Re: Properties don't work as expected
On Wednesday, 6 July 2016 at 05:51:04 UTC, Ola Fosheim Grøstad wrote: Maybe you could give me an useful example in D that does not involve «static if» or «string mixins» that would be difficult to represent in C++? anything involving templates. c++ template syntax is awful.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 22:03:43 UTC, ketmar wrote: On Tuesday, 5 July 2016 at 21:58:39 UTC, Ola Fosheim Grøstad wrote: On Tuesday, 5 July 2016 at 21:46:19 UTC, ketmar wrote: C++ templates vs D templates. this alone is enough. They are almost the same... yep. just like C is *almost* the assembler. Maybe you could give me an useful example in D that does not involve «static if» or «string mixins» that would be difficult to represent in C++?
Re: AA with dynamic array value
On Wednesday, 6 July 2016 at 02:33:02 UTC, ketmar wrote: On Wednesday, 6 July 2016 at 02:19:47 UTC, Craig Dillabaugh wrote: [...] this is true for any dynamic array, including AAs. until something is added to array, it actually a `null` pointer. i.e. arrays (and AAs) generally consisting of pointer to data and some length/info field. while array is empty, pointer to data is `null`. and when you passing your dynamic array slice/AA to function, it makes a copy of those internal fields. reallocing `null` doesn't affect the original variable. generally speaking, you should use `ref` if you plan to make your dynamic array/AA grow. i.e. void insertValue (ref int[][string]aa, string key, int value) Thanks for giving me the correct solution, and for the explanation. Cheers, Craig
Re: AA with dynamic array value
On Wednesday, 6 July 2016 at 02:19:47 UTC, Craig Dillabaugh wrote: Why doesn't my function allow me to insert elements into an empty associative array, but succeeds for an AA with some element in it? this is true for any dynamic array, including AAs. until something is added to array, it actually a `null` pointer. i.e. arrays (and AAs) generally consisting of pointer to data and some length/info field. while array is empty, pointer to data is `null`. and when you passing your dynamic array slice/AA to function, it makes a copy of those internal fields. reallocing `null` doesn't affect the original variable. generally speaking, you should use `ref` if you plan to make your dynamic array/AA grow. i.e. void insertValue (ref int[][string]aa, string key, int value)
Re: AA with dynamic array value
On Wednesday, 6 July 2016 at 02:03:54 UTC, Adam D. Ruppe wrote:
On Wednesday, 6 July 2016 at 01:58:31 UTC, Craig Dillabaugh
wrote:
*(keyvalue) ~ value; // This line fails.
That should prolly be ~= instead of ~.
Ahh, I was so close. Thank you that seems to do the trick.
However, now I have another issue.
For the following main function:
int main( string[] args) {
int[][string] myAA;
//int[] tmp;
//tmp ~= 7;
//myAA["world"] = tmp;
insertValue( myAA, "hello", 1 );
insertValue( myAA, "goodbye", 2 );
insertValue( myAA, "hello", 3 );
foreach (k; myAA.keys.sort)
{
writefln("%3s %d", k, myAA[k].length);
}
return 0;
}
If I run this, it prints out nothing. However, if I uncomment
adding an element for 'world' then it prints (as expected):
goodbye 1
hello 2
world 1
Why doesn't my function allow me to insert elements into an empty
associative array, but succeeds for an AA with some element in it?
Re: AA with dynamic array value
On Wednesday, 6 July 2016 at 01:58:31 UTC, Craig Dillabaugh wrote: *(keyvalue) ~ value; // This line fails. That should prolly be ~= instead of ~.
AA with dynamic array value
How can I create (and update) and associative array where the key
is a string, and the value is a dynamic array of integers?
For example:
void insertValue( int[][string]aa, string key, int value )
{
int[]* keyvalue;
keyvalue = ( key in aa );
if ( keyvalue !is null )
{
*(keyvalue) ~ value; // This line fails.
}
else {
int[] tmp;
tmp ~= value;
aa[key] = tmp;
}
}
int main( string[] args) {
int[][string] myAA;
insertValue( myAA, "hello", 1 );
insertValue( myAA, "goodbye", 2 );
insertValue( myAA, "hello", 3 );
return 0;
}
Fails with:
...(16): Error: ~ has no effect in expression (*keyvalue ~ value)
Thanks for any help.
Re: How to get current time as long or ulong?
Thank you for confirming the change. It hasn't made any difference
during the tests so far, but it sounds like it soon would have.
I don't really want a long...but an int rolls over too quickly, and
there's no 48 bit time. The time is basically for use over smaller
intervals, but occasionally I may need to compare across multiple
months, or even years. So the reason is because I want one time unit to
have multiple uses. It's going to end up being stored on disk, but
order of access is going to frequently be important, and occasionally
the relative age of quite different entities is going to be important.
For the second use I could use a much lower precision timer, but that
would mean using two separate times for each item.
On 07/05/2016 05:10 PM, Jonathan M Davis via Digitalmars-d-learn wrote:
On Tuesday, July 05, 2016 16:18:19 Charles Hixson via Digitalmars-d-learn
wrote:
I guess I was expressing myself poorly, probably due to muddled thinking
about the representation of time.
Based on various hints from you and others my current guess is that I
should use:
longnow() { returnClock.currTime().stdTime;}
IIUC this should return the current system clock time offset to start at
the start of 1 C.E. (with a standard systematic error that common across
all machines allowing for drift since the last time their clocks were
updated by NTP). And that this is the supported way to get this time.
(Which is probably about the same as MonoTime.currTime(), but *is*
updated when NTP updates the system clock.) And which is standardly a
64 bit number.
MonoTime and stdTime have _nothing_ to do with each other. stdTime is the
number of hecto-nanoseconds since midnight, January 1st, 1 A.D. MonoTime
contains a timestamp in system ticks, and how many of those there are per
second as well as how long ago 0 was are completely system-dependent.
The monotonic time is used for timing things not for anything related to the
wall clock. If what you care about is the wall clock, then use SysTime. If
what you care about is timing stuff, then use MonoTime.
I don't know why you'd want a long for the system time. There's nothing
standard about stdTime (which is why it's a horrible name, but
unfortunately, there really isn't a good name for it like there is with unix
time). SysTime exposes stdTime for the rare code that actually needs it, but
in general, code should either be using SysTime or converting SysTime to
the ISO or ISO extended formats, because those are standard. But you
certainly can store the stdTime somewhere if you want to.
- Jonathan M Davis
Re: How to get current time as long or ulong?
On Tuesday, July 05, 2016 12:51:54 Charles Hixson via Digitalmars-d-learn
wrote:
> On 07/05/2016 11:43 AM, Jonathan M Davis via Digitalmars-d-learn wrote:
> > On Tuesday, July 05, 2016 11:16:31 Charles Hixson via Digitalmars-d-learn
> >
> > wrote:
> >> What I'm looking for is the opposite of the "FromUnixTime" function.
> >
> > SysTime has toUnixTime, which is right above fromUnixTime in the
> > documentation.
> >
> > But if what you want is a time_t, and you don't want to deal with SysTime,
> > there's no point in using std.datetime. Just use core.time to call C's
> > time
> > function.
> >
> > - Jonathan M Davis
>
> That's what I want, but I'm worried by the documentation saying:
> " This has no relation to the wall clock time, as the wall clock time
> can be adjusted (e.g. by NTP), whereas the monotonic clock always moves
> forward."
> What I want is the system clock time, which *is* adjusted by NTP. I
> know it's not guaranteed monotonic, but different computers should have
> the same time (or be able to be synchronized to the same NTP time). And
> it's "approximately monotonic". time_t is fine, as 32 bit hardware is
> becoming scarce, and the application I'm working on will probably never
> encounter any. (More than 32 bits of precision is required as I don't
> want it to roll over every 42.5 days.)
