RE: GHC Core question
If you use -dppr-debug GHC will show you the unique number of each identifier,
and that'll show you that the two $dMonads are distinct even though they have
the same print-name. CoreTidy makes the print-name unique too.
Perhaps the Core printer should be a bit keener to print unique numbers, but it
adds a lot of clutter.
Simon
| -Original Message-
| From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of
| Neil Mitchell
| Sent: 05 January 2008 20:01
| To: GHC Users
| Subject: GHC Core question
|
| Hi
|
| I've compiled the Debug.Trace module to Core, but can't understand the
| resulting output. The original code is:
|
| trace string expr = unsafePerformIO $ do
| putTraceMsg string
| return expr
|
| The core is:
|
| Debug.Trace.trace =
|\ (@ a) -
| __letrec {
|trace :: GHC.Base.String - a - a
|[]
|trace =
| \ (string :: GHC.Base.String) (expr :: a) -
|GHC.Base.$
| @ (GHC.IOBase.IO a)
| @ a
| (GHC.IOBase.unsafePerformIO @ a)
| ( @ () @ a (Debug.Trace.putTraceMsg string) (return @ a expr));
|$dMonad :: GHC.Base.Monad GHC.IOBase.IO
|[]
|$dMonad = $dMonad;
|return :: forall a. a - GHC.IOBase.IO a
|[]
|return = GHC.Base.return @ GHC.IOBase.IO $dMonad;
|$dMonad :: GHC.Base.Monad GHC.IOBase.IO
|[]
|$dMonad = GHC.IOBase.$f16;
| :: forall a b.
| GHC.IOBase.IO a - GHC.IOBase.IO b - GHC.IOBase.IO b
|[]
| = GHC.Base. @ GHC.IOBase.IO $dMonad;
| } in trace;
|
| And my Haskell reformatting of that is:
|
| Debug.Trace.trace = let
|trace string expr = unsafePerformIO $ putTraceMsg string return expr
|$dMonad = $dMonad;
|return = GHC.Base.return $dMonad;
|$dMonad = GHC.IOBase.$f16;
| = GHC.Base. $dMonad;
| in trace
|
| However, that let expression has two bindings for $dMonad, one of
| which looks like a black-hole. Are the semantics of __letrec different
| from let in some way?
|
| Thanks
|
| Neil
| ___
| Glasgow-haskell-users mailing list
| Glasgow-haskell-users@haskell.org
| http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC Core question
Hi How are you printing out the Core? showSDoc $ ppr c where c :: [CoreBind] It looks like the unique ids are missing (you can see them if you pass the -ppr-debug flag, which can be set using the API) I have now set the -ppr-debug flag, but that has no effect. It's not entirely surprising, as I guess setting the flag only applies through the GHC session, and this code is being run outside that. How can I print the output (to a file) using the unique id's? Simon Peyton-Jones says: CoreTidy makes the print-name unique too. Can I invoke CoreTidy using the GHC API? Thanks Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC Core question
On 1/7/08, Neil Mitchell [EMAIL PROTECTED] wrote: Hi How are you printing out the Core? showSDoc $ ppr c where c :: [CoreBind] It looks like the unique ids are missing (you can see them if you pass the -ppr-debug flag, which can be set using the API) I have now set the -ppr-debug flag, but that has no effect. It's not entirely surprising, as I guess setting the flag only applies through the GHC session, and this code is being run outside that. How can I print the output (to a file) using the unique id's? Good point about the session, I forgot about that. It looks like you can call showSDocDebug instead of showSDoc (see utils/Outputable.lhs), which acts as if -dppr-debug is set, but I haven't actually tried it. Can I invoke CoreTidy using the GHC API? Yes, but you'll need to grab a post-Dec-25 build if you haven't already, since I added this recently. Once you have, see compileToCoreSimplified in main/GHC.hs. Cheers, Tim -- Tim Chevalier * http://cs.pdx.edu/~tjc * Often in error, never in doubt It's easy to consider women more emotional than men when you don't consider rage to be an emotion. -- Brenda Fine ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC Core question
