[CMake] CMake with Lua Experiment

[Ken Martin]

I doubt seriously we will adopt a second language in CMake. There is no
question of maintaining the current language. It has to and will be kept in
CMake. It was very easy to add Lua to CMake which is nice (literally it was
probably 15 hours of effort). Part of this experiment was to see if it was
even programtically practical to add a second language. It turns out it is.
Doing a complete nice integration would be pretty easy except for variables
and syntax. That is where the two approaches significantly differ and as
others have posted that is one place where CMake currently does not scale
well. For those of us accustomed to functions and local variables the macro
command is not quite right. We do need to address the variable/scope issue
in CMake and I am sure we will. Starting from scratch I would use Lua for
all the benefits a mature language provides, but adding it (or transitioning
to it) I *suspect* is not worth it. (although part of me thinks in the long
ten-year-out view it is worth it) Sometimes these issues take a while to
gel.

Ken

Ken Martin PhD 
Kitware Inc.
28 Corporate Drive
Clifton Park NY 12065
518 371 3971