Throw exception on segmentation fault in GNU/Linux
What should I add in the D program in GNU/Linux to throw exception if I have segmentation fault error? I read somewhere that it's possible, but I don't know how to do it.
Re: Throw exception on segmentation fault in GNU/Linux
On Tuesday, 22 April 2014 at 14:49:58 UTC, Dicebot wrote: On Tuesday, 22 April 2014 at 09:58:45 UTC, ilya-stromberg wrote: What should I add in the D program in GNU/Linux to throw exception if I have segmentation fault error? I read somewhere that it's possible, but I don't know how to do it. etc.linux.memoryerror Just remember that it is more of hack than reliable production-ready solution ;) Thanks. How shall I use the module? Should I just import it or call any init function?
Re: Any library with OAuth support?
On Wednesday, 22 January 2014 at 11:58:17 UTC, Rikki Cattermole wrote: On Wednesday, 22 January 2014 at 11:14:22 UTC, ilya-stromberg wrote: Do you know any library with OAuth support? Not currently. But I can add it to my todo list for Cmsed[0]. [0] https://github.com/rikkimax/Cmsed Yes, it will be great.
Any library with OAuth support?
Do you know any library with OAuth support?
Re: Any library with OAuth support?
On Wednesday, 22 January 2014 at 14:54:00 UTC, Adam D. Ruppe wrote: On Wednesday, 22 January 2014 at 11:14:22 UTC, ilya-stromberg wrote: Do you know any library with OAuth support? I did one extremely biased toward what I needed to do: Do you have OAuth server implementation?
Any library with string encoding/decoding support?
Do you know any library with string encoding/decoding support? I need more encodings than provides `std.encoding`.
Re: Compiling an app to a single binary - possible?
On Sunday, 17 November 2013 at 18:40:34 UTC, Jacek Furmankiewicz
wrote:
It is possible to import an entire folder and subfolders of
assets? (e.g. static HTML with all of its pieces, i.e. CSS,
JSS. etc)
Are we talking about Vibe.d? Yes, it's possible:
http://vibed.org/docs
shared static this()
{
auto router = new URLRouter;
router.get(*, serveStaticFiles(./public/));
listenHTTP(new HTTPServerSettings, router);
}
Re: Compiling an app to a single binary - possible?
On Monday, 18 November 2013 at 00:12:57 UTC, Jacek Furmankiewicz wrote: In this case is the content of ./public compiled directly into the executable (let's say the way all web resources are compiled into a Java WAR file), or does it have to be a separate folder on the filesystem, deployed alongside the main executable? The ./public folder have to be a separate folder. All Diet templates in ./views folder compile directly into the executable. See also The recommended structure for a project is about as follows: section.
Re: Efficient string concatenation?
On Friday, 15 November 2013 at 23:51:42 UTC, Jacek Furmankiewicz wrote: Thanks for the book! I printed it, all 673 pages of it. Immense work you have there. I think it's good to listen a little critics from newcomers. I belive that it helps Ali Cehreli to improve the book. Also, you can use `text` function from `std.conv`. It can convert any data to the `string`. string newString = text(string1, 1, string2, 2, string3, 3); Note that it use `~` operator, so `appender` can be faster. P.S. We also have great book for D templates: https://github.com/PhilippeSigaud/D-templates-tutorial
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Friday, 15 November 2013 at 15:21:59 UTC, Jacek Furmankiewicz wrote: So what happens when the write operation is doing map[1] = map[1].editData(5); and at the same time 50 threads are simultaneously reading the value in map[1]?. Is that reassignment operation thread safe? Or would I get corrupted reads with potentially a partially overriden value? Jacek Yes, this is thread safe. Put attention to the `MyMap` class definition, it's marked as `synchronized`. It means that all class functions use the same Mutex. So, write operation will block map and all 50 threads will wait.
