Re: PHP to D Conversion
On Friday, 18 October 2019 at 06:22:33 UTC, Vino wrote:
Hi All,
Request your help in converting a PHP code to D equivalent
code
You can get one connection object and close it :)
```D
import hunt.database;
class AvmTest {
private Database _db;
this() {
_db = new
Database("mysql://testusr:x...@test.srv.com:3910/test");
}
string[string][] getHostname() {
string[string][] data;
auto conn = _db.getConnection();
foreach(row; conn.query("SELECT host_name FROM
hosts_coll"))
{
string[string] host;
host["HostName"] = row["host_name"];
data ~= host;
}
conn.close();
return data;
}
}
```
Re: PHP to D Conversion
On Monday, 21 October 2019 at 15:36:25 UTC, Andre Pany wrote:
On Monday, 21 October 2019 at 15:29:33 UTC, zoujiaqing wrote:
On Friday, 18 October 2019 at 06:22:33 UTC, Vino wrote:
[...]
import hunt.database;
class avmtest {
private Database db;
this() {
db = new
Database("mysql://testusr:x...@test.srv.com:3910/test");
}
string[string][] getHostname() {
string[string] data;
foreach(row; db.query("SELECT host_name FROM hosts_coll"))
{
string[string] host;
host["HostName"] = row["host_name"];
data ~= host;
}
return data;
}
}
Is this database library compatible with the fiber programming
model of vibe-d?
Kind regards
Andre
Yes.
There are no conflicts.
Re: exceptions and optimization
On Monday, 21 October 2019 at 21:09:32 UTC, Peter Jacobs wrote: On Monday, 21 October 2019 at 20:37:32 UTC, Nicholas Wilson wrote: What kind of conditions are you wanting to throw exception on? infinities, NaNs, ill conditioning, something else? As always the best way to check is to mark the function of interest, nothrow take a look at the disassembly and compare to without nothrow. You may also want to look to the optimisation summary that I _think_ you can get LDC to generate. Our methods take a few short cuts and occasionally step over a stability boundary, so I guess that it may look like ill-conditioning. The reason I asked that is to see what sort of action you take because there may be better architectures that you can use to handle that kind of change. For example, you are integrating with some scheme and hit a region of high curvature and need to rollback and change scheme (to either a less coarse time step or better integrator). In which case it may be best to take a page out of databases and use a change-commit kind of approach to short circuit through your calculations and if at the end of your update loop a flag is set that says this update is invalid then retry with another scheme. Thank you for the explanation and suggestions.
Re: exceptions and optimization
On Monday, 21 October 2019 at 20:37:32 UTC, Nicholas Wilson wrote: What kind of conditions are you wanting to throw exception on? infinities, NaNs, ill conditioning, something else? As always the best way to check is to mark the function of interest, nothrow take a look at the disassembly and compare to without nothrow. You may also want to look to the optimisation summary that I _think_ you can get LDC to generate. Our methods take a few short cuts and occasionally step over a stability boundary, so I guess that it may look like ill-conditioning. Thank you for the explanation and suggestions.
Re: contains method on immutable sorted array
On Monday, 21 October 2019 at 10:14:54 UTC, Andrey wrote:
Hello,
I have got a global constant immutable array:
immutable globalvalues = sort(cast(wstring[])["й", "ц", "ук",
"н"]);
Somewhere in program I want to check an existance:
globalvalues.contains("ук"w).writeln;
But get an error:
Error: template std.range.SortedRange!(wstring[], "a <
b").SortedRange.contains cannot deduce function from argument
types !()(wstring) immutable, candidates are:
/dlang/ldc-1.17.0/bin/../import/std/range/package.d(10993):
std.range.SortedRange!(wstring[], "a <
b").SortedRange.contains(V)(V value) if
(isRandomAccessRange!Range)
Why I can't check?
pragma(msg,typeof(globalvalues));
gives immutable(SortedRange!(wstring[], "a < b"))
and
(cast(SortedRange!(wstring[], "a <
b"))globalvalues).contains("ук"w).writeln;
works, so I guess contains doesn't work with immutable?
If you can do some more research into this and confirm it then,
please file a bug report.
