Re: Annotations or custom attributes
On 2012-03-10 00:23, Andrei Alexandrescu wrote: P.S. Please don't overquote, you systematically do so. Thanks! I'll try to think about that. -- /Jacob Carlborg
Annotations or custom attributes
Does D have a nice way to add annotations or custom attributes to entities? In Java/C# for example, it is common to annotate things with useful compile time information. I'd like to be able to do that in D on occasion. For instance, I'm serialising some struct/class using reflection to some text format, but there are a couple of members in a particular class that I don't want to be written. A nice solution might be that I could annotate various members: @DoNotSerialise int thing; ... or something along those lines, whatever concept you want to apply, which I could then inspect in static if() logic to produce some requested additional behaviour. This is a trivial example, but looking at C#/Java, you can see how many useful things can be done with this sort of system. How would it be done currently?
Re: Annotations or custom attributes
On 09-03-2012 11:56, Manu wrote: Does D have a nice way to add annotations or custom attributes to entities? Unfortunately, no. In Java/C# for example, it is common to annotate things with useful compile time information. I'd like to be able to do that in D on occasion. Yes. This is a very needed feature. For instance, I'm serialising some struct/class using reflection to some text format, but there are a couple of members in a particular class that I don't want to be written. A nice solution might be that I could annotate various members: @DoNotSerialise int thing; ... or something along those lines, whatever concept you want to apply, which I could then inspect in static if() logic to produce some requested additional behaviour. This is a trivial example, but looking at C#/Java, you can see how many useful things can be done with this sort of system. How would it be done currently? Probably not at all (to my knowledge anyway). -- - Alex
Re: Annotations or custom attributes
On 2012-03-09 11:56, Manu wrote: Does D have a nice way to add annotations or custom attributes to entities? Unfortunately no. In Java/C# for example, it is common to annotate things with useful compile time information. I'd like to be able to do that in D on occasion. For instance, I'm serialising some struct/class using reflection to some text format, but there are a couple of members in a particular class that I don't want to be written. A nice solution might be that I could annotate various members: @DoNotSerialise int thing; ... or something along those lines, whatever concept you want to apply, which I could then inspect in static if() logic to produce some requested additional behaviour. This is a trivial example, but looking at C#/Java, you can see how many useful things can be done with this sort of system. How would it be done currently? Yeah, it would be so nice to have. As a workaround you can mixin some code, variables or similar in a class/struct. For serialization you could use my library Orange, which already supports this. You can have a look at the NonSerialized template at: http://dl.dropbox.com/u/18386187/orange_docs/orange.serialization.Serializable.html https://github.com/jacob-carlborg/orange -- /Jacob Carlborg
Re: Annotations or custom attributes
On 09.03.2012 14:56, Manu wrote: Does D have a nice way to add annotations or custom attributes to entities? There is a potential for them. At least technically everything with @ in front of it was supposed to be an annotation (like @property). I think it's just, sort of, reserved for future. [...] -- Dmitry Olshansky
Re: Annotations or custom attributes
Okay, so the consensus is, it doesn't currently exist, but there is no real resistance, and is tentatively planned? Sounds good to me. On 9 March 2012 15:42, Dmitry Olshansky dmitry.o...@gmail.com wrote: On 09.03.2012 14:56, Manu wrote: Does D have a nice way to add annotations or custom attributes to entities? There is a potential for them. At least technically everything with @ in front of it was supposed to be an annotation (like @property). I think it's just, sort of, reserved for future. [...] -- Dmitry Olshansky
Re: Annotations or custom attributes
Manu: Okay, so the consensus is, it doesn't currently exist, but there is no real resistance, and is tentatively planned? Sounds good to me. As far as I know there are no concrete ideas yet for the semantics and precise usage of this feature. And I think there are different ideas regarding what this feature has to do (example: I think of it as as a user-defined extension of the type system. Other people think of this feature more like the C#, Scala or Java ones). So if you want this feature to happen and you have good ideas, then I suggest you to write down a little concrete proposal of definition syntax/semantics (implementation isn't needed now). Bye, bearophile
Re: Annotations or custom attributes
On 9 March 2012 17:20, bearophile bearophileh...@lycos.com wrote: Manu: Okay, so the consensus is, it doesn't currently exist, but there is no real resistance, and is tentatively planned? Sounds good to me. As far as I know there are no concrete ideas yet for the semantics and precise usage of this feature. And I think there are different ideas regarding what this feature has to do (example: I think of it as as a user-defined extension of the type system. Other people think of this feature more like the C#, Scala or Java ones). So if you want this feature to happen and you have good ideas, then I suggest you to write down a little concrete proposal of definition syntax/semantics (implementation isn't needed now). Bye, bearophile Okay, well I'll do that at some point, but not now. My other multiple return values thread is about a thousand times more important to me at this point, so I'll keep driving that for the time being :P
Re: Annotations or custom attributes
On 3/9/12 2:56 AM, Manu wrote:
Does D have a nice way to add annotations or custom attributes to entities?