>
> I understand why some purposes would really want a monotonic time, but
> that's not a strong constraint for me. But I do want it to be a long or
> ulong. (I don't really care where 0 is. What I'm using now is:
> aliaslongClockT;
> ClockTnow(){returnMonoTime.currTime();}
> And it's working fine during testing, but the documentation about the
> setting of MonoTime bothers me.
The Monotonic clock has nothing to do with the wall clock. It's giving the
number of system clock ticks which have occurred since some arbitrary time
that the system clock decided was 0, and the number of ticks per second is
completely system dependent. You wouldn't even want to share that number
between programs, let alone between runs of the same programe or between
computers. It's used for timing, not for knowing what time it is. e.g.
auto before = MonoTime.currTime;
// ... do a bunch of stuff
auto after = Monotime.currTime;
// The amount of time that that stuff took
auto diff = after - before;
It's the difference that becomes meaningful. The actual values of before and
after would be meaningless outside of this exact run of the program. What
makes the monotonic clock work for timing unlike the wall clock is that it
always moves forward by a fixed number of ticks per second. It's all about
timing and not at all about determing what time of day it is.
The wall clock time, on the other hand, is all about the time of day. It's
this particular hour, minute, second, etc. on this particular day of this
particular month of this particular year. And because the system's wall
clock time can be changed (be it because of NTP or someone manually changing
the time - or even because of a change in time zone if you're dealing with
the local time), it is not guaranteed to always move forward at a fixed
rate. It could change radically, which is why it does not work for timing.
It's all about knowing what time of day that something happened.
There really should never be a question of whether the monotonic time or the
wall clock time is appropriate. If you're ever asking that question, then
you almost certainly don't understand what they are.
If what you want is to time stuff (e.g. this happened x minutes into the run
of this program or this operation took y seconds), then you want the
monotonic time. If what you want is to know when something happens - i.e.
the time of day and/or date - then what you want is the wall clock time.
What you're using it for should make it obvious which you need.
But I would have to know more about what you're trying to do to have any
clue what you should be using. And I don't know why you would be so
interested in having the time as an integral value. That's usually a bad
idea. It's almost always better to use a time type that actually involves
units and context rather than a naked integral value.
- Jonathan M Davis
Re: How to get current time as long or ulong?
On Tuesday, July 05, 2016 16:18:19 Charles Hixson via Digitalmars-d-learn
wrote:
> I guess I was expressing myself poorly, probably due to muddled thinking
> about the representation of time.
>
> Based on various hints from you and others my current guess is that I
> should use:
>
> longnow() { returnClock.currTime().stdTime;}
>
> IIUC this should return the current system clock time offset to start at
> the start of 1 C.E. (with a standard systematic error that common across
> all machines allowing for drift since the last time their clocks were
> updated by NTP). And that this is the supported way to get this time.
> (Which is probably about the same as MonoTime.currTime(), but *is*
> updated when NTP updates the system clock.) And which is standardly a
> 64 bit number.
MonoTime and stdTime have _nothing_ to do with each other. stdTime is the
number of hecto-nanoseconds since midnight, January 1st, 1 A.D. MonoTime
contains a timestamp in system ticks, and how many of those there are per
second as well as how long ago 0 was are completely system-dependent.
The monotonic time is used for timing things not for anything related to the
wall clock. If what you care about is the wall clock, then use SysTime. If
what you care about is timing stuff, then use MonoTime.
I don't know why you'd want a long for the system time. There's nothing
standard about stdTime (which is why it's a horrible name, but
unfortunately, there really isn't a good name for it like there is with unix
time). SysTime exposes stdTime for the rare code that actually needs it, but
in general, code should either be using SysTime or converting SysTime to
the ISO or ISO extended formats, because those are standard. But you
certainly can store the stdTime somewhere if you want to.
- Jonathan M Davis
Re: How to get current time as long or ulong?
I guess I was expressing myself poorly, probably due to muddled thinking
about the representation of time.
Based on various hints from you and others my current guess is that I
should use:
longnow() { returnClock.currTime().stdTime;}
IIUC this should return the current system clock time offset to start at
the start of 1 C.E. (with a standard systematic error that common across
all machines allowing for drift since the last time their clocks were
updated by NTP). And that this is the supported way to get this time.
(Which is probably about the same as MonoTime.currTime(), but *is*
updated when NTP updates the system clock.) And which is standardly a
64 bit number.
On 07/05/2016 11:53 AM, Jonathan M Davis via Digitalmars-d-learn wrote:
On Tuesday, July 05, 2016 11:43:32 Jonathan M Davis via Digitalmars-d-learn
wrote:
But if what you want is a time_t, and you don't want to deal with SysTime,
there's no point in using std.datetime. Just use core.time to call C's time
function.
Actually, I should qualify this. I keep forgetting that time_t is not
guaranteed to be unix time on non-POSIX systems. If what you want is time_t,
then use C's time function via core.time, but if what you want is actual
unix time, then just do Clock.currTime.toUnixTime, since that's the simplest
way to do it. If you're using Microsoft's runtime, then time_t is indeed
unix time, but it's not for the Digital Mars runtime (and the standard -
unfortunately - doesn't require it to be). Digital Mars uses someting that's
_close_ to time_t but isn't actually time_t. :(
- Jonathan M Davis
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 21:58:39 UTC, Ola Fosheim Grøstad wrote: On Tuesday, 5 July 2016 at 21:46:19 UTC, ketmar wrote: C++ templates vs D templates. this alone is enough. They are almost the same... yep. just like C is *almost* the assembler.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 21:46:19 UTC, ketmar wrote: C++ templates vs D templates. this alone is enough. They are almost the same...
Re: How to get current time as long or ulong?
On 7/5/16 3:51 PM, Charles Hixson via Digitalmars-d-learn wrote: On 07/05/2016 11:43 AM, Jonathan M Davis via Digitalmars-d-learn wrote: On Tuesday, July 05, 2016 11:16:31 Charles Hixson via Digitalmars-d-learn wrote: What I'm looking for is the opposite of the "FromUnixTime" function. SysTime has toUnixTime, which is right above fromUnixTime in the documentation. But if what you want is a time_t, and you don't want to deal with SysTime, there's no point in using std.datetime. Just use core.time to call C's time function. That's what I want, but I'm worried by the documentation saying: " This has no relation to the wall clock time, as the wall clock time can be adjusted (e.g. by NTP), whereas the monotonic clock always moves forward." Clock.currTime.toUnixTime? https://dlang.org/library/std/datetime/clock.curr_time.html SysTime is just a type. What you are looking at is documentation for clock sources, not the type. Clock should give you the wall time. -Steve
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 17:50:46 UTC, Ola Fosheim Grøstad wrote: On Tuesday, 5 July 2016 at 16:20:52 UTC, ketmar wrote: so, my PoV is: yes, D has it's warts, but they are much more tolerable than C++ warts, for example. and D has alot to offer which C++ simply won't be able to offer, ever. D has «static if», but what else are you thinking of? C++ templates vs D templates. this alone is enough.
Re: Asynchronous Programming and Eventhandling in D
On Tuesday, 5 July 2016 at 08:24:43 UTC, O/N/S wrote:
Hi ("Grüss Gott")
I like the asynchronous events in Javascript.
Is something similar possible in D?
Found Dragos Carp's asynchronous library
(https://github.com/dcarp/asynchronous).
Are there any more integrated (in Phobos/in D) ways to work
asynchronously?
An example: One server ask a second server to calculate
something big.
