Re: How to use std.bind?
On Mon, 17 Jan 2011 17:03:15 +, Sean Eskapp wrote:
I used to use boost::bind all the time, but std.bind has me stumped, as
I keep getting static asserts with a cryptic argument has no
parameters message. At this point, the code is just:
class Foo
{
void bar(int i) { writeln(i); }
}
void main()
{
auto foobar = new Foo;
bind(foobar.bar, 5)();
}
I've tried a myriad of different ways, but keep coming up with the same
error. Using bindAlias gives me an error that std.bind.bindAlias(alias
FT) is not a function template.
I'm using DMD v2.051 on a Windows platform. Help anybody?
Like BlazingWhitester said, std.bind is scheduled for deprecation. (It
will be marked as such starting with the next DMD release.) It is a
relic from D1, and I don't think it has worked well with D2 for quite a
while.
Luckily, you don't need it at all. You can do the same thing with D2's
built-in features, such as nested functions and lambdas.
// Lambda example
int add2(int i) { return i + 2; }
void main()
{
auto seven = () { return add2(5); };
assert (seven() == 7);
}
-Lars
Re: std.container.Array/RefCounted(T) leaking memory?
On Tue, 18 Jan 2011 01:16:51 +, %u wrote:
I find it very hard to believe that struct dtors are never called.
Sorry, that part was my bad -- last time I checked, they didn't get
called, but maybe my example was too complicated, since they did get
called for a *simple* example.
However, here's a situation in which no postblit or destructor is called
whatsoever:
import std.stdio;
struct S
{
this(int dummy) { writeln(ctor); }
this(this) { writeln(postblit); }
~this() { writeln(dtor); }
}
S test(int depth) { return depth 0 ? test(depth - 1) : S(0); } int
main(string[] argv) { test(3); }
That would be bug 3516, wouldn't it?
http://d.puremagic.com/issues/show_bug.cgi?id=3516
-Lars
std.date / std.datetime
Hello, I'm in the process of learning D, and to do so I'm converting some older code. I need to print out the current local date and time, which is causing some difficulties because std.date doesn't seem adequate in this respect. I understand there is soon to be a replacement, std.datetime, which I suspect will be much easier. When are we likely to see a new release which includes std.datetime? If not relatively soon I presume the easiest thing to do is to download it myself and recompile the phobos library to include it. In which case there seems to be already a std.datetime with different functionality, is this used elsewhere in phobos? i.e. if I replace it with the new std.datetime is that OK? Many thanks, Richard
Re: std.date / std.datetime
On Tuesday 18 January 2011 03:34:06 Richard Chamberlain wrote: Hello, I'm in the process of learning D, and to do so I'm converting some older code. I need to print out the current local date and time, which is causing some difficulties because std.date doesn't seem adequate in this respect. I understand there is soon to be a replacement, std.datetime, which I suspect will be much easier. When are we likely to see a new release which includes std.datetime? If not relatively soon I presume the easiest thing to do is to download it myself and recompile the phobos library to include it. In which case there seems to be already a std.datetime with different functionality, is this used elsewhere in phobos? i.e. if I replace it with the new std.datetime is that OK? std.datetime is currently in Phobos' svn repository and will be in the next release. - Jonathan M Davis
Re: std.date / std.datetime
Hi Jonathan, I'm also stuck with the existing std.date and would want to try out your new module std.datetime. Do you have any sense when the next release of Phobos is going to be? If not, what is the procedure to get a development snapshot of the latest version of Phobos installed? thanks, fil
Re: std.date / std.datetime
On Tuesday 18 January 2011 04:15:20 %fil wrote: Hi Jonathan, I'm also stuck with the existing std.date and would want to try out your new module std.datetime. Do you have any sense when the next release of Phobos is going to be? I don't know. The last release was about a month ago, and the one before that was about a month and a half before that. I'm not aware of there being any hard and fast rules or plan about when releases are done. However, they tend to be a month or two apart. If not, what is the procedure to get a development snapshot of the latest version of Phobos installed? The latest code can be found here: http://www.dsource.org/projects/phobos However, you're going to have to have the latest druntime as well: http://www.dsource.org/projects/druntime - Jonathan M Davis
enum of struct not calling constructor
Example 1:
import std.stdio;
enum WindowSizes : QSize
{
Minimum = QSize(10)
}
struct QSize
{
int store;
this(int x)
{
store = x + 10;
}
}
void main()
{
auto foo = WindowSizes.Minimum;
assert(foo.store == 10); // What?
auto bar = QSize(10);
assert(bar.store == 20);
}
It appears the constructor is never called for the enum. It does field by field
assignments instead, just take a look at this case:
import std.stdio;
enum WindowSizes : Inverted
{
Minimum = Inverted(10, 20)
}
struct Inverted
{
int x;
int y;
this(int in_x, int in_y)
{
x = in_y;
y = in_x;
}
}
void main()
{
auto foo = WindowSizes.Minimum;
assert(foo.x == 10);
assert(foo.y == 20);
auto bar = Inverted(10, 20);
assert(bar.x == 20);
assert(bar.y == 10);
}
As can be seen, this could be a potential source of bugs. Should I file it?