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Friday, 15 November 2013 at 16:36:56 UTC, Jacek Furmankiewicz wrote: How can you achieve lock-free reads with the synchronized MyMap approach? In this case you can use Readers-writer lock http://en.wikipedia.org/wiki/Readers%E2%80%93writer_lock It allows multiple reads and single write. I think that the easiest way is use OS spesific function, for example `pthread_rwlock_t` for POSX. Note that D supports C ABI, so you can call any C function from D. I don't know any D implementation of Readers-writer lock, but you can ask this question - maybe it already exist.
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Friday, 15 November 2013 at 17:09:54 UTC, Dicebot wrote: On Friday, 15 November 2013 at 17:03:15 UTC, ilya-stromberg wrote: I don't know any D implementation of Readers-writer lock, but you can ask this question - maybe it already exist. http://dlang.org/phobos/core_sync_rwmutex.html Thank you. I just never use it.
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Friday, 15 November 2013 at 17:46:41 UTC, Russel Winder wrote: If D programmers are being told to use locks in applications code, then the D programming model and library are failing. Or the advice is wrong ;-) It's possible to implement lock-free data structures in D, you can use core.atomic http://dlang.org/phobos/core_atomic.html But it's REALLY difficult to implement and it can be SLOWER than Mutex version (not only in D, it depends from usage situation).
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Friday, 15 November 2013 at 18:16:17 UTC, Jacek Furmankiewicz wrote: taskPool looks like the closest equivalent in D that I could find. Yes, that's sad truth: if you want to use D, be ready make something yourself. BTW, why did you decide to migrate to D? Any problems with Java?
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Thursday, 14 November 2013 at 17:36:09 UTC, Jacek Furmankiewicz wrote: In our Java code, we make heavy use of ConcurrentHashMap for in-memory caches: Try to look dcollections: http://www.dsource.org/projects/dcollections Also, Vibe.d has own hashmap: https://github.com/rejectedsoftware/vibe.d/blob/master/source/vibe/utils/hashmap.d
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Thursday, 14 November 2013 at 20:00:10 UTC, Jacek
Furmankiewicz wrote:
I looked at the dcollections docs, but none of their
collections seem thread safe. The vibe.d I guess is because it
is meant to be used from async I/O in a single thread...but
once you add multi-threading to an app I am guessing it would
not be usable.
No, you can:
1) Use different hashmap per tread. I don't know your situation,
but it can be possible fo read-only cache like this:
import vibe.utils.hashmap;
HashMap!(int, int) map;
void foo()
{
//use map
map[1] = 1;
}
2) Use `shared` storage class and mutex like this:
import vibe.utils.hashmap;
shared HashMap!(int, int) map;
void foo()
{
synchronized
{
//use map
map[1] = 1;
}
}
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Thursday, 14 November 2013 at 21:16:15 UTC, TheFlyingFiddle
wrote:
If that is the case are you not limited in the way you can
update the map eg only in a single block?
Yes, it's probably not the best example. It's valid if you have
only 1 synchronized block for map. But you can use something like
this:
void bar()
{
synchronized(map)
{
map[1] = 1;
}
synchronized(map)
{
map[2] = 2;
}
}
Or this:
//Note: valid only if you have 1 function that use map
synchronized void bar()
{
map[1] = 1;
map[2] = 2;
}
Or this:
shared myMap;
synchronized class MyMap
{
HashMap!(int, int) map;
void foo()
{
map[1] = 1;
}
void bar()
{
map[2] = 2;
}
}
//init map
shared static this()
{
myMap = new MyMap();
}
Probably, it's the best example.
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Thursday, 14 November 2013 at 21:31:52 UTC, Jacek Furmankiewicz wrote: hashmap per thread is not an option. The cache may be a few GBs of data, there is no way we can duplicate that data per thread. Not to mention the start up time when we have to warm up the cache. How often do you change the data? Probably, you should use `immutable` variables.
Re: What is the closest to ConcurrentHashMap and NavigableMap in Java?
On Thursday, 14 November 2013 at 22:12:10 UTC, Jacek
Furmankiewicz wrote:
On Thursday, 14 November 2013 at 21:36:46 UTC, ilya-stromberg
wrote:
On Thursday, 14 November 2013 at 21:31:52 UTC, Jacek
Furmankiewicz wrote:
How often do you change the data? Probably, you should use
`immutable` variables.