The first server continues with his work, until the answer come
back from the second.
And so on...
Using threads or fibers would be a way, but has not the same
elegancy like the Javascript way. (To avoid discussions: D is
better ;-)
Greetings from Munich,
Ozan
Servus,
I'm currently rewriting the base skeleton of libev in D (only for
linux for now) for web development aswell. And the next step
would be data structures, basic server, futures and yo on...
I was working with dcarp's asynchronous and i found it very very
good. It is till now the best I've seen in D for async
programming ( I mean its design and usability).
Can you describe what would you like to see more concretly. I
know js but how is it supposed to work for D? Maybe you can give
some example, kind of pseudo code? It would help me much to build
a concept and maybe we will see someday something usable in this
area :)
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:58:03 UTC, Andrew Edwards wrote: On Tuesday, 5 July 2016 at 19:43:02 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:34:48 UTC, Andrew Edwards wrote: It's more than that. Now, it fails because it can't find DMD. As you can see in the build.bat from DCD it is hardcoded to DMD: https://github.com/Hackerpilot/DCD/blob/master/build.bat Maybe I should have been a little clearer. Following your instructions from earlier (skip DCD by selecting 2,3) the process failed again: 'dmd' is not recognized as an internal or external command, operable program or batch file. Error while compiling Dscanner. Program exited with code 1 But if DCD doesn't compile with LDC, I don't think there is a way other than getting both DMD and LDC right now except if you are on linux. It's not that LDC cannot compile DCD in this case, it's that your build script is searching for DMD when it cannot use DMD. in the .bat you can try to replace "dmd" with "ldmd2". ldmd2 allows to compile with LDC but with DMD command line interface. I can't guarantee that it gonna work but this is the simpliest option.
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:58:03 UTC, Andrew Edwards wrote: On Tuesday, 5 July 2016 at 19:43:02 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:34:48 UTC, Andrew Edwards wrote: It's more than that. Now, it fails because it can't find DMD. As you can see in the build.bat from DCD it is hardcoded to DMD: https://github.com/Hackerpilot/DCD/blob/master/build.bat Maybe I should have been a little clearer. Following your instructions from earlier (skip DCD by selecting 2,3) the process failed again: 'dmd' is not recognized as an internal or external command, operable program or batch file. Error while compiling Dscanner. Program exited with code 1 But if DCD doesn't compile with LDC, I don't think there is a way other than getting both DMD and LDC right now except if you are on linux. It's not that LDC cannot compile DCD in this case, it's that your build script is searching for DMD when it cannot use DMD. Oh right it runs the build.bat from the Dscanner repository which is also hardcoded to DMD. So easiest way to build workspace-d right now is just getting DMD and LDC.
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:43:02 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:34:48 UTC, Andrew Edwards wrote: It's more than that. Now, it fails because it can't find DMD. As you can see in the build.bat from DCD it is hardcoded to DMD: https://github.com/Hackerpilot/DCD/blob/master/build.bat Maybe I should have been a little clearer. Following your instructions from earlier (skip DCD by selecting 2,3) the process failed again: 'dmd' is not recognized as an internal or external command, operable program or batch file. Error while compiling Dscanner. Program exited with code 1 But if DCD doesn't compile with LDC, I don't think there is a way other than getting both DMD and LDC right now except if you are on linux. It's not that LDC cannot compile DCD in this case, it's that your build script is searching for DMD when it cannot use DMD.
Re: How to get current time as long or ulong?
On 07/05/2016 11:43 AM, Jonathan M Davis via Digitalmars-d-learn wrote:
On Tuesday, July 05, 2016 11:16:31 Charles Hixson via Digitalmars-d-learn
wrote:
What I'm looking for is the opposite of the "FromUnixTime" function.
SysTime has toUnixTime, which is right above fromUnixTime in the
documentation.
But if what you want is a time_t, and you don't want to deal with SysTime,
there's no point in using std.datetime. Just use core.time to call C's time
function.
- Jonathan M Davis
That's what I want, but I'm worried by the documentation saying:
" This has no relation to the wall clock time, as the wall clock time
can be adjusted (e.g. by NTP), whereas the monotonic clock always moves
forward."
What I want is the system clock time, which *is* adjusted by NTP. I
know it's not guaranteed monotonic, but different computers should have
the same time (or be able to be synchronized to the same NTP time). And
it's "approximately monotonic". time_t is fine, as 32 bit hardware is
becoming scarce, and the application I'm working on will probably never
encounter any. (More than 32 bits of precision is required as I don't
want it to roll over every 42.5 days.)
I understand why some purposes would really want a monotonic time, but
that's not a strong constraint for me. But I do want it to be a long or
ulong. (I don't really care where 0 is. What I'm using now is:
aliaslongClockT;
ClockTnow(){returnMonoTime.currTime();}
And it's working fine during testing, but the documentation about the
setting of MonoTime bothers me.
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:34:48 UTC, Andrew Edwards wrote: On Tuesday, 5 July 2016 at 19:25:50 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:14:32 UTC, Andrew Edwards wrote: There is on --config=client for the current version of dub so I went to the location of the source for experimental_allocator and ran dub build --build=release --config=library instead, which generated the missing file. Problem is I don't know how to fix this in your build instructions so that the compellation will resume or continue to completion. Please assist. It fails on installing DCD. On the installation.bat just select 2,3 and get prebuilt DCD binaries from the project page or build them yourself. It's more than that. Now, it fails because it can't find DMD. Now, I see no reason to use both DMD and LDC. Ultimately I'd like to use DMD because it is the simplest to install for a newcomer but your workspace-d/code-d requires LDC on windows platforms. If that's the case why would it now be failing because it cannot find DMD? As you can see in the build.bat from DCD it is hardcoded to DMD: https://github.com/Hackerpilot/DCD/blob/master/build.bat So I guess you would need to use some DMD argument wrapper for LDC (ldmd) to compile it but I can't guarantee that it will work. Though if you have LDC v1.0.0 it should most probably work. I would love to support DMD on workspace-d for windows but there is some bug in DMD's phobos causing workspace-d to hang every time you want to start the auto completion service. We found where it hangs but we couldn't find the cause or how to reproduce it yet. My best guess would be some win32 I/O functions are somehow wrongly used in there. The LDC phobos version doesn't have any issue there. But if DCD doesn't compile with LDC, I don't think there is a way other than getting both DMD and LDC right now except if you are on linux.
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:25:50 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:14:32 UTC, Andrew Edwards wrote: There is on --config=client for the current version of dub so I went to the location of the source for experimental_allocator and ran dub build --build=release --config=library instead, which generated the missing file. Problem is I don't know how to fix this in your build instructions so that the compellation will resume or continue to completion. Please assist. It fails on installing DCD. On the installation.bat just select 2,3 and get prebuilt DCD binaries from the project page or build them yourself. It's more than that. Now, it fails because it can't find DMD. Now, I see no reason to use both DMD and LDC. Ultimately I'd like to use DMD because it is the simplest to install for a newcomer but your workspace-d/code-d requires LDC on windows platforms. If that's the case why would it now be failing because it cannot find DMD?
