[Omake] non-file rules

[Sam Steingold]

Hi,
we maintain transitive dependencies using the file system, i.e., we have a huge 
directory tree which mirrors the library names we have with tiny little files.
(find prints 3,638 entries which take 15M according to du, but only 1.4M 
according to wc `find . -type f`; disk space, of course, is not the issue here, 
but the speed of the build process - which has to access all those files - _IS_).

we would like to replace the directory tree with an in-memory map.
alas, the entries of this map object have to be updated based on each other, 
which is very easy with files (we have omake functions which create the rules 
which update the files) but not so easy with the in-memory map (e.g., the map 
entries do not have explicit timestamps).

so, my question is: is there a way to tap into the omake built-in dependency 
resolution and tracking algorithm to maintain the transitive dependency map?

thanks
Sam