[GHC] #4121: Ghc stage1 panic, ASSERT failure: libraries/base/Control/Applicative.hs
#4121: Ghc stage1 panic, ASSERT failure: libraries/base/Control/Applicative.hs
-+--
Reporter: dterei| Owner:
Type: bug | Status: new
Priority: normal| Component: Compiler
Version: 6.12.2|Keywords:
Os: Unknown/Multiple |Testcase:
Architecture: Unknown/Multiple | Failure: Building GHC failed
-+--
While comping GHC Head using the devel1 flavour and ghc-6.12.2 as the
bootstrap compiler, I get the following assertion failure:
{{{
inplace/bin/ghc-stage1 -H64m -O -fasm-package-name base-4.3.0.0
-hide-all-packages -i -ilibraries/base/. -ilibraries/base/dist-
install/build -ilibraries/base/dist-install/build/autogen -Ilibraries/base
/dist-install/build -Ilibraries/base/dist-install/build/autogen
-Ilibraries/base/include -optP-DOPTIMISE_INTEGER_GCD_LCM -optP-include
-optPlibraries/base/dist-install/build/autogen/cabal_macros.h -package
ghc-prim-0.2.0.0 -package integer-gmp-0.2.0.0 -package rts-1.0 -package-
name base -XMagicHash -XExistentialQuantification -XRank2Types
-XScopedTypeVariables -XUnboxedTuples -XForeignFunctionInterface
-XUnliftedFFITypes -XDeriveDataTypeable -XGeneralizedNewtypeDeriving
-XFlexibleInstances -XStandaloneDeriving -XPatternGuards -XEmptyDataDecls
-XNoImplicitPrelude -XCPP -no-user-package-conf -rtsopts -O -dcore-lint
-fno-warn-deprecated-flags -odir libraries/base/dist-install/build
-hidir libraries/base/dist-install/build -stubdir libraries/base/dist-
install/build -hisuf hi -osuf o -hcsuf hc -c
libraries/base/./Control/Applicative.hs -o libraries/base/dist-
install/build/Control/Applicative.o
WARNING: file compiler/simplCore/CSE.lhs line 349 a_aup
WARNING: file compiler/simplCore/CSE.lhs line 349 a_aup
WARNING: file compiler/stgSyn/CoreToStg.lhs line 220
Control.Applicative.$fAlternativeSTM
ghc-stage1: panic! (the 'impossible' happened)
(GHC version 6.13 for i386-unknown-linux):
ASSERT failed! file compiler/stgSyn/CoreToStg.lhs line 187
base:Control.Applicative.$fAlternativeSTM{v rk} [gid[DFunId]]
let {
sat_s1oj{v} [lid]
:: forall a{tv 12} [tv].
ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E}
- (# ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E},
a{tv 12} [tv] #)
[LclId]
sat_s1oj{v} [lid] =
\ (@ a{tv 12} [tv])
(eta_B1{v} [lid]
:: ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E}) -
ghc-prim:GHC.Prim.retry#{(w) v 93U} [gid[PrimOp]]
@ a{tv 12} [tv] eta_B1{v} [lid] } in
base:Control.Applicative.D:Alternative{v rrp} [gid[DataCon]]
@ ntbase:GHC.Conc.STM{tc r2r}
base:Control.Applicative.$fApplicativeSTM{v r2q} [gid[DFunId]]
(sat_s1oj{v} [lid]
`cast` (forall a{tv aIy} [tv].
ghc-prim:GHC.Prim.sym{(w) tc 34v}
(base:GHC.Conc.NTCo:STM{tc r2m} a{tv aIy} [tv])
:: (forall a{tv aIy} [tv].
ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E}
- (# ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E},
a{tv aIy} [tv] #))
~
(forall a{tv aIy} [tv]. base:GHC.Conc.STM{tc r2r} a{tv aIy}
[tv])))
(base:GHC.Conc.orElse1{v re9} [gid]
`cast` (forall a{tv aIx} [tv].
base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- ghc-prim:GHC.Prim.sym{(w) tc 34v}
(base:GHC.Conc.NTCo:STM{tc r2m} a{tv aIx} [tv])
:: (forall a{tv aIx} [tv].
base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E}
- (# ghc-prim:GHC.Prim.State#{(w) tc 32q}
ghc-prim:GHC.Prim.RealWorld{(w) tc 31E},
a{tv aIx} [tv] #))
~
(forall a{tv aIx} [tv].
base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv]
- base:GHC.Conc.STM{tc r2r} a{tv aIx} [tv])))
(base:Control.Applicative.$fAlternativeSTM3{v r2n} [gid]
`cast` (forall a{tv aup} [sk].
base:GHC.Conc.STM{tc r2r} a{tv aup} [sk]
- ghc-prim:GHC.Prim.sym{(w) tc 34v}
(base:GHC.Conc.NTCo:STM{tc r2m} [a{tv aup} [sk]])
:: (forall a{tv aup} [sk].
base:GHC.Conc.STM{tc r2r} a{tv
Re: [GHC] #4116: Type supplement for constructor specific uses of sum types
#4116: Type supplement for constructor specific uses of sum types -+-- Reporter: gabrielrf | Owner: Type: proposal | Status: new Priority: normal| Component: Compiler Version: 6.13 |Keywords: Os: Unknown/Multiple |Testcase: Architecture: Unknown/Multiple | Failure: None/Unknown -+-- Comment(by gabrielrf): Related theoretical article: http://winterkoninkje.livejournal.com/56979.html -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4116#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3961: -O results in incorrect behavior
#3961: -O results in incorrect behavior -+-- Reporter: RichardG |Owner: simonpj Type: bug | Status: new Priority: high |Milestone: 6.14.1 Component: Compiler | Version: 6.12.1 Keywords:| Difficulty: Os: MacOS X | Testcase: Architecture: x86 | Failure: Incorrect result at runtime -+-- Changes (by simonmar): * milestone: 6.12.3 = 6.14.1 Comment: This won't be fixed for 6.12.3, but we almost have a fix ready for HEAD. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3961#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3822: guards in arrow notation (Arrows extension) case statement cause compiler panic
#3822: guards in arrow notation (Arrows extension) case statement cause compiler panic -+-- Reporter: StephenBlackheath |Owner: ross Type: bug | Status: new Priority: high |Milestone: 6.12.3 Component: Compiler | Version: 6.12.1 Keywords: arrows guards case panic | Difficulty: Os: Unknown/Multiple | Testcase: patternGuard.hs Architecture: Unknown/Multiple | Failure: Compile-time crash -+-- Comment(by simonmar): Ross: sorry for the delay in getting back to you. Which bit of code is responsible for recognising variables as being used? Is it arrows- specific, or somewhere else? Can you help us fix it? (Cheers, Simon Simon) -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3822#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3972: ghc 6.12.1 and 6.13.20090922 consume a lot more memory than 6.10.4 when compiling language-python package
#3972: ghc 6.12.1 and 6.13.20090922 consume a lot more memory than 6.10.4 when compiling language-python package ---+ Reporter: bjpop |Owner: simonpj Type: bug | Status: new Priority: high|Milestone: 6.14.1 Component: Compiler| Version: 6.12.1 Keywords: memory usage| Difficulty: Os: Linux | Testcase: http://projects.haskell.org/language-python/language-python-0.2.tar.gz Architecture: x86_64 (amd64) | Failure: Compile-time performance bug ---+ Changes (by simonmar): * milestone: 6.12.3 = 6.14.1 Comment: Punting to 6.14.1 for a real fix; for 6.12 use one of the workarounds (probably the `-fomit-interface-pragmas` one is better). -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3972#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #4120: Iface type variable out of scope in cast
#4120: Iface type variable out of scope in cast
-+--
Reporter: benl | Owner:
Type: bug | Status: new
Priority: normal| Component: Compiler (Type checker)
Version: 6.13 |Keywords:
Os: Unknown/Multiple |Testcase:
Architecture: Unknown/Multiple | Failure: Runtime performance bug
-+--
Compiling the following module against vector-0.6 or 0.7:
{{{
module Thing where
import Data.Vector.Unboxed
import Data.Vector.Unboxed.Mutable as MV
thing :: Vector Int
thing = create (MV.new 5)
}}}
Complains about:
{{{
desire:tmp benl$ ghc -O -c -fglasgow-exts Thing.hs -fforce-recomp
/Users/benl/.cabal/lib/vector-0.7/ghc-6.13.20100607/Data/Vector/Unboxed.hi
Declaration for create
Unfolding of Data.Vector.Unboxed.create:
Iface type variable out of scope: s
}}}
Looking in the interface file we have:
{{{
create :: forall a.