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:14:32 UTC, Andrew Edwards wrote: I cloned the package and ran install.bat. The result is $ dub build --build=release --config=client Performing "release" build using ldc2 for x86. experimental_allocator 2.70.0-b1: building configuration "library"... Using Visual Studio: C:\Program Files (x86)\Microsoft Visual Studio 14.0\ LINK : fatal error LNK1104: cannot open file '..\..\..\..\Roaming\dub\packages\experimental_allocator-2.70.0-b1\experimental_allocator\.dub\build\library-release-windows-x86-ldc_0-341F845AB271E17D9C62794DCB77B6FB\experimental_allocator.lib' Error: `C:\WINDOWS\system32\cmd.exe /s /c "C:\D\ldc2\bin\amd64.bat lib.exe"` failed with status: 1104 ldc2 failed with exit code 1104. Error while compiling DCD. Program exited with code 1 There is on --config=client for the current version of dub so I went to the location of the source for experimental_allocator and ran dub build --build=release --config=library instead, which generated the missing file. Problem is I don't know how to fix this in your build instructions so that the compellation will resume or continue to completion. Please assist. Thanks, Andrew It fails on installing DCD. On the installation.bat just select 2,3 and get prebuilt DCD binaries from the project page or build them yourself. I could maybe add an option to compile from source and instead ship pre-built binaries from the github repositories instead.
Re: webfreak001: Request assist installing workspace-d on Windows
On Tuesday, 5 July 2016 at 19:25:50 UTC, WebFreak001 wrote: On Tuesday, 5 July 2016 at 19:14:32 UTC, Andrew Edwards wrote: [...] It fails on installing DCD. On the installation.bat just select 2,3 and get prebuilt DCD binaries from the project page or build them yourself. I could maybe add an option to compile from source and instead ship pre-built binaries from the github repositories instead. Actually DCD doesn't have any pre-built binaries yet. But following the compilation guide on the project page¹ should help you compile it. Not sure if it works with LDC but it definitely works with DMD* ¹: https://github.com/Hackerpilot/DCD *: assuming its the newest version
webfreak001: Request assist installing workspace-d on Windows
I cloned the package and ran install.bat. The result is $ dub build --build=release --config=client Performing "release" build using ldc2 for x86. experimental_allocator 2.70.0-b1: building configuration "library"... Using Visual Studio: C:\Program Files (x86)\Microsoft Visual Studio 14.0\ LINK : fatal error LNK1104: cannot open file '..\..\..\..\Roaming\dub\packages\experimental_allocator-2.70.0-b1\experimental_allocator\.dub\build\library-release-windows-x86-ldc_0-341F845AB271E17D9C62794DCB77B6FB\experimental_allocator.lib' Error: `C:\WINDOWS\system32\cmd.exe /s /c "C:\D\ldc2\bin\amd64.bat lib.exe"` failed with status: 1104 ldc2 failed with exit code 1104. Error while compiling DCD. Program exited with code 1 There is on --config=client for the current version of dub so I went to the location of the source for experimental_allocator and ran dub build --build=release --config=library instead, which generated the missing file. Problem is I don't know how to fix this in your build instructions so that the compellation will resume or continue to completion. Please assist. Thanks, Andrew
Re: How to get current time as long or ulong?
On Tuesday, July 05, 2016 11:43:32 Jonathan M Davis via Digitalmars-d-learn wrote: > But if what you want is a time_t, and you don't want to deal with SysTime, > there's no point in using std.datetime. Just use core.time to call C's time > function. Actually, I should qualify this. I keep forgetting that time_t is not guaranteed to be unix time on non-POSIX systems. If what you want is time_t, then use C's time function via core.time, but if what you want is actual unix time, then just do Clock.currTime.toUnixTime, since that's the simplest way to do it. If you're using Microsoft's runtime, then time_t is indeed unix time, but it's not for the Digital Mars runtime (and the standard - unfortunately - doesn't require it to be). Digital Mars uses someting that's _close_ to time_t but isn't actually time_t. :( - Jonathan M Davis
Re: How to get current time as long or ulong?
On Tuesday, July 05, 2016 18:25:17 John via Digitalmars-d-learn wrote: > On Tuesday, 5 July 2016 at 18:16:31 UTC, Charles Hixson wrote: > > I've been reading std.datetime documentation backwards and > > forwards, but if the information is there, I've been missing it. > > > > How do I get the current time as a long? > > > > Clock.currTime() returns a SysTime, and while currently I can > > convert that to a long, this is because I looked into the code. > > What's the supported way? All the documentation seems to be > > based around auto, which is great if you don't need to store it > > in memory with a defined number of bits allocated...but lousy > > if you do. (E.g., I don't want to store a time zone, just the > > UTC time. > > > > What I'm looking for is the opposite of the "FromUnixTime" > > function. > > Clock.currTime.stdTime That would give you the badly named "std" time and not "unix" time. "std" time is what SysTime uses internally and is the number of hecto-nanoseconds since midnight, January 1st, 1 A.D., whereas unix time is the number of seconds since midnight, January 1st, 1970. What SysTime uses is essentially the same thing that C# uses with its DateTime type with the poor name of "ticks", whereas unix time is what you normally get with C - though technically, if you're not on a POSIX system, there is no guarantee that time_t is equivalent to unix time - it just usually is. - Jonathan M Davis
Re: How to get current time as long or ulong?
On Tuesday, July 05, 2016 11:16:31 Charles Hixson via Digitalmars-d-learn wrote: > What I'm looking for is the opposite of the "FromUnixTime" function. SysTime has toUnixTime, which is right above fromUnixTime in the documentation. But if what you want is a time_t, and you don't want to deal with SysTime, there's no point in using std.datetime. Just use core.time to call C's time function. - Jonathan M Davis
Re: How to get current time as long or ulong?
On 07/05/2016 08:16 PM, Charles Hixson via Digitalmars-d-learn wrote: What I'm looking for is the opposite of the "FromUnixTime" function. That would be the "toUnixTime" method then, I suppose. https://dlang.org/phobos/std_datetime.html#.SysTime.toUnixTime
Re: How to get current time as long or ulong?
On Tuesday, 5 July 2016 at 18:16:31 UTC, Charles Hixson wrote: I've been reading std.datetime documentation backwards and forwards, but if the information is there, I've been missing it. How do I get the current time as a long? Clock.currTime() returns a SysTime, and while currently I can convert that to a long, this is because I looked into the code. What's the supported way? All the documentation seems to be based around auto, which is great if you don't need to store it in memory with a defined number of bits allocated...but lousy if you do. (E.g., I don't want to store a time zone, just the UTC time. What I'm looking for is the opposite of the "FromUnixTime" function. Clock.currTime.stdTime
How to get current time as long or ulong?
I've been reading std.datetime documentation backwards and forwards, but if the information is there, I've been missing it. How do I get the current time as a long? Clock.currTime() returns a SysTime, and while currently I can convert that to a long, this is because I looked into the code. What's the supported way? All the documentation seems to be based around auto, which is great if you don't need to store it in memory with a defined number of bits allocated...but lousy if you do. (E.g., I don't want to store a time zone, just the UTC time. What I'm looking for is the opposite of the "FromUnixTime" function.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 16:20:52 UTC, ketmar wrote: so, my PoV is: yes, D has it's warts, but they are much more tolerable than C++ warts, for example. and D has alot to offer which C++ simply won't be able to offer, ever. D has «static if», but what else are you thinking of? The only thing I can think of that is hard in C++ is to conditionally remove fields from a struct.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 16:11:58 UTC, zabruk70 wrote: On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote: Property functions are used wrong by a compiler when it needs i am sorry for my dumbness, what wrong with this code? as OP said, this one won't call setter on "+=" and company.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 14:07:25 UTC, zodd wrote: http://forum.dlang.org/post/mailman.1463.1361561853.22503.digitalmars-d-le...@puremagic.com : "Don't use 'in', because it doesn't mean what it seems to mean, and it's not correctly implemented at the moment." it is freakin' 2013! ;-) http://forum.dlang.org/post/lgqcjiuigsseoazir...@forum.dlang.org - "cast `shared` away. yes, this is how you supposed to use it now: cast it away." yes, `shared` need some love. it actually never moved from the concept to something really useful. alas. I don't want to say that "D is unfinished" actually, it is unfinished. ;-) but it already has alot to offer. I'm just trying to figure out what D is and how can I use it. sorry for overreacting. that "D is crap" thread makes me... nervous. ;-) Answering your other question: I think that production ready language should have a "finished" design and its detailed description (not a basic overview of the features). Andrei's book is fairly detailed. And Ali's book is excellent too. it's hard to expect a small, but complete descrion for modern multiparadigm language. ;-) so, my PoV is: yes, D has it's warts, but they are much more tolerable than C++ warts, for example. and D has alot to offer which C++ simply won't be able to offer, ever.
