Hi Barney, This may be of interest, since all types already have an Int associated with them: http://haskell.org/ghc/docs/latest/html/libraries/base/Data-Typeable.html#v%... Thanks Neil On 9/18/07, Barney Hilken <b.hilken@ntlworld.com> wrote:
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.
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