Data.Vector.Unboxed.Base.Unbox a =
(forall s. GHC.ST.ST s (Data.Vector.Unboxed.Base.MVector s a))
- Data.Vector.Unboxed.Base.Vector a
{- Arity: 2, Strictness: U(SA)C(U(LL)),
Inline: INLINE (sat-args=0),
Unfolding: InlineRule (1, False, False)
(\ @ a
$dUnbox :: Data.Vector.Unboxed.Base.Unbox a
eta :: forall s.
GHC.ST.ST
s
(Data.Vector.Generic.Base.Mutable
Data.Vector.Unboxed.Base.Vector s a)
-
Data.Vector.Generic.new
@ Data.Vector.Unboxed.Base.Vector
@ a
(Data.Vector.Unboxed.Base.$p1Unbox @ a $dUnbox)
(Data.Vector.Generic.New.New
@ Data.Vector.Unboxed.Base.Vector
@ a
eta))
`cast`
(forall a.
Data.Vector.Unboxed.Base.Unbox a =
GHC.ST.ST s
(Data.Vector.Unboxed.Base.TFCo:R:MutableVector s a)
- Data.Vector.Unboxed.Base.Vector a) -}
}}}
The variable `s` in the right of the cast is indeed not in scope.
This prevents `create` being inlined into client modules, which kills
performance for benchmarks that create lots of small vectors (like a
version of quickhull in DPH).
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4120
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler
___
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3984: interpret layout in GHCi
#3984: interpret layout in GHCi --+- Reporter: aavogt | Owner: Type: feature request | Status: new Priority: normal | Milestone: 6.14.1 Component: GHCi |Version: 6.12.1 Resolution: | Keywords: Difficulty: | Os: Unknown/Multiple Testcase: | Architecture: Unknown/Multiple Failure: None/Unknown | --+- Changes (by igloo): * owner: igloo = * status: closed = new * resolution: fixed = Comment: We still need to fix the editing, e.g. up should give you the whole multi-line input at once, rather than giving it to you line-by-line. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3984#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3982: Random instance for Double can generate values out of requested range
#3982: Random instance for Double can generate values out of requested range --+- Reporter: mokus| Owner: igloo Type: bug | Status: closed Priority: normal | Milestone: 6.14.1 Component: libraries/random |Version: 6.12.1 Resolution: fixed| Keywords: Difficulty: | Os: Unknown/Multiple Testcase: | Architecture: Unknown/Multiple Failure: Incorrect result at runtime | --+- Changes (by igloo): * status: patch = closed * resolution: = fixed Comment: Applied, thanks! -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3982#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3984: interpret layout in GHCi
#3984: interpret layout in GHCi --+- Reporter: aavogt | Owner: igloo Type: feature request | Status: closed Priority: normal | Milestone: 6.14.1 Component: GHCi |Version: 6.12.1 Resolution: fixed| Keywords: Difficulty: | Os: Unknown/Multiple Testcase: | Architecture: Unknown/Multiple Failure: None/Unknown | --+- Changes (by igloo): * status: patch = closed * resolution: = fixed Comment: Applied, thanks! -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3984#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4115: hsc2hs puts linker flags before object file, causes linker errors
#4115: hsc2hs puts linker flags before object file, causes linker errors -+-- Reporter: guest | Owner: Type: bug | Status: new Priority: normal| Component: hsc2hs Version: 6.10.2|Keywords: Os: Unknown/Multiple |Testcase: Architecture: Unknown/Multiple | Failure: Other -+-- Comment(by duncan): Patch needs testing. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4115#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #4119: File buffering isn't flushed at exit
