-- P.cabal Exposed-modules: Data Build-Depends: base, time
-- Data.hs (yes..) module Data(module Time) where import Data.Time as Time
I'm a bit confused; is this Data module necessary? If so, is its name important? Are you proposing a new extension?
for context: - i suggested that there should be a base package that would depend on the packages split off from the old base, and would simply reexport their modules to provide the full functionality of the old base on top of the spin-off packages - Ross pointed out that packages can't simply re-export modules, so the straightforward solution of a package without sources, just with a .cabal file, seems barred for the moment (though i don't understand why this restriction is there, so perhaps i am asking for an extension?) - taking time as a small example, i was looking for a way around this limitation, to reexport time's modules via a different package: - it seems that cabal needs some sources for exported modules - module Data.Time where import Data.Time, then exposing Data.Time, does not work, because of cycle - module Data(module Time) import Data.Time as Time, then exposing Data, does work, as demonstrated
configure, build, install, and 'ghc -package P Y.hs' seems to work. $ ghc -package P Y.hs
Why is -package P better than -package time?
not better, it just demonstrates that we can re-export a module from package time via package P. so, presumably, one could re-export the modules distributed over the packages split off from the old base via a thin package base, avoiding breakage. there may be other ways, i just needed one way to confirm that it is possible. claus