Customer specific. It may change once a year. It may change
multiple times per second for a while, then nothing again for
weeks.
Others may do mass loads of business rules, hence do mass
changes every few hours.
Next to impossible to predict.
You can use `immutable` variables. It allows you to share the
data without any synchronization. Like this:
class MyData
{
int data1;
string data2;
//creates new object
this(int data1, string data2)
{
this.data1 = data1;
this.data2 = data2;
}
//modify the data
immutable(MyData) editData(int i) const
{
//copy this object - we can't change immutable variables
MyData dataCopy = new MyData(this.data1, this.data2)
//modify the data copy
dataCopy.data1 += i;
//assume that `dataCopy` is immutable
return cast(immutable(MyData)) dataCopy;
}
}
shared myMap;
//map implementation
synchronized class MyMap
{
HashMap!(int, immutable(MyData)) map;
void foo()
{
map[1] = new immutable MyData(1, data);
}
void bar()
{
map[1] = map[1].editData(5);
}
}
//init map
shared static this()
{
myMap = new MyMap();
}
void main()
{
myMap.foo();
myMap.bar();
}
Re: D / GtkD for SQL Server
On Sunday, 27 October 2013 at 00:06:35 UTC, John Joyus wrote: On 10/25/2013 04:04 AM, Gary Willoughby wrote: 1). Does D has any support for MSSQL? See here: http://forum.dlang.org/thread/qcxoafwuachwnnwqk...@forum.dlang.org Thanks for the link, but what I meant by MSSQL is Microsoft SQL Server. Not MySQL. John, It's interesting if you can connect to the MS SQL.
Re: D / GtkD for SQL Server
On Sunday, 20 October 2013 at 08:13:35 UTC, John Joyus wrote: I am learning D and itching to create some small tools (basically Windows executables) for our internal use, but any tool I think of creating also needs some support for SQL Server! So my question is: 1). Does D has any support for MSSQL? Look at the OpenDBX bindings: https://github.com/rikkimax/Derelict3-Extras/tree/master/import/derelict/opendbx It supports a lot of databases, including SQL Server. Disclaimer: I didn't use it.
Re: CommonType and non-built-in types
On Tuesday, 1 October 2013 at 17:56:17 UTC, Dicebot wrote: Definition of common type is pretty simple - it is a type both types can be implicitly converted to. For `int` and `BigInt` common type should be `BigInt` if it was possible to define that implicit conversion. AFAIK it is not possible and thus they can't have common type. Yes, we need implicit conversion support for usage cases like this. May be only from build-in types to the user-defined as you said before, but it will be really useful. I really don't know any usage example for implicit conversion from `int` to `BigInt` when it produces problems.
Re: User defined attributes use
On Monday, 16 September 2013 at 07:36:13 UTC, simendsjo wrote:
I don't have a full example without adding a lot of code, but
this partial
example might give you the gist of it.