Re: exceptions and optimization
On Monday, 21 October 2019 at 20:12:19 UTC, Peter Jacobs wrote: Toward the end of Walter's recent talk, D at 20, he says something to the effect that optimizations are disabled when exceptions can be thrown. We have a compressible flow solver in which it is very convenient to be able to throw an exception from deep within the code and catch it at a relatively high level where we can partially recover and continue the calculation. Because our calculations can run for days across hundreds of processors, we also care about letting the optimizer do its best. In what parts of our program would the optimizer be disabled because of the presence of the exception and its handling code? How do we tell? It really comes into effect if you use: a) structs with destructors b) scope(exit) and scope(failure) as these need to be run, regardless of the return mode of the function i.e. normally or via an exception. Also if the function is nothrow (possibly inferred because its a template, n.b. also that nothrow function can throw Errors as these are considered terminal) then you should also be fine. The effect of exceptions on optimisation effect logic heavy code a lot more that math heavy code. What kind of conditions are you wanting to throw exception on? infinities, NaNs, ill conditioning, something else? As always the best way to check is to mark the function of interest, nothrow take a look at the disassembly and compare to without nothrow. You may also want to look to the optimisation summary that I _think_ you can get LDC to generate.
exceptions and optimization
Toward the end of Walter's recent talk, D at 20, he says something to the effect that optimizations are disabled when exceptions can be thrown. We have a compressible flow solver in which it is very convenient to be able to throw an exception from deep within the code and catch it at a relatively high level where we can partially recover and continue the calculation. Because our calculations can run for days across hundreds of processors, we also care about letting the optimizer do its best. In what parts of our program would the optimizer be disabled because of the presence of the exception and its handling code? How do we tell?
Re: Small program producing binary with large filesize
On Wednesday, 1 August 2018 at 15:58:53 UTC, Jacob Shtokolov wrote: On Tuesday, 31 July 2018 at 15:19:19 UTC, Dan Barbarito wrote: Hi all, I am starting to write a command line tool. Hi! First, Vibe.d will increase your binary size because it contains a lot of unnecessary things inside it. So instead of using the entire vibe.d library, you may point dub to specific vibe.d parts, like `vibe.d:core`, `vibe.d:http` etc. If you put the whole vibe.d framework as a dub dependency and use it like `import vibe;` the things like mongodb drivers, email libraries, redis driver etc. will be linked to your binary as well, even if you don't need them. Second, you need to compile your code in the release mode to cut all debug information out of it. Also, you can try to use the `strip` command line tool to cut all export symbols if your binary is an executable file, not a library. This will reduce the size. In some cases a lot. The third thing is already mentioned: by default, the DMD compiler builds and links the code statically. In other words, your binary contains parts of the DRuntime and the Phobos libraries (those parts that you've used in your program). This thing helps to distribute compiled binaries without external dependencies (except libc and libpthread), because your binary is already contains all needed stuff. If you're not happy with it, you can try to use the LDC compiler, which uses the dynamic linking by default. Your binary will be really tiny, but in order to execute it, you'll need to have the libdruntime.so and libphobos.so installed in your system. This may add additional issues if you plan to distribute your program. Sadly, we still don't have the D runtime libraries installed in all popular OSes. Currently only the libc has this privilege I hope the situation will change in the future. Hi, I was trying with ldc (source ~/dlang/ldc-1.17.0/activate) and the size of binary is even worse dub with dmd 2.89 MB dub with ldc 3.50 MB It is very simple program but use derelict-gl3 and derelict-sdl2 I want to link them all dynamically (I don't plan to distribute binary any time soon) What exactly should I specify to make it link dynamcially and produce as small binary as possible (without increasing compilation time) ?
Re: ... use of ... is hidden by ...; use alias ... to introduce base class overload set ??
On 2019-10-21 07:04:33 +, John Chapman said:
This should work:
class FilterSubject : SubjectObject!message {
alias subscribe = typeof(super).subscribe;
Disposable subscribe(myWidget observer){...}
}
This now gives:
rx_filter_subject.d(66,23): Error:
rx_filter_subject.FilterSubject.subscribe called with argument types
(myWidget) matches both:
/Users/robby/.dub/packages/rx-0.13.0/rx/source/rx/subject.d(72,16):
rx.subject.SubjectObject!(message).SubjectObject.subscribe!(myWidget).subscribe(myWidget
observer)
and:
rx_filter_subject.d(47,14):
rx_filter_subject.FilterSubject.subscribe(myWidget observer)
So, now there is an ambiguty.
