring buffer should be like array, not list, so it's possible that the whole buffer should be moved. Is it neccessary to be real immutable, may be some form of fake immutabitiy is enough? I'd like to try immutability in my app, and ring buffer is what I don't know how to use in the realm of immutability. Thanks
Re: problem with gc?
On Wednesday, 27 May 2015 at 08:42:01 UTC, zhmt wrote: When I enable the --profle, get something like this, it doesnt give me too much help: [...] Tried callgrind and kcachegrind? If nothing else it's better at illustrating the same output, assuming you have graphviz/dot installed. Given --dump-instr you can also get instruction-level profiling if you're really wondering what's happening.
Re: problem with gc?
On Wednesday, 27 May 2015 at 09:39:42 UTC, Anonymouse wrote: On Wednesday, 27 May 2015 at 08:42:01 UTC, zhmt wrote: When I enable the --profle, get something like this, it doesnt give me too much help: [...] Tried callgrind and kcachegrind? If nothing else it's better at illustrating the same output, assuming you have graphviz/dot installed. Given --dump-instr you can also get instruction-level profiling if you're really wondering what's happening. @Anonymouse Thank u very much, I have tried this: valgrind --tool=callgrind ./gamelibdtest callgrind_annotate callgrind.out.29234 Ir file:function 124,918,002 ???:_D9invariant12_d_invariantFC6ObjectZv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 27,235,809 ???:_D2gc2gc2GC6mallocMFNbmkPmxC8TypeInfoZPv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 22,484,758 /mnt/hgfs/mydoc/dworkspace/gamelibdtest//usr/include/dmd/phobos/std/format.d:_D3std6format74__T14formatUnsignedTS3std6format16__T7sformatTaTiZ7sformatFAaxAaiZ4SinkTaZ14formatUnsignedFNaNfS3std6format16__T7sformatTaTiZ7sformatFAaxAaiZ4SinkmKS3std6format18__T10FormatSpecTaZ10FormatSpeckbZv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 19,171,341 ???:_D2gc2gc3Gcx10smallAllocMFNbhKmkZPv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 16,334,730 ???:pthread_mutex_lock [/usr/lib64/libpthread-2.17.so] 14,519,760 ???:pthread_mutex_unlock [/usr/lib64/libpthread-2.17.so] 14,503,272 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/epollapi.d:_D8gamelibd3net5linux8epollapi8bitExistFiiZb [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 13,521,278 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/TcpLinuxConn.d:_D8gamelibd3net5linux12TcpLinuxConn12TcpLinuxConn8readSomeMFAhZi'2 [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 12,695,373 ???:_D2gc2gc3Gcx10smallAllocMFNbhKmkZ8tryAllocMFNbZb [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 12,558,147 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/linuxconn.d:_D8gamelibd3net5linux9linuxconn11handleEventFAS8gamelibd3net5linux8epollapi11epoll_eventZv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 12,091,173 ???:_D4core6thread5Fiber39__T4callVE4core6thread5Fiber7Rethrowi1Z4callMFZC6object9Throwable [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 11,153,058 /mnt/hgfs/mydoc/dworkspace/gamelibdtest//usr/include/dmd/phobos/std/format.d:_D3std6format18__T10FormatSpecTaZ10FormatSpec75__T17writeUpToNextSpecTS3std6format16__T7sformatTaTiZ7sformatFAaxAaiZ4SinkZ17writeUpToNextSpecMFNaNfS3std6format16__T7sformatTaTiZ7sformatFAaxAaiZ4SinkZb [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 10,877,409 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/epollapi.d:_D8gamelibd3net5linux8epollapi8changeEvFiiPviZv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 10,676,006 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/TcpLinuxConn.d:_D8gamelibd3net5linux12TcpLinuxConn12TcpLinuxConn9writeSomeMFAhZi [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 10,279,096 ???:pthread_getspecific [/usr/lib64/libpthread-2.17.so] 9,741,852 ???:__GI_memset [/usr/lib64/libc-2.17.so] 9,645,888 ???:_d_arraycopy [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 9,430,244 ???:_D2gc2gc3Gcx5sweepMFNbZm [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 8,866,869 ???:_D4core6atomic50__T11atomicStoreVE4core6atomic11MemoryOrderi0TbTbZ11atomicStoreFNaNbNiKObbZv [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest] 8,661,662 /mnt/hgfs/mydoc/dworkspace/gamelibdtest/../gamelibd/source/gamelibd/net/linux/TcpLinuxConn.d:_D8gamelibd3net5linux12TcpLinuxConn12TcpLinuxConn5writeMFAhZi [/mnt/hgfs/mydoc/dworkspace/bin/gamelibdtest]
Re: Expanding asm.dlang.org
On Monday, 25 May 2015 at 16:45:26 UTC, Andrei Alexandrescu wrote: On 5/25/15 7:36 AM, Iain Buclaw via Digitalmars-d wrote: I can add any cross compilers hosted on gdcproject.org http://gdcproject.org. You'd need to go through Godbolt to get it on his host. asm.dlang.org http://asm.dlang.org is a no go because it has been tailored for dmd only. The right answer is to tailor asm.dlang.org for everything. -- Andrei We also have http://dpaste.dzfl.pl/ (which has GDC, LDC, and actually runs the code).
Re: Expanding asm.dlang.org
On 27 May 2015 13:25, Mike via Digitalmars-d digitalmars-d@puremagic.com wrote: I've updated explore.dgnu.org with gdc-4.9, along with ARM and ARMHF variants. ARM supports -mthumb code generation. http://goo.gl/NmdnU1 Iain I added a few platform flags and compared the output with my cross-compiler. They look identical. This is great! Thanks! Awesome, thanks for clarifying.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 08:38:48 UTC, Per Nordlöw wrote:
AFAIK, in current DMD, I can't get any help in avoiding
patterns such as
char[] saved_line;
foreach (line; File(foo.txt).byLine)
{
saved_line = line; // should give error
}
If I understand you correctly, a new kind of qualifier for `line`
may be motivated here. The semantic meaning of `scope` D is not
related to volatile property. I guess the problem is somewhat
related to reference counting and ownership, right.
Re: problem with gc?
When I enable the --profle, get something like this, it doesnt give me too much help: Timer Is 3579545 Ticks/Sec, Times are in Microsecs Num TreeFuncPer CallsTimeTimeCall 1298756 4996649885 49875773773840 int gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.writeSome(ubyte[]) 30358909 14353678347 4433441425 146 void gamelibd.net.linux.linuxconn.selectAndProcessNetEvents(ulong) 30359249 1670090296 1582462941 52 long gamelibd.util.utcNow() 1298744 874889280 858583339 661 _D8gamelibd3net5linux12TcpLinuxConn12TcpLinuxConn8readSomeMFAhZ9__lambda2MFZv 1300549 25997 803742026 618 int gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.readSome(ubyte[]) 2597506 756203332 702092233 270 void gamelibd.net.linux.epollapi.changeEv(int, int, void*, int) 30358909 9920075665 285890739 9 void gamelibd.net.linux.linuxconn.handleEvent(gamelibd.net.linux.epollapi.epoll_event[]) 1298744 5131800498 244989946 188 void gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.doRead(gamelibd.net.linux.epollapi.epoll_event*) 1298768 0 223952199 172 void gamelibd.net.linux.IoEventHandler.IoEventHandler.autoReaderFiberSetting(void delegate()) 1298756 5207337081 210684924 162 int gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.write(ubyte[]) 30358953 162443804 162443804 5 @property bool gamelibd.util.LinkedList!(gamelibd.net.exceptionsafefiber.ExceptionSafeFiber).LinkedList.isEmpty() 648485 989705094 139972636 215 int gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.read(ubyte[]) 1298919 1008643391 124807374 96 void gamelibd.net.exceptionsafefiber.ExceptionSafeFiber.resume() 303590728843187288431872 2 pure nothrow @nogc @safe gamelibd.net.exceptionsafefiber.TimerTask std.container.rbtree.__T12RedBlackTreeTC8gamelibd3net18exceptionsafefiber9TimerTaskVAyaa25_612e737461727454696d65203c20622e737461727454696d65Vbi1Z.RedBlackTree.front() 1298750 157489732887384898 67 void gamelibd.net.linux.IoEventHandler.IoEventHandler.tryResumeReaderFiber() 303590727732591577325915 2 pure nothrow @property @nogc @safe ulong std.container.rbtree.__T12RedBlackTreeTC8gamelibd3net18exceptionsafefiber9TimerTaskVAyaa25_612e737461727454696d65203c20622e737461727454696d65Vbi1Z.RedBlackTree.length() 45448316156034761560347 13 pure @safe bool std.exception.enforce!(bool).enforce(bool, lazy object.Throwable) 25975005190564251905642 19 void gamelibd.net.linux.TcpLinuxConn.TcpLinuxConn.throwExceptionIfErrAfterOp(long) 12989514939205649392056 38 gamelibd.net.exceptionsafefiber.ExceptionSafeFiber gamelibd.net.exceptionsafefiber.ExceptionSafeFiber.getThis() 25975188087718146297298 17 gamelibd.mem.Ptr!(gamelibd.net.provider.Conn).Ptr.getinout(ref @property inout(gamelibd.net.provider.Conn) function()) 25976935172573037629038 14 gamelibd.mem.Ptr!(gamelibd.net.exceptionsafefiber.ExceptionSafeFiber).Ptr.getinout(ref @property inout(gamelibd.net.exceptionsafefiber.ExceptionSafeFiber) function()) 1298756 47994165534717468 26 void gamelibd.net.linux.IoEventHandler.IoEventHandler.enableRead()
DConf 2015 Livestreaming?