#4119: File buffering isn't flushed at exit ---+ Reporter: EyalLotem | Owner: Type: bug | Status: new Priority: normal | Component: libraries/base Version: 6.12.1 |Keywords: file buffers Os: Linux |Testcase: Architecture: x86_64 (amd64) | Failure: Incorrect result at runtime ---+ In C, there's an atexit handler to fflush all FILE* files. In most other environments (e.g: Python files), file buffers are flushed in a graceful exit. With GHC 6.12.1, they aren't. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4119 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4106: undefined reference to `__stg_EAGER_BLACKHOLE_INFO'
#4106: undefined reference to `__stg_EAGER_BLACKHOLE_INFO'
---+
Reporter: Mikolaj | Owner: simonmar
Type: bug | Status: closed
Priority: normal| Milestone:
Component: Compiler |Version: 6.12.1
Resolution: fixed | Keywords:
Difficulty:| Os: Linux
Testcase:| Architecture: powerpc
Failure: Other |
---+
Comment(by Mikolaj):
Thank you. The problems with black hole are gone. I've recompiled Debian's
ghc6_6.12.1-13 after applying your change, and the parallel tests now are:
{{{
3 total tests, which gave rise to
19 test cases, of which
0 caused framework failures
15 were skipped
4 expected passes
0 expected failures
0 unexpected passes
0 unexpected failures
}}}
where the skipped tests are unrelated to black hole and probably due to
the Ghostscript problem, as in the previously attached log.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4106#comment:3
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler
___
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #4118: GHC forces gcc version on mingw32
#4118: GHC forces gcc version on mingw32 -+-- Reporter: uzytkownik| Owner: Type: bug | Status: new Priority: normal| Component: Compiler Version: 6.12.1|Keywords: Os: Unknown/Multiple |Testcase: Architecture: Unknown/Multiple | Failure: Building GHC failed -+-- GHC forces internal gcc version on mingw32 instead of using system one. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4118 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #4117: GHC does not accept --srcdir
#4117: GHC does not accept --srcdir -+-- Reporter: uzytkownik| Owner: Type: bug | Status: new Priority: normal| Component: Compiler Version: 6.12.1|Keywords: Os: Unknown/Multiple |Testcase: Architecture: Unknown/Multiple | Failure: Building GHC failed -+-- GHC does not accept --srcdir during building. (Yes - I know of error but it should be fixed). PS. Priority is probably lower then normal PPS. For question why - I try to integrate it with takeoffgw so I try to write cygbuild which uses separate build directory. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4117 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3947: ghc: panic! (the 'impossible' happened)
#3947: ghc: panic! (the 'impossible' happened) ---+ Reporter: steenreem | Owner: Type: bug | Status: closed Priority: normal| Milestone: Component: Compiler |Version: 6.10.4 Resolution: duplicate | Keywords: Difficulty:| Os: Unknown/Multiple Testcase:| Architecture: Unknown/Multiple Failure: None/Unknown | ---+ Changes (by simonmar): * status: infoneeded = closed * version: 6.12.1 = 6.10.4 * resolution: = duplicate * milestone: 6.12.3 = Comment: Dup of #3435. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3947#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4116: Type supplement for constructor specific uses of sum types
#4116: Type supplement for constructor specific uses of sum types
-+--
Reporter: gabrielrf | Owner:
Type: proposal | Status: new
Priority: normal| Component: Compiler
Version: 6.13 |Keywords:
Os: Unknown/Multiple |Testcase:
Architecture: Unknown/Multiple | Failure: None/Unknown
-+--
Comment(by gabrielrf):
Benefits: Avoid ''error'' calls (runtime), exception control and Maybe
types
in partially defined (constructor specific) functions on sum types
Method: by refining function argument types with a list of constructors
applyable
and detecting the target constructor at the caller through pattern
matching,
flagging with compiler errors the unmatched cases.
