Re: Unmanaged drop in replacemet for [] and length -= 1
Also, how to handle foreach(i, x; w) (use index + value)?
Unmanaged drop in replacemet for [] and length -= 1
I wanted to switch to std.container.Array but it doesn't seem to
mimic [] for some odd ball reason. I threw this class together
and it seems to work.
The only problem is that I can't do
carray.length -= 1;
I can't override `-=` because that is on the class. can I
override it for length somehow or do I have to create a length
wrapper class that has it overridden in it? Or is there a way to
do it in cArray?
Basically I want to support code that does something like
auto x = [];
x.length -= 1;
and not have to rewrite that to x.length = x.length - 1;
public class cArray(T)
{
Array!T data;
public void assumeSafeAppend() { };
public @property int length()
{
return data.length;
}
public @property int length(int len)
{
for(int i = 0; i < len; i++)
data.removeBack();
return data.length;
}
ref T opIndex(int i) { return data[i]; }
@property int opDollar(size_t dim : 0)() { return
data.length; }
this() { data = Array!T(); }
int opApply(int delegate(ref T) dg)
{
int result = 0;
for (int i = 0; i < data.length; i++)
{
result = dg(data[i]);
if (result)
break;
}
return result;
}
int opApplyReverse(int delegate(ref T) dg)
{
int result = 0;
for (int i = 0; i < data.length; i++)
{
result = dg(data[i]);
if (result)
break;
}
return result;
}
void opOpAssign(string op)(T d)
{
if (op == "~")
{
data ~= d;
}
}
bool canFind(T)(T d)
{
for(int i = 0; i < data.length; i++)
{
if (data[i] == d)
return true;
}
return false;
}
}
Re: canFind doesn't work on Array, replacing [] with array doesn't work, etc...
On Saturday, 18 June 2016 at 17:46:26 UTC, ag0aep6g wrote:
On Saturday, 18 June 2016 at 17:02:40 UTC, Joerg Joergonson
wrote:
3. can't use canFind from algorithm. Complains it can't find a
matching case. I tried many variations to get this to work.
canFind takes a range. Array isn't a range itself, but you can
get one by slicing it with []:
import std.container.array;
import std.algorithm;
void main()
{
Array!int a = [1, 2, 3];
assert(a[].canFind(2));
assert(!a[].canFind(0));
}
Thanks. I've decided to implement a wrapper around Array so it is
a drop in replacement for [].
Re: How to get access to Voldemort / private thingies
On Saturday, 18 June 2016 at 17:50:51 UTC, cy wrote: On Saturday, 18 June 2016 at 08:41:30 UTC, Johan Engelen wrote: Without going in too much detail, the problem is that I am not linking to opaque .o files. The problem is the compiler has to assume you *might* be linking to opaque .o files, so it can't provide any introspection capabilities. There's no way to tell which "hidden type" that the getObject function is returning, since that's decided in the (possibly opaque) function body. The function body is not opaque. In my compilation unit, the compiler knows it, and that's exactly why I run into troubles. For ease of discussion, just pretend the function that returns the Voldemort type is in the same file as the user code: let's say it's all in one source file. Just like there is a way to get private types out of structs (using .tupleof or the Fields!Strukt[*] thing I pasted above), I was hoping there was a way to get a Voldemort type out of a function. This is of course all a big hack. The pragma(mangle,..) thing works well, but unfortunately conflicts with the LDC inlining improvement I'm working on. Like you say, I could copy the whole function definition, but it would mean copying quite a lot and some more types etc... - Johan
Re: How to group similar member functions from different classes?
On Saturday, 18 June 2016 at 07:03:25 UTC, cy wrote:
So how would you do it? Defining A.foo, B.foo, etc in one
place, and A.bar, B.bar, etc in another?
No such thing in D. But you can always be creative and use an
overloaded helper function containing the actual implementation
if you want to group the code by functionality and not by type:
class A { int foo() { return doFoo(this); }
class B : A { int foo() { return doFoo(this); }
...
void doFoo(A a) { ... }
void doFoo(B b) { ... }
If you need full access to the members, the helpers would need to
be in the same module, otherwise you can put them into a separate
helper.
Re: How to group similar member functions from different classes?
