[Haskell-cafe] Package versioning policy - Harmless type changes?

Heinrich Apfelmus apfelmus at quantentunnel.de
Thu Sep 22 12:37:00 CEST 2011

Dear all,

the package versioning policy specifies that changing the type of any 
entity makes a change of the B number in A.B.C necessary.

However, it seems to me that a small selection of type changes don't 
break dependent code. In particular, consider the following example, 
where I drop a Typeable class constraint:

   - foo :: Typeable a => AddHandler a -> NetworkDescription (Event a)
   + foo :: AddHandler a -> NetworkDescription (Event a)

Can removing a type class constraint on a function break dependent code? 
Should I change the B number or just the C in version A.B.C when 
introducing this change?

Best regards,
Heinrich Apfelmus


More information about the Haskell-Cafe mailing list