[CMake] CMake and Lua

[Sylvain Benner]

>> While the cmake language may not be beautiful, it works, and the users
>> (developers) are not supposed to write programs with it.
>>     
>
>
> I do get your point that people should not *have* to program to do common
> tasks. Some other build systems seem to rely on the user to do far too much.
> The build system should include support for all common tasks at a high level
> as macros or commands etc. But I think you still need programming power for
> the corner cases large projects bump into.
>   
I second this. Large projects need some glue to correctly drive them. 
For instance we have +150 MSVC/XCode projects to manage and our managing 
framework is heavily scripted in CMake scripts with +10k LOC. Without 
the "programming power" of CMake we could not build a consistent 
framework and have such a flexibilty and easiness in CMakeLists.txt 
files, so in our case this feature is by far the most important one.

Since we were able to achieve everything we need without using any other 
scripting language, I think that adding new scripting languages to CMake 
is not worth it. It prevents people from correctly learning the CMake 
scripting language which is powerful enough to build a strong, stable 
and consistent framework.

--Sylvain