Re: enum of struct not calling constructor
On Tuesday, January 18, 2011 08:44:02 Andrej Mitrovic wrote:
Example 1:
import std.stdio;
enum WindowSizes : QSize
{
Minimum = QSize(10)
}
struct QSize
{
int store;
this(int x)
{
store = x + 10;
}
}
void main()
{
auto foo = WindowSizes.Minimum;
assert(foo.store == 10); // What?
auto bar = QSize(10);
assert(bar.store == 20);
}
It appears the constructor is never called for the enum. It does field by
field assignments instead, just take a look at this case:
import std.stdio;
enum WindowSizes : Inverted
{
Minimum = Inverted(10, 20)
}
struct Inverted
{
int x;
int y;
this(int in_x, int in_y)
{
x = in_y;
y = in_x;
}
}
void main()
{
auto foo = WindowSizes.Minimum;
assert(foo.x == 10);
assert(foo.y == 20);
auto bar = Inverted(10, 20);
assert(bar.x == 20);
assert(bar.y == 10);
}
As can be seen, this could be a potential source of bugs. Should I file it?
Absolutely.
- Jonathan M Davis
Re: std.date / std.datetime
On 2011-01-18 16:34:53 +, Jonathan M Davis said: On Tuesday 18 January 2011 04:15:20 %fil wrote: Hi Jonathan, I'm also stuck with the existing std.date and would want to try out your new module std.datetime. Do you have any sense when the next release of Phobos is going to be? I don't know. The last release was about a month ago, and the one before that was about a month and a half before that. I'm not aware of there being any hard and fast rules or plan about when releases are done. However, they tend to be a month or two apart. If not, what is the procedure to get a development snapshot of the latest version of Phobos installed? The latest code can be found here: http://www.dsource.org/projects/phobos However, you're going to have to have the latest druntime as well: http://www.dsource.org/projects/druntime - Jonathan M Davis Thanks Jonathan. I think I'll hang around for the official update.
Re: enum of struct not calling constructor
http://d.puremagic.com/issues/show_bug.cgi?id=5460
Re: std.date / std.datetime
On Tue, 2011-01-18 at 08:34 -0800, Jonathan M Davis wrote: [ . . . ] I don't know. The last release was about a month ago, and the one before that was about a month and a half before that. I'm not aware of there being any hard and fast rules or plan about when releases are done. However, they tend to be a month or two apart. [ . . . ] The latest code can be found here: http://www.dsource.org/projects/phobos However, you're going to have to have the latest druntime as well: http://www.dsource.org/projects/druntime Might it be worth putting in some infrastructure whereby people can use a distributed DMD or GDC but have a current snapshot or perhaps latest build of Phobos (where there is consistency between DMD/GDC on the one hand and Phobos on the other). This is actually one thing Go does supremely well, you can pull the Mercurial snapshot and build the entire system within about 5 minutes. It makes it very easy to test new stuff. -- Russel. = Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net 41 Buckmaster Roadm: +44 7770 465 077 xmpp: rus...@russel.org.uk London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder signature.asc Description: This is a digitally signed message part
Re: How to use std.bind?
On 1/18/11, Lars T. Kyllingstad public@kyllingen.nospamnet wrote:
On Mon, 17 Jan 2011 17:03:15 +, Sean Eskapp wrote:
I used to use boost::bind all the time, but std.bind has me stumped, as
I keep getting static asserts with a cryptic argument has no
parameters message. At this point, the code is just:
class Foo
{
void bar(int i) { writeln(i); }
}
void main()
{
auto foobar = new Foo;
bind(foobar.bar, 5)();
}
I've tried a myriad of different ways, but keep coming up with the same
error. Using bindAlias gives me an error that std.bind.bindAlias(alias
FT) is not a function template.
I'm using DMD v2.051 on a Windows platform. Help anybody?
Like BlazingWhitester said, std.bind is scheduled for deprecation. (It
will be marked as such starting with the next DMD release.) It is a
relic from D1, and I don't think it has worked well with D2 for quite a
while.
Luckily, you don't need it at all. You can do the same thing with D2's
built-in features, such as nested functions and lambdas.
