[CMake] lexical scoping

[KSpam]

Bill,

> set(a "world")
> variable_scope_begin(a)
> set(a "hello")
> message(${a})
> variable_scope_end(a)
> message(${a})

This would be a workable solution for me.  It would certainly be a step in the 
right direction, especially if it is easy enough to implement.  I was into 
PERL years ago, so "my" declarations are still ingrained in my head ... try 
writing a large set of PERL scripts without "use strict" and "my" :-)

It sure would be nice if there were more standard ways to denote scope though.  
The whole "begin ... end" construct gets to be tedious after a while.  I am a 
big fan of curly braces ( { ... } ) personally, although I am sure that this 
would require quite a bit more work to the CMake scripting language.

With a construct to control variable scope and curly braces to 
replace "begin ... end", I would be quite satisfied with CMake scripting :-)

Thanks,
Justin