As an example, with
{{{
data List a = Nil | Cons a (List a)
}}}
* Actual system: undefined cases are discriminated with runtime errors or
exception throwing or optional Maybe results.
{{{
hd :: List a - a
hd (Cons x _) - x
hd Nil - error error: hd: empty list -- (as in GHC Data.List head)
}}}
* Proposed system: supplement types with
a suffix ''@Constructor'' or ''@{Constructor1, Constructor2}''
denoting the list of constructors to which the function can be applied.
{{{
hd :: List @Cons a - a
hd (Cons x _) = x
-- no definition for unappropriate constructors.
}}}
The caller must do pattern matching before applying the constructor-
specific function.
In a pattern ''var @ (Constructor {})''
the compiler should set a ''constructorAt'' property for ''var''
to the specified pattern constructor
and when used in a constructor specific parameter position
match the type supplement constructor list
using it:
{{{
accumulateHead :: (a-b) - a - List a - b
accumulateHead f accum list = case list of
li @ Cons {} - f accum $ hd li -- constructorAt li == 'Cons'
-- should pass typechecker at ''hd'' for
''List @ Cons''
li @ Nil - f accum $ hd li -- compiler error !!
-- constructorAt li == 'Nil' ; no match
_ - f accum $ hd list -- compiler error !!
-- constructorAt list == Nothing ; no
match
_ - accum -- default option closing pattern matching
exhaustivity.
}}}
(from Jason Dagit contribution)
Syntax {Cons, Cons2} for more than one constructor
{{{
data List2 a = Nil | Cons a (List2 a) | Cons2 a a (List2 a)
hd :: List2 @ {Cons, Cons2} a - a
}}}
Discussion thread:
[http://thread.gmane.org/gmane.comp.lang.haskell.cafe/75586]
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4116#comment:2
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler
___
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4115: hsc2hs puts linker flags before object file, causes linker errors
#4115: hsc2hs puts linker flags before object file, causes linker errors -+-- Reporter: guest |Owner: Type: bug | Status: patch Priority: normal|Milestone: Component: hsc2hs| Version: 6.10.2 Keywords:| Difficulty: Os: Unknown/Multiple | Testcase: Architecture: Unknown/Multiple | Failure: Other -+-- Changes (by igloo): * status: new = patch -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4115#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #2458: Unknown symbol `_environ' on MacOS X
#2458: Unknown symbol `_environ' on MacOS X
-+--
Reporter: IgorBoehm | Owner:
Type: bug | Status: new
Priority: high| Milestone: 6.14.1
Component: libraries/base |Version: 6.10.1
Resolution: | Keywords: environ
Difficulty: Unknown | Os: MacOS X
Testcase: | Architecture: x86
Failure: None/Unknown|
-+--
Changes (by igloo):
* priority: normal = high
* milestone: 6.12.3 = 6.14.1
Comment:
{{{
[20:55] safiire Has anyone here ran into a problem of trying to link a
library compiled with ghc -c into a C++ project and
receiving an unresolved symbol _environ. I am aware
that
_environ is supposed to be defined in crt1.o, however
the
C++ project I am building is an audio unit plugin on
OSX, so
it never links against crt1.o as it is not an
executable,
but a shared object itself. There is something called
the
osx _environ bug which is the cause of t
[20:55] safiire his. The work around is that OSX applications are not
supposed to call environ(), but are supposed to call
_NSGetEnviron(), or, that is the workaround at least.
