Re: Class info on interfaces
On 2015-08-26 20:59, Adam D. Ruppe wrote: Yes, exactly. COM and C++ things won't necessarily have a D TypeInfo available and since interfaces can be them, it can't be sure. What I do there is to just cast the interface to Object. Then you should check for null to cover those cases, then you can typeid or classinfo it. Is it possible to detect at compile time if an interface is not a native D interface? Now when I think about it, we actually have four (!) different kinds of interfaces. Native D, C++, Objective-C and COM. -- /Jacob Carlborg
How to get the current Timezone
From the docs in std.datetime, I figured I could write: Clock.currTime.timezone().name() to get the timezone this system is in. However, it just returns an empty string. Anyone know how to get the timezone of the machine easily? Thanks!
Re: Class info on interfaces
On Friday, 28 August 2015 at 06:19:55 UTC, Jacob Carlborg wrote: On 2015-08-26 20:59, Adam D. Ruppe wrote: Yes, exactly. COM and C++ things won't necessarily have a D TypeInfo available and since interfaces can be them, it can't be sure. What I do there is to just cast the interface to Object. Then you should check for null to cover those cases, then you can typeid or classinfo it. Is it possible to detect at compile time if an interface is not a native D interface? Now when I think about it, we actually have four (!) different kinds of interfaces. Native D, C++, Objective-C and COM. I don't know about Objective-C, but: - for native D interfaces __traits(getVirtualIndex, NativeInterface.firstFunction) == 1 since the first entry in vtbl is the contained object - for C++ interfaces __traits(getVirtualIndex, CPPInterface.firstFunction) == 0 - COM interfaces: __traits(getVirtualIndex, CPPInterface.firstFunction) == 0 and inherit IUnknown At runtime, it's simple, you have the m_flags member of TypeInfo_Class (isCPPclass, isCOMclass)
Re: How to get the current Timezone
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation ?
Re: (De)Serializing interfaces
On 2015-08-22 21:14, nims wrote: I think interfaces are very powerful and I heavily use them. The only problem I have with them is that serializing/deserializing them to XML or JSON doesn't seem to work. So far I got to try Orange and painlessjson. Using Orange all I got was a lot of compiler errors. I've added support for interfaces to Orange now. -- /Jacob Carlborg
Re: How to get the current Timezone
On Friday, 28 August 2015 at 14:07:37 UTC, wobbles wrote: However, it just returns an empty string. from the doc: Note that this always returns the empty string. This is because time zones cannot be uniquely identified by the attributes given by the OS (such as the stdName and dstName), and neither Posix systems nor Windows systems provide an easy way to get the TZ Database name of the local time zone. Anyone know how to get the timezone of the machine easily? Best you can do is try the stdName or dstName properties of Timezone, perhaps checking if dstInEffect to choose which one to print. Or ou could use the utcOffsetAt function to print a number (like UTC-4:00, after formatting it) The actual location the user sets in the timezone settings of the computer I think the docs are right about - it isn't available on either OS, even using platform specific APIs... though I'm sure it is stored somewhere and maybe you could e.g. dig into the Windows registry to find it.
Re: Class info on interfaces
On Friday, 28 August 2015 at 06:19:55 UTC, Jacob Carlborg wrote: Is it possible to detect at compile time if an interface is not a native D interface? Not fully, no, but you might be able to reflect into the methods and see what kind of linkage they have. http://dlang.org/phobos/std_traits.html#functionLinkage The interface itself won't necessarily be marked extern - on the binary level, they are all the same (I think... just a pointer to a list of function pointers), but if you look at the methods you can make a reasonably good guess. However, you can't do anything with an interface that isn't in there anyway without a runtime cast, so you might want to just skip any compile time guesses and just go with the runtime check. Now when I think about it, we actually have four (!) different kinds of interfaces. Native D, C++, Objective-C and COM. aye, and since the interface is so simple at the binary level, it is possible to use them for other things too (I think a glib object in C is also binary compatible...); I'm sure this won't be the end of the list.
Re: How to get the current Timezone
On Friday, 28 August 2015 at 23:03:16 UTC, Jonathan M Davis wrote: I _really_ wish that Microsoft would just use the TZ database like everyone else... - Jonathan M Davis Starting with Windows 8.1, it does, but only in Windows Runtime (so called modern/store apps).