Isn't there any live-streaming of DConf this year?
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 10:53:48 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 09:54:33 UTC, Marc Schütz wrote:
Yes. First of all, `File.byLine.front` is the function that
needs to get annotated, like this:
char[] front() return {
// ...
return buffer;
}
The `return` keyword here means the same thing as in DIP25,
Is this supportd in 2.067 with -dip25 flag?
If so shouldn't we qualify `File.byLine.front` with return when
DIP-25 becomes stable?
I qualified `front` with `return` here
https://github.com/nordlow/justd/blob/master/bylinefast.d#L84
but compiling this with DMD 2.067 along with flag -dip25 doesn't
complain about
https://github.com/nordlow/justd/blob/master/bylinefast.d#L188
Did you mean that this too is a planned feature?
Re: DIP78 - macros without syntax extensions
On Tuesday, 26 May 2015 at 23:47:41 UTC, Dennis Ritchie wrote: If this proposal is considered, it is required to propose to look at the implementation of macros in Nemerle. Many believe that it is in Nemerle macros implemented the most successful compared to other modern languages. Of course, the most successful macros are implemented in Lisp, but the syntax of the language is poor :) The problem with declarative macro system is that you would need to learn yet another language. Possibly turing-complete. And a declarative turing-complete language is an overkill both for usage and implementation. Imperative macros get it done in an intuitive way in the existing language.
Re: DConf 2015 Livestreaming?
On Wednesday, 27 May 2015 at 10:20:04 UTC, Per Nordlöw wrote: Isn't there any live-streaming of DConf this year? Unfortunately, there doesn't seem to be any streaming this year: http://forum.dlang.org/thread/zpwxvgiaigdbweach...@forum.dlang.org
Re: How to implement immutable ring buffer?
On 27.05.2015 11:04, thedeemon wrote: This whole idea sounds self-contradictory. Ring buffer is a mutable-array-based implementation of something, for example of a queue. You can ask about immutable implementations of a queue, but that would be another question, not involving a ring buffer. What do you want to do with this buffer, what do you need it for? In general I need to have the last n instances of some objects queue. Now it implemented using ring buffer. Probably, you're right about immutable queue, it is more suitable definition here.
Re: DMD Symbol Reference Analysis Pass
On Tuesday, 26 May 2015 at 21:22:38 UTC, Per Nordlöw wrote: No, DMD cannot currently handle scope on foreach elements. It errors as Error: basic type expected, not scope Quite possible, didn't test it. Anyway, my point was that it simply isn't necessary to ever mark a local variable as `scope`. The compiler sees all local variables and can figure things out by itself. It only needs help in function signatures, in the form of explicit `scope` and `return` annotations. example, it would figure out that you're assigning a reference to a value with shorter lifetime (i.e. the slice to the buffer) to a value with longer lifetime (saved_line), which it would disallow. (Btw, I don't think to!string is enough, because it is probably a no-op in this case: string - string). No to!string is not a no-op in this case. It allocates but it needs to create an immutable char array that is: char[] - string I see, File.byLine returns a range of char[], I thought it returned a string range. Then you're of course right. However, byLine has another problem, which boils down to the same cause as the problem with RCArray, namely that the content of the buffer is reused in each iteration. This is what I meant with volatile. Is there a better word for this? I guess it's fine, and now I remember again that ranges with this property have been called volatile ranges. the owner can be modified while references to it exist. For byLine, this is not a safety violation, but for RCArray it is. A solution applicable to both is to detect this and then either treat such a situation as @system, or make the owner `const` as long as the references are alive. AFAIK: Allowing scope in foreach would solve this problem in my case. See above. Conceptually, you can of course treat it as if it were marked with `scope`, but an actual annotation should not be necessary.
Re: problem with gc?
@jklp
And also you could try to surround the whole block with
`GC.disable` and `GC.enable`. This would help to determine if
the GC is involved:
---
Ptr!Conn conn = connect(127.0.0.1,8881);
GC.disable;
ubyte[100] buf;
string str;
for(int i=0; iN; i++)
{
str = format(%s,i);
conn.write(cast(ubyte[]) str);
conn.read(buf[0..str.length]);
n++;
}
GC.enable;
conn.close();
---
I have tried this, and throughput falls down as well too. Does
this mean the gc is not involved? I am confused.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 08:43:07 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 08:38:48 UTC, Per Nordlöw wrote:
AFAIK, in current DMD, I can't get any help in avoiding
patterns such as
char[] saved_line;
foreach (line; File(foo.txt).byLine)
{
saved_line = line; // should give error
}
If I understand you correctly, a new kind of qualifier for
`line` may be motivated here. The semantic meaning of `scope` D
is not related to volatile property. I guess the problem is
somewhat related to reference counting and ownership, right.
See my other reply. Originally I thought so too, but it turns out
they can't really be separated. It's basically an instance of
Rust's restriction exactly one mutable reference, or N immutable
references, but not both at the same time.
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 09:40:35 UTC, Kagamin wrote: The point is to streamline ast creation. I think, helper methods can be provided by phobos in, say, std.macros to simplify ast creation for common constructs. Well, in a way libraries are a form of DSL... std.macros it may, this is the right way! At least, it would suit me :)
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 08:30:33 UTC, Marc Schütz wrote:
See above. Conceptually, you can of course treat it as if it
were marked with `scope`, but an actual annotation should not
be necessary.
But now you're talking about an upcoming feature in DMD, right?
AFAIK, in current DMD, I can't get any help in avoiding patterns
such as
char[] saved_line;
foreach (line; File(foo.txt).byLine)
{
saved_line = line; // should give error
}
Right?
Are you saying that adding DMD support for qualifying `line` as
`scope` is not the right way to solve this problem?
Re: DIP78 - macros without syntax extensions
On Tuesday, 26 May 2015 at 20:23:11 UTC, Kagamin wrote: http://wiki.dlang.org/DIP78 - Proposal for a macro system without syntactical extensions to the language. Hence it doesn't allow arbitrary syntax. I really like how powerful and easy to use are AST macros in nim. IMO, if D gets such, it would become the language with the best meta-programming abilities D - :D Here's a nice presentation about them: http://www.infoq.com/presentations/nimrod
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 08:14:36 UTC, Kagamin wrote: The problem with declarative macro system is that you would need to learn yet another language. Possibly turing-complete. And a declarative turing-complete language is an overkill both for usage and implementation. Imperative macros get it done in an intuitive way in the existing language. Yes, declarative macros can destroy an imperative language, because they can change the syntax of the language beyond recognition. Ie macrosystem will be more powerful than the language itself. Unfortunately, Nemerle, Scala and turned :) But, in my opinion, there should be options to combine declarative macros with imperative languages. You just need to properly limit these macros to a certain moment. Is not it possible to combine in the desired degree of declarative macros with imperative languages?
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 09:31:33 UTC, Dennis Ritchie wrote: Is not it possible to combine in the desired degree of declarative macros with imperative languages? The point is to streamline ast creation. I think, helper methods can be provided by phobos in, say, std.macros to simplify ast creation for common constructs. Well, in a way libraries are a form of DSL...
