February 2003 - Glasgow-haskell-users

RE: Pattern matching, implict par. question
by Simon Peyton-Jones 14 Feb '03

14 Feb '03

Well the definition clearly falls under the monomorphism restriction as laid down by the Report, because you haven't given a signature for us,n,j. I suggest ctPar :: (?ctPar::CTPar) => CTPar ctPar = ?ctPar (us,n,j) = ctPar That should work Simon | -----Original Message----- | From: Jorge Adriano [mailto:jadrian@mat.uc.pt] | Sent: 13 February 2003 14:36 | To: Haskell Cafe; glasgow-haskell-users(a)haskell.org | Subject: Pattern matching, implict par. question | | Hello, When trying | | type CTPar = ([Double],Int,Int) | ctPar ::(?ctPar::CTPar)=>CTPar | ctPar@(us,n,j) = ?ctPar | | I got this error message in ghci is: | " Illegal overloaded type signature(s) | in a binding group for ctPar, us, n, j | that falls under the monomorphism restriction | When generalising the type(s) for ctPar, us, n, j | Failed, modules loaded: CrossTypeOps." | | Should the monomorphis restriction really apply here? | The values of us,j,n do depend on the context, but not their types (right?). | | J.A. | | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

1 0

RE: MArrayt and runST
by Simon Marlow 13 Feb '03

13 Feb '03

> However the problem comes when I try and use runST to run it... > > runMatrix :: Array (Int,Int) Int > runMatrix = runST $ wrapper > > This is becase 's' escapes > Expected: ST s a -> b > Inferred: (forall s1. ST s1 a) -> a Delete the dollar? Cheers, Simon

3 2

Pattern matching, implict par. question
by Jorge Adriano 13 Feb '03

13 Feb '03

Hello, When trying type CTPar = ([Double],Int,Int) ctPar ::(?ctPar::CTPar)=>CTPar ctPar@(us,n,j) = ?ctPar I got this error message in ghci is: " Illegal overloaded type signature(s) in a binding group for ctPar, us, n, j that falls under the monomorphism restriction When generalising the type(s) for ctPar, us, n, j Failed, modules loaded: CrossTypeOps." Should the monomorphis restriction really apply here? The values of us,j,n do depend on the context, but not their types (right?). J.A.

1 0

Pattern matching with implicit par. bug
by Jorge Adriano 13 Feb '03

13 Feb '03

There it goes, J.A. type CTPar = ([Double],Int,Int) us :: (?ctPar :: CTPar) => [Double] us = let (us',_,_) = ?ctPar in us' ghc-5.04: panic! (the `impossible' happened, GHC version 5.04): tcSplitTyConApp {?ctPar{-r2kd-} :: ([GHCziFloat.Double{-3u-}], GHCziBase.Int{-3J-}, GHCziBase.Int{-3J-})} Please report it as a compiler bug to glasgow-haskell-bugs(a)haskell.org, or http://sourceforge.net/projects/ghc/.

1 0

GHCi-5.04.2: Windows Open with ... problem.
by Calle Lejdfors 13 Feb '03

13 Feb '03

Hello. I am having a problem using the Open with ... on haskell-files under WinXP. The problem is this: create a file on my desktop and then right-click and try to open it using Open with -> ghci. I get the following error message: can't find module `C:\Documents' (while processing "C:\\Documents") Obviously GHCi incorrectly handles white space in the path. If I run under Cygwin I can use a script like: c:\\ghc\\ghc-5.04.2\\bin\\ghci `cygpath -d $1`; But how do I solve this if I'm not using cygwin? Thanks, Calle

2 4

RE: ghc feature request: core notes
by Simon Marlow 13 Feb '03

13 Feb '03

> Yes in source code (albeit I have not tested this recently). > 'inline' is [was] a magic Id whose unfolding is the relevant > core goop. Like I say, the last time I visted this was years ago! It doesn't appear to exist anymore. But maybe it would be a nice thing to have? Cheers, Simon

