- Glasgow-haskell-users

Unboxed types and FFI (GHC Users Guide, Section 8.1.1)
by Dimitry Golubovsky 04 Jan '06

04 Jan '06

The section 8.1.1 of the GHC User's Guide says this: The following unboxed types may be used as basic foreign types (see FFI Addendum, Section 3.2): Int#, Word#, Char#, etc Does this mean that when declaring a foreign function import for a C function int fun(int) I may write foreign import ccall "bla.h fun" fun :: Int# -> Int# instead of using CInt? Are there any examples of using unboxed types with FFI? -- Dimitry Golubovsky Anywhere on the Web

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Two issues bulding ghc 6.4.1
by Dimitry Golubovsky 04 Jan '06

04 Jan '06

I have encountered two issues trying to build ghc-6.4.1 from the source tarball. 1. (fixed) GNU make v 3.79 does not work (was discussed on irc yesterday: at least two people including myself got this issue), v 3.80 works. If not already in FAQ/wiki perhaps worth including. 2. Error while assembling (or mangling?) ForeignObj.lhs; fragments of make output below (long lines wrapped/truncated, the whole file is too long to post it here but I'll provide it if needed): ======================================================================= ------------------------------------------------------------------------ ../../ghc/compiler/ghc-inplace -M -optdep-f -optdep.depend -optdep-s -optdepp -osuf o -H16m -O -ign <<ghc: 13519236 bytes, 3 GCs, 92336/92336 avg/max bytes residency (1 samples), 16M in use, 0.02 INIT ( ------------------------------------------------------------------------ ==fptools== make boot -wr; in /home/dima_ext/ghc-6.4.1/hslibs/doc ------------------------------------------------------------------------ ------------------------------------------------------------------------ ===fptools== Finished making `boot' in lang concurrent posix util data text net hssource doc ... PWD = /home/dima_ext/ghc-6.4.1/hslibs ------------------------------------------------------------------------ make[1]: Leaving directory `/home/dima_ext/ghc-6.4.1/hslibs' make[1]: Entering directory `/home/dima_ext/ghc-6.4.1/hslibs' ------------------------------------------------------------------------ ===fptools== Recursively making `all' in lang concurrent posix util data text net hssource doc ... PWD = /home/dima_ext/ghc-6.4.1/hslibs ------------------------------------------------------------------------ ------------------------------------------------------------------------ ==fptools== make all -wr; in /home/dima_ext/ghc-6.4.1/hslibs/lang ------------------------------------------------------------------------ ------------------------------------------------------------------------ ===fptools== Recursively making `all' for ways: p ... PWD = /home/dima_ext/ghc-6.4.1/hslibs/lang ------------------------------------------------------------------------ ------------------------------------------------------------------------ ==fptools== make way=p all; PWD = /home/dima_ext/ghc-6.4.1/hslibs/lang ------------------------------------------------------------------------ rm -f ForeignObj.p_o; if [ ! -d ForeignObj_split ]; then mkdir ForeignObj_split; else /usr/bin/find Fo ../../ghc/compiler/ghc-inplace -H16m -O -cpp -fglasgow-exts -Icbits -imonads -ignore-package lang -O - ForeignObj.lhs:98:0: Warning: Module `Addr' is deprecated: This library will go away soon; use Foreign.Ptr instead ForeignObj.lhs:98:0: Warning: Deprecated use of data constructor `A#' (imported from Addr): This library will go away soon; use Foreign.Ptr instead ForeignObj.lhs:98:0: Warning: Deprecated use of `addrToPtr' (imported from Addr): This library will go away soon; use Foreign.Ptr instead [more deprecated API warnings follow] ForeignObj.lhs:98:0: Warning: Deprecated use of type constructor or class `Addr' (imported from Addr): This library will go away soon; use Foreign.Ptr instead ForeignObj.lhs:136:0: Warning: foreign declaration uses deprecated non-standard syntax ghc-asm: (mangler) still have jump involving %edi! pushl 4(%esi) call EnterFunCCS addl $4,%esp cmpl $0,era je .L580 movl 8(%esi),%eax andl $1073709056,%eax orl $1073741824,%eax [more assembly language follows] movl %eax,CCCS jmp *(%ebp) .align 4 .L582: jmp *-4(%ebx) .Lfe5: <<ghc: 92002572 bytes, 15 GCs, 2799244/5043524 avg/max bytes residency (3 samples), 17M in use, 0.01 I make[3]: *** [ForeignObj.p_o] Error 255 make[2]: *** [all] Error 1 make[1]: *** [all] Error 1 make[1]: Leaving directory `/home/dima_ext/ghc-6.4.1/hslibs' make: *** [build] Error 1 ======================================================================================================= What was used: GHC to bootstrap: bash$ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.2.2 bash$ gcc --version egcs-2.91.66 bash$ as --version GNU assembler 2.9.1 Copyright 1997 Free Software Foundation, Inc. This program is free software; you may redistribute it under the terms of the GNU General Public License. This program has absolutely no warranty. This assembler was configured for a target of `i386-slackware-linux'. Has anyone else had this? Earlier, GHC 6.2.2 built with these tools OK. Thanks for any ideas. Dimitry