Re: Properties don't work as expected
On Tue, Jul 05, 2016 at 04:11:58PM +, zabruk70 via Digitalmars-d-learn
wrote:
> On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote:
> > Property functions are used wrong by a compiler when it needs
>
> i am sorry for my dumbness, what wrong with this code?
>
> import std.stdio;
>
> struct A {
> @property ref int value() {
> return value_;
> }
>
> @property void value(int v) {
> value_ = v;
> }
This overload is redundant, now that the first overload is ref.
> private:
> int value_;
> }
[...]
T
--
He who does not appreciate the beauty of language is not worthy to bemoan its
flaws.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote:
Property functions are used wrong by a compiler when it needs
i am sorry for my dumbness, what wrong with this code?
import std.stdio;
struct A {
@property ref int value() {
return value_;
}
@property void value(int v) {
value_ = v;
}
private:
int value_;
}
int main(string[] args) {
A a;
a.value = 10;
writeln(a.value);
a.value += 20;
writeln(a.value);
return 0;
}
Re: Initializing static array with contents of (static and dynamic) arrays
Am 05.07.2016 um 17:22 schrieb Marc Schütz:
> auto concat(T : E[n], E, size_t n)(const E[][] args...) @nogc
> {
> size_t offset = 0;
> T result = void;
> foreach(arr; args) {
> result[offset .. offset+arr.length] = arr;
> offset += arr.length;
> }
> assert(offset == result.length);
> return result;
> }
>
> static immutable ubyte[4] sigma0 = [101, 120, 112, 97];
> static immutable ubyte[4] sigma1 = [110, 100, 32, 51];
> static immutable ubyte[4] sigma2 = [ 50, 45, 98, 121];
> static immutable ubyte[4] sigma3 = [116, 101, 32, 107];
>
> void func(in ref ubyte[32] key, in ref ubyte[16] n) @nogc
> {
> ubyte[64] buf;
> buf[0..4] = sigma0;
> buf[4..20] = key[0..16];
> buf[20..24] = sigma1;
> buf[24..40] = n;
> buf[40..44] = sigma2;
> buf[44..60] = key[16..$];
> buf[60..64] = sigma3;
>
> auto buf2 = concat!(ubyte[64])(sigma0, key[0..16], sigma1, n,
> sigma2, key[16..$], sigma3);
>
> assert(buf == buf2);
> }
>
> void main() {
> ubyte[32] key =
> [0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1];
> ubyte[16] n = key[0..16];
> func(key, n);
> }
>
>
> Some remarks:
>
> * I added `ref` to `func`'s parameters, because the arrays are
> relatively large, so passing them by value might be costly (you should
> measure it if you care).
>
> * The `void` initialization in `concat` is an optimization that is valid
> only for POD types.
>
> * Returning the array is cheap because of NRVO.
This seems to be exactly what I was looking for. Thanks a lot!
Re: Initializing static array with contents of (static and dynamic) arrays
Am 05.07.2016 um 17:12 schrieb Johannes Loher:
> Am 05.07.2016 um 16:39 schrieb Rene Zwanenburg:
>> On Tuesday, 5 July 2016 at 12:34:20 UTC, Johannes Loher wrote:
>>> I tried this, but it does not work correctly with slices.
>>
>> The length of a slice is a runtime value, which is why it can't be used
>> to set static array size. What were you trying to achieve? Avoid copying
>> the input arrays, or accepting any slice?
>>
>> In case of the first, you can put ref in front of the Args:
>> auto combineArrays(Args...)(ref Args args)
>>
>> The second case will be a bit harder to solve nicely..
>
> I would like to be able, to accept any slice. In the example in my first
> post, I need this for key[0..16] and key[16..$] (which are slices).
> Strangely enough, the solution I am leaning towards at the moment also
> uses length, but it does work for slices of static arrays (i.e. key[0..16]):
>
> template expand(alias A)
> {
> auto ref M(alias I)() @property { return A[I]; }
> mixin(q{alias expand = TypeTuple!(}
> ~ iota(A.length).map!(a => "M!" ~ a.to!string).join(",")
> ~ q{);});
> }
>
> ubyte[64] buf = [expand!sigma0,
> expand!key[0..16],
> expand!sigma1,
> expand!n,
> expand!sigma2,
> expand!key[16..$],
> expand!sigma3];
>
> I suppose this is because the length of those slices is actually known
> at copiletime, but it looks a bit strange to me...
>
> I was trying to write another template that takes several arrays and
> expands all of them:
>
> template expand(Args...)
> {
> mixin(q{alias expand = TypeTuple!(}
> ~ iota(Args.length).map!(a => "expand!(Args[" ~ a.to!string ~
> "])").join(",")
> ~ q{);});
> }
>
> It works for static arrays, but not for slices, because the template
> parameters are not alias parameters, so the length is then not "known"
> at compile time (at least that's what I think why it fails). Is there a
> way to specify variadic templates taking any number of alias template
> parameters?
>
Well, I just realized my method does not work in the case that I want to
use expand on static arrays, which are returned from template functions...
Re: Initializing static array with contents of (static and dynamic) arrays
auto concat(T : E[n], E, size_t n)(const E[][] args...) @nogc
{
size_t offset = 0;
T result = void;
foreach(arr; args) {
result[offset .. offset+arr.length] = arr;
offset += arr.length;
}
assert(offset == result.length);
return result;
}
static immutable ubyte[4] sigma0 = [101, 120, 112, 97];
static immutable ubyte[4] sigma1 = [110, 100, 32, 51];
static immutable ubyte[4] sigma2 = [ 50, 45, 98, 121];
static immutable ubyte[4] sigma3 = [116, 101, 32, 107];
void func(in ref ubyte[32] key, in ref ubyte[16] n) @nogc
{
ubyte[64] buf;
buf[0..4] = sigma0;
buf[4..20] = key[0..16];
buf[20..24] = sigma1;
buf[24..40] = n;
buf[40..44] = sigma2;
buf[44..60] = key[16..$];
buf[60..64] = sigma3;
auto buf2 = concat!(ubyte[64])(sigma0, key[0..16], sigma1, n,
sigma2, key[16..$], sigma3);
assert(buf == buf2);
}
void main() {
ubyte[32] key =
[0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1];
ubyte[16] n = key[0..16];
func(key, n);
}
Some remarks:
* I added `ref` to `func`'s parameters, because the arrays are
relatively large, so passing them by value might be costly (you
should measure it if you care).
* The `void` initialization in `concat` is an optimization that
is valid only for POD types.
* Returning the array is cheap because of NRVO.
Re: Initializing static array with contents of (static and dynamic) arrays
Am 05.07.2016 um 16:39 schrieb Rene Zwanenburg:
> On Tuesday, 5 July 2016 at 12:34:20 UTC, Johannes Loher wrote:
>> I tried this, but it does not work correctly with slices.
>
> The length of a slice is a runtime value, which is why it can't be used
> to set static array size. What were you trying to achieve? Avoid copying
> the input arrays, or accepting any slice?