In Java/C# for example, it is common to annotate things with useful
compile time information. I'd like to be able to do that in D on occasion.
For instance, I'm serialising some struct/class using reflection to some
text format, but there are a couple of members in a particular class
that I don't want to be written.
A nice solution might be that I could annotate various members:
@DoNotSerialise int thing; ... or something along those lines, whatever
concept you want to apply, which I could then inspect in static if()
logic to produce some requested additional behaviour.
This is a trivial example, but looking at C#/Java, you can see how many
useful things can be done with this sort of system.
How would it be done currently?
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
Andrei
Re: Annotations or custom attributes
That's easy to implement and extremely ugly.
On Fri, Mar 9, 2012 at 8:15 PM, Andrei Alexandrescu
seewebsiteforem...@erdani.org wrote:
On 3/9/12 2:56 AM, Manu wrote:
Does D have a nice way to add annotations or custom attributes to
entities?
In Java/C# for example, it is common to annotate things with useful
compile time information. I'd like to be able to do that in D on occasion.
For instance, I'm serialising some struct/class using reflection to some
text format, but there are a couple of members in a particular class
that I don't want to be written.
A nice solution might be that I could annotate various members:
@DoNotSerialise int thing; ... or something along those lines, whatever
concept you want to apply, which I could then inspect in static if()
logic to produce some requested additional behaviour.
This is a trivial example, but looking at C#/Java, you can see how many
useful things can be done with this sort of system.
How would it be done currently?
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
Andrei
--
Bye,
Gor Gyolchanyan.
Re: Annotations or custom attributes
On 2012-03-09 17:15, Andrei Alexandrescu wrote:
On 3/9/12 2:56 AM, Manu wrote:
Does D have a nice way to add annotations or custom attributes to
entities?
In Java/C# for example, it is common to annotate things with useful
compile time information. I'd like to be able to do that in D on
occasion.
For instance, I'm serialising some struct/class using reflection to some
text format, but there are a couple of members in a particular class
that I don't want to be written.
A nice solution might be that I could annotate various members:
@DoNotSerialise int thing; ... or something along those lines, whatever
concept you want to apply, which I could then inspect in static if()
logic to produce some requested additional behaviour.
This is a trivial example, but looking at C#/Java, you can see how many
useful things can be done with this sort of system.
How would it be done currently?
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
Andrei
As may serialization library Orange already does:
http://dl.dropbox.com/u/18386187/orange_docs/orange.serialization.Serializable.html
Look for NonSerialized.
--
/Jacob Carlborg
Re: Annotations or custom attributes
On 9 March 2012 18:15, Andrei Alexandrescu seewebsiteforem...@erdani.orgwrote:
On 3/9/12 2:56 AM, Manu wrote:
Does D have a nice way to add annotations or custom attributes to
entities?
In Java/C# for example, it is common to annotate things with useful
compile time information. I'd like to be able to do that in D on occasion.
For instance, I'm serialising some struct/class using reflection to some
text format, but there are a couple of members in a particular class
that I don't want to be written.
A nice solution might be that I could annotate various members:
@DoNotSerialise int thing; ... or something along those lines, whatever
concept you want to apply, which I could then inspect in static if()
logic to produce some requested additional behaviour.
This is a trivial example, but looking at C#/Java, you can see how many
useful things can be done with this sort of system.
How would it be done currently?
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
Andrei
Yep, that sure is horribly ugly! Sadly, that's what I thought the case was
currently. Let's hope for user defined attributes in the future ;)
Re: Annotations or custom attributes
On 2012-03-09 16:15:30 +, Andrei Alexandrescu
seewebsiteforem...@erdani.org said:
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
It's ugly, but it works… only to a point though. Try to annotate
overloaded functions and it'll become a mess: either you duplicate the
function name and all the argument types for each function, or you wrap
the whole function body in the mixin.