HSBase4.2.0.0.a does not do this on OSX apparently.
Does
anyone know how I can get my linker resolve this
symbol, or
not care that it is undefined, short of recompling
haskel
from source and manually patching it to not call
environ()?
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/2458#comment:7
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler
___
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4118: GHC forces gcc version on mingw32
#4118: GHC forces gcc version on mingw32 +--- Reporter: uzytkownik | Owner: Type: bug | Status: closed Priority: normal | Component: Compiler Version: 6.12.1 | Resolution: wontfix Keywords: | Os: Unknown/Multiple Testcase: | Architecture: Unknown/Multiple Failure: Building GHC failed | +--- Changes (by duncan): * status: new = closed * resolution: = wontfix Comment: This is the intended behaviour. We cannot by default rely on an existing mingw or cygwin installation. There are sometimes subtle compatibility issues. Of course if you specifically want to use a different gcc installation then that is fine. It is just that ghc should not use a different one automatically without the user knowing about it. You can override the gcc that ghc uses by using command line flags (see the [http://www.haskell.org/ghc/docs/6.12.2/html/users_guide/options- phases.html#replacing-phases ghc user guide for details ] and note that you will need to specify all of `-pgmc`, `-pgma` and `-pgml`). -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4118#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3649: inconsistent exception between unix/windows for running non-existant program
#3649: inconsistent exception between unix/windows for running non-existant program --+- Reporter: duncan |Owner: Type: bug| Status: new Priority: normal |Milestone: 6.14.1 Component: libraries/process | Version: 6.10.4 Keywords: | Difficulty: Os: Unknown/Multiple | Testcase: Architecture: Unknown/Multiple | Failure: None/Unknown --+- Comment(by duncan): Another instance of the same problem is when we do not have permission to execute the program (see ticket #4110 where the original example is about /tmp being mounted noexec). -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3649#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #4110: hsc2hs gives bad error message when it cannot execute the generated program
#4110: hsc2hs gives bad error message when it cannot execute the generated program -+-- Reporter: duncan| Owner: Type: bug | Status: new Priority: normal| Component: hsc2hs Version: 6.12.2|Keywords: Os: Unknown/Multiple |Testcase: Architecture: Unknown/Multiple | Failure: None/Unknown -+-- Comment(by duncan): A fix for #3649 would likely also help this case. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/4110#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: ANNOUNCE: MonadCatchIO-foreign
On 03/06/2010 07:29, Evan Laforge wrote: On Sun, May 30, 2010 at 5:15 PM, Antoine Latteraslat...@gmail.com wrote: Hi GHC, Is there a reason that Foreign.Marshall.Array.allocaArray calls into allocaBytes instead of allocaBytesAligned? Since alloca needs the alignment, wouldn't allocaArray also need it? I'm not too up on how memory access is supposed to work, it was just something that jump out at me. I've been waiting for a response on this, because I'm curious too, in fact I always have been. At the upgrade to 6.10, ghc suddenly started using 'alignment' and all my programs which had defined it to 'undefined' since I didn't know what alignment was for and it didn't seem to be used, started crashing. So I dug around, dug up the '#let alignment' macro boilerplate, and copy and pasted it around. However, at the same time, my program started rarely but consistently crashing with an assertion failure from the gc runtime. I'm suspicious of the inconsistent use of alignment, but it's hard to use allocaBytesAligned since it's not exported, and the ffi lib is part of ghc and it's not obvious how to modify it. Here's the ticket: http://hackage.haskell.org/trac/ghc/ticket/2917 Lennart's patch added allocaBytesAligned to Foreign.Marshal.Alloc, but we'll have to do a library proposal to add that. If you can reproduce the assertion failure, please submit a bug report. Cheers, Simon ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
[Haskell] Re: [Haskell-cafe] Please check your dependencies on fgl
ivan.miljenovic: Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. How about you give the library a different name then -- so as not to break all those programs? A complete rewrite with a new maintainer: fgl-awesome -- Don ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell] Workshop on Generic Programming (WGP) 2010 Final Call for papers!