// This is the type that validates
struct matches(string mustMatch)
{
alias re = ctRegex!(mustMatch);
static string[] validate(T)(const ref T t)
{
static if(!isSomeString!T)
static assert(0, matches only works on strings,
not ~T.stringof);
return match(t, re).empty ? [no match] : null;
}
}
// and this is the code that runs all validators for a variable
void validate(alias T)(ref Appender!(string[]) app)
{
static if(isTupleWrapper!T)
{
validate!(T.Head)(app);
validate!(T.Tail)(app);
}
else
{
foreach(memberAttr; getValidaterAttrs!T)
{
foreach(attr; memberAttr.Tail)
{
foreach(msg; attr.validate(T))
if(msg.length)
app.put(msg);
}
}
}
}
// .. And here is some of the plumbing
string[] validate(Vars...)()
{
auto app = appender!(string[])();
validate!Vars(app);
return app.data();
}
// The getMembersAndAttributesWhere are templates in my little
library that isn't released. Uses quite some custom __traits
stuff, but it's basically __traits(getAttributes
template getValidaterAttrs(alias T)
{
alias getValidaterAttrs =
TypeTuple!(getMembersAndAttributesWhere!(T,
isValidationAttr).Elements,
getMembersAndAttributesWhere!(TypeOf!T,
isValidationAttr).Elements);
}
// Well.. Incomplete
template isValidationAttr(alias T)
{
enum isValidationAttr = hasMember!(TypeOf!T, validate);
}
Can I explicitly specify when I can use attribute? Something like
this:
@attribute(field)
struct matches(string mustMatch)
{
}
string wrongAttribute
{
}
class Foo
{
@matches([0-9]+)
string someNumber; //OK, it's a field
}
@matches([0-9]+) //Error, it's a class, not a field
class Bar
{
}
@wrongAttribute //Error, this attribute doesn't exist
class C
{
}
Re: User defined attributes use
On Sunday, 15 September 2013 at 18:31:40 UTC, simendsjo wrote:
On Sunday, 15 September 2013 at 17:34:06 UTC, matovitch wrote:
Hi everyone,
I read the documentation about user defined attributes, but I
don't see their uses. Ok, it'a a template expression you can
link to a declaration, but what are they useful for ? (not
sure about the syntax ;-))
Can you declare a template constraint as a user defined
attribute to do something like :
void
template_function_which_go_back_and_forth(@(Bidirectional)
@(Range) BR)(BR br) {...}
This would be awesome (even if not really occidental) to do
something like:
@(SmallTypeSet) @(MediumTypeSet) @(LargeTypeSet) Type
This could allow to build tree based category structure.
It enables declarative programming.
And because this is D, there is no runtime overhead.
A common use is to add semantics to types and instances that is
difficult or very intrusive to do by creating structs/classes
by hand.
A little validation example:
@nonNull // An instance shouldn't be allowed to be null
class C {
@matches([0-9]+)
string someNumber;
@interval!(](0, 10) // (0, 10] range
int someInt;
}
C c;
validate(c); // returns [C is null, someNumber doesn't match
'[0-9]+', someInt is outside the interval '(0, 10]']
And ORMs usually use annotations:
@table(some_tablename)
class C {
@id(id_field_name)
int id;
}
Take a look at C# and Java libraries to see how many uses
attributes/annotations - they are still quite new in D, so they
are still underutilized.
A very big difference is of course that UDAs are available at
compile time :)
Can you print a full examle? For example, can you implement
matches UDA and validate function.
It's intresting how can I create new UDA and check if it's
available for class/field.
Re: User defined attributes use
On Monday, 16 September 2013 at 15:12:05 UTC, Maxim Fomin wrote:
On Monday, 16 September 2013 at 10:29:12 UTC, matovitch wrote:
All your examples are great, thank you ! Is there a way to
omit validate such that the compiler would call it implicitly ?
For example :
class C {
...
}
void fun(@nonNull C c) {
...
};
C c;
fun(c); //compilation error since C is null
No, this isn't doable with UDAs because what you want requires
runtime check. It is doable using other language features.
It's intresting how can I check that pointer is not null at the
compile time. Can you print a example, please?
I know that we can use contract programming, but it requires
runtime check.
Re: User defined attributes use
On Monday, 16 September 2013 at 17:50:16 UTC, Maxim Fomin wrote: Ideally structs should have default constructors (hello to those who miss them - problem #2) which could initialize class instance. Do you know why D structs don't have default constructors? I really miss.
Re: User defined attributes use
On Monday, 16 September 2013 at 19:28:22 UTC, Andrei Alexandrescu
wrote:
On 9/16/13 11:56 AM, Namespace wrote:
And I agree absolute, to disable default CTor's by struct's
was a huge
mistake. But D is full of those. ;)
They are not disabled. It seems many people are having trouble
with getting default constructors to evaluate code, so I assume
you mean that. One possibility (or first step) would be to
relax the language to allow CTFE-executable code in default
constructors.