If you need to annotate a struct or a class you'll have the same
problem, just at a bigger scale. And it gets worse if you want to
annotate templated types and functions: how can the attribute apply to
each instance?
I'm not saying any of this is impossible using mixins, just that it
becomes impractical as you go beyond the most simple cases.
--
Michel Fortin
michel.for...@michelf.com
http://michelf.com/
Re: Annotations or custom attributes
On 9 March 2012 19:23, Michel Fortin michel.for...@michelf.com wrote:
On 2012-03-09 16:15:30 +, Andrei Alexandrescu
seewebsiteforem...@erdani.org** said:
I think a good approach in D would be to define mixins that work in
conjunction with the feature involved, for example:
class A {
int thing;
mixin(DoNotSerialize!thing);
...
}
or together:
class A {
mixin(DoNotSerialize!(int, thing));
...
}
It's ugly, but it works… only to a point though. Try to annotate
overloaded functions and it'll become a mess: either you duplicate the
function name and all the argument types for each function, or you wrap the
whole function body in the mixin.
If you need to annotate a struct or a class you'll have the same problem,
just at a bigger scale. And it gets worse if you want to annotate templated
types and functions: how can the attribute apply to each instance?
I'm not saying any of this is impossible using mixins, just that it
becomes impractical as you go beyond the most simple cases.
It seems to me that everyone agrees on the usefulness of proper user
defined annotations, so I'm personally satisfied that it *will* come :) ..
It's certainly not urgent for me, but it sure would be nice!
Re: Annotations or custom attributes
On Friday, March 09, 2012 16:00:03 Manu wrote: Okay, so the consensus is, it doesn't currently exist, but there is no real resistance, and is tentatively planned? Sounds good to me. I wouldn't really say that it's tentatively planned. I don't recall Walter ever weighing in on it at all, and no one is working on it. Rather, the current situation does not prevent it, and there's definitely some desire for it in the community, so there's a decent chance that it'll be implemented eventually. There are no plans for it though. Regardless, adding them should be backwards compatible, so it's really not a problem to wait until other more pressing issues have been addressed and the language has better stabilized before adding such a feature. - Jonathan M Davis
Re: Annotations or custom attributes
On 3/9/12 8:30 AM, Jacob Carlborg wrote: As may serialization library Orange already does: http://dl.dropbox.com/u/18386187/orange_docs/orange.serialization.Serializable.html Look for NonSerialized. Saw that after posting. Cool! Andrei P.S. Please don't overquote, you systematically do so. Thanks!
Re: Annotations or custom attributes
On Fri, 09 Mar 2012 18:23:17 -0500, Andrei Alexandrescu seewebsiteforem...@erdani.org wrote: On 3/9/12 8:30 AM, Jacob Carlborg wrote: As may serialization library Orange already does: http://dl.dropbox.com/u/18386187/orange_docs/orange.serialization.Serializable.html Look for NonSerialized. Saw that after posting. Cool! Andrei P.S. Please don't overquote, you systematically do so. Thanks! Please continue to quote the previous two messages for context if you feel like it. I enjoy not having to look back to previous messages. Thanks! -Steve
Re: Annotations or custom attributes
What are you talking about?
Re: Annotations or custom attributes
On Fri, 09 Mar 2012 19:05:00 -0500, Ary Manzana a...@esperanto.org.ar wrote: What are you talking about? Who are you talking to? :) Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) -Steve
Re: Annotations or custom attributes
On 3/10/12, Steven Schveighoffer schvei...@yahoo.com wrote: Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) LOL. I was honestly wondering if this was an issue or not. I blame the gmail quick-reply box. It has two options: quote everything, or quote nothing. Otherwise there's a full reply button and then I can quickly select a piece of text to quote. But I *thought* that by using quick reply without fully quoting it would mean my reply would sit right next to the last poster's reply. I'm just used to using forum software and when I do a quick-reply there my post is right below the last user's post, and it's easy to figure out who I'm replying to. Anyway, I'll stop posting replies to the void. :p (thanks for letting me know btw)
Re: Annotations or custom attributes
On Fri, Mar 09, 2012 at 07:24:34PM -0500, Steven Schveighoffer wrote: On Fri, 09 Mar 2012 19:05:00 -0500, Ary Manzana a...@esperanto.org.ar wrote: What are you talking about? Who are you talking to? :) Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) [...] You guys should just use a threading mail reader. Like mutt. :-P :-P (Though Ary's post didn't make sense to me either, because I'd deleted the parent post already. Ah well. The joys of impersonal online communication...) T -- I see that you JS got Bach.