Re: Uphill
On Tuesday, 26 May 2015 at 17:13:18 UTC, ketmar wrote: On Tue, 26 May 2015 10:07:08 +, Chris wrote: With Go I have the sinking feeling that it won't be able to contend with C++ - or D for that matter. It took off due to Google and a fool-proof, easy-to-use infrastructure. But it is way too limited and limiting to be useful for more sophisticated tasks. Go's core devs even say that they wanted it to be an easy-to-use, middle-of-the-road language for those who work in their code mines, focusing on a high output, and it doesn't matter, if you have to write the same function or for-loop with slight modifications over and over and over again. and it really doesn't matter... for Rob Pike. he also don't like shared libraries and other bells and whistles. sometimes he is right, but sometimes he is too radical. Go is a java from google, aimed to raise a bunch of easily replaceable programmers. Exactly. As such it cannot be a serious contender as regards quality and versatility. There will be loads of Go code around, millions of for-loops on hundreds of thousands of servers, but I don't think it will go any further. Languages like D that are flexible and take useful concepts on board are much better suited for the programming challenges of the future (e.g. sophisticated high speed data processing algorithms). The thing is that Java and Python (and soon Go?) hit a brick wall sooner or later. Huge efforts are made to improve speed, flexibility and whatnot (JIT, Cython etc). But the real problem lies in rigid and narrow minded design decisions taken more than a decade ago. This is why it's still back to C and C++ for serious stuff.[1] [1] For more than a decade I've been hearing that with Java 8.x/9.x/10.x this or that issue will be fixed, or that Python will soon have native performance. It never happens and it never will. It's time to move on. Take the D train. :-) so, like java, Go can't be complicated. both Gosling and Pike are highly talented people, and that talent helps them to design dumb languages (which is not as easy as it seems ;-).
Re: How to implement immutable ring buffer?
On Wed, 27 May 2015 09:20:52 + drug via Digitalmars-d-learn digitalmars-d-learn@puremagic.com wrote: Could somebody share his thoughts on the subject? Would it be efficient? Is it possible to avoid memory copying to provide immutability? To avoid cache missing ring buffer should be like array, not list, so it's possible that the whole buffer should be moved. Is it neccessary to be real immutable, may be some form of fake immutabitiy is enough? I'd like to try immutability in my app, and ring buffer is what I don't know how to use in the realm of immutability. Thanks Maybe http://dlang.org/phobos/std_typecons.html#.Rebindable could help you.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 08:38:48 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 08:30:33 UTC, Marc Schütz wrote:
See above. Conceptually, you can of course treat it as if it
were marked with `scope`, but an actual annotation should not
be necessary.
But now you're talking about an upcoming feature in DMD, right?
Well, obviously, nothing of what we're talking about works with
current DMD. Even scope doesn't do anything (except for
delegates).
AFAIK, in current DMD, I can't get any help in avoiding
patterns such as
char[] saved_line;
foreach (line; File(foo.txt).byLine)
{
saved_line = line; // should give error
}
Right?
Yes.
Are you saying that adding DMD support for qualifying `line` as
`scope` is not the right way to solve this problem?
Yes. First of all, `File.byLine.front` is the function that needs
to get annotated, like this:
char[] front() return {
// ...
return buffer;
}
The `return` keyword here means the same thing as in DIP25,
namely that the returned value is owned by `this`. In your
example, the owner is the temporary returned by
`File(foo.txt).byLine`, which means that the returned buffer
must no longer be used when that temporary gets destroyed, i.e.
the read strings must not escape the foreach (without being
copied), which allows the buffer to be safely released then. This
is the original problem that `scope` was meant to address.
Conceptually, you're right that now `line` needs to be annotated
with `scope`, because otherwise you wouldn't be allowed to store
the scoped slices there. But there really isn't any point in
actually adding that annotation, because it can always be
inferred by the compiler (it can add the annotation for you when
it sees that you assign a scoped value to it).
This alone is then already enough to prevent the volatility
problem in your example, because it is longer possible for the
individual lines to outlive the byLine() temporary that gets
iterated over.
However, it is not enough in the general case:
auto lines = stdin.ByLine;
auto line1 = lines.front;
lines.popFront();
// line1 now changes
auto line2 = lines.front;
In this case, the rule that `line1` must not outlive `lines` is
fulfilled, but still it gets invalidated. With byLine(), this
just leads to unexpected behaviour, but with e.g. reference
counting, it can cause memory corruption (use after free).
Therefore, any complete scope proposal needs to address this
problem, too.
What I propose is the following: The compiler keeps track of
outstanding loans to owned objects. As long as any such loan
exists (in the above example, `line1` and `line2`), the owner
(i.e. `lines`) will either become read-only (const), or
alternatively, it will stay mutable, but mutating it will become
@system. This effectively addresses both the safety problems as
well as volatile ranges, because they are actually the same
problem.
I hope it is now clear what I want to say. It is unfortunately a
complicated topic...
Re: problem with gc?
On Wednesday, 27 May 2015 at 10:24:59 UTC, zhmt wrote: @Anonymouse Thank u very much, I have tried this: valgrind --tool=callgrind ./gamelibdtest callgrind_annotate callgrind.out.29234 Ir file:function [...] Without touching on the actual profile (which I'll leave to those better knowledgeable than I), open those callgrind.out.pid.* files in KCachegrind to get callgraphs. See https://imgur.com/AZEutCE,XXIDBvB,qehWaHg,bpTxS,3YfcJdh for some examples.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 09:54:33 UTC, Marc Schütz wrote:
Yes. First of all, `File.byLine.front` is the function that
needs to get annotated, like this:
char[] front() return {
// ...
return buffer;
}
The `return` keyword here means the same thing as in DIP25,
Is this supportd in 2.067 with -dip25 flag?
If so shouldn't we qualify `File.byLine.front` with return when
DIP-25 becomes stable?
Re: How to implement immutable ring buffer?
This whole idea sounds self-contradictory. Ring buffer is a mutable-array-based implementation of something, for example of a queue. You can ask about immutable implementations of a queue, but that would be another question, not involving a ring buffer. What do you want to do with this buffer, what do you need it for?
Re: problem with gc?
What happened when the code changes a little? Who will give an
explaination,Thanks a lot?
what happend if you use sformat instead?
Ptr!Conn conn = connect(127.0.0.1,8881);
ubyte[100] buf;
char[100] buf2;
for(int i=0; iN; i++)
{
auto str = sformat(buf2, %s,i);
conn.write((cast(ubyte*)str.ptr)[0..str.length]);
conn.read(buf[0..str.length]);
n++;
}
conn.close();
@Daniel Kozák
Thanks for reply.
I have tried sformat, but it doesnt work: throughput falls down,
and the cpu keeps busy.
Re: problem with gc?
If I pass a timeout with 1ms to epoll_wait,the cpu will not be busy when throughput falls down.
Re: problem with gc?
It seems that dlang library is not so effient?
Re: Expanding asm.dlang.org
I've updated explore.dgnu.org with gdc-4.9, along with ARM and ARMHF variants. ARM supports -mthumb code generation. http://goo.gl/NmdnU1 Iain I added a few platform flags and compared the output with my cross-compiler. They look identical. This is great! Thanks!
Re: How to implement immutable ring buffer?
On 27.05.2015 11:10, Daniel Kozák via Digitalmars-d-learn wrote: On Wed, 27 May 2015 09:20:52 + drug via Digitalmars-d-learn digitalmars-d-learn@puremagic.com wrote: Could somebody share his thoughts on the subject? Would it be efficient? Is it possible to avoid memory copying to provide immutability? To avoid cache missing ring buffer should be like array, not list, so it's possible that the whole buffer should be moved. Is it neccessary to be real immutable, may be some form of fake immutabitiy is enough? I'd like to try immutability in my app, and ring buffer is what I don't know how to use in the realm of immutability. Thanks Maybe http://dlang.org/phobos/std_typecons.html#.Rebindable could help you. I guess it won't be efficient, because it would be ring buffer of (in some form) pointers. It's suitable if elements of the buffer are processed independently each other. In other case cache misses are provided, I think.
Re: shared libs for OSX
On Tuesday, 26 May 2015 at 16:25:52 UTC, bitwise wrote: Isn't it better to avoid private undocumented functions? Not only better, but mandatory, otherwise Apple will reject the app from the app store. Calling back into an unloaded image without proving a mean to deregister the callback is a bug, so you might fix it. Looking at the code [1] again there is also an interesting sImagesToNotifyAboutOtherImages. [1]: http://opensource.apple.com/source/dyld/dyld-95.3/src/dyld.cpp
Re: DConf parking info and code
Where is the conference itself?