On Saturday, 18 June 2016 at 07:03:25 UTC, cy wrote:
So how would you do it? Defining A.foo, B.foo, etc in one
place, and A.bar, B.bar, etc in another?
The only thing I've been able to figure is a horrible hack, where
your member functions are something like
// off in define_foos.d
template foo_for(T) {
static if(is(T == A)) {
enum foo_for = q{
int foo () {
return bar+42;
}
};
} else static if(is(T == B)) {
enum foo_for = q{
int foo () {
return bar+23;
}
};
}
}
// in classes.d
import define_foos: foo_for;
struct A {
int bar;
mixin(foo_for!A);
}
struct B {
int bar;
mixin(foo_for!B);
}
// etc
void main() {
import std.stdio;
A a = A(0);
B b = B(1);
writeln(b.foo());
writeln(a.foo());
}
Re: How to get access to Voldemort / private thingies
On Saturday, 18 June 2016 at 08:41:30 UTC, Johan Engelen wrote:
Without going in too much detail, the problem is that I am not
linking to opaque .o files.
The problem is the compiler has to assume you *might* be linking
to opaque .o files, so it can't provide any introspection
capabilities. There's no way to tell which "hidden type" that the
getObject function is returning, since that's decided in the
(possibly opaque) function body.
You could hack something with debugging, I suppose. (Probably
not. DWARF/ptrace is ridiculously undocumented.) Perhaps you
could make an alternate version of the function with the same
source code, that returns auto instead of an Object type? As in...
Object evil() {
class Vold {...}
Vold v = new Vold(...);
return v;
}
auto notevil() {
static class Vold {...}
Vold v = new Vold(...);
return v;
}
...
auto hack = new typeof(notevil());
That can magically allow you to return type Vold, even though
it's an error to say
Vold notevil() {
static class Vold { ... }
...
}
Re: Templated class defaults and inheritence
This is solved through simple inheritance constraints and aliasing with qualification. class X; class subfoo; class subbaz : subfoo; class foo(T) if (is(T : subfoo)) X; class baz(T) if (is(T : subbaz)) foo!T; then when we need foo with "default", alias foo = qualified.foo!subfoo; Without the qualification, which I guess requires having this stuff in a separate module, there is no conflict. alias foo = foo!subfoo; fails circularly.
Re: canFind doesn't work on Array, replacing [] with array doesn't work, etc...
On Saturday, 18 June 2016 at 17:02:40 UTC, Joerg Joergonson wrote:
3. can't use canFind from algorithm. Complains it can't find a
matching case. I tried many variations to get this to work.
canFind takes a range. Array isn't a range itself, but you can
get one by slicing it with []:
import std.container.array;
import std.algorithm;
void main()
{
Array!int a = [1, 2, 3];
assert(a[].canFind(2));
assert(!a[].canFind(0));
}
canFind doesn't work on Array, replacing [] with array doesn't work, etc...
Have working code that uses []. Trying to replace with Array! 1. Can't use make in field initialization. Complains about malloc in static context. 2. can't decrement the length. So Darr.length = Darr.length - 1; fails This means we can't remove the element easily. I see a removeBack but since I can't get the code to compile I don't know if this is a replacement. If so, why now allow setting the length? can't set the length to 0. Why not? Why not just allow length to be set? 3. can't use canFind from algorithm. Complains it can't find a matching case. I tried many variations to get this to work.
Re: Can anybody install DDT on Eclipse Neon or Mars?
On Saturday, 18 June 2016 at 16:46:26 UTC, Mark wrote: I've spent may hours trying to do this in OSX. Everything goes fine from the marketplace window...until I restart Eclipse and find no files have been added? Any words of consolation or advice will be greatly appreciated. Desperately, Mark Unfortunately I can't help you any DDT, but are you sure you really need this? D is so simple that basically every plain text editor works great. If you need a bit more convenience you might have a look for options here: https://wiki.dlang.org/IDEs
Can anybody install DDT on Eclipse Neon or Mars?
I've spent may hours trying to do this in OSX. Everything goes fine from the marketplace window...until I restart Eclipse and find no files have been added? Any words of consolation or advice will be greatly appreciated. Desperately, Mark
Re: Is it possible to create a static factory method on a templated struct?
