desperately seeking RULES help

[Claus Reinke]

> Right. There are two things here:
> 
>    1) -frewrite-rules
> 
> enables rules to fire.
> 
>    2) -fglasgow-exts
> 
> enables parsing of RULES pragmas, and their interpretation.
> 
> You need both if you wish to both write your own rules, and have them
> fire.

nope!-) -fglasgow-exts is sufficient for the RULE to be parsed
and applied in Lennart's code, -frewrite-rules doesn't seem to
serve any noticable purpose.

but i see now this is under re-evaluation, aptly titled:

    "Confusing flags for rewrite rules"
    http://hackage.haskell.org/trac/ghc/ticket/2213
    (see simonpj's comment at the end)

claus

$ head -1 Rules.hs
{-# OPTIONS_GHC -O2 -Wall -fglasgow-exts #-}

$ /cygdrive/c/fptools/ghc/ghc-6.9.20080514/bin/ghc -fno-method-sharing -ddump-simpl-stats -c Rules.
hs

==================== FloatOut stats: ====================
0 Lets floated to top level; 0 Lets floated elsewhere; from 3 Lambda groups



==================== FloatOut stats: ====================
0 Lets floated to top level; 0 Lets floated elsewhere; from 3 Lambda groups



==================== Grand total simplifier statistics ====================
Total ticks:     60

18 PreInlineUnconditionally
11 PostInlineUnconditionally
5 UnfoldingDone
1 RuleFired
    1 toInt/fromInt
2 EtaReduction
22 BetaReduction
1 KnownBranch
11 SimplifierDone