>
> In case of the first, you can put ref in front of the Args:
> auto combineArrays(Args...)(ref Args args)
>
> The second case will be a bit harder to solve nicely..
I would like to be able, to accept any slice. In the example in my first
post, I need this for key[0..16] and key[16..$] (which are slices).
Strangely enough, the solution I am leaning towards at the moment also
uses length, but it does work for slices of static arrays (i.e. key[0..16]):
template expand(alias A)
{
auto ref M(alias I)() @property { return A[I]; }
mixin(q{alias expand = TypeTuple!(}
~ iota(A.length).map!(a => "M!" ~ a.to!string).join(",")
~ q{);});
}
ubyte[64] buf = [expand!sigma0,
expand!key[0..16],
expand!sigma1,
expand!n,
expand!sigma2,
expand!key[16..$],
expand!sigma3];
I suppose this is because the length of those slices is actually known
at copiletime, but it looks a bit strange to me...
I was trying to write another template that takes several arrays and
expands all of them:
template expand(Args...)
{
mixin(q{alias expand = TypeTuple!(}
~ iota(Args.length).map!(a => "expand!(Args[" ~ a.to!string ~
"])").join(",")
~ q{);});
}
It works for static arrays, but not for slices, because the template
parameters are not alias parameters, so the length is then not "known"
at compile time (at least that's what I think why it fails). Is there a
way to specify variadic templates taking any number of alias template
parameters?
Re: Dynamic arrays, emplace and GC
On Tuesday, 5 July 2016 at 13:48:46 UTC, Claude wrote: Ah ok. I tried using void[size] static array and it seems to work without having to use GC.addRange(). Correct. void[] means the type of the data is unknown, so the GC has to assume it can contain pointers. This also means that _everything_ in any void buffer has to be treated as a potential pointer. In other words, if you allocate a void buffer and fill it with ints, and one of those ints happens to have a value equal to the address of a GC-allocated object, the GC will assume the int is a pointer to that object and not free it.
Re: Initializing static array with contents of (static and dynamic) arrays
On Tuesday, 5 July 2016 at 12:34:20 UTC, Johannes Loher wrote: I tried this, but it does not work correctly with slices. The length of a slice is a runtime value, which is why it can't be used to set static array size. What were you trying to achieve? Avoid copying the input arrays, or accepting any slice? In case of the first, you can put ref in front of the Args: auto combineArrays(Args...)(ref Args args) The second case will be a bit harder to solve nicely..
Re: Possible bug
On Tuesday, 5 July 2016 at 13:48:50 UTC, ag0aep6g wrote: Something is also going wrong in dmd. There should be a deprecation message. Exactly.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 13:37:50 UTC, ketmar wrote: you *can* workaround this limitation for now. it won't be the cleanest code in the world, but you can do it. hint: alias this + returning temporary struct with pointer. Of course, I can. I have been creating a lot of such workarounds with C++ for years. And this is one of the flaws of C++ - for every simple task (like a delegate or properties) you need to create a workaround because C++ standardization Committee thinks that it shouldn't be a part of the language.
Re: Error: incompatible types for 'shared(SysTime)' and 'shared(SysTime)'
On 07/05/2016 07:25 AM, ketmar wrote: cast `shared` away. yes, this is how you supposed to use it now: cast it away. after having ensured thread safety that is
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 13:37:50 UTC, ketmar wrote: if this minor thing blocks you from using D... alas. otherwise, just make a workaroung and keep going. *eventually* this will be fixed, but you'd better don't wait for it. No, this issue doesn't block me from using D. I'm asking because I encountered with a few things (like this one), which seems like they're a bit "unfinished". For example: http://forum.dlang.org/post/mailman.1463.1361561853.22503.digitalmars-d-le...@puremagic.com : "Don't use 'in', because it doesn't mean what it seems to mean, and it's not correctly implemented at the moment." http://forum.dlang.org/post/lgqcjiuigsseoazir...@forum.dlang.org - "cast `shared` away. yes, this is how you supposed to use it now: cast it away." Reading topics like these doesn't add confidence. But don't get me wrong, I don't want to say that "D is unfinished" or "D has a bad design". I don't know it good enough to make such loud statements. I'm just trying to figure out what D is and how can I use it. Answering your other question: I think that production ready language should have a "finished" design and its detailed description (not a basic overview of the features).
Re: Possible bug
On 07/05/2016 12:47 PM, Jack Applegame wrote:
ttt.d
import std.string;
void main() {
lastIndexOf("aa","bb");
}
rdmd ttt.d
compiles successfully without any errors or warnings
rdmd -dw ttt.d
compiles successfully without any errors or warnings
rdmd -de ttt.d
/usr/include/dmd/phobos/std/string.d(1239): Error: template
std.algorithm.searching.endsWith cannot deduce function from argument
types !((a, b) => std.uni.toLower(a) ==
std.uni.toLower(b))(const(char)[], const(char)[]), candidates are:
[...]
There sure is at least one bug. I guess this has to do with recent
changes to symbol lookup/visibility rules.
On the line from the error message there are fully qualified references
to std.uni.toLower, but std.uni isn't imported as a module. This can
easily be fixed in phobos. I've filed an issue:
https://issues.dlang.org/show_bug.cgi?id=16238
Something is also going wrong in dmd. There should be a deprecation message.
Re: Dynamic arrays, emplace and GC
On Tuesday, 5 July 2016 at 12:43:14 UTC, ketmar wrote: On Tuesday, 5 July 2016 at 10:04:05 UTC, Claude wrote: So here's my question: Is it normal??? yes. `ubyte` arrays by definition cannot hold pointers, so GC doesn't bother to scan 'em. Ah ok. I tried using void[size] static array and it seems to work without having to use GC.addRange().
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 13:14:29 UTC, zodd wrote: Why do you have so pessimistic opinion? it is realistic. Is D a perspective language to learn or it's stagnating and never be production ready? what do you want here: "non-stagnating" or "production ready"? D is "production ready", and that means that D should be STABLE. we can't introduce features just 'cause they are cool. we can't even change the features without long and hard discussion. if we'll finalize property specs, we'll stick with it forever. and devs have many other things to do too, most of it for free and in their spare time. that's why finalizing properties is postponed, for undefined time. you *can* workaround this limitation for now. it won't be the cleanest code in the world, but you can do it. hint: alias this + returning temporary struct with pointer. and, of course, you can hire Walter or Andrei on a full time to implement the feature you want. otherwise -- this is minor thing, which, nevertheless, require a huge amout of design work. it is unlikely that language devs will drop all other things, and go design and implementing it. and DIP will not help much: W&A still should evaluate it, and it's almost as hard as writing it from scratch. if this minor thing blocks you from using D... alas. otherwise, just make a workaroung and keep going. *eventually* this will be fixed, but you'd better don't wait for it.