On Saturday, 18 June 2016 at 16:05:53 UTC, Gary Willoughby wrote: I've tried the following code and I get the error: you still have to instantiate you `Foo` here: auto foo = Foo.of!(string); no, you can't call even static methods of *uninstantiated* template. uninstantiated template doesn't exist at all. this works, for example: auto foo = Foo!int.of!(string);
Re: ARSD PNG memory usage
On Saturday, 18 June 2016 at 02:01:29 UTC, Adam D. Ruppe wrote: On Saturday, 18 June 2016 at 01:20:16 UTC, Joerg Joergonson wrote: Error: undefined identifier 'sleep', did you mean function 'Sleep'? "import core.thread; sleep(10);" It is `Thread.sleep(10.msecs)` or whatever time - `sleep` is a static member of the Thread class. They mention to use PeekMessage and I don't see you doing that, not sure if it would change things though? I am using MsgWaitForMultipleObjectsEx which blocks until something happens. That something can be a timer, input event, other message, or an I/O thing... it doesn't eat CPU unless *something* is happening. Yeah, I don't know what though. Adding Sleep(5); reduces it's consumption to 0% so it is probably just spinning. It might be the nvidia issue that creates some weird messages to the app. I'm not too concerned about it as it's now done to 0, it is minimal wait time for my app(maybe not acceptable for performance apps but ok for mine... at least for now). As I continue to work on it, I might stumble on the problem or it might disappear spontaneously.
Re: Templated class defaults and inheritence
On Saturday, 18 June 2016 at 12:15:56 UTC, Klaus Kalsesh wrote:
On Saturday, 18 June 2016 at 02:11:23 UTC, Joerg Joergonson
wrote:
I have something like
class X;
class subfoo : X;
class subbaz : X;
class foo : X
{
subfoo bar;
}
class baz : X;
which I have modified so that
class subbaz : subfoo;
class baz : foo;
(essentially baz is now a derivation of foo while before it
was of X)
the problem is that subbaz uses subfoo bar; when it also needs
to use a derived type. (so it is a full derivation of foo and
subfoo)
To accomplish that I parameterized foo so I can do
class foo!T : X
{
T bar;
}
and I can now do
class baz : foo!subbaz;
There are two problems with this though:
1. How can I create a default foo!(T = subfoo) so I can just
instantiate classes like new foo() and it is the same as
foo!subfoo()? I tried creating a class like class foo :
foo!subfoo; but I get a collision. I guess an alias will work
here just fine though?(just thought of it)
You must declare an alias:
alias FooSubfoo = foo!subfoo;
FooSubfoo fsf = new FooSubfoo;
No, this is not what I'm asking
I would want something like
alias foo = foo!subfoo;
Not sure, though, if a when I instantiate like
new foo();
If the compiler will understand it is new foo!subfoo(); I see no
problem here but haven't tested it.
2. The real problem is that baz isn't really a true derivation
of foo like it should be. foo!subfoo and foo!subbaz are
different types. I want the compiler to realize that
foo!subbaz(and hence baz) is really a derived foo!subfoo and
ultimately X.
For multiple inheritence in classes, the standard way of doing
is with interfaces.
This is not multiple inheritance and alias this won't work.
Let me explain better:
X -> foo%subfoo
-> baz%subbaz
by -> I mean inherits and by %, I mean "uses"(say, as a field or
method parameter or whatever)
This then says that foo uses subfoo and is derived from X.
Similarly for baz.
These are two distinct types(hence the two different lines)
Now, if baz inherits from foo instead of X, we have
X -> foo%subfoo -> baz%subfoo
But if subfoo -> subbaz, then we should be able to do
X -> foo%subfoo -> (baz%subfoo) -> baz%subbaz.
Note the are now on the same line. baz%subbaz is a derived type
of foo%subfoo, not just X as in the first two line case.
This is an important distinction in the type system.
It's sort of multiple inheritance in that multiple types are used
but each type only inherits once.
In C# we have the "where" keyword that lets us tell the compiler
something like "where subbaz inherits from subfoo".
Dlang once had a page that had ways to express stuff like this
but I can no longer find it ;/
It might be a syntax like
class baz!T : foo!(T : subfoo);
which may say "T must be derived from subfoo". Then baz!subbaz
would work and it would be a derived type of foo!subfoo(rather
than just X).