--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster
Re: PHP to D Conversion
On Monday, 21 October 2019 at 15:29:33 UTC, zoujiaqing wrote:
On Friday, 18 October 2019 at 06:22:33 UTC, Vino wrote:
[...]
import hunt.database;
class avmtest {
private Database db;
this() {
db = new
Database("mysql://testusr:x...@test.srv.com:3910/test");
}
string[string][] getHostname() {
string[string] data;
foreach(row; db.query("SELECT host_name FROM hosts_coll"))
{
string[string] host;
host["HostName"] = row["host_name"];
data ~= host;
}
return data;
}
}
Is this database library compatible with the fiber programming
model of vibe-d?
Kind regards
Andre
Re: PHP to D Conversion
On Friday, 18 October 2019 at 06:22:33 UTC, Vino wrote:
Hi All,
Request your help in converting a PHP code to D equivalent
code
PHP Code:
class avmtest {
private $con;
function __construct() {
global $config;
$this->con = new mysqli(test.srv.com:3910,
testusr, #, test);
if($this->con->connect_errno) { die("Connection
Failed.\n"); }
}
function getHostname() {
$qdata = $this->con->prepare("SELECT host_name
FROM hosts_coll");
$qdata->execute();
$qdata->bind_result($host);
while($qdata->fetch()) {
$data[] = array("HostName" => $host);
}
$sdata->close();
return $data;
}
}
D Code:
module avm.test;
import mysql;
import std.array : array;
import std.conv;
import std.variant;
class avmtest
{
private conn;
auto avmconnect()
{
auto connectionStr =
"host=test.srv.com;port=3910;user=testusr;pwd=#;db=test";
Connection conn = new Connection(connectionStr);
scope(exit) conn.close();
}
auto getHostname()
{
ResultRange qdata = conn.query("SELECT host_name FROM
`hosts_coll`");
Row row = qdata.front;
Variant h = row[0];
qdata.close();
return h.to!string;
}
}
Error: Error: no identifier for declarator conn
From,
Vino.B
import hunt.database;
class avmtest {
private Database db;
this() {
db = new
Database("mysql://testusr:x...@test.srv.com:3910/test");
}
string[string][] getHostname() {
string[string] data;
foreach(row; db.query("SELECT host_name FROM hosts_coll"))
{
string[string] host;
host["HostName"] = row["host_name"];
data ~= host;
}
return data;
}
}
Re: PHP to D Conversion
On Monday, 21 October 2019 at 11:36:00 UTC, Vino wrote: On Saturday, 19 October 2019 at 20:40:36 UTC, Boris Carvajal wrote: [...] Hi Boris, [...] Hi, Where do you call avmconnect? Is this.conn null when connection fails? What happens if the query does not contains rows? Kind regards Andre
Re: PHP to D Conversion
On Saturday, 19 October 2019 at 20:40:36 UTC, Boris Carvajal
wrote:
On Saturday, 19 October 2019 at 19:08:45 UTC, Vino wrote:
On Friday, 18 October 2019 at 14:56:05 UTC, Andre Pany wrote:
On Friday, 18 October 2019 at 09:21:46 UTC, Vino wrote:
On Friday, 18 October 2019 at 09:17:24 UTC, Vino wrote:
[...]
And now getting the error : Program exited with code
-1073741819
Hi,
Maybe port 8080 is blocked, because there is an instance of
your application running on the background. Just check by
changing the port in the source code.
Kind regards
Andre
Hi Andre,
Tried with different ports still no luck getting this error
: Program exited with code -1073741819.
From,
Vino.B
Your program is crashing probably because you are dereferencing
a null/ dangling pointer.
Build your program in debug mode and run it in a debugger, that
way you will get a backtrace telling you the exactly line of
the code when it happens.
