[Pharo-dev] Pragmas - compile time versus run time

[Ben Coman]

In consideration of Issue 11880, I wanted to better understand the 
concept of pragmas and how they are used in Pharo. 

"Pragmas" seem to be used in other languages to provide "compile time" 
directives, but Pharo seems search for pragmas at runtime, for example 
to do things like build menus.  Mostly I'd consider menus fairly static 
(with any dynamism statically defined).   In Issue 11880 adding a few 
caches brings menu generation from 80ms down to 5ms - but then there is 
the complexity of resetting them when the code that defines them changes. 

So I wonder... can/do pragmas cause actions at compile time, like 
setting a class variable to nil when a method is compiled?  That seems a 
good way to reset a cache whose builder uses that method, but maybe 
there are problems I don't see?

https://pharo.fogbugz.com/default.asp?11880
cheers -ben