Yes, we REALLY need this. I know that we can init struct fields
via user-defined value, but for many cases is not enough. And in
that days I remembered C++.
Buy the way, what does it mean They are not disabled?
struct Foo
{
int i = 5; //works
}
struct Bar
{
int i;
this()
{
i = 5;
}
}
DMD:
src/app.d(10): Error: constructor app.Bar.this default
constructor for structs only allowed with @disable and no body
Re: User defined attributes use
On Monday, 16 September 2013 at 20:16:45 UTC, Namespace wrote: And maybe also for delete: we need something to delete the memory manually. And we need built-in memory allocators, not only GC.
Support implicit conversion between types
I have some code like this:
struct Foo
{
this(int i)
{
//do something useful
}
}
void bar(Foo f)
{
//do something else
}
void main()
{
Foo f = 5;//works
bar(f);//works
bar(Foo(5));//works
bar(5);//Error: function app.bar (Foo f) is not callable using
argument types (int)
}
D can't implicitly convert type int to type Foo, but
constructor Foo(int) exists. Explicit conversion works fine.
What should I do to support this convertion implicitly?
Re: Support implicit conversion between types
On Wednesday, 4 September 2013 at 19:44:17 UTC, Namespace wrote:
What's about:
void bar(int i) {
bar(Foo(i));
}
?
No, I wrote very simple example. I have 10 from types and a lot
of different bar functions. Your way will be more painful then
explicit conversion.
Re: Support implicit conversion between types
On Wednesday, 4 September 2013 at 20:14:06 UTC, Kozzi wrote: So you can use templates, something like this: I know, it will work. But I really have **a lot of** different bar functions, so that way will be painful. So, the question is: what should I add to Foo struct to allow implicit conversions from int to Foo?
How compile program with curl support?
I try to compile program with curl support, but I have error:
import std.net.curl;
void main()
{
}
rdmd main.d
/usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function
`_D3std3net4curl4Curl19_sharedStaticCtor34FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticCtor34FZv+0xf):
undefined reference to `curl_global_init'
/usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function
`_D3std3net4curl4Curl19_sharedStaticDtor35FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticDtor35FZv+0x5):
undefined reference to `curl_global_cleanup'
I try to import libcurl.a library, the same problem:
rdmd -L/usr/lib/x86_64-linux-gnu/libcurl.a main.d
/usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function
`_D3std3net4curl4Curl19_sharedStaticCtor34FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticCtor34FZv+0xf):
undefined reference to `curl_global_init'
/usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function
`_D3std3net4curl4Curl19_sharedStaticDtor35FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticDtor35FZv+0x5):
undefined reference to `curl_global_cleanup'
What should I do to get curl support?
OS is Linux Ubuntu 12.10.
Re: How compile program with curl support?
On Thursday, 22 August 2013 at 10:24:49 UTC, David wrote: What should I do to get curl support? OS is Linux Ubuntu 12.10. Install libcurl-dev http://packages.ubuntu.com/de/lucid/libcurl-dev Add -L-lcurl to your commandline Thanks for help. Correct answer was here: http://forum.dlang.org/post/mailman.1089.1350735488.5162.digitalmar...@puremagic.com $ dmd -L-lphobos2 -L-lcurl main.d As I can see by google, this is common issue. How can we document the compilation proses?
Re: How compile program with curl support?
On Thursday, 22 August 2013 at 13:20:44 UTC, evilrat wrote: why do u link phobos when compiler do this for you? Because without it doesn't work: $ dmd -L-lcurl main.d /usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function `_D3std3net4curl4Curl19_sharedStaticCtor34FZv': std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticCtor34FZv+0xf): undefined reference to `curl_global_init' /usr/lib/x86_64-linux-gnu/libphobos2.a(curl.o): In function `_D3std3net4curl4Curl19_sharedStaticDtor35FZv': std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticDtor35FZv+0x5): undefined reference to `curl_global_cleanup' Have you got any ideas why?!