Re: shared libs for OSX
On Wednesday, 27 May 2015 at 06:45:49 UTC, Jacob Carlborg wrote: I'm not sure. The ___tls_get_addr function [1] is used when accessing a TLS variable on OS X. In all native implementations, both on OS X and Linux, the parameter is not just a void* but struct containing the image header as well. On Linux you call it with an dso index and an offset. The DSO index is assigned by the runtime linker (there is a special relocation for that). Something similar could be done manually if not natively supported on OSX.
Re: problem with gc?
On 5/27/15 2:42 AM, zhmt wrote: When I enable the --profle, get something like this, it doesnt give me too much help: I don't see any GC function here, I don't think you are are focusing on the right portion of the code. Seems like the gamelib library is consuming all the time. You may want to check with the author of that code for help. -Steve
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:37:51 UTC, Kagamin wrote: On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote: What if use the symbol '#' ? Yep, I like this symbol for macro too. https://issues.dlang.org/show_bug.cgi?id=2660 OK. This symbol is already used in a wrong place :) http://dlang.org/lex.html#special-token-sequence You can still use `:`. The colon is used even to refer to some Lisp macros, for example: (loop :for key :in keys :collect (cons key 0)) Still, as an option, you can use the `'` . This symbol is also used in Lisp, in some places, for example: (key-weight 'sweet) Or apostrophes, too, somewhere involved in the D?
Re: Proof of concept - library AA
On Monday, 25 May 2015 at 23:39:18 UTC, IgorStepanov wrote: On Sunday, 24 May 2015 at 14:13:26 UTC, Martin Nowak wrote: Would be interesting to get some opinions on this. https://github.com/D-Programming-Language/druntime/pull/1282 BTW, I have one idea. We may declare the AA ABI: AA is a pointer to the next layout: This is intended as temporary solution to simplify the transition to a library aa. Extending this conversion to other types for against the goal to replace the built-in AA.
Null argument and function resolution
Check this example:
http://dpaste.dzfl.pl/53f85bae4382
Calling with null, both c-tor match.
Is there a way to solve this?
Something like:
this(in ubyte* data) if( ??? )
{
}
Andrea
Re: DerelictMantle - unofficial, experimental, reverse-engineered
On Wednesday, 27 May 2015 at 12:06:20 UTC, ParticlePeter wrote: http://code.dlang.org/packages/derelict_extras-mantle/~master Currently Windows only. Don't know if this will ever change. AMD: The initial iteration of Mantle is intended specifically for Windows on PCs. Please let me know if you get the triangle drawn or displayed. Cheers, ParticlePeter Probably a good basis for the future DerelictVulkan :)
Re: Uphill
On Wednesday, 27 May 2015 at 10:01:35 UTC, Chris wrote: On Tuesday, 26 May 2015 at 17:13:18 UTC, ketmar wrote: On Tue, 26 May 2015 10:07:08 +, Chris wrote: With Go I have the sinking feeling that it won't be able to contend with C++ - or D for that matter. It took off due to Google and a fool-proof, easy-to-use infrastructure. But it is way too limited and limiting to be useful for more sophisticated tasks. Go's core devs even say that they wanted it to be an easy-to-use, middle-of-the-road language for those who work in their code mines, focusing on a high output, and it doesn't matter, if you have to write the same function or for-loop with slight modifications over and over and over again. and it really doesn't matter... for Rob Pike. he also don't like shared libraries and other bells and whistles. sometimes he is right, but sometimes he is too radical. Go is a java from google, aimed to raise a bunch of easily replaceable programmers. Exactly. As such it cannot be a serious contender as regards quality and versatility. There will be loads of Go code around, millions of for-loops on hundreds of thousands of servers, but I don't think it will go any further. Languages like D that are flexible and take useful concepts on board are much better suited for the programming challenges of the future (e.g. sophisticated high speed data processing algorithms). The thing is that Java and Python (and soon Go?) hit a brick wall sooner or later. Huge efforts are made to improve speed, flexibility and whatnot (JIT, Cython etc). But the real problem lies in rigid and narrow minded design decisions taken more than a decade ago. This is why it's still back to C and C++ for serious stuff.[1] [1] For more than a decade I've been hearing that with Java 8.x/9.x/10.x this or that issue will be fixed, or that Python will soon have native performance. It never happens and it never will. It's time to move on. Take the D train. :-) Only when I can sell D to customers that put money into this kind of stuff http://www.azulsystems.com/press-2014/azul-systems-and-orc-partner-to-enable-smarter-high-performance-trading http://chronicle.software/products/koloboke-collections/ http://devblogs.nvidia.com/parallelforall/next-wave-enterprise-performance-java-power-systems-nvidia-gpus/ Ecosystems count more than language features. -- Paulo
Re: problem with gc?
On Wednesday, 27 May 2015 at 10:27:08 UTC, zhmt wrote: It seems that dlang library is not so effient? The gamelibd could be doing a lot more than just echoing... it sounds to me that your socket might be blocking and epoll is busy looping waiting for it to become available again.
Re: Prevent slices from referencing old array after realocation?
On 5/27/15 1:55 AM, Gr8Ape wrote: I'm writing a program that handles lots of slices of larger arrays. I need the data of each of them all together for one operation, but otherwise it's more convenient to handle the elements in small groups. I could just store a pointer to my array, an offset, and a length but since I'm using D I'd much prefer to use slices... So I was looking through the documentation on slices and found out that if the array has to realocate then slices pointing to that array will keep on pointing to that block of memory, rather than the new location. Given that I'll be working with arrays that can vary wildly in size and that giving all of them the maximum capacity so they never realocate would be extremely inefficent, I need a workaround. So I'm wondering if there's a way to tell all the slices of an underlying array to now point to the new underlying array upon reallocation? Or would I have to iterate through and reassign every slice? Slices can't do this, because they have no idea about each other. So when you append to one slice, you can't have it update all other relevant slices. However, you could create a type that does this. -Steve
Re: DIP78 - macros without syntax extensions
On 2015-05-27 10:06, Kagamin wrote: I believe 78 allows a simpler implementation and requires less changes to the language, though I'm not sure if frontend can get it done on a purely semantical level: similar techniques like mixins and static if rely on syntax. DIP50 would require a minimal amount of syntax change, the only thing is prefixing a function with the macro keyword. DIP78 on the other hand, it's not so easy to see that a function declaration is actual a macro declaration. In that case I would prefer the macro keyword. It's already a reserved, for exactly this purpose, so it will be backwards compatible. I would say that neither of the DIP's contain a lot of detail. So it's hard to know which one is more complex. In DIP50 there's quite a lot of optional/bonus features. To me, implementing only the minimal requirements look very similar to DIP78. One thing that would be more complex in DIP50 would be the Context class. Although I'm not sure if that's needed in DIP78 as well. Maybe a macro should be called with a special syntax, e.g. myAssert!(a==b); I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. -- /Jacob Carlborg
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg wrote: DIP50 would require a minimal amount of syntax change, the only thing is prefixing a function with the macro keyword. DIP78 on the other hand, it's not so easy to see that a function declaration is actual a macro declaration. Well, that's the point: the function is a normal function, only some of its parameters require specially prepared arguments, this can't be missed as soon as arguments are passed to the respective parameters. In that case I would prefer the macro keyword. It's already a reserved, for exactly this purpose, so it will be backwards compatible. Well, maybe, I just didn't need the keyword. One thing that would be more complex in DIP50 would be the Context class. Although I'm not sure if that's needed in DIP78 as well. No, passing of Context is not proposed. Maybe a macro should be called with a special syntax, e.g. myAssert!(a==b); I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. I mean, the template instantiation syntax can inform the compiler that the expression is evaluated at compile time with possible code generation, so that the compiler is prepared to what macro will do. This resembles similarity between macros and templates. If macros can use existing syntax of a function call, I see no problem if they use another existing syntax.
Re: DIP78 - macros without syntax extensions
On Wed, 27 May 2015 12:07:09 + Dennis Ritchie via Digitalmars-d digitalmars-d@puremagic.com wrote: On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg wrote: I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. What if use the symbol '#' ? Yep, I like this symbol for macro too.
problem with custom predicate
I am trying to use a Container class with a custom predicate, but
the following code does not compile. Any hints on how to do it?
import std.container;
class C
{
int[] prio;
RedBlackTree!(int, (a,b)=prio[a]prio[b]) tree;
}
I think I understand the reason why this does not work (the
lambda cannot access the 'this' to get to 'prio'), but I can't
think of a way to make it work. Any Ideas?