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"Duplicate instance declarations"
by Bulat Ziganshin 28 Dec '05

28 Dec '05

Hello all why the folowing is not allowed even with all extensions enabled both in Hugs and GHC? class BufStream h where class CharStream h where instance (CharStream h) => BufStream h where class MemoryStream h where instance (MemoryStream h) => BufStream h where i plan to implement many streams, some of which are supporting getBuf/putBuf interface of MemoryStream, and some getChar/putChar interface of CharStream and then automatically derive BufStream using the appropriate operations. but that just fail how can i pass around these restriction? can this be supported in future Hugs/GHC versions? ... just now i encountered this problem again: -- Copy entire contents of Stream to another Stream class (Stream h1, Stream h2) => StreamCopying h1 h2 where copyStream :: h1 -> h2 -> IO () instance (MemoryStream h1, BufStream h2) => StreamCopying h1 h2 where copyStream h1 h2 = return () instance (BufStream h1, MemoryStream h2) => StreamCopying h1 h2 where copyStream h1 h2 = return () -- Best regards, Bulat mailto:bulatz@HotPOP.com

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RE: [STM] Better name for waitUntil?
by Simon Marlow 23 Dec '05

23 Dec '05

On 19 December 2005 09:43, Tomasz Zielonka wrote: > On Mon, Dec 19, 2005 at 09:34:19AM -0000, Simon Peyton-Jones wrote: >> waitUntil sounds like a plausible name. > > But how do I name "itsBefore"? > dontWaitUntil? ;-) > >> Better than itsAfter or timeAfter. > >> But perhaps sleepUntil would be better, because it's a variant of >> sleep? > > Well yes, but an STM compatible one, so you can simultaneously > waitUntil and try to read from channel, and you get whatever > happens first. > Also, the interface is entirely in STM - no need to initialize the > timer in IO. Simon Marlow gave a nice example for usefulness of this: >> Interesting. You could use that do wait for idle time, for example: >> >> atomically $ do >> t <- readTVar last_mouse_click >> waitUntil (t+1000) >> ... >> >> so this transaction only completes when some idle time has passed >> since the last mouse click. > > Let's assume I am going to implement itsBefore (seems to be quite > straightforward), so I want a pair of opposite names. Some > variations: > > itsAfter / itsBefore > guardTimeAfter / guardTimeBefore > waitUntil / ??? How about retryIfEarlierThan / retryIfLaterThan retryIfBefore / retryIfAfter I like making it clear that the operation behaves like retry given certain conditions. Cheers, Simon

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RE: Preferred way of submitting patches
by Simon Marlow 23 Dec '05

23 Dec '05

On 17 December 2005 16:21, Einar Karttunen wrote: > What is the preferred way of submitting patches at the moment? > I tried using Trac but it seems that users without an account > on haskell.org cannot attach files... Is using Trac and > linking to the patch hosted externally the way to go? I think I've now tweaked the permissions to allow anonymous users to attach files. Please have a go. Cheers, Simon

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RE: Preferred way of submitting patches
by Simon Peyton-Jones 21 Dec '05

21 Dec '05

Einar Simon M's on holiday for Xmas; but he's the man to answer this when he gets back. Simon | -----Original Message----- | From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users- | bounces(a)haskell.org] On Behalf Of Einar Karttunen | Sent: 17 December 2005 16:21 | To: glasgow-haskell-users(a)haskell.org | Subject: Preferred way of submitting patches | | Hello | | What is the preferred way of submitting patches at the moment? | I tried using Trac but it seems that users without an account | on haskell.org cannot attach files... Is using Trac and | linking to the patch hosted externally the way to go? | | - Einar Karttunen | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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RE: instance inference
by Simon Peyton-Jones 19 Dec '05