1 0

RE: ghc feature request: core notes
by Simon Peyton-Jones 13 Feb '03

13 Feb '03

Hal, OK. If you want to change CoreSyn.Note to have an extra constructor, thus: data Note = SCC CostCentre | Coerce Type Type | InlineMe | InlineCall | NoteString String -- NEW and check that the rest of the compiler does something sensible with NoteString, I do not object. There are only 12 lines of the compiler than mention InlineCall, for example, so I expect NoteString would be similarly low-impact. [Incidentally, InlineCall is an undocumented feature. You can write inline f x to mean the same as (f x), except that this particular call to f will be inlined.] Simon | -----Original Message----- | From: Alastair Reid [mailto:alastair@reid-consulting-uk.ltd.uk] | Sent: 06 February 2003 11:28 | To: Simon Peyton-Jones | Cc: Hal Daume III; GHC Users Mailing List | Subject: Re: ghc feature request: core notes | | | "Hal Daume III" <hdaume(a)ISI.EDU> writes: | > I'm not sure how "generally useful" this would be, but I would | > find it useful to be able to attach notes to core expressions from | > the Haskell code. The idea being something along the lines of a | > code annotation like a pragma. [...] | | Simon Peyton-Jones <simonpj(a)microsoft.com> writes: | > [...] There is an annotation facility in Core, but it's easy for the notes | > to be discarded. So if they are conveying important info, it might | > easily get lost... and if not, what's it doing there in the first | > place. What do you expect to happen to these annotations? [...] | | It seems like _scc_ is (almost) exactly what you need here. When used | for profiling, you mark subexpressions you want profiled and ghc takes | care to preserve and propagate them in a semantically meaningful way. | Any _scc_ annotations that ghc chooses to drop can be reported as | bugs :-) | | I say "almost" because what the semantics used when profiling may not | be the right ones for your purposes. (I'm being vague because I don't | know your purposes.) | | Naturally, you'd want to be able to use these notes independently of | profiling - which can probably be done with a little preprocessor | hackery. Assuming that the 1st argument to 'NOTE' is a literal string | in the following: | | #ifdef TRACK_NOTES | #define NOTE(x,y) (_scc_ "<NOTE " x ">" (y)) | #else | #define NOTE(x,y) {- nothing -} | #endif | | -- | Alastair Reid

3 3

Building snapshot ghc-5.05.20030123 on macOSX
by Arthur Baars 12 Feb '03

12 Feb '03

I want to play a bit with Template Haskell, so I downloaded a cvs snapshot (ghc-5.05.20030123.tar.gz) and tried to compile it on my mac (OSX 10.2). I figured out that I needed a stage2 or stage3 compiler to get TH working, so I tried 'make stage3' . GHC started to compile itself three times. At lot of hours later it finished. Unfortunately, when I tried run the thing on a Prinf example, I got the following message. compiler/stage3-> ./ghc-inplace -c Printf.hs -fglasgow-exts -package haskell-src Template Haskell bracket illegal in a stage-1 compiler [| \s -> s |] The thing in"compiler/stage3" was just a stage-1 compiler, so ghc had achieved nothing useful after re-compiling three times :-( The problem is that GHCi support is not turned on for MacOSX. I guess GHCi is used to do compile-time evaluation of code for TH. In file "mk/config.mk.in" it says: # Include GHCi in the compiler. Default to NO for the time being. ifneq "$(findstring $(HostOS_CPP), mingw32 cygwin32 linux solaris2 freebsd netbsd openbsd)" "" GhcWithInterpreter=YES else GhcWithInterpreter=NO endif In the list of supported systems MacOSX is missing. After adding "darwin" to this list, and waiting for hours, I got a working TH-compiler. Can someone add OSX("darwin") to the "mk/config.mk.in" file? It would also be nice to get a warning if one tries to compile a stage-(N>1) compiler without GHCi support. Cheers, Arthur

3 2

RE: ghc feature request: core notes
by Simon Peyton-Jones 12 Feb '03

12 Feb '03

Yes in source code (albeit I have not tested this recently). 'inline' is [was] a magic Id whose unfolding is the relevant core goop. Like I say, the last time I visted this was years ago! S | -----Original Message----- | From: Simon Marlow [mailto:simonmar@microsoft.com] | Sent: 12 February 2003 16:56 | To: Simon Peyton-Jones; Alastair Reid | Cc: Hal Daume III; GHC Users Mailing List | Subject: RE: ghc feature request: core notes | | | > [Incidentally, InlineCall is an undocumented feature. You can write | > | > inline f x | > | > to mean the same as (f x), except that this particular call | > to f will be | > inlined.] | | Not in source code, surely? It certainly doesn't look like 'inline' is | a keyword. In external Core, you can write '%note InlineCall' to get | this effect though. | | Cheers, | Simon | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

1 0

RE: ghc feature request: core notes
by Simon Marlow 12 Feb '03

12 Feb '03

> [Incidentally, InlineCall is an undocumented feature. You can write > > inline f x > > to mean the same as (f x), except that this particular call > to f will be > inlined.] Not in source code, surely? It certainly doesn't look like 'inline' is a keyword. In external Core, you can write '%note InlineCall' to get this effect though. Cheers, Simon

1 0