Re: Null argument and function resolution
Two options:
1) add an overload that takes typeof(null)
this(typeof(null)) { /* handles the null literal specially */ }
2) Cast null to a specific type when making it:
new YourClass(cast(ubyte*) null);
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg wrote: I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. What if use the symbol '#' ?
DerelictMantle - unofficial, experimental, reverse-engineered
http://code.dlang.org/packages/derelict_extras-mantle/~master Currently Windows only. Don't know if this will ever change. AMD: The initial iteration of Mantle is intended specifically for Windows on PCs. Please let me know if you get the triangle drawn or displayed. Cheers, ParticlePeter
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:55:05 UTC, Dennis Ritchie wrote: Or apostrophes, too, somewhere involved in the D? Similarly, this option is no longer, as is used as: char c = 'c'; Though...
Re: Parallelism
Thank you, core.thread was exactly what I would have started with if I'd just seen the derived line in the example. My earlier careless reading led me to believe I needed to compose my own class, which felt more complicated than it should be.
Re: shared libs for OSX
On Tuesday, 26 May 2015 at 16:25:52 UTC, bitwise wrote: Since all global functions and symbols are shared between images anyways, receiving the callback in the main image would be fine. So in this case, unregistering the callbacks is no longer needed. That only works when the host executable is linked against druntime, but falls when you load runtime dynamically, e.g. a D plugin for a C host.
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 13:12:05 UTC, Meta wrote: As far as I know, the : and ' symbols in Lisp don't have anything to do with macros. : is for keyword arguments and ' is for creating AST literals. It makes sense that these would be heavily used with macros, of course, but they are not part of Lisp's macro system. Yes, but IMO, these symbols can be activated in the future macrosystem D.
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote: On Wed, 27 May 2015 12:07:09 + Dennis Ritchie via Digitalmars-d digitalmars-d@puremagic.com wrote: On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg wrote: I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. What if use the symbol '#' ? Yep, I like this symbol for macro too. What's wrong with using the word macro? We don't want symbol soup.
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote: What if use the symbol '#' ? Yep, I like this symbol for macro too. https://issues.dlang.org/show_bug.cgi?id=2660
Re: DerelictMantle - unofficial, experimental, reverse-engineered
On Wednesday, 27 May 2015 at 12:44:29 UTC, ponce wrote: On Wednesday, 27 May 2015 at 12:06:20 UTC, ParticlePeter wrote: http://code.dlang.org/packages/derelict_extras-mantle/~master Currently Windows only. Don't know if this will ever change. AMD: The initial iteration of Mantle is intended specifically for Windows on PCs. Please let me know if you get the triangle drawn or displayed. Cheers, ParticlePeter Probably a good basis for the future DerelictVulkan :) Yes, and get a head start in learning the Vulkan API :)
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:55:05 UTC, Dennis Ritchie wrote: On Wednesday, 27 May 2015 at 12:37:51 UTC, Kagamin wrote: On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote: What if use the symbol '#' ? Yep, I like this symbol for macro too. https://issues.dlang.org/show_bug.cgi?id=2660 OK. This symbol is already used in a wrong place :) http://dlang.org/lex.html#special-token-sequence You can still use `:`. The colon is used even to refer to some Lisp macros, for example: (loop :for key :in keys :collect (cons key 0)) Still, as an option, you can use the `'` . This symbol is also used in Lisp, in some places, for example: (key-weight 'sweet) Or apostrophes, too, somewhere involved in the D? As far as I know, the : and ' symbols in Lisp don't have anything to do with macros. : is for keyword arguments and ' is for creating AST literals. It makes sense that these would be heavily used with macros, of course, but they are not part of Lisp's macro system.
Signals
I'm writing a daemon in D on linux. I need to be able to stop (kill) it. The traditional C method is a signal handler. I can do this, but I can't figure out how to get the handler to do anything to tell the rest of the daemon to quit. In a C++ handler, I closed the files that were open, removed a PID file and exited. Nothing complicated in the job. It was more complicated in the implementation - I did a longjump from the signal handler to execute the cleanup code. I would love to setup std.signals classes and from the core.stdc.signal signal handler call std.signals emit() to trigger the std.signals observer. Is there a canonical D way of catching a SIGTERM and unwinding everything? RC
Re: Signals
The way I do it is to set a global variable in the signal
handler, then have the loop watch for it. So like
__gshared bool terminated = false;
extern(C) void handleSigTerm(int) { terminated = true; }
void main() {
while(!terminated) {
if(select() 0)
if(errno == EINTR) continue; // let the loop check
the flag again
// the rest of the stuff
}
// do normal cleanup here, and as the functions return
// naturally they will do unwinding.
}
Of course, with this strategy, if there's some long operation
running inside the loop it won't get a chance to check the
flag how you handle that is up to you. Maybe check that flag
from time to time and throw an exception from work functions if
it is set.
But there's no convenient way to exit from the handler itself
while doing unwinding. You can exit, sure (use the C exit
function), and the OS will clean up a lot of stuff but D
destructors won't be called that way.
Re: Martin Nowak's talk cancelled
On 26/05/15 15:25, Andrei Alexandrescu wrote: Sad news - Martin missed his flight and found no viable alternative to make it to DConf. For his slot at 10:00 AM on Thursday, we'll look into teleconferencing options for him. Alternatively, we're now taking applications from the other speakers and attendees to fill his slot. Please email your proposals to Walter and myself if interested. Andrei Daniel suggested to turn it into a round of lightning talks. These are more spontaneous and don't need preparation. Might get people to talk that wouldn't fill a 1-hour talk. L.
Now official: we are livestreaming DConf 2015
Thanks to John Colvin! He rigged his webcam centrally so we can livestream DConf 2015 in passable quality to youtube. Link: https://www.youtube.com/watch?v=-OCl-jWyT9E It's live now (30 minutes of break still ongoing so not a lot going on at the moment). Schedule at: http://dconf.org/2015/schedule/index.html Times are in MDT (GMT-0600). Andrei
Re: Now official: we are livestreaming DConf 2015
On Wednesday, 27 May 2015 at 19:01:00 UTC, Andrei Alexandrescu wrote: Thanks to John Colvin! He rigged his webcam centrally so we can livestream DConf 2015 in passable quality to youtube. Link: https://www.youtube.com/watch?v=-OCl-jWyT9E It's live now (30 minutes of break still ongoing so not a lot going on at the moment). Schedule at: http://dconf.org/2015/schedule/index.html Times are in MDT (GMT-0600). Andrei Hi! Any chance to change the YouTube settings? Here in Germany I get only the message: Live streaming is not available in your country due to rights issues. Regards, Kai
Re: problem with custom predicate
On 5/27/15 9:59 AM, Meta wrote: I thought unaryFun *does* work with all callables, including structs/classes with opCall? It (binaryFun actually) declares an alias. But you need an actual instance to use in this case. You simply can't declare that in a type definition, and it won't be set up properly in the constructor even if you could. You need an instance in order to use an alias to that instance. What likely would happen is if the functor is a callable type, and that type is not a functor itself (i.e. doesn't define static opCall), is that RedBlackTree would then require an instance of that type as part of the constructor. -Steve
Re: problem with gc?
On Wednesday, 27 May 2015 at 05:48:13 UTC, zhmt wrote: The code you posted is the client code, but the issue seems to be on the server side. Can you post the server code and also the timing code?
Re: Prevent slices from referencing old array after realocation?
On Wednesday, 27 May 2015 at 07:55:29 UTC, Gr8Ape wrote: You can keep an index and a count instead of a slice. If you know your data well, you can exploit this knowledge, and this has the potential to save you many bytes per slice when dealing with large data sets. Depending on your access patterns, it also has the potential to be fairly more cpu-efficient.
Re: DConf 2015 Livestreaming?
On Wednesday, 27 May 2015 at 17:32:06 UTC, Gary Willoughby wrote: On Wednesday, 27 May 2015 at 10:32:32 UTC, Liam McSherry wrote: On Wednesday, 27 May 2015 at 10:20:04 UTC, Per Nordlöw wrote: Isn't there any live-streaming of DConf this year? Unfortunately, there doesn't seem to be any streaming this year: http://forum.dlang.org/thread/zpwxvgiaigdbweach...@forum.dlang.org I hope there is at least downloadable videos. That has always been the case..