Is it possible to create a static factory method on a templated struct?
I've tried the following code and I get the error:
Error: template Foo(A) does not have property 'of'
struct Foo(A)
{
private int _foo;
@disable this();
public this(int foo)
{
this._foo = foo;
}
public static auto of(B)()
{
return Foo!(B)(8);
}
}
void main(string[] args)
{
auto foo = Foo.of!(string);
}
Is it possible to even have static methods on structs like this?
What am I doing wrong?
Re: How to enable feedback for AssertError?
Sorry for the necromancy. I failed to reproduce the issue for single threaded programs. Which is good. As far as std.concurrency is concerned I still have questions. 1. How does the main thread of a program print an (Assert)Error/Exception when it is terminated by it ? 2. Where is the place to make a suggestion for a documentation update for std.concurrency? For someone unware to this pitfall it can be quite a time waster so a Notice in the docs would be nice. Thanks for the help.
Re: Is there a more elegant way of testing T for multiple types?
On 06/18/2016 04:37 PM, Gary Willoughby wrote:
Here I'm testing T is either a class or interface:
void foo(T)(T bar) if (is(T == class) || is(T == interface))
{
...
}
Is there a more elegant way of testing T for multiple types? Because it
doesn't scale well if I need to add more.
I would love to use something like this:
void foo(T)(T bar) if (T in [class, interface])
{
...
}
Is something like this currently possible using type tuples?
There's std.meta.staticIndexOf [1]. Use it like so:
void foo(T)(T bar) if (staticIndexOf!(T, int, float) >= 0) { ... }
Doesn't work with `class` or `interface`, though, because those are not
types.
[1] https://dlang.org/phobos/std_meta.html#.staticIndexOf
Is there a more elegant way of testing T for multiple types?
Here I'm testing T is either a class or interface:
void foo(T)(T bar) if (is(T == class) || is(T == interface))
{
...
}
Is there a more elegant way of testing T for multiple types?
Because it doesn't scale well if I need to add more.
I would love to use something like this:
void foo(T)(T bar) if (T in [class, interface])
{
...
}
Is something like this currently possible using type tuples?
Re: Vanilla Vim with D
On Saturday, 18 June 2016 at 12:36:04 UTC, Adam D. Ruppe wrote: On Saturday, 18 June 2016 at 07:55:41 UTC, Dlangofile wrote: - compile from inside (rdmd or dmd right now) - jump in the code fixing the compilation errors? :set makeprg=rdmd\ % Do that to setup, then just :make to tell it to run that command and jump around to the errors it sees. Thank you Adam, so I'm going to learn about the quickfix...
Re: Vanilla Vim with D
On Saturday, 18 June 2016 at 07:55:41 UTC, Dlangofile wrote: - compile from inside (rdmd or dmd right now) - jump in the code fixing the compilation errors? :set makeprg=rdmd\ % Do that to setup, then just :make to tell it to run that command and jump around to the errors it sees.
Re: Templated class defaults and inheritence
On Saturday, 18 June 2016 at 02:11:23 UTC, Joerg Joergonson wrote:
I have something like
class X;
class subfoo : X;
class subbaz : X;
class foo : X
{
subfoo bar;
}
class baz : X;
which I have modified so that
class subbaz : subfoo;
class baz : foo;
(essentially baz is now a derivation of foo while before it was
of X)
the problem is that subbaz uses subfoo bar; when it also needs
to use a derived type. (so it is a full derivation of foo and
subfoo)
To accomplish that I parameterized foo so I can do
class foo!T : X
{
T bar;
}
and I can now do
class baz : foo!subbaz;
There are two problems with this though:
1. How can I create a default foo!(T = subfoo) so I can just
instantiate classes like new foo() and it is the same as
foo!subfoo()? I tried creating a class like class foo :
foo!subfoo; but I get a collision. I guess an alias will work
here just fine though?(just thought of it)
You must declare an alias:
alias FooSubfoo = foo!subfoo;
FooSubfoo fsf = new FooSubfoo;
2. The real problem is that baz isn't really a true derivation
of foo like it should be. foo!subfoo and foo!subbaz are
different types. I want the compiler to realize that
foo!subbaz(and hence baz) is really a derived foo!subfoo and
ultimately X.
