DIP11: Automatic downloading of libraries

[Andrei Alexandrescu]

On 6/14/11 1:14 PM, Jesse Phillips wrote:
> Andrei Alexandrescu Wrote:
>
>> http://www.wikiservice.at/d/wiki.cgi?LanguageDevel/DIPs/DIP11
>>
>> Destroy.
>>
>>
>> Andrei
>
> I'm in agreement with those saying it doesn't belong in the compiler/language. In order for it to make sense in this location it would need to take on of a build tool role, which has already be stated to add cause more confusion when something goes wrong.
>
> How confusing is it to say, DMD downloads required modules for you, but will fail to build an executable because you must tell it to use those files. Sure using rdmd is to provide a seamless experience, but this results in more back and forth between compiler and build tool.

I agree that if this makes it through, we need to have a means to 
instruct dmd to also include the module in the build.

> Then there is the caching issue. The proposal has no solution on this, and for good reason. The goal isn't to cache it is to install the library, meaning it is persistent and usable by other projects.

I used "caching" informally and I mentioned the liabilities of using 
e.g. /tmp/ for it. CPAN uses a similar technique, it puts installed 
libraries in a dir dictated by PERL5LIB. We should devise a similar method.

> Installing a library can involve many things, and especially for D can mean compiling C or installing libraries. This solution is looking at a smaller scope, but I don't think it really saves on a "configuration" file.

I agree there are libraries that won't be automatically installable with 
this feature.

> On a note about build tools. I'm like you and Walter in that they always seem so complicated and very fragile. And personally go with simple Makefiles. I'm not really familiar with the problems many of these tools are trying to solve.
>
> I was reading up on redo, and whether it was intended or not, I found one idea that really stuck with me. File transformation operations. Make does a really nice job of dependency resolution and I think this idea of taking a list of dependencies and transforming them into another file makes simple files. So to do an incremental build for D:
>
> .o: .d
>      dmd -c $2
>
> : .o
>      dmd -of$3 $2
>
> mytarget: target.d depended.d on.d files.d
>
> Ok, I haven't gone into depth with what build tools should also be solving, or how to get it working. but this is just my initial "hey I want that."

I use rdmd in conjunction with small makefiles too. I think the proposal 
complements such approaches.


Andrei