Re: Properties don't work as expected
On 7/5/16 6:52 AM, zodd wrote: Is there a chance, that this weird behavior will be fixed in the near future? What can I do to help fix it? Properties do not support read-modify-write operations. You can return a reference, or return a wrapper type to enable the operations you want. D does not support any of the normally-expected property rewrites that many languages do. For example: a.b.c = 5 where b is a property may not do what you expect. It has been suggested in the past to have this behavior, but I doubt it will happen. It's possible to write such mechanisms as a library, but I've never seen someone do it. -Steve
Re: Properties don't work as expected
D is being used productively by some companies, so I guess we can call it production-ready. This doesn't meant there are not rough corners. The language is being actively developed, and I see that some work is being done on those rough corners. However, keep in mind that: 1) Maybe what you perceive as a strong deficiency isn't seen as a top priority for the D developers. This issue with properties, for instance, is annoying (I agree with you!), but most of the time (if not ever) it can be easily circumvented (as Satoshi has shown). 2) Sometimes, changing language features have subtle side effects, and the devs must take everything into account. A fix that looks obvious for us mere mortals can actually open a can of worms and introduce many new issues. Hope this answers your quesiton, LMB On Tue, Jul 5, 2016 at 10:14 AM, zodd via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote: > On Tuesday, 5 July 2016 at 12:45:33 UTC, ketmar wrote: > >> Is there a chance, that this weird behavior will be fixed in the near >>> future? What can I do to help fix it? >>> >> >> almost as much as you can expect snowfall in hell. >> > > Why do you have so pessimistic opinion? Is D a perspective language to > learn or it's stagnating and never be production ready? >
Re: Implementing a cache
On 7/2/16 8:10 AM, qznc wrote: I want to implement some caching for HTTP GET requests. Basically a map of URL to content. A cache needs some additional meta data (size, age, etc). There seem to be two basic data structures available: Associative array (AA) or red black tree (RBT). With AA cache eviction is inefficient. It requires to sort the keys of the AA with respect to a field in the value. Stack overflow says "use RBT instead" [0]. With RBT retrieving something is inefficient. To get an entry, we need to create an fake entry with the key> and get a range of entries 'equal' to the fake one? Yes, it is annoying to have to deal with creating a fake element. In dcollections, I have a TreeMap wrapper which does this for you: https://github.com/schveiguy/dcollections/blob/master/dcollections/TreeMap.d#L881 We should probably add support for the searching functions that allows parameters other than full elements if the element supports comparison with that type. In terms of using equalRange, it should be pretty efficient. If you are allowing duplicates, then it does 2 binary searches (one for the beginning node and one for the end). If no duplicates, one binary search, and the equalRange will be 0 or 1 element (depending on if the key is present). Or can I exploit some "find on sorted range" algorithm somewhere? There is find on sorted range support in std.algorithm, but it must be a random-access range. RBTree range is not RA. What's wrong with the binary search support in the tree itself? -Steve
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 12:45:33 UTC, ketmar wrote: Is there a chance, that this weird behavior will be fixed in the near future? What can I do to help fix it? almost as much as you can expect snowfall in hell. Why do you have so pessimistic opinion? Is D a perspective language to learn or it's stagnating and never be production ready?
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote: It's a very inconvenient. Why don't just call a getter and then a setter functions in such cases? 'cause property specs aren't even finalized yet. Is there a chance, that this weird behavior will be fixed in the near future? What can I do to help fix it? almost as much as you can expect snowfall in hell.
Re: Dynamic arrays, emplace and GC
On Tuesday, 5 July 2016 at 10:04:05 UTC, Claude wrote: So here's my question: Is it normal??? yes. `ubyte` arrays by definition cannot hold pointers, so GC doesn't bother to scan 'em.
Re: Initializing static array with contents of (static and dynamic) arrays
Am 05.07.2016 um 00:41 schrieb Rene Zwanenburg: > On Monday, 4 July 2016 at 19:22:52 UTC, Johannes Loher wrote: >> This looks really nice, but I have several occurences of this, with >> different arrays (and lengths), so i would need to create several of >> those structs. But it looks really clean :) > > You can use a template to remove the boilerplate. Here's a quick example: > > https://dpaste.dzfl.pl/43b379992648 I tried this, but it does not work correctly with slices.
Re: Probably trivial Linux link problem that I've spent hours on.
Am Tue, 5 Jul 2016 00:37:54 -0700 schrieb Ali Çehreli : > On 07/04/2016 08:32 PM, WhatMeWorry wrote: > > > /usr/bin/ld: cannot find -lsqlite3 > > collect2: error: ld returned 1 exit status > > I had the same issue when building Button with dub on Ubuntu 16.04. > My hack was to create the following symlink to the already existing > libsqlite3.so.0: > >sudo ln -s /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 > /usr/lib/x86_64-linux-gnu/libsqlite3.so > > Ali > Some time ago Debian (and therefore Ubuntu as well) moved the unversioned .so symlinks into the -dev packages. This means you'll always need the -dev packages now when linking with a C library, even if you only use the dynamic library.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 11:02:11 UTC, Satoshi wrote:
On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote:
Property functions are used wrong by a compiler when it needs
to get and set a value at the same time:
[...]
Try
@property ref int value() {
return value_;
}
What if I need a setter function? I would never bother with
properties and just used the field itself otherwise.
Re: Properties don't work as expected
On Tuesday, 5 July 2016 at 10:52:10 UTC, zodd wrote:
Property functions are used wrong by a compiler when it needs
to get and set a value at the same time:
[...]
Try
@property ref int value() {
return value_;
}
Properties don't work as expected
Property functions are used wrong by a compiler when it needs to
get and set a value at the same time:
import std.stdio;
struct A {
@property int value() const {
return value_;
}
@property ref int value(int v) {
value_ = v;
return value_;
}
private:
int value_;
}
int main(string[] args) {
A a;
a.value += 20; // < Error: a.value() is not an lvalue
return 0;
}
It's a very inconvenient. Why don't just call a getter and then a
setter functions in such cases?
I found the D language specification and it doesn't bother to
explain how properties should behave in such cases. Is there a
full language specification somewhere?
Also, I've googled a little and found a similar topic from 2012
(http://forum.dlang.org/thread/srhwzxgpiqucknche...@forum.dlang.org). So, since 2012 nobody cared about it? What a shame!
Even a D Wiki page with properties discussion
(https://wiki.dlang.org/Property_Discussion_Wrap-up) gives an
example of property usage, which can't be compiled by the latest
version of dmd:
a.weeks++;
a.weeks -=2;
Is there a chance, that this weird behavior will be fixed in the
near future? What can I do to help fix it?
Possible bug
ttt.d
import std.string;
void main() {
lastIndexOf("aa","bb");
}
rdmd ttt.d
compiles successfully without any errors or warnings
rdmd -dw ttt.d
compiles successfully without any errors or warnings
rdmd -de ttt.d
/usr/include/dmd/phobos/std/string.d(1239): Error: template
std.algorithm.searching.endsWith cannot deduce function from
argument types !((a, b) => std.uni.toLower(a) ==
std.uni.toLower(b))(const(char)[], const(char)[]), candidates
are:
/usr/include/dmd/phobos/std/algorithm/searching.d(981):
std.algorithm.searching.endsWith(alias pred = "a == b", Range,
Needles...)(Range doesThisEnd, Needles withOneOfThese) if
(isBidirectionalRange!Range && Needles.length > 1 &&
is(typeof(.endsWith!pred(doesThisEnd, withOneOfThese[0])) :
bool) && is(typeof(.endsWith!pred(doesThisEnd,
withOneOfThese[1..__dollar])) : uint))
/usr/include/dmd/phobos/std/algorithm/searching.d(1048):
std.algorithm.searching.endsWith(alias pred = "a == b", R1,
R2)(R1 doesThisEnd, R2 withThis) if (isBidirectionalRange!R1 &&
isBidirectionalRange!R2 &&
is(typeof(binaryFun!pred(doesThisEnd.back, withThis.back)) :
bool))
/usr/include/dmd/phobos/std/algorithm/searching.d(1076):
std.algorithm.searching.endsWith(alias pred = "a == b", R, E)(R
doesThisEnd, E withThis) if (isBidirectionalRange!R &&
is(typeof(binaryFun!pred(doesThisEnd.back, withThis)) : bool))
/usr/include/dmd/phobos/std/algorithm/searching.d(1086):
std.algorithm.searching.endsWith(alias pred, R)(R doesThisEnd)
if (isInputRange!R && ifTestable!(typeof(doesThisEnd.front),
unaryFun!pred))
ttt.d(4): Error: template instance
std.string.lastIndexOf!(char, char) error instantiating
Dynamic arrays, emplace and GC
Hello,
I've been working on some kind of allocator using a dynamic array
as a memory pool. I used emplace to allocate class instances
within that array, and I was surprised to see I had to use
GC.addRange() to avoid the GC to destroy stuff referenced in that
array.