Re: Annotations or custom attributes
On Fri, 09 Mar 2012 19:53:29 -0500, Andrej Mitrovic andrej.mitrov...@gmail.com wrote: On 3/10/12, Steven Schveighoffer schvei...@yahoo.com wrote: Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) LOL. I was honestly wondering if this was an issue or not. I blame the gmail quick-reply box. It has two options: quote everything, or quote nothing. Otherwise there's a full reply button and then I can quickly select a piece of text to quote. But I *thought* that by using quick reply without fully quoting it would mean my reply would sit right next to the last poster's reply. I think it does, actually. It's just the post you are responding to isn't always the last poster :D I'm just used to using forum software and when I do a quick-reply there my post is right below the last user's post, and it's easy to figure out who I'm replying to. The forum software does not by default thread discussions, but my newsreader does. Anyway, I'll stop posting replies to the void. :p (thanks for letting me know btw) I hope you realize I didn't mean it in a bad/condescending way :) I realize we all use software that sometimes doesn't do the right thing, and it's not always our fault for liking some shitty software. But whose fault is it? Yours for using a forum-like software, or mine for trying to thread the newsgroup? If a tree posts a reply in the wrong thread, and the forest doesn't use threading readers, does anyone care? -Steve
Re: Annotations or custom attributes
On Fri, 09 Mar 2012 19:58:37 -0500, H. S. Teoh hst...@quickfur.ath.cx wrote: On Fri, Mar 09, 2012 at 07:24:34PM -0500, Steven Schveighoffer wrote: Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) [...] You guys should just use a threading mail reader. Like mutt. :-P :-P (Though Ary's post didn't make sense to me either, because I'd deleted the parent post already. Ah well. The joys of impersonal online communication...) You should not delete old posts :) I find it invaluable for searching for old discussions sometimes (I use opera with google-like searching). -Steve
Re: Annotations or custom attributes
On Fri, Mar 09, 2012 at 08:07:47PM -0500, Steven Schveighoffer wrote: On Fri, 09 Mar 2012 19:58:37 -0500, H. S. Teoh hst...@quickfur.ath.cx wrote: On Fri, Mar 09, 2012 at 07:24:34PM -0500, Steven Schveighoffer wrote: Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) [...] You guys should just use a threading mail reader. Like mutt. :-P :-P (Though Ary's post didn't make sense to me either, because I'd deleted the parent post already. Ah well. The joys of impersonal online communication...) You should not delete old posts :) I find it invaluable for searching for old discussions sometimes (I use opera with google-like searching). [...] While I agree with you on principle, after having accumulated YEARS of archives for several high-volume mailing lists in the past I'm starting to doubt the value of doing it. Sometimes the signal-to-noise ratio is just too low to justify archiving *everything*. So I usually only save threads that I find interesting and has lasting value and delete the rest (esp. since there's an online archive for it anyway). T -- In a world without fences, who needs Windows and Gates? -- Christian Surchi
Re: Annotations or custom attributes
On 3/10/12, Steven Schveighoffer schvei...@yahoo.com wrote: I hope you realize I didn't mean it in a bad/condescending way :) No problemo! I don't take things too seriously around this place (or the internets in general). But whose fault is it? I'd say it's the technology's fault. A newsgroup seems to be the equivalent of a source file, but with each person having a compiler with different semantics. Related: http://www.youtube.com/watch?v=Fc1P-AEaEp8
Re: Annotations or custom attributes
On 3/9/12 4:24 PM, Steven Schveighoffer wrote: On Fri, 09 Mar 2012 19:05:00 -0500, Ary Manzana a...@esperanto.org.ar wrote: What are you talking about? Who are you talking to? :) Seriously, though, I think Andrej sometimes quotes *nothing* (no offense for picking on you Andrej), and couple that with the newsgroup's seemingly random decision to start a new thread, or put a reply at the same level, I sometimes have no idea what he's talking about :) There are extremes, of course. I, for one, take pains to make sure I quote about the right amount of context. I know it's time well spent because every second I save for one reader is multiplied by many of them. I think it's very jarring to see a 300-line discussion quoted and followed by a brief answer. If that much context is necessary, I'd have no business reading that message unless I actually followed the conversation. Andrei
