Ganesh write:
> We need to sort out haskell_policy, the ratification of readFile all
> over the place is just silly. Replacing it with hlint as has been
> suggested sounds like a very good idea.

The tests/haskell_policy.sh script is a historical in-house utility
for catching gotchas that have caused us problems in the past.

The problem is that this script doesn't have a Haskell parser, so it
cannot distinguish between e.g. use of Prelude.readFile (bad) and the
readFile of other modules (OK).  This results in whitelist comments:

    -- ratify readFile: haskell_policy is stupid.

There is a third-party tool called hlint[0] which seems like an ideal
replacement for haskell_policy.  The maintainer is happy to work with
us if hlint needs "extra smarts" to be useful for us.

This has been discussed earlier on the mailing list, but it seems no
BTS ticket was created.  Early messages in that thread have these
Message-IDs:

    <3063erpba3.fsf_-_@gmail.com>
    <b97f58860906200205w5c6048acrd299c797125738f1@mail.gmail.com>
    <87ocsjz294.fsf_-_@mornfall.net>

The work to resolve this task is: 1) make sure that hlint can test
everything that haskell_policy tests; 2) replace haskell_policy's
innards with calls to hlint.

[0] http://hackage.haskell.org/package/hlint

Assigning to Gwern as I understand he's working on it

Fixed by

Fri Aug  7 08:57:36 CEST 2009  Petr Rockai <me@mornfall.net>
  * Re-implement haskell_policy in terms of hlint.
  
  This also comes with a change to the ratification mechanism, which now uses a
  separate Ratified module, from which you have to import the unsafe
  functions. Requires a recent hlint.

with thanks to Gwern for initial implementation