Hi Boris,
I tired to build the code in debug mode and ran the program in
debugger , the debugger is complaining about the line "this.conn
= new Connection(connectionStr);", not sure what is wrong in the
below code, hence request your help. Have the checked the
connection string and the info is correct.
import vibe.vibe;
import mysql;
import std.array : array;
import std.conv;
import std.variant;
class avmtest
{
private Connection conn;
auto avmconnect()
{
auto connectionStr =
"host=test.srv.com;port=3910;user=testusr;pwd=#;db=test";
this.conn = new Connection(connectionStr);
}
auto getHostname()
{
ResultRange qdata = conn.query("SELECT host_name FROM
`hosts_coll`");
Row row = qdata.front;
Variant h = row[0];
qdata.close();
return h.to!string;
}
}
void hello(HTTPServerRequest req, HTTPServerResponse res)
{
auto t = new avmtest();
res.writeBody(t.getHostname);
}
void main()
{
auto settings = new HTTPServerSettings;
settings.port = 8130;
settings.bindAddresses = ["127.0.0.1"];
listenHTTP(settings, );
logInfo("Please open http://127.0.0.1:8130/ in your browser.");
runApplication();
}
From,
Vino.B
contains method on immutable sorted array
Hello,
I have got a global constant immutable array:
immutable globalvalues = sort(cast(wstring[])["й", "ц", "ук",
"н"]);
Somewhere in program I want to check an existance:
globalvalues.contains("ук"w).writeln;
But get an error:
Error: template std.range.SortedRange!(wstring[], "a <
b").SortedRange.contains cannot deduce function from argument
types !()(wstring) immutable, candidates are:
/dlang/ldc-1.17.0/bin/../import/std/range/package.d(10993):
std.range.SortedRange!(wstring[], "a <
b").SortedRange.contains(V)(V value) if
(isRandomAccessRange!Range)
Why I can't check?
SQL Questions Query
Hello Everyone, I am looking for SQL interview questions list. I have scheduled my interviews in the upcoming week, Recruiters told me they might test my SQL knowledge too. What kind of questions should I expect? One is a consultant swe / data scientist and the other is an application developer.
Re: Any 3D Game or Engine with examples/demos which just work (compile) out of the box on linux ?
On Sunday, 20 October 2019 at 22:48:25 UTC, Jonathan Marler wrote:
On Friday, 18 October 2019 at 06:11:37 UTC, Ferhat Kurtulmuş
wrote:
On Friday, 18 October 2019 at 05:52:19 UTC, Prokop Hapala
wrote:
Already >1 year I consider to move from C++ to Dlang or to
Rust in my hobby game development (mostly based on physical
simulations
https://github.com/ProkopHapala/SimpleSimulationEngine). I
probably prefer Dlang because it compiles much faster, and I
can copy C/C++ code to it without much changes.
[...]
I cannot make any comment for others. But Dagon should work. I
wrote a very little demo game some time ago
https://github.com/aferust/dagon-shooter. I didn't try to
compile and run it on Linux.I think you need to have a
nuklear.so in your path, since Bindbc loaders try to load
It looks like the maintainer of dagon changed the API a lot. I
could run my demo game using version 0.10.0. dub.json:
{
"description": "My first project",
"dependencies": {
"dagon": "0.10.0",
"bindbc-soloud": "*"
},
"authors": [
"aferust"
],
"copyright": "Copyright © 2019, aferust",
"license": "Boost",
"name": "dagon-shooter"
}
But texture rendering seems weird for some reason. Obviously,
dagon-shooter needs some updates according to new dagon API
Re: ... use of ... is hidden by ...; use alias ... to introduce base class overload set ??
On Sunday, 20 October 2019 at 21:45:35 UTC, Robert M. Münch wrote:
class myWidget : Observer!message {...}
class FilterSubject : SubjectObject!message {
Disposable subscribe(myWidget observer){...}
}
I tried to add "alias subscribe = SubjectObject.subscribe;" in
different places, but that didn't help. Nor do I have any how
that should help...
This should work:
class FilterSubject : SubjectObject!message {
alias subscribe = typeof(super).subscribe;
Disposable subscribe(myWidget observer){...}
}
