phobos dependencies

[Dmitry Olshansky]

19-Dec-2013 01:40, Andrei Alexandrescu пишет:
> On 12/18/13 1:16 PM, Dmitry Olshansky wrote:
>> 19-Dec-2013 01:06, Andrei Alexandrescu пишет:
>>> http://chopapp.com/#fvepfd8 shows the number of dependencies (plus 1)
>>> for each module in phobos. Those include druntime dependencies.
>>>
>>
>> So the bill of using pretty much anything in Phobos is pulling in 87
>> modules. Pretty much what I feared it is.
>
> There are several directions we can take this.
>
> 1. Improve the compiler to handle imports lazily, i.e. an unused import
> is never opened. That's unlikely to help a lot of uses because most
> unqualified name lookups require all imports to be loaded (even after
> the name if resolved, the compiler must still look for ambiguities).
>
> 2. Push imports from top level into the entities (functions, classes
> etc) that use them.
>
> 3. Apply classic dependency management (break larger modules in smaller
> ones, accept some code duplication etc).
>
> I favor (2).
>

I'd add something that might help make (2) possible in case of templates.

4. Split modules at least into a package of with at least 2 parts:
- Meta (traits) - constraints, type definitions etc.
- API - functions, globals and other "meat" of the module.

One prime example is std.range - isInputRange, isForwardRange etc. need 
not to be "bought together" with all of range adapters and std.algorithm 
dependency.

-- 
Dmitry Olshansky