19 Dec '05

Martin Sulzmann is the world expert on this stuff. Maybe he'll know. Simon | -----Original Message----- | From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users- | bounces(a)haskell.org] On Behalf Of Ross Paterson | Sent: 19 December 2005 10:16 | To: Simon Peyton-Jones | Cc: glasgow-haskell-users(a)haskell.org | Subject: Re: instance inference | | As a termination test, how about no restrictions on context and head | except: | | Each assertion in the context must satisfy | * the variables of the assertion are a sub-multiset of those of the | head (though they may be the same), and | * the assertion has fewer type constructors and variables (taken | together and counting repetitions) than the head. | | This ensures that under any ground substitution the context assertion has | fewer type constructors than the head. | | It would accept all instances accepted by the current test, plus | | instance C a | instance C (s a) => C (Sized s a) | instance (C1 a, C2 b) => C a b | instance C1 Int a => C2 Bool [a] | instance C1 Int a => C2 [a] b | instance C a a => C [a] [a] | | But not things like | | instance (C1 a, C2 a, C3 a) => C a | | because that would need to check other instances as well. | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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RE: [STM] Better name for waitUntil?
by Simon Peyton-Jones 19 Dec '05

19 Dec '05

waitUntil sounds like a plausible name. Better than itsAfter or timeAfter. But perhaps sleepUntil would be better, because it's a variant of sleep? Simon | -----Original Message----- | From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users- | bounces(a)haskell.org] On Behalf Of Tomasz Zielonka | Sent: 19 December 2005 09:28 | To: GHC-users | Subject: [STM] Better name for waitUntil? | | Hello! | | I am finishing my waitUntil implementation for STM. It's a new | STM action that will allow to wait for a given time point. | | waitUntil :: UTCTime -> STM () | | (UTCTime is from Ashley Yakeley's Time library.) | | The intended semantics is that | | waitUntil t | | will succeed as soon as time passes t, or more precisely when (now >= t). | | Right now I am to find a better name for waitUntil. Maybe it should be | more declarative, like "itsAfter" or "timeAfter"? I am not a native english | speaker, so I am probably missing many options. Any ideas? | | I also think about adding something like "itsBefore", which would mean | (now < t). | | How about "it'sAfter" ? | Maybe only "after", without "it's" ? | | Thanks in advance for your help. | | PS. I imagine that it would be possible to implement waitUntil more | efficiently in GHC's RTS, but my implementation can be a nice | showcase for STM's expressivity, and it's still quite efficient | (I used some (quite elegant :) hacks to implement subsecond | precision waitUntil efficiently). | | Best regards | Tomasz | | -- | I am searching for a programmer who is good at least in some of | [Haskell, ML, C++, Linux, FreeBSD, math] for work in Warsaw, Poland | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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[STM] Better name for waitUntil?
by Tomasz Zielonka 19 Dec '05

19 Dec '05

Hello! I am finishing my waitUntil implementation for STM. It's a new STM action that will allow to wait for a given time point. waitUntil :: UTCTime -> STM () (UTCTime is from Ashley Yakeley's Time library.) The intended semantics is that waitUntil t will succeed as soon as time passes t, or more precisely when (now >= t). Right now I am to find a better name for waitUntil. Maybe it should be more declarative, like "itsAfter" or "timeAfter"? I am not a native english speaker, so I am probably missing many options. Any ideas? I also think about adding something like "itsBefore", which would mean (now < t). How about "it'sAfter" ? Maybe only "after", without "it's" ? Thanks in advance for your help. PS. I imagine that it would be possible to implement waitUntil more efficiently in GHC's RTS, but my implementation can be a nice showcase for STM's expressivity, and it's still quite efficient (I used some (quite elegant :) hacks to implement subsecond precision waitUntil efficiently). Best regards Tomasz -- I am searching for a programmer who is good at least in some of [Haskell, ML, C++, Linux, FreeBSD, math] for work in Warsaw, Poland

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Preferred way of submitting patches
by Einar Karttunen 17 Dec '05

17 Dec '05

Hello What is the preferred way of submitting patches at the moment? I tried using Trac but it seems that users without an account on haskell.org cannot attach files... Is using Trac and linking to the patch hosted externally the way to go? - Einar Karttunen

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