For multiple inheritence in classes, the standard way of doing is
with interfaces.
So instead of a template:
class foo: interfaceThis, interfaceThat
{}
alias this can work too but there only can be one:
class foo!T : X
{
T bar;
alias bar this;
}
This pattern is called the "Curiously recurring template" BTW.
With the alias this it's almost usable, which was not the case in
the original form (because you have an indirection to access the
derived type that's indicated by the template parameter.
Actually from the machine code POV it's still the case but in the
source code it's hidden by the alias this shortcut.
Re: How to get access to Voldemort / private thingies
Someone figured out how to do it and put it in std.traits! ;-)
Example:
```
import std.stdio;
import core.thread;
import std.traits;
void main()
{
Fields!Thread[11] a;
writeln(typeid(a));
}
```
This prints "core.thread.Thread.Context" , which is a private
struct type of core.thread.Thread.
Success! :-)
-Johan
Re: How to get access to Voldemort / private thingies
On Friday, 17 June 2016 at 21:07:31 UTC, cy wrote: On Friday, 17 June 2016 at 19:49:18 UTC, Johan Engelen wrote: Hi all, Is there another way to get access to Voldemort class methods, or private class members, other than using [... snip ...] Because of the guarantee that you can link to opaque .o files, Thanks for your response. Without going in too much detail, the problem is that I am not linking to opaque .o files. The user symbol has to have the same type (as the hidden type) internally in the compiler; both will be present in the same translation unit because of inlining, and so if the mangled names are the same, their types have to be the same. Hmm... -Johan
Re: Variadic function with parameters all of a specific type
On Friday, 17 June 2016 at 21:20:01 UTC, Timon Gehr wrote:
void foo(T[] a...)@nogc{}
void bar()@nogc{
foo(1,2,3);
}
Ahh, cool. I was completely unaware of this feature.
Doc here:
https://dlang.org/spec/function.html#typesafe_variadic_functions
Vanilla Vim with D
Hi to all, I'm trying to approach Vim as an editor for D, starting from scratch... I've a pretty vanilla vimrc, and only CtrlP as a plugin: not a so bad experience right now! First question, what's the best, simplest and fast approach for: - compile from inside (rdmd or dmd right now) - jump in the code fixing the compilation errors? Thanks vim guys! /DF
Re: vibe.d - asynchronously wait() for process to exit
On Friday, 17 June 2016 at 13:53:15 UTC, Vladimir Panteleev wrote: Geod24 on IRC suggested signalfd + createFileDescriptorEvent. I think this would work, but isn't it possible to wrap the fd returned by signalfd into a Vibe.d stream and read it directly? I'm just not sure how. Well, vibe.d streams are defined as interfaces, so you'd have to import vibe.core.stream: InputStream, and create a SignalFdInput class that implemented all the required methods. When it requires you to "wait" for data available, you save core.task.Task.getThis() somewhere, and... basically do what you're doing with createFileDescriptorEvent, just resuming the task instead of handling the event in a callback. I should point out that createFileDescriptorEvent is an assert(0) for libasync.
How to group similar member functions from different classes?
When I define functions like:
class A {
abstract void format(...) {...}
}
class B : A {
void format(...) {...}
}
class C : A {
void format(...) {...}
}
and so on, often these different member functions all share a lot
in common. Maybe they are the only ones that require formatting
modules, that do I/O, that do string manipulation, that sort of
thing.
But if I made a second function, say for instance clone() or
replaceWithDucks(), it too might import a lot of modules, and
perform a lot of logic. And there may be many, many different
types of object here.
In C++ I could forward declare the member functions, then put all
"::format(...)" member functions together in their own source
file, making everything pretty neat and tidy. How do I do that in
D? As near as I can tell, you can only define member functions
inside the class definition itself, and you can't add to that
definition piece-wise like
// file 1
class A ... {
void format(...) { ... }
}
...
// file 2
class A ... {
void doathing() { ... }
}
...
So how would you do it? Defining A.foo, B.foo, etc in one place,
and A.bar, B.bar, etc in another?
