ghc --make feature request

Jan-Willem Maessen jmaessen@alum.mit.edu
Fri, 26 Oct 2001 09:41:13 -0400


"Simon Marlow" <simonmar@microsoft.com> writes:
> GHC actually has rather sophisticated recompilation checking which
> goes beyond just checking whether the interface changed - it keeps
> version information for each entity exported by a module and only
> recompiles if any of the entities actually used by the module have
> changed (this is described in the user's guide under the section on
> recompilation checking).
> 
> So the upshot is that what you're describing shouldn't happen, and it
> may be a bug.  Could you send us more info?

Note that in GHC, the "version number" of a function can often change
for hard-to-spot reasons.  You just need to change (for example) the
strictness properties of the function, which can be very easy to do
when making changes to your code.  The compiler cares about (much)
more than just the types of imported objects.  I tend to expect
recompiles whenever something depends on a function I've changed, even
if I don't think the changes were very significant.

-Jan-Willem Maessen