Re: DConf 2015 Livestreaming?
On Wednesday, 27 May 2015 at 17:32:06 UTC, Gary Willoughby wrote: On Wednesday, 27 May 2015 at 10:32:32 UTC, Liam McSherry wrote: On Wednesday, 27 May 2015 at 10:20:04 UTC, Per Nordlöw wrote: Isn't there any live-streaming of DConf this year? Unfortunately, there doesn't seem to be any streaming this year: http://forum.dlang.org/thread/zpwxvgiaigdbweach...@forum.dlang.org I hope there is at least downloadable videos. Yes, the university organizing the event is recording videos that will be put online at some point.
Re: DConf 2015 Livestreaming?
On Wednesday, 27 May 2015 at 18:06:31 UTC, extrawurst wrote: On Wednesday, 27 May 2015 at 17:32:06 UTC, Gary Willoughby wrote: On Wednesday, 27 May 2015 at 10:32:32 UTC, Liam McSherry wrote: On Wednesday, 27 May 2015 at 10:20:04 UTC, Per Nordlöw wrote: Isn't there any live-streaming of DConf this year? Unfortunately, there doesn't seem to be any streaming this year: http://forum.dlang.org/thread/zpwxvgiaigdbweach...@forum.dlang.org I hope there is at least downloadable videos. That has always been the case.. Let me rephrase it for him, I hope there is at least downloadable videos within the next month instead of last year's fiasco.
Re: Proof of concept - library AA
On Wed, May 27, 2015 at 05:16:51PM +, IgorStepanov via Digitalmars-d wrote: On Wednesday, 27 May 2015 at 14:12:02 UTC, Martin Nowak wrote: On Sunday, 24 May 2015 at 15:13:41 UTC, Vladimir Panteleev wrote: Could you elaborate on what these magic semantics are? and no easy solution exists for the ++aa[key1][key2] case. Is this specific to the pre-increment? aa[key1][key2]++ is generally a useful pattern. This applies to pre/post increment as well as assignment and opOpAssign. When an lvalue is needed the compiler will call a special runtime function GetX to obtain an lvalue for aa[key1], i.e. the entry will be default initialized iff missing. If the expression is an rvalue though (aa[key1][key2]), a missing key1 will trigger a range error. In an opIndex(Key) you have no idea whether the whole expression I an lvalue or an rvalue. IIRC the construction/assignment of a value is also handled specifically. BTW, may be we should create DIP about opIndex extending? [...] See: https://issues.dlang.org/show_bug.cgi?id=7753 This issue has been known since 2012. T -- Genius may have its limitations, but stupidity is not thus handicapped. -- Elbert Hubbard
Re: DConf 2015 Livestreaming?
Inofficial ad-hoc stream : https://www.youtube.com/watch?v=-OCl-jWyT9E (may randomly stop and get restarted) (thanks John Colvin)
Re: DConf 2015 Livestreaming?
On 5/27/15, Dicebot via Digitalmars-d digitalmars-d@puremagic.com wrote: Inofficial ad-hoc stream : https://www.youtube.com/watch?v=-OCl-jWyT9E (may randomly stop and get restarted) (thanks John Colvin) Nice! Btw, youtube preemptively blocks this in Germany, only because it is a live-stream and I guess they're just scared they'll get sued. Luckily VPN here is to save the day. :)
Re: shared libs for OSX
On 2015-05-27 15:38, Martin Nowak wrote: On Linux you call it with an dso index and an offset. The DSO index is assigned by the runtime linker (there is a special relocation for that). Something similar could be done manually if not natively supported on OSX. It is natively support. -- /Jacob Carlborg
Re: Expanding asm.dlang.org
On 5/27/15 5:38 AM, Vladimir Panteleev wrote: On Monday, 25 May 2015 at 16:45:26 UTC, Andrei Alexandrescu wrote: On 5/25/15 7:36 AM, Iain Buclaw via Digitalmars-d wrote: I can add any cross compilers hosted on gdcproject.org http://gdcproject.org. You'd need to go through Godbolt to get it on his host. asm.dlang.org http://asm.dlang.org is a no go because it has been tailored for dmd only. The right answer is to tailor asm.dlang.org for everything. -- Andrei We also have http://dpaste.dzfl.pl/ (which has GDC, LDC, and actually runs the code). That should also get integrated into the Borg: ide.dlang.org. Vladimir, are you up for it? -- Andrei
Re: DConf 2015 Livestreaming?
On 2015-05-27 20:24, weaselcat wrote: Let me rephrase it for him, I hope there is at least downloadable videos within the next month instead of last year's fiasco. 20 talks, one talk per week, that is five months for all talks. -- /Jacob Carlborg
Re: DIP78 - macros without syntax extensions
On 2015-05-27 14:17, Kagamin wrote: Well, that's the point: the function is a normal function, only some of its parameters require specially prepared arguments, this can't be missed as soon as arguments are passed to the respective parameters. I prefer to be more explicit in this case, especially since the keyword is already available. In that case I would prefer the macro keyword. It's already a reserved, for exactly this purpose, so it will be backwards compatible. Well, maybe, I just didn't need the keyword. I don't need it either, it's just what I preferred. No, passing of Context is not proposed. The feeling I have it that it's hard to know if it's needed or not without implementing/using the macro system. I mean, the template instantiation syntax can inform the compiler that the expression is evaluated at compile time with possible code generation, so that the compiler is prepared to what macro will do. This resembles similarity between macros and templates. If macros can use existing syntax of a function call, I see no problem if they use another existing syntax. True, but how would that the syntax look like for template macro, if possible? -- /Jacob Carlborg
Re: problem with custom predicate
On 5/27/15 9:11 AM, Simon =?UTF-8?B?QsO8cmdlciI=?= simon.buer...@rwth-aachen.de wrote: On Wednesday, 27 May 2015 at 14:58:39 UTC, drug wrote: Do you want to dynamically change priority? Actually yes. In my actual code I am not using a RedBlackTree but my own Container (a heap with the possibility to modify elements inside), which is notified when prio changes so it can do a (local) reordering. It would be a very bad idea to change prio if the RBTree is constructed already (and if this works). Why prio is outside of your predicate? Well, how would I get it into the lambda? In C++ I would use a comparision class, and the constructor of the container would take an instance of that class. But D's RedBlackTree-constructor does not take such a (run-time) argument. And I dont see a way to get prio into the predicate, which is a template-argument. This is true, RedBlackTree does not take a functor as a parameter to the constructor, it just uses an alias. This should work if your RedBlackTree is scoped inside a function where the data exists. But at the time of declaration inside the class, the instance of prio doesn't exist, so you can't alias it. It would be a good enhancement I think to add support for function objects. -Steve
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 08:14:36 UTC, Kagamin wrote:
On Tuesday, 26 May 2015 at 23:47:41 UTC, Dennis Ritchie wrote:
If this proposal is considered, it is required to propose to
look
at the implementation of macros in Nemerle. Many believe that
it
is in Nemerle macros implemented the most successful compared
to
other modern languages. Of course, the most successful macros
are
implemented in Lisp, but the syntax of the language is poor :)
The problem with declarative macro system is that you would
need to learn yet another language. Possibly turing-complete.
And a declarative turing-complete language is an overkill both
for usage and implementation. Imperative macros get it done in
an intuitive way in the existing language.
