“(a `op`) is not \x -> a `op` x” is wrong according to the report about articles HOT 4 CLOSED

2014-02-11 21:58:16 haasn   quchen: https://github.com/quchen/articles/blob/master/fbut.md#a-op-is-not-x---a-op-x is this a bug?
2014-02-11 21:58:29 haasn   the haskell report clearly specifies (e op) = \ x -> e op x 
2014-02-11 22:01:44 thoughtpolice   haasn: http://www.haskell.org/onlinereport/haskell2010/haskellch6.html#x13-1260006.2
2014-02-11 22:01:52 thoughtpolice   "As a consequence, ⊥ is not the same as \x -> ⊥, since seq can be used to distinguish them. For the same reason, the existence of seq weakens Haskell’s parametricity properties."
2014-02-11 22:02:25 shachaf thoughtpolice: Yes, I think haasn is aware.
2014-02-11 22:02:40 shachaf Hence the issue with (x `op`) being _|_
2014-02-11 22:03:11 shachaf I think this issue is not quite important enough to care about making GHC compliant.
2014-02-11 22:03:19 shachaf I would probably rather have PostfixOperators go into the Report.
2014-02-11 22:03:46 thoughtpolice   oh, i misread. the *sections* are the complaint. i take back my annoying quote of the report

2013-07-02 15:53:01 haasn   these are just simple translation rules; (a ==) literally parses as (==) a; and (== a) literally parses as \x -> (==) x a
2013-07-02 15:54:16 shachaf haasn: No, it doesn't parse as that, and it also doesn't mean that (in standard Haskell, anyway).
...
2013-07-02 15:56:15 haasn   Translation: The following identities hold:
2013-07-02 15:56:15 haasn   (op e)  =  \ x -> x op e
2013-07-02 15:56:15 haasn   (e op)  =  \ x -> e op x
2013-07-02 15:56:30 haasn   looks like my (a ==) case was incorrect
2013-07-02 15:56:39 elliott I assume shachaf is referring to the fact that ((==) a) isn't quite the same as (\b -> a == b)
2013-07-02 15:56:49 shachaf Yes, what elliott said.
2013-07-02 15:56:56 elliott though frankly I think we'd all like to forget that that isn't true, and I believe we usually act as such
...
2013-07-02 15:57:25 quchen  elliott: Pedantry or not, what's the difference between the two?
2013-07-02 15:58:03 elliott quchen: _|_
2013-07-02 15:58:13 elliott > (undefined :: () -> ()) `seq` ()
2013-07-02 15:58:14 lambdabot     *Exception: Prelude.undefined
2013-07-02 15:58:23 haasn   > let (==) = undefined in seq (\x -> () == x) ()
2013-07-02 15:58:24 lambdabot     ()
2013-07-02 15:59:23 quchen  elliott: Ah, the ability of seq to distinguish between bottom and (const bottom)