I want to get the (ddoc)-comment of a certain function/member/struct … so I can generate help-messages at compiletime, without the need to duplicate the comments. Like pythons function.__doc__ or class.__doc__ etc. is there anything planed for D, e.g. __traits(getComment, foo.bar)?

If not what do you think of it, I would love this addition.

David:

> I want to get the (ddoc)-comment of a certain function/member/struct … so I can generate help-messages at compiletime, without the need to duplicate the comments. Like pythons function.__doc__ or class.__doc__ etc. is there anything planed for D, e.g. __traits(getComment, foo.bar)?
>
> If not what do you think of it, I would love this addition.

+1 Yeah! :-)

Bye,
bearophile

David:

> I want to get the (ddoc)-comment of a certain function/member/struct … so I can generate help-messages at compiletime, without the need to duplicate the comments.

I am sure there are MANY other possible applications for such a trait. Compile-time doctests maybe are a bit too much (but they are OK for compile-time functions!), but things like this become possible:
http://pypi.python.org/pypi/docopt/0.1

Bye,
bearophile

Am 19.08.2012 15:30, schrieb bearophile:
> David:
>
>> I want to get the (ddoc)-comment of a certain function/member/struct …
>> so I can generate help-messages at compiletime, without the need to
>> duplicate the comments.
>
> I am sure there are MANY other possible applications for such a trait.
> Compile-time doctests maybe are a bit too much (but they are OK for
> compile-time functions!), but things like this become possible:
> http://pypi.python.org/pypi/docopt/0.1
>
> Bye,
> bearophile

Actually, that's why I want that trait :)

David:

> Actually, that's why I want that trait :)

But in practice, as your command line programs get a little more complex, docopt is not enough, you need normal programming with things like argparse.

So maybe a mix of the two ideas is better, to write most stuff in the docstring, and then refine its semantics below with normal code.

Bye,
bearophile

Am Sun, 19 Aug 2012 15:30:33 +0200
schrieb "bearophile" <bearophileHUGS@lycos.com>:

> David:
> 
> > I want to get the (ddoc)-comment of a certain function/member/struct … so I can generate help-messages at compiletime, without the need to duplicate the comments.
> 
> I am sure there are MANY other possible applications for such a
> trait. Compile-time doctests maybe are a bit too much (but they
> are OK for compile-time functions!), but things like this become
> possible:
> http://pypi.python.org/pypi/docopt/0.1
> 
> Bye,
> bearophile

Jesus! Did Nick write docopt? It's full of swear words. Hmm, no, Vladimir Keleshev. It sounds nice, I would see the common Python way of parsing options a big step forward already. E.g. including help texts and printing the usage info to stdout.

-- 
Marco

Am 19.08.2012 16:36, schrieb bearophile:
> David:
>
>> Actually, that's why I want that trait :)
>
> But in practice, as your command line programs get a little more
> complex, docopt is not enough, you need normal programming with things
> like argparse.
>
> So maybe a mix of the two ideas is better, to write most stuff in the
> docstring, and then refine its semantics below with normal code.
>
> Bye,
> bearophile

I am not writing an actual argparsing-library, I thought of starting one, but then I realized, I don't have the time to do something amazing like argparse, so I decided to go with a less complex and heavily CTFE'd version. It looks like that:

struct AppArguments {
    string username;
    Alias!("username") u;

    string password;
    Alias!("password") p;

    bool credentials;
    Alias!("credentials") c;

    uint width = 1024;
    uint height = 800;

    string host;
    Alias!("host") h;
    ushort port = 25565;

    bool no_snoop = false;
}

void main() {
    auto args = get_options!AppArguments();
}

I added a default --help function to it, if there is no "help" member declared in AppArguments, but I realized ... --help without messages is kinda pointless ...

On 19-Aug-12 18:45, David wrote:
> Am 19.08.2012 16:36, schrieb bearophile:
>> David:
>>
>>> Actually, that's why I want that trait :)
>>
>> But in practice, as your command line programs get a little more
>> complex, docopt is not enough, you need normal programming with things
>> like argparse.
>>
>> So maybe a mix of the two ideas is better, to write most stuff in the
>> docstring, and then refine its semantics below with normal code.
>>
>> Bye,
>> bearophile
>
> I am not writing an actual argparsing-library, I thought of starting
> one, but then I realized, I don't have the time to do something amazing
> like argparse, so I decided to go with a less complex and heavily CTFE'd
> version. It looks like that:
>
> struct AppArguments {
>      string username;
>      Alias!("username") u;
>
>      string password;
>      Alias!("password") p;
>
>      bool credentials;
>      Alias!("credentials") c;
>
>      uint width = 1024;
>      uint height = 800;
>
>      string host;
>      Alias!("host") h;
>      ushort port = 25565;
>
>      bool no_snoop = false;
> }
>
> void main() {
>      auto args = get_options!AppArguments();
> }
>
> I added a default --help function to it, if there is no "help" member
> declared in AppArguments, but I realized ... --help without messages is
> kinda pointless ...

What's wrong with std.getopt? I thought there was some movement to improve it (including auto-generating usage messages).

-- 
Olshansky Dmitry

> What's wrong with std.getopt? I thought there was some movement to
> improve it (including auto-generating usage messages).

It uses std.getopt for parsing.

Am 19.08.2012 14:26, schrieb David:
> I want to get the (ddoc)-comment of a certain function/member/struct …
> so I can generate help-messages at compiletime, without the need to
> duplicate the comments. Like pythons function.__doc__ or class.__doc__
> etc. is there anything planed for D, e.g. __traits(getComment, foo.bar)?
>
> If not what do you think of it, I would love this addition.

So no official word to it?