But D already has such a declarative language - the one used in
template metaprogramming. I think a macro system that plays well
with that template metaprogramming sub-language will be really
nice. For example, CTFE that works like a macro and returns
types/aliases:
Auto deduceType(Auto args) {
// some complex imperative code to deduce the type from
the args
return DeducedType;
}
struct Foo(T...) {
deduceType(T) value;
}
Re: problem with custom predicate
On 05/27/2015 05:30 PM, Steven Schveighoffer wrote: On 5/27/15 9:11 AM, Simon =?UTF-8?B?QsO8cmdlciI=?= simon.buer...@rwth-aachen.de wrote: On Wednesday, 27 May 2015 at 14:58:39 UTC, drug wrote: Do you want to dynamically change priority? Actually yes. In my actual code I am not using a RedBlackTree but my own Container (a heap with the possibility to modify elements inside), which is notified when prio changes so it can do a (local) reordering. It would be a very bad idea to change prio if the RBTree is constructed already (and if this works). Why prio is outside of your predicate? Well, how would I get it into the lambda? In C++ I would use a comparision class, and the constructor of the container would take an instance of that class. But D's RedBlackTree-constructor does not take such a (run-time) argument. And I dont see a way to get prio into the predicate, which is a template-argument. This is true, RedBlackTree does not take a functor as a parameter to the constructor, it just uses an alias. This should work if your RedBlackTree is scoped inside a function where the data exists. But at the time of declaration inside the class, the instance of prio doesn't exist, so you can't alias it. It would be a good enhancement I think to add support for function objects. -Steve Also, apart from missing implementation, there is no good reason why the code given should not work, is there? I think nested template instantiation should work in all scopes. (Of course, there is the issue that nested structs are somewhat arbitrarily not given a context pointer when declared within a class/struct, so this might be a little inconsistent in case it also works for structs, no question for classes though: just instantiate as nested class.)
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 11:02:24 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 10:53:48 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 09:54:33 UTC, Marc Schütz wrote:
Yes. First of all, `File.byLine.front` is the function that
needs to get annotated, like this:
char[] front() return {
// ...
return buffer;
}
The `return` keyword here means the same thing as in DIP25,
Is this supportd in 2.067 with -dip25 flag?
If so shouldn't we qualify `File.byLine.front` with return
when DIP-25 becomes stable?
I qualified `front` with `return` here
https://github.com/nordlow/justd/blob/master/bylinefast.d#L84
but compiling this with DMD 2.067 along with flag -dip25
doesn't complain about
https://github.com/nordlow/justd/blob/master/bylinefast.d#L188
Did you mean that this too is a planned feature?
I might be wrong, but I thought dip25 was only enabled in @safe
annotated code?
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 12:39:52 UTC, ixid wrote: On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote: On Wed, 27 May 2015 12:07:09 + Dennis Ritchie via Digitalmars-d digitalmars-d@puremagic.com wrote: On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg wrote: I have thought of that too. But I haven't been able to come up with a syntax that looks good and doesn't conflict with any existing syntax/symbol. The above syntax is already used for template instantiation. What if use the symbol '#' ? Yep, I like this symbol for macro too. What's wrong with using the word macro? We don't want symbol soup. this, there's a reason people don't use lisp.
Re: DIP78 - macros without syntax extensions
On Wednesday, 27 May 2015 at 15:20:38 UTC, weaselcat wrote:
On Wednesday, 27 May 2015 at 12:39:52 UTC, ixid wrote:
On Wednesday, 27 May 2015 at 12:34:49 UTC, Daniel Kozák wrote:
On Wed, 27 May 2015 12:07:09 +
Dennis Ritchie via Digitalmars-d
digitalmars-d@puremagic.com wrote:
On Wednesday, 27 May 2015 at 11:53:00 UTC, Jacob Carlborg
wrote:
I have thought of that too. But I haven't been able to
come up with a syntax that looks good and doesn't conflict
with any existing syntax/symbol. The above syntax is
already used for template instantiation.
What if use the symbol '#' ?
Yep, I like this symbol for macro too.
What's wrong with using the word macro? We don't want symbol
soup.
this, there's a reason people don't use lisp.
Lisp is not used due to other reasons, symbol soup typical for
Perl :)
$? ? s:;s:s;;$?: : s;;=]=%-{-|}|`{; ;
y; -/:-@[-`{-};`-{/ -; ;
s;;$_;see
Re: problem with custom predicate
On Wednesday, 27 May 2015 at 15:30:28 UTC, Steven Schveighoffer wrote: On 5/27/15 9:11 AM, Simon =?UTF-8?B?QsO8cmdlciI=?= simon.buer...@rwth-aachen.de wrote: On Wednesday, 27 May 2015 at 14:58:39 UTC, drug wrote: Do you want to dynamically change priority? Actually yes. In my actual code I am not using a RedBlackTree but my own Container (a heap with the possibility to modify elements inside), which is notified when prio changes so it can do a (local) reordering. It would be a very bad idea to change prio if the RBTree is constructed already (and if this works). Why prio is outside of your predicate? Well, how would I get it into the lambda? In C++ I would use a comparision class, and the constructor of the container would take an instance of that class. But D's RedBlackTree-constructor does not take such a (run-time) argument. And I dont see a way to get prio into the predicate, which is a template-argument. This is true, RedBlackTree does not take a functor as a parameter to the constructor, it just uses an alias. This should work if your RedBlackTree is scoped inside a function where the data exists. But at the time of declaration inside the class, the instance of prio doesn't exist, so you can't alias it. It would be a good enhancement I think to add support for function objects. -Steve I thought unaryFun *does* work with all callables, including structs/classes with opCall?
Re: Signals
I'm using nanomsg to communicate between various components (actually distributed across a number of computers) and my main event loops are waiting for a message. The reads are encapsulated in a class, so I guess I'll change from a recv to a poll and add a second channel to communicate when it is time to die. In the signal handler I can send a message and in the class, send a std.signal to end the thread and then clean up the main loop and exit. nn_poll is a c routine, so I should work comfortably in the handler. I wish there was a more direct way to do this. Signals are a bread and butter aspect of the Linux architecture. I guess mangling is at the root of the problem. Thank you.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 14:13:03 UTC, Marc Schütz wrote: I general, `return` is supposed to work (with -dip25), but only in combination with `ref`, not slices or pointers. DMD probably ignores it here instead of printing an error message. So, *should* it error for slices or not?
Re: Wiki table for available compiler packages by platform/OS
Great page. Thanks for it. It's a very helpful guide for the different flavours of D compilers. Regards, Ozan
[Issue 14093] [REG2.065] __traits(compiles, cast(Object)(tuple)) is true even if it doesn't compile.
https://issues.dlang.org/show_bug.cgi?id=14093
Igor Stepanov wazar.leoll...@yahoo.com changed:
What|Removed |Added
Status|RESOLVED|REOPENED
CC||wazar.leoll...@yahoo.com
Resolution|FIXED |---
--- Comment #6 from Igor Stepanov wazar.leoll...@yahoo.com ---
This issue is not fully solved.
There is simpler example:
-
struct FooBar
{
int a;
int b;
}
void test14093()
{
FooBar foo;
auto obj = cast(Object)foo; //e2ir: cannot cast foo of type FooBar to type
object.Object
}
-
Moreover, I think, this issue is solved incorrectly: alias this mechanism
should reject `cast(Object)(point._tupleAliasThis_)` variant and continue
process the root casting cast(Object)point excluding alias this.
And result error message should be
Error: cannot cast expression point of type Tuple!(int, x, int, y) to
object.Object.
We are interested in subtyping (alias this, or inheritance) only when it can
done its work (casting, .member ...).
--
Re: Proof of concept - library AA
On Sunday, 24 May 2015 at 15:13:41 UTC, Vladimir Panteleev wrote: Could you elaborate on what these magic semantics are? and no easy solution exists for the ++aa[key1][key2] case. Is this specific to the pre-increment? aa[key1][key2]++ is generally a useful pattern. This applies to pre/post increment as well as assignment and opOpAssign. When an lvalue is needed the compiler will call a special runtime function GetX to obtain an lvalue for aa[key1], i.e. the entry will be default initialized iff missing. If the expression is an rvalue though (aa[key1][key2]), a missing key1 will trigger a range error. In an opIndex(Key) you have no idea whether the whole expression I an lvalue or an rvalue. IIRC the construction/assignment of a value is also handled specifically.
Re: DMD Symbol Reference Analysis Pass
On Wednesday, 27 May 2015 at 11:02:24 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 10:53:48 UTC, Per Nordlöw wrote:
On Wednesday, 27 May 2015 at 09:54:33 UTC, Marc Schütz wrote:
Yes. First of all, `File.byLine.front` is the function that
needs to get annotated, like this:
char[] front() return {
// ...
return buffer;
}
The `return` keyword here means the same thing as in DIP25,
Is this supportd in 2.067 with -dip25 flag?
If so shouldn't we qualify `File.byLine.front` with return
when DIP-25 becomes stable?
I qualified `front` with `return` here
https://github.com/nordlow/justd/blob/master/bylinefast.d#L84
but compiling this with DMD 2.067 along with flag -dip25
doesn't complain about
https://github.com/nordlow/justd/blob/master/bylinefast.d#L188
Did you mean that this too is a planned feature?
