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Today's Topics:
1. Re: pipe and IO (David McBride)
2. Re: pipe and IO (PICCA Frederic-Emmanuel)
3. Re: How to call popCnt64#? (John Ky)
4. let x = x in x (GHC.Prim) (John Ky)
5. Re: let x = x in x (GHC.Prim) ([email protected])
----------------------------------------------------------------------
Message: 1
Date: Tue, 22 Mar 2016 13:08:53 -0400
From: David McBride <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] pipe and IO
Message-ID:
<can+tr43kpc5+959shf066rokn-yfvtduv8y+cy_sztwe_5p...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Yield in your producer is of type DataFrameHkI3D -> Producer DataFrameHkl3D
IO ()
But you are putting an (IO DataFrameHkI3D) in as an argument.
You should be able to do something like this:
getDataFrameHkl3D :: DataFrameHkl3DH5SixsUhv -> Producer DataFrameHkl3D IO
()
getDataFrameHkl3D d = do
n <- lift $ hkl_h5_len (h5mu d)
frames <- forM [0..n] $ \i -> lift (getDataFrameHkl3D' d i) -- ::
Producer DataFrameHkl3D IO [DataFrameHkl3D]
forM_ frames yield
I have a feeling it may be more efficient to yield immediately on each loop
as such:
getDataFrameHkl3D :: DataFrameHkl3DH5SixsUhv -> Producer DataFrameHkl3D IO
()
getDataFrameHkl3D d = do
n <- lift $ hkl_h5_len (h5mu d)
forM_ [0..n] (\i -> lift (getDataFrameHkl3D' d i) >>= yield)
You may also substitutde liftIO for lift, if you wish.
On Tue, Mar 22, 2016 at 12:37 PM, PICCA Frederic-Emmanuel <
[email protected]> wrote:
> Hello,
>
> Still playing with the Pipe module
>
> here the code I try to write
>
> getDataFrameHkl3D' :: DataFrameHkl3DH5SixsUhv -> Int -> IO DataFrameHkl3D
> getDataFrameHkl3D' d i = do
> positions <- get_position (h5mu d) i
> return $ DataFrameHkl3D { df_n = i
> , df_image = positions
> }
>
> getDataFrameHkl3D :: DataFrameHkl3DH5SixsUhv -> Producer DataFrameHkl3D IO
> ()
> getDataFrameHkl3D d = do
> n <- lift $ hkl_h5_len (h5mu d)
> forM_ [0..n] $ \i -> yield $ getDataFrameHkl3D' d i
>
>
> but when I compile it I get this error message
>
> src/hkl3d.hs:274:3:
> Couldn't match type `IO DataFrameHkl3D' with `DataFrameHkl3D'
> Expected type: Proxy X () () DataFrameHkl3D IO ()
> Actual type: Proxy X () () (IO DataFrameHkl3D) IO ()
> In a stmt of a 'do' block:
> forM_ [0 .. n] $ \ i -> yield $ getDataFrameHkl3D' d i
> In the expression:
> do { n <- lift $ hkl_h5_len (h5mu d);
> forM_ [0 .. n] $ \ i -> yield $ getDataFrameHkl3D' d i }
> In an equation for `getDataFrameHkl3D':
> getDataFrameHkl3D d
> = do { n <- lift $ hkl_h5_len (h5mu d);
> forM_ [0 .. n] $ \ i -> yield $ getDataFrameHkl3D' d i }
>
> I do not know how to fix my code...
>
> Frederic
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
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Message: 2
Date: Tue, 22 Mar 2016 17:12:22 +0000
From: PICCA Frederic-Emmanuel
<[email protected]>
To: "The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell" <[email protected]>
Subject: Re: [Haskell-beginners] pipe and IO
Message-ID:
<a2a20ec3b8560d408356cac2fc148e53b305c...@sun-dag3.synchrotron-soleil.fr>
Content-Type: text/plain; charset="us-ascii"
> getDataFrameHkl3D :: DataFrameHkl3DH5SixsUhv -> Producer DataFrameHkl3D IO ()
> getDataFrameHkl3D d = do
> n <- lift $ hkl_h5_len (h5mu d)
> forM_ [0..n] (\i -> lift (getDataFrameHkl3D' d i) >>= yield)
Yes I prefer this one because the getDataFrameHkl3D' will take plenty of memory
(big images)
thanks a lot
Frederic
------------------------------
Message: 3
Date: Tue, 22 Mar 2016 23:03:10 +0000
From: John Ky <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] How to call popCnt64#?
Message-ID:
<CAMB4o-DwL2s7kQ_3-t9f8Ts9_YNxk7Eid0fFTh6S8=appcr...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Hi Marcin,
That explanation helps. Thanks!
-John
On Tue, 22 Mar 2016 at 18:25 Marcin Mrotek <[email protected]>
wrote:
> Hi,
>
> In general, the problem is that GHCi is attempting to call `show` on the
> results of expressions you type in, but `show` (like any other polymorphic
> function; though you can look into "levity polymorphism" if you want to
> know more) can only accept values of types of kind * (boxed, lifted) - so
> it can print Word, but not Word#.
>
> If you wanted to stay in GHCi, you can do it like:
>
> Prelude> import GHC.Prim
> Prelude GHC.Prim> import GHC.Types
> Prelude GHC.Prim GHC.Types> :set -XMagicHash
> Prelude GHC.Prim GHC.Types> :t W#
> W# :: Word# -> Word
> Prelude GHC.Prim GHC.Types> :t popCnt64#
> popCnt64# :: Word# -> Word#
> Prelude GHC.Prim GHC.Types> let foo = (1 :: Word)
> Prelude GHC.Prim GHC.Types> :set -XBangPatterns
> Prelude GHC.Prim GHC.Types> let !(W# w) = foo in W# (popCnt64# w)
> 1
>
> Best regards,
> Marcin Mrotek
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
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Message: 4
Date: Tue, 22 Mar 2016 23:10:09 +0000
From: John Ky <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: [Haskell-beginners] let x = x in x (GHC.Prim)
Message-ID:
<CAMB4o-BrGNfBVEPG=HKAafrUodusyzxLPAuiE6hNMfxdkD=7...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Hello Haskellers,
I'm trying to write a faster popCount function for x86 systems.
I tried cloning the ghc-prim package and repurposing it for my own needs,
but it isn't working as hoped.
In particular, popCnt64# was implemented in GHC.Prim as:
popCnt64# = let x = x in x
Which shouldn't terminate. Yet when I call it, it magically finds the C
implementation in hs_popcnt64 and returns the correct value.
My cloned project doesn't behave that way. Instead it doesn't terminate as
I would expect.
Anyone know what's happening here, if there is a way to make this work or
tell me if I'm going about this completely the wrong way?
Cheers,
-John
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Message: 5
Date: Wed, 23 Mar 2016 06:37:13 +0530
From: [email protected]
To: John Ky <[email protected]>, The Haskell-Beginners Mailing
List - Discussion of primarily beginner-level topics related to
Haskell <[email protected]>
Subject: Re: [Haskell-beginners] let x = x in x (GHC.Prim)
Message-ID: <[email protected]>
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