Pointer to std.container.Array data for C library
Hello! Is it possible to get pointer to a data in std.container.Array like .ptr from an array? I need to pass a pointer to some C function (from DerelictGL3 binding) and avoid GC allocation. Thank you!
Re: Pointer to std.container.Array data for C library
On Friday, 28 August 2015 at 18:21:04 UTC, John Colvin wrote: On Friday, 28 August 2015 at 17:45:21 UTC, Oleg wrote: Hello! Is it possible to get pointer to a data in std.container.Array like .ptr from an array? I need to pass a pointer to some C function (from DerelictGL3 binding) and avoid GC allocation. Thank you! I'm pretty sure you can just take the address of the first element, e.g. a[0] or a.front I've tried, it throws core.exception.RangeError@/usr/include/dmd/phobos/std/container/array.d(571): Range violation If I make an array from the Array container with foreach ad pass it's .ptr - it works
Re: Pointer to std.container.Array data for C library
On Friday, 28 August 2015 at 18:46:23 UTC, Oleg wrote: I found solution. I call length instead of reserve. It calls ensureInitialized and everything works fine. By default, Array won't initialize store. Oh, reserve calls it too. My mistake. I found the problem, that's because I passed an empty Array (like Array!int.init).
Re: Pointer to std.container.Array data for C library
On Friday, 28 August 2015 at 18:40:33 UTC, John Colvin wrote: On Friday, 28 August 2015 at 18:31:00 UTC, Oleg wrote: On Friday, 28 August 2015 at 18:21:04 UTC, John Colvin wrote: On Friday, 28 August 2015 at 17:45:21 UTC, Oleg wrote: Hello! Is it possible to get pointer to a data in std.container.Array like .ptr from an array? I need to pass a pointer to some C function (from DerelictGL3 binding) and avoid GC allocation. Thank you! I'm pretty sure you can just take the address of the first element, e.g. a[0] or a.front I've tried, it throws core.exception.RangeError@/usr/include/dmd/phobos/std/container/array.d(571): Range violation That's unexpected. Could you provide a full example that does this? I found solution. I call length instead of reserve. It calls ensureInitialized and everything works fine. By default, Array won't initialize store.
Re: How to get the current Timezone
On Friday, 28 August 2015 at 17:59:06 UTC, WhatMeWorry wrote: Stupid question. If it always returns an empty string, why is it even there? It can return meaningful information in other subclasses; it is a method from the interface and is just blank in the LocalTime class. If you construct one of the other subclasses, you may provide a name which can be retrieved through it, or perhaps some future class might implement it too.
Re: Pointer to std.container.Array data for C library
On Friday, 28 August 2015 at 18:31:00 UTC, Oleg wrote: On Friday, 28 August 2015 at 18:21:04 UTC, John Colvin wrote: On Friday, 28 August 2015 at 17:45:21 UTC, Oleg wrote: Hello! Is it possible to get pointer to a data in std.container.Array like .ptr from an array? I need to pass a pointer to some C function (from DerelictGL3 binding) and avoid GC allocation. Thank you! I'm pretty sure you can just take the address of the first element, e.g. a[0] or a.front I've tried, it throws core.exception.RangeError@/usr/include/dmd/phobos/std/container/array.d(571): Range violation That's unexpected. Could you provide a full example that does this?
Re: How to get the current Timezone
On Friday, August 28, 2015 18:04:16 Adam D. Ruppe via Digitalmars-d-learn wrote: On Friday, 28 August 2015 at 17:59:06 UTC, WhatMeWorry wrote: Stupid question. If it always returns an empty string, why is it even there? It can return meaningful information in other subclasses; it is a method from the interface and is just blank in the LocalTime class. If you construct one of the other subclasses, you may provide a name which can be retrieved through it, or perhaps some future class might implement it too. A prime example would be PosixTimeZone. It knows exactly what its name is. Ultimately though, the name field probably isn't very useful - particularly since I really need to deprecate the functions for converting between the TZ database names and Microsft's names, because it's system dependent, and they keep changing it, so there's no guarantee that the mapping is correct or even that the result exists on a given box (since that box could be out-of-date, or the D program may not have been updated). That being the case, the name property really just becomes applicable to PosixTimeZone. I _really_ wish that Microsoft would just use the TZ database like everyone else... - Jonathan M Davis
Re: Class info on interfaces
On Friday, 28 August 2015 at 19:36:37 UTC, Jacob Carlborg wrote:
On 2015-08-28 17:41, rumbu wrote:
I don't know about Objective-C, but:
- for native D interfaces __traits(getVirtualIndex,
NativeInterface.firstFunction) == 1 since the first entry in
vtbl is the
contained object
- for C++ interfaces __traits(getVirtualIndex,
CPPInterface.firstFunction) == 0
- COM interfaces: __traits(getVirtualIndex,
CPPInterface.firstFunction)
== 0 and inherit IUnknown
I'm wondering how reliable that is. Might be better to check
the linkage of a method in the interface as Adam suggested.