I general, `return` is supposed to work (with -dip25), but only
in combination with `ref`, not slices or pointers. DMD probably
ignores it here instead of printing an error message.
Re: DConf parking info and code
On Wednesday, 27 May 2015 at 14:00:20 UTC, Adam D. Ruppe wrote: Where is the conference itself? Sorenson centre, sc213a/b
Re: DConf parking info and code
On 5/27/15 8:34 AM, John Colvin wrote: On Wednesday, 27 May 2015 at 14:00:20 UTC, Adam D. Ruppe wrote: Where is the conference itself? Sorenson centre, sc213a/b Sorensen Andrei informs me :) -Steve
Re: DConf parking info and code
On 5/27/15 8:34 AM, John Colvin wrote: On Wednesday, 27 May 2015 at 14:00:20 UTC, Adam D. Ruppe wrote: Where is the conference itself? Sorenson centre, sc213a/b In case this helps: https://www.google.com/maps/place/Sorensen+Center,+Utah+Valley+University,+800+W+University+Pkwy,+Orem,+UT+84058/@40.2784748,-111.7140463,18z/data=!4m2!3m1!1s0x874d9ae2291a2bf5:0xf88259cc27d3c4b3 -Steve
Re: Null argument and function resolution
The first answer is the one I was looking for. Very useful.
You should add to next this week in d tips.
On Wednesday, 27 May 2015 at 14:09:48 UTC, Adam D. Ruppe wrote:
Two options:
1) add an overload that takes typeof(null)
this(typeof(null)) { /* handles the null literal specially */ }
2) Cast null to a specific type when making it:
new YourClass(cast(ubyte*) null);
Re: problem with custom predicate
On 27.05.2015 13:50, Simon Bürger simon.buer...@rwth-aachen.de wrote:
I am trying to use a Container class with a custom predicate, but the
following code does not compile. Any hints on how to do it?
import std.container;
class C
{
int[] prio;
RedBlackTree!(int, (a,b)=prio[a]prio[b]) tree;
}
I think I understand the reason why this does not work (the lambda
cannot access the 'this' to get to 'prio'), but I can't think of a way
to make it work. Any Ideas?
Do you want to dynamically change priority? Why prio is outside of your
predicate?
Re: problem with custom predicate
On Wednesday, 27 May 2015 at 14:58:39 UTC, drug wrote: Do you want to dynamically change priority? Actually yes. In my actual code I am not using a RedBlackTree but my own Container (a heap with the possibility to modify elements inside), which is notified when prio changes so it can do a (local) reordering. Why prio is outside of your predicate? Well, how would I get it into the lambda? In C++ I would use a comparision class, and the constructor of the container would take an instance of that class. But D's RedBlackTree-constructor does not take such a (run-time) argument. And I dont see a way to get prio into the predicate, which is a template-argument. As I am implementing my own container anyway, I could of course do it the C++-way. But I was wondering if there is another way.
Re: DIP78 - macros without syntax extensions
On 05/27/15 17:47, Idan Arye via Digitalmars-d wrote:
On Wednesday, 27 May 2015 at 08:14:36 UTC, Kagamin wrote:
On Tuesday, 26 May 2015 at 23:47:41 UTC, Dennis Ritchie wrote:
If this proposal is considered, it is required to propose to look
at the implementation of macros in Nemerle. Many believe that it
is in Nemerle macros implemented the most successful compared to
other modern languages. Of course, the most successful macros are
implemented in Lisp, but the syntax of the language is poor :)
The problem with declarative macro system is that you would need to learn
yet another language. Possibly turing-complete. And a declarative
turing-complete language is an overkill both for usage and implementation.
Imperative macros get it done in an intuitive way in the existing language.
But D already has such a declarative language - the one used in template
metaprogramming. I think a macro system that plays well with that template
metaprogramming sub-language will be really nice. For example, CTFE that
works like a macro and returns types/aliases:
Auto deduceType(Auto args) {
// some complex imperative code to deduce the type from the args
return DeducedType;
}
struct Foo(T...) {
deduceType(T) value;
}
That already works. Eg:
alias deduceType(Args...) = typeof({
// some complex imperative code to deduce the type from the args
import std.range;
return mixin(iota(Args.length).map!q{`Args[`~text(a)~']'}().join(+));
}());
struct Foo(T...) {
deduceType!(T) value;
}
static assert(is(typeof(Foo!(short, ubyte, bool).value)==int));
What all these proposals seem to be about is:
a) better introspection (ie exposing a (preferably simplified and std) AST)
b) AST injection
c) better syntax
d) better optimizations, meaning skipping the emission of code and data
that is never used at runtime.
artur
Re: Signals
On Wednesday, 27 May 2015 at 13:52:33 UTC, Robbin wrote:
I'm writing a daemon in D on linux. I need to be able to stop
(kill) it. The traditional C method is a signal handler. I can
do this, but I can't figure out how to get the handler to do
anything to tell the rest of the daemon to quit.
In a C++ handler, I closed the files that were open, removed a
PID file and exited. Nothing complicated in the job. It was
more complicated in the implementation - I did a longjump from
the signal handler to execute the cleanup code.
I would love to setup std.signals classes and from the
core.stdc.signal signal handler call std.signals emit() to
trigger the std.signals observer.
Is there a canonical D way of catching a SIGTERM and unwinding
everything?
RC
I've usually just done this:
import core.stdc.stdlib : exit;
import core.sys.posix.signal : bsd_signal, SIGTERM;
extern(C) void handleTermination(int signal)
{
// Clean up code here.
exit(signal);
}
bsd_signal(SIGTERM, handleTermination);
Re: DConf 2015 Livestreaming?
On Wednesday, 27 May 2015 at 10:32:32 UTC, Liam McSherry wrote: On Wednesday, 27 May 2015 at 10:20:04 UTC, Per Nordlöw wrote: Isn't there any live-streaming of DConf this year? Unfortunately, there doesn't seem to be any streaming this year: http://forum.dlang.org/thread/zpwxvgiaigdbweach...@forum.dlang.org I hope there is at least downloadable videos.
Re: Proof of concept - library AA
On Wednesday, 27 May 2015 at 14:12:02 UTC, Martin Nowak wrote:
On Sunday, 24 May 2015 at 15:13:41 UTC, Vladimir Panteleev
wrote:
Could you elaborate on what these magic semantics are?
and no easy solution exists for the ++aa[key1][key2] case.
Is this specific to the pre-increment? aa[key1][key2]++ is
generally a useful pattern.
This applies to pre/post increment as well as assignment and
opOpAssign.
When an lvalue is needed the compiler will call a special
runtime function GetX to obtain an lvalue for aa[key1], i.e.
the entry will be default initialized iff missing.
If the expression is an rvalue though (aa[key1][key2]), a
missing key1 will trigger a range error.
In an opIndex(Key) you have no idea whether the whole
expression I an lvalue or an rvalue.
IIRC the construction/assignment of a value is also handled
specifically.
BTW, may be we should create DIP about opIndex extending?
What do you want about following?
Let, if opIndex is template, and the first template argument is a
bool value, compiler should pass true, if this is a part of
l-value expression:
struct Foo
{
Foo[] children;
this(int value)
{
this.value = value;
}
int value;
ref Foo opIndex(bool lvl)(size_t idx)
{
if (idx children.length)
return children[idx];
static if (lvl)
{
children.length = idx + 1;
return children[idx];
}
else
{
throw new Exception(out of bounds);
}
}
}
Foo f;
f[5][3] = Foo(42); translates to
f.opIndex!(true)(5).opIndex!(true)(3) = Foo(42);
auto x = f[5][4]; translates to
auto x = f.opIndex!(false)(5).opIndex!(false)(3);
Re: Null argument and function resolution
On Wed, 27 May 2015 14:09:47 +, Adam D. Ruppe wrote:
Two options:
1) add an overload that takes typeof(null)
this(typeof(null)) { /* handles the null literal specially */ }
you keep breaking my box of thinking. ;-) never thought about such
declaration.
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Re: Martin Nowak's talk cancelled
On 27/05/15 13:01, Andrei Alexandrescu wrote: On 5/27/15 12:13 PM, Lionello Lunesu wrote: Daniel suggested to turn it into a round of lightning talks. These are more spontaneous and don't need preparation. Might get people to talk that wouldn't fill a 1-hour talk. Good. So you go first? -- Andrei Sure :)
