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