The linkage check it's good as long you don't have an abomination
like this:
extern(C++) interface CPPInterface
{
extern(D) void foo();
}
Anyway, the problem is the availability of such function. If the
interface doesn't contain any function, there is no way to detect
the type, except for COM Interfaces which are clearly
implementing IUnknown.
But deriving a new interface and defining a sentinel function, it
works:
import std.stdio;
import std.traits;
import core.sys.windows.com;
interface NativeInterface {}
interface COMInterface : IUnknown {}
extern(C++) interface CPPInterface {}
enum InterfaceKind { native, windows, cpp }
template interfaceKind(I) if (is(I == interface))
{
interface J : I { void __foo__(); }
static if (functionLinkage!(J.__foo__) == D)
enum interfaceKind = InterfaceKind.native;
else static if (functionLinkage!(J.__foo__) == Windows)
enum interfaceKind = InterfaceKind.windows;
else static if (functionLinkage!(J.__foo__) == C++)
enum interfaceKind = InterfaceKind.cpp;
else static assert(false, Unknown interface kind.);
}
int main(string[] argv)
{
static assert(interfaceKind!NativeInterface ==
InterfaceKind.native);
static assert(interfaceKind!COMInterface ==
InterfaceKind.windows);
static assert(interfaceKind!CPPInterface == InterfaceKind.cpp);
return 0;
}
Re: How to get the current Timezone
On Friday, 28 August 2015 at 14:18:24 UTC, Adam D. Ruppe wrote: On Friday, 28 August 2015 at 14:07:37 UTC, wobbles wrote: However, it just returns an empty string. from the doc: Note that this always returns the empty string. This is because time zones cannot be uniquely identified by the attributes given by the OS (such as the stdName and dstName), and neither Posix systems nor Windows systems provide an easy way to get the TZ Database name of the local time zone. Stupid question. If it always returns an empty string, why is it even there?
Re: Pointer to std.container.Array data for C library
On Friday, 28 August 2015 at 17:45:21 UTC, Oleg wrote: Hello! Is it possible to get pointer to a data in std.container.Array like .ptr from an array? I need to pass a pointer to some C function (from DerelictGL3 binding) and avoid GC allocation. Thank you! I'm pretty sure you can just take the address of the first element, e.g. a[0] or a.front
Re: Class info on interfaces
On 2015-08-28 16:31, Adam D. Ruppe wrote: Not fully, no, but you might be able to reflect into the methods and see what kind of linkage they have. http://dlang.org/phobos/std_traits.html#functionLinkage That might work. However, you can't do anything with an interface that isn't in there anyway without a runtime cast, so you might want to just skip any compile time guesses and just go with the runtime check. Well, this would be for my serialization library. If the static type it's not a native D interface I don't have way to recreate the instance when deserializing, at least not with the default deserialization process. -- /Jacob Carlborg
Re: Class info on interfaces
On 2015-08-28 17:41, rumbu wrote: I don't know about Objective-C, but: - for native D interfaces __traits(getVirtualIndex, NativeInterface.firstFunction) == 1 since the first entry in vtbl is the contained object - for C++ interfaces __traits(getVirtualIndex, CPPInterface.firstFunction) == 0 - COM interfaces: __traits(getVirtualIndex, CPPInterface.firstFunction) == 0 and inherit IUnknown I'm wondering how reliable that is. Might be better to check the linkage of a method in the interface as Adam suggested. -- /Jacob Carlborg