Dear all, This a final reminder that the deadline for WGP submissions is in one week! See the call for papers below: == CALL FOR PAPERS WGP 2010 6th ACM SIGPLAN Workshop on Generic Programming Baltimore, Maryland, US Sunday, September 26th, 2010 http://osl.iu.edu/wgp2010 Collocated with the International Conference on Functional Programming (ICFP 2010) == Goals of the workshop - Generic programming is about making programs more adaptable by making them more general. Generic programs often embody non-traditional kinds of polymorphism; ordinary programs are obtained from them by suitably instantiating their parameters. In contrast with normal programs, the parameters of a generic program are often quite rich in structure; for example they may be other programs, types or type constructors, class hierarchies, or even programming paradigms. Generic programming techniques have always been of interest, both to practitioners and to theoreticians, and, for at least 20 years, generic programming techniques have been a specific focus of research in the functional and object-oriented programming communities. Generic programming has gradually spread to more and more mainstream languages, and today is widely used in industry. This workshop brings together leading researchers and practitioners in generic programming from around the world, and features papers capturing the state of the art in this important area. We welcome contributions on all aspects, theoretical as well as practical, of * polytypic programming, * programming with dependent types, * programming with type classes, * programming with (C++) concepts, * generic programming, * programming with modules, * meta-programming, * adaptive object-oriented programming, * component-based programming, * strategic programming, * aspect-oriented programming, * family polymorphism, * object-oriented generic programming, * and so on. Organizers -- Co-Chair Bruno C. d. S. Oliveira, Seoul National University Co-Chair Marcin Zalewski, Indiana University Programme Committee --- Alley Stoughton, Kansas State University Andrei Alexandrescu, Facebook Bruno C. d. S. Oliveira (Co-Chair), Seoul National University Doug Gregor, Apple Gilad Bracha, I am a Computational Theologist Emeritus Magne Haveraaen, Universitetet i Bergen Marcin Zalewski (Co-Chair), Indiana University Neil Mitchell, Standard Chartered Ralf Lämmel, University of Koblenz-Landau Shin-Cheng Mu, Academia Sinica Thorsten Altenkirch, University of Nottingham Ulf Norell, Chalmers University Important Information - We plan to have formal proceedings, published by the ACM. Submission details Deadline for submission: Sunday2010-06-13 Notification of acceptance: Monday2010-07-12 Final submission due: Tuesday 2010-07-27 Workshop:Sunday2010-09-26 Authors should submit papers, in postscript or PDF format, formatted for A4 paper, to the WGP09 EasyChair instance by 13th of June 2010. The length should be restricted to 12 pages in standard (two-column, 9pt) ACM format. Accepted papers are published by the ACM and will additionally appear in the ACM digital library. History of the Workshop on Generic Programming -- This year: * Baltimore, Maryland, US 2010 (affiliated with ICFP10) Earlier Workshops on Generic Programming have been held in * Edinburgh, UK 2009 (affiliated with ICFP09) * Victoria, BC, Canada 2008 (affiliated with ICFP), * Portland 2006 (affiliated with ICFP), * Ponte de Lima 2000 (affiliated with MPC), * Marstrand 1998 (affiliated with MPC). Furthermore, there were a few informal workshops * Utrecht 2005 (informal workshop), * Dagstuhl 2002 (IFIP WG2.1 Working Conference), * Nottingham 2001 (informal workshop), There were also (closely related) DGP workshops in Oxford (June 3-4 2004), and a Spring School on DGP in Nottingham (April 24-27 2006, which had a half-day workshop attached). Additional information: The WGP steering committee consists of J Gibbons, R Hinze, P Jansson, J Jarvi, J Jeuring, B Oliveira, S Schupp and M Zalewski___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell] VSTTE 2010: 2nd Call for Poster Session Submissions