Here's a chunk of code[1]:
struct Pool(T)
{
public:
T alloc(Args...)(Args args)
{
mData.length++;
import core.memory : GC;
//GC.addRange(mData[$ - 1].data.ptr, mData[$ -
1].data.length);
import std.conv : emplace;
auto t = emplace!T(mData[$ - 1].data, args);
return t;
}
private:
struct Storage
{
ubyte[__traits(classInstanceSize, T)] data;
}
Storage[] mData;
}
class Foo
{
this(int a)
{
aa = a;
}
~this()
{
import std.stdio; writefln("DTOR");
aa = 0;
}
int aa;
}
class Blob
{
this(int b)
{
foo = new Foo(b);
}
Foo foo;
}
void main()
{
Pool!Blob pool;
Blob blob;
foreach(a; 0 .. 1)
{
blob = pool.alloc(6);
}
while(true){}
import std.stdio; writefln("END");
}
Basically Blob instances are allocated in the array using
emplace. And Blob creates references to Foo. If I comment out
GC.addRange(), I see that Foo destructor is called by the GC[2].
If I leave it uncommented, the GC leaves the array alone.
So here's my question: Is it normal???
I thought that allocating memory in a dynamic array using
"mData.length++;" was GC-compliant (unlike
core.stdc.stdlib.malloc()), and I did not have to explictly use
GC.addRange().
[1] I left out alignment management code. It's not the issue here.
[2] I used the helpful destructor tracker function of p0nce
there: https://p0nce.github.io/d-idioms/#GC-proof-resource-class
Re: Asynchronous Programming and Eventhandling in D
Hello, It looks interesting. This is now my current list of asynchronous libraries written in D (not a C lib wrapper). Collie : https://github.com/putao-dev/collie libasync : https://github.com/etcimon/libasync eventcore : https://github.com/vibe-d/eventcore asynchronous: https://github.com/dcarp/asynchronous A benchmarking test suite is still missing. We need a reference to compare performance of the libraries.
Re: Most elegant way for split array of struct into components
On 07/05/2016 01:10 AM, Miguel L wrote:
> could it be possible to implement some class or
> struct method that works on an array of objects of that class or method?
>
> class A
> {
> void Y(A[] a){...}
> }
>
> A[] array;
> array.Y();
>
Yes, but that normally belongs outside the type. Luckily, D's UFCS
feauter lets one call a non-member function as if it's a member function:
import std.stdio;
import std.algorithm;
import std.range;
class A {
int i;
this(int i) {
this.i = i;
}
}
// Not a member:
void Y(A[] a){
foreach (e; a) {
writefln("working with %s", e.i);
}
}
void main() {
A[] array = iota(5).map!(i => new A(i)).array;
// Can be called like a member:
array.Y();
}
Still, it's debatable whether an array-processing functions should be
executed with the member function syntax. I would write Y(array). When
you discover the ranges, you will realize that instead of defining
functions like Y that contain explicit loops, combining functions that
work with just a single A is more maintainable, scalable, and almost
always faster (sometimes you won't need to hold actual arrays of anything).
void y(A a) {
writefln("working with %s", a.i);
}
void main() {
// Objects are created but not a single array is in sight:
iota(5)
.map!(i => new A(i))
.each!y;
}
The output is the same:
working with 0
working with 1
working with 2
working with 3
working with 4
Ali
Asynchronous Programming and Eventhandling in D
Hi ("Grüss Gott")
I like the asynchronous events in Javascript.
Is something similar possible in D?
Found Dragos Carp's asynchronous library
(https://github.com/dcarp/asynchronous).
Are there any more integrated (in Phobos/in D) ways to work
asynchronously?
An example: One server ask a second server to calculate something
big.
The first server continues with his work, until the answer come
back from the second.
And so on...
Using threads or fibers would be a way, but has not the same
elegancy like the Javascript way. (To avoid discussions: D is
better ;-)
Greetings from Munich,
Ozan
Re: Most elegant way for split array of struct into components
On Tuesday, 5 July 2016 at 07:33:40 UTC, Ali Çehreli wrote:
On 07/04/2016 11:07 PM, Miguel L wrote:
> [...]
> [...]
my_array?
The simplest is to pick the element by std.algorithm.map:
[...]
Thank you Ali, that works.
On the same subject, could it be possible to implement some class
or struct method that works on an array of objects of that class
or method?
class A
{
void Y(A[] a){...}
}
A[] array;
array.Y();
Sorry for my ignorance, i am just starting to work in D.
Re: Probably trivial Linux link problem that I've spent hours on.
On 07/04/2016 08:32 PM, WhatMeWorry wrote: > /usr/bin/ld: cannot find -lsqlite3 > collect2: error: ld returned 1 exit status I had the same issue when building Button with dub on Ubuntu 16.04. My hack was to create the following symlink to the already existing libsqlite3.so.0: sudo ln -s /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 /usr/lib/x86_64-linux-gnu/libsqlite3.so Ali
Re: Most elegant way for split array of struct into components
On 07/04/2016 11:07 PM, Miguel L wrote:
> struct A
> {
> int x;
> int y;
> }
> would be the best way to get an array of x or y component of my_array?
The simplest is to pick the element by std.algorithm.map:
import std.stdio;
import std.range;
import std.array;
import std.algorithm;
struct A {
int x;
int y;
}
void main() {
A[] my_array = iota(3)
.map!(i => A(i, 11 * i))
.array;
writeln("The whole array:");
writeln(my_array);
writeln("Just the x members");
auto xs = my_array.map!(a => a.x);
writeln(xs);
writeln("Just the y members");
auto ys = my_array.map!(a => a.y);
writeln(ys);
}
Prints
The whole array:
[A(0, 0), A(1, 11), A(2, 22)]
Just the x members
[0, 1, 2]
Just the y members
[0, 11, 22]
map has a shortcut: If there is a function foo that takes A, then you
can do just this:
writeln(my_array.map!foo);
(foo can be a member function or a non-member function.)
With the great risk of polluting the namespace, here is a draft of
creating non-member accessor functions automatically:
string memberAccessors(T)() {
import std.string;
string accessors;
foreach(m; __traits(allMembers, T)) {
accessors ~= format("auto %s(%s a) { return a.%s; }\n", m,
T.stringof, m);
}
return accessors;
}
mixin(memberAccessors!A);
That generates and mixes in accessor functions for each member. A
pragma(msg) can show what is generated:
pragma(msg, memberAccessors!A);
Prints at compile time:
auto x(A a) { return a.x; }
auto y(A a) { return a.y; }
(Crazy idea. :) )
But then, it's as simple as the following:
writeln(my_array.map!y);
Ali
Re: Probably trivial Linux link problem that I've spent hours on.
On Tuesday, 5 July 2016 at 03:32:25 UTC, WhatMeWorry wrote: Just learning Linux. Got my first vibe/dub project which dies at: Compiling diet template 'index.dt'... Linking... /usr/bin/ld: cannot find -lsqlite3 collect2: error: ld returned 1 exit status I downloaded DUB's d2sqlite3 and built it fine. I've got sqlite3 on my system by default (came with Xununtu) I You need *-dev package probabily. Something like: sudo apt-get install libsqlite3-dev Andrea
