Mutually-recursive/cyclic module imports

Duncan Coutts duncan.coutts at
Sat Aug 16 13:11:29 EDT 2008

On Fri, 2008-08-15 at 09:27 -0400, Isaac Dupree wrote:
> Haskell-98 specifies that module import cycles work 
> automatically with cross-module type inference.


I'd very much like you to consider in any proposal like this how easy it
is to implement module dependency chasing. If the dependency chaser has
to know too much about Haskell it makes it very difficult for tools like
Cabal or hmake and we could be stuck with only ghc --make or ghc -M. Our
plan with Cabal is to do dependency chasing which would enable
incremental and parallel rebuilds.

I'm not saying it's a problem with your proposal, I'd just like it to be
taken into account. For example do dependency chasers need to grok just
import lines and {-# SOURCE -#} pragmas or do they need to calculate


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