2008-10-11 Hackage status with GHC 6.10

[Simon Peyton-Jones]

| RULES are always parsed (no flags or language extensions needed). They
| also go into the .hi files (unless you use the obscure option to change
| that), so they are exported for all client modules.

The latter isn't true, and I think that's what Henning is objecting to.

Currently, without -O GHC puts the absolute minimum in interface files to get the clients to compile: just the exports and their types.  For example, if you have
        f x = x
GHC will not put that unfolding in the interface file, tiny though it is.

Currently without -O GHC therefore does *not* put RULES in the interface file.  I thought that was consistent, since they are to do with optimisation.


If, however, there's a consensus that RULES should be persisted even without -O, that'd be easy to arrange. For example, I think that deprecations are persisted unconditionally.

Simon

| -----Original Message-----
| From: Duncan Coutts [mailto:duncan.coutts at worc.ox.ac.uk]
| Sent: 16 October 2008 05:57
| To: Henning Thielemann
| Cc: Simon Peyton-Jones; libraries at haskell.org
| Subject: RE: 2008-10-11 Hackage status with GHC 6.10
|
| On Wed, 2008-10-15 at 20:47 +0200, Henning Thielemann wrote:
|
| >   I found it just confusing to switch on two features (namely 'optimization
| > including application of rules' and 'parsing, checking and storing new
| > rules') with one option (namely -O). It remains confusing for me also if
| > one of the two features can be enabled separately with
| > -fno-omit-interface-pragmas, but the other feature cannot. Also the option
| > sounds like it also applies not only to RULES. I also find the doubled
| > negation in 'no omit' confusing. What about
| > '-finclude-all-interface-pragmas'?
| >   What concerns documentation: The description of an option for enabling
| > parsing of RULES I would expect in ghc-doc/users_guide/rewrite-rules.html.
|
| While it used to be more complex, the situation now is quite simple:
|
| RULES are always parsed (no flags or language extensions needed). They
| also go into the .hi files (unless you use the obscure option to change
| that), so they are exported for all client modules.
|
| RULES get used/applied with -O. Again, there is an option to turn off
| the use of rules (without affecting other optimisations).
|
| This seems pretty sane and easy to explain.
|
| Duncan
|