Heads up, ACM members!
As fans of functional programming, you can provide input on the future
of the CS curriculum guidance provided by ACM. In particular, you
could support the SIGPLAN alternate proposal for the programming
language part (wiki.acm.org/cs2001/index.php?title=SIGPLAN_Proposa
This isn't great, but it's not really different than is the case for
non-overlapping instances. Suppose module B1 declares 'instance C T',
and uses that instance; and module B2 declares a *different* 'instance
C T', and uses that instance; and Main imports B1 and B2, but does not
use either insta
Yes indeed, this is one of those "well-known" (ie not at all well known, but
folk lore) problems with overlapping instances, at least in programs where
different instances can be in scope at different times.
It's discussed (not very clearly) in
http://www.haskell.org/ghc/docs/latest/html/users_