Hi I have now set the -ppr-debug flag, but that has no effect. It's not entirely surprising, as I guess setting the flag only applies through the GHC session, and this code is being run outside that. How can I print the output (to a file) using the unique id's? Good point about the session, I forgot about that. It looks like you can call showSDocDebug instead of showSDoc (see utils/Outputable.lhs), which acts as if -dppr-debug is set, but I haven't actually tried it. That does indeed work - and I can now see exactly why you don't leave it on all the time! Can I invoke CoreTidy using the GHC API? Yes, but you'll need to grab a post-Dec-25 build if you haven't already, since I added this recently. Once you have, see compileToCoreSimplified in main/GHC.hs. /me upgrades Many thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC Core question
On 1/5/08, Neil Mitchell [EMAIL PROTECTED] wrote:
Hi
I've compiled the Debug.Trace module to Core, but can't understand the
resulting output. The original code is:
trace string expr = unsafePerformIO $ do
putTraceMsg string
return expr
The core is:
Debug.Trace.trace =
\ (@ a) -
__letrec {
trace :: GHC.Base.String - a - a
[]
trace =
\ (string :: GHC.Base.String) (expr :: a) -
GHC.Base.$
@ (GHC.IOBase.IO a)
@ a
(GHC.IOBase.unsafePerformIO @ a)
( @ () @ a (Debug.Trace.putTraceMsg string) (return @ a expr));
$dMonad :: GHC.Base.Monad GHC.IOBase.IO
[]
$dMonad = $dMonad;
return :: forall a. a - GHC.IOBase.IO a
[]
return = GHC.Base.return @ GHC.IOBase.IO $dMonad;
$dMonad :: GHC.Base.Monad GHC.IOBase.IO
[]
$dMonad = GHC.IOBase.$f16;
:: forall a b.
GHC.IOBase.IO a - GHC.IOBase.IO b - GHC.IOBase.IO b
[]
= GHC.Base. @ GHC.IOBase.IO $dMonad;
} in trace;
And my Haskell reformatting of that is:
Debug.Trace.trace = let
trace string expr = unsafePerformIO $ putTraceMsg string return expr
$dMonad = $dMonad;
return = GHC.Base.return $dMonad;
$dMonad = GHC.IOBase.$f16;
= GHC.Base. $dMonad;
in trace
However, that let expression has two bindings for $dMonad, one of
which looks like a black-hole. Are the semantics of __letrec different
from let in some way?
How are you printing out the Core? It looks like the unique ids are
missing (you can see them if you pass the -ppr-debug flag, which can
be set using the API) -- if the unique ids were being printed, you
would see that the bindings for $dMonad (likely) have different
uniques.
Cheers,
Tim
--
Tim Chevalier * http://cs.pdx.edu/~tjc * Often in error, never in doubt
...Losing your mind, like losing your car keys, is a real hassle. --
Andrew Solomon
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
GHC Core question
Hi
I've compiled the Debug.Trace module to Core, but can't understand the
resulting output. The original code is:
trace string expr = unsafePerformIO $ do
putTraceMsg string
return expr
The core is:
Debug.Trace.trace =
\ (@ a) -
__letrec {
trace :: GHC.Base.String - a - a
[]
trace =
\ (string :: GHC.Base.String) (expr :: a) -
GHC.Base.$
@ (GHC.IOBase.IO a)
@ a
(GHC.IOBase.unsafePerformIO @ a)
( @ () @ a (Debug.Trace.putTraceMsg string) (return @ a expr));
$dMonad :: GHC.Base.Monad GHC.IOBase.IO
[]
$dMonad = $dMonad;
return :: forall a. a - GHC.IOBase.IO a
[]
return = GHC.Base.return @ GHC.IOBase.IO $dMonad;
$dMonad :: GHC.Base.Monad GHC.IOBase.IO
[]
$dMonad = GHC.IOBase.$f16;
:: forall a b.
GHC.IOBase.IO a - GHC.IOBase.IO b - GHC.IOBase.IO b
[]
= GHC.Base. @ GHC.IOBase.IO $dMonad;
} in trace;
And my Haskell reformatting of that is:
Debug.Trace.trace = let
trace string expr = unsafePerformIO $ putTraceMsg string return expr
$dMonad = $dMonad;
return = GHC.Base.return $dMonad;
$dMonad = GHC.IOBase.$f16;
= GHC.Base. $dMonad;
in trace
However, that let expression has two bindings for $dMonad, one of
which looks like a black-hole. Are the semantics of __letrec different
from let in some way?
Thanks
Neil
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
