unique id for data types
Barney Hilken
b.hilken at ntlworld.com
Tue Sep 18 09:51:17 EDT 2007
In order to make my records system practically useable, I need a type
family
> type family NameCmp n m
which totally orders datatypes. More precisely, it should return one
of the
following types:
> data NameLT = NameLT
> data NameEQ = NameEQ
> data NameGT = NameGT
for each pair of datatypes n & m, according to whether n < m, n = m,
or n > m
in some global ordering. This ordering needs to be independent of the
context,
so it can't be affected by whatever imports there are in the current
module.
What I want to know is: does GHC give datatypes any global id I could
use to
generate such an ordering? Would fully qualified names work?
Secondly (assuming it's possible) how easy would it be for me to
write a patch
to add NameCmp to GHC? Where in the source should I start looking?
Thanks,
Barney.
More information about the Glasgow-haskell-users
mailing list