// Lambda example
int add2(int i) { return i + 2; }
void main()
{
auto seven = () { return add2(5); };
assert (seven() == 7);
}
-Lars
This is better:
http://www.digitalmars.com/d/2.0/phobos/std_functional.html#curry
Re: std.date / std.datetime
On Tuesday, January 18, 2011 09:18:33 Russel Winder wrote: On Tue, 2011-01-18 at 08:34 -0800, Jonathan M Davis wrote: [ . . . ] I don't know. The last release was about a month ago, and the one before that was about a month and a half before that. I'm not aware of there being any hard and fast rules or plan about when releases are done. However, they tend to be a month or two apart. [ . . . ] The latest code can be found here: http://www.dsource.org/projects/phobos However, you're going to have to have the latest druntime as well: http://www.dsource.org/projects/druntime Might it be worth putting in some infrastructure whereby people can use a distributed DMD or GDC but have a current snapshot or perhaps latest build of Phobos (where there is consistency between DMD/GDC on the one hand and Phobos on the other). This is actually one thing Go does supremely well, you can pull the Mercurial snapshot and build the entire system within about 5 minutes. It makes it very easy to test new stuff. There has been discussion of D needing some sort of package management system. Perhaps that would deal with that issue. And maybe with dmd, druntime, and Phobos being moved over to git and github (which is currently being worked on) will make that easier. I don't know. However, I think that the focus of the dev team overall has been more on getting done than making it easier for people to get current development snapshots or know exactly what's going on with development at the moment. That's not to say that such things shouldn't be improved or that the dev team doesn't want to improve them, but there have been other priorities which have taken precedence. There's also a strong tendency for things to get done because someone wants them done and takes the time to do them, and if there's no one who's motivated enough to do something, then it often doesn't get done in a timely manner. - Jonathan M Davis
Re: std.date / std.datetime
On 18.01.2011 12:34, Richard Chamberlain wrote: Hello, I'm in the process of learning D, and to do so I'm converting some older code. I need to print out the current local date and time, which is causing some difficulties because std.date doesn't seem adequate in this respect. I understand there is soon to be a replacement, std.datetime, which I suspect will be much easier. When are we likely to see a new release which includes std.datetime? If not relatively soon I presume the easiest thing to do is to download it myself and recompile the phobos library to include it. In which case there seems to be already a std.datetime with different functionality, is this used elsewhere in phobos? i.e. if I replace it with the new std.datetime is that OK? You could always use the C functions, if you import core.stdc.time. The ctime and strftime functions should do the trick. http://cplusplus.com/reference/clibrary/ctime/
about float double
Hello, Is there somewhere a (clear) doc about float/double internals? Some more particuliar questions: What is the internal bit layout? (mantissa, sign, exponent) Can I assume the integral range is [-2^(m-1) .. 2^⁽m-1)-1], where m is the number of mantissa bits? What are the values used to represent thingies like NaNs, inf, error? (Or are there not represented as values?) How would you get a float's integral and fractional parts without performing arithmetic? (I think at bit ops, indeed) Denis _ vita es estrany spir.wikidot.com
const vs immutable
In cases where they are the same, for instance declaring: const int x = oldX + 5; vs immutable int x = oldX + 5; Or in non-class, non-array function parameters, does it make a difference which is used?
Re: about float double
spir wrote:
Is there somewhere a (clear) doc about float/double internals?
A very good read is:
http://digitalmars.com/d/2.0/d-floating-point.html
Some more particuliar questions:
What is the internal bit layout? (mantissa, sign, exponent)
IEEE floating point format. This page has links to different
representations:
http://en.wikipedia.org/wiki/Ieee_floating_point
Specifically:
http://en.wikipedia.org/wiki/Single_precision_floating-point_format
http://en.wikipedia.org/wiki/Double_precision_floating-point_format
What are the values used to represent thingies like NaNs, inf, error?
(Or are there not represented as values?)
They are available on the documents above.
How would you get a float's integral and fractional parts without
performing arithmetic? (I think at bit ops, indeed)
Here is a function with endianness issues that I had used with
different types:
import std.stdio;
void display_bytes(T)(ref T variable)
{
const ubyte * begin = cast(ubyte*)variable;
writefln(type : %s, T.stringof);
writefln(value : %s, variable);
writefln(address : %s, begin);
writef( representation: );
foreach (p; begin .. begin + T.sizeof) {
writef(%02x , *p);
}
writeln();
writeln();
}
void main()
{
auto d_nan = double.nan;
auto d_inf = double.infinity;
display_bytes(d_nan);
display_bytes(d_inf);
}
Ali
Re: const vs immutable
Sean Eskapp Wrote: In cases where they are the same, for instance declaring: const int x = oldX + 5; vs immutable int x = oldX + 5; Or in non-class, non-array function parameters, does it make a difference which is used? Use immutable, it documents the type better. And const items cannot be used as immutable parameters (value types don't have such restriction).
Re: std.container.Array/RefCounted(T) leaking memory?
That would be bug 3516, wouldn't it? Huh... yes, it indeed would. Thanks for the link, I couldn't think of the right keywords to search for. :)