*** Apologies for multiple copies *** *** Call for POSTERS *** 3rd International Conference on Verified Software: Theories, Tools, and Experiments (VSTTE 2010) Edinburgh, Scotland August 16th-19th, 2010 http://www.macs.hw.ac.uk/vstte10 POSTER SESSION The complementary themes of Theories, Tools and Experiments makes VSTTE an unique conference. Through the introduction of a POSTER session at VSTTE 2010, we are aiming to widen the body of researchers that are involved in the Verified Software Initiative (VSI) and its related Challenges (more details on VSTTE VSI are provided below). Limited financial support will be available if necessary to enable attendance of both MSc and PhD students whose posters are accepted. Specifically, we aim to attract students who are already engaged in theories or tools or experiments relevant to verification; and give them an opportunity to meet other students and researchers engaged in complementary experiments or theories or tools. Note that the POSTER session is open to all researchers, not just students. With regards to submissions, we require the following: 1. 1-page abstract of your research 2. Poster OR a poster plan 3. For students, a supporting statement from your supervisor Submissions should be sent electronically to vstt...@macs.hw.ac.uk. The timetable for POSTER authors is as follows: JUNE 18: Submission of abstract poster (plan) deadline JUNE 30: Notification of decision JULY 31: Camera-ready abstract deadline AUGUST 17: Poster session Note that a collection of abstracts for the accepted posters will be distributed at the conference. Poster authors will be expected to bring their poster with them to the conference. Details of the size of the final posters will be provided in due course. Financial support will be allocated on a case-by-case basis, and will support around 30 partial/fully funded places, including 10 SICSA PhD funded places. If you have any queries, please direct them to vstt...@macs.hw.ac.uk MORE DETAILS ON VSTTE 2010 SPONSORS National Science Foundation (NSF) Engineering and Physical Sciences Research Council (EPSRC) Microsoft Research Scottish Informatics Computer Science Alliance (SICSA) Altran Praxis Software Systems Engineering Initiative (SSEI) Formal Methods Europe (FME) WHAT IS THE HISTORY OF VSTTE? The Third International Conference on Verified Software: Theories, Tools, and Experiments follows a successful inaugural working conference at Zurich (2005) and a successful conference in Toronto (2008). This conference is part of the Verified Software Initiative (VSI), a fifteen-year, cooperative, international project directed at the scientific challenges of large-scale software verification. VSI also includes UKCRC's Grand Challenge 6, i.e. Dependable Systems Evolution. VSTTE is open to anyone who is interested in participating actively in the VSI effort. SCOPE The goal of this conference is to advance the state of the art in the science and technology of software verification through the interaction of theory development, tool evolution, and experimental validation. Authors are encouraged to submit work in progress, particularly if the work involves collaboration, theory unification, and tool integration. Topics of interest include requirements modeling specification languages specification/verification case-studies formal calculi programming languages language semantics software design methods software testing automatic code generation refinement methodologies type systems computer security verification tools (static analysis, dynamic analysis, model checking, theorem proving, satisfiability) tool integration benchmarks challenge problems integrated verification environments We also encourage researchers to submit challenges in theory, formalization, systems verification, code verification, and applications. Contributions relating to existing challenges will also be welcomed, i.e. * POPLMark (http://tinyurl.com/poplmark) * Tokeneer (http://www.adacore.com/home/products/sparkpro/tokeneer) * POSIX file system (http://tinyurl.com/qyzqk9) * medical devices (http://tinyurl.com/pnztqb) VENUE VSTTE 2010 is being hosted by Heriot-Watt University in Edinburgh. The conference dates coincide with the 2010 Edinburgh International Festival and the Edinburgh Festival Fringe -- collectively the largest annual arts festival on the planet! The technical programme will take place in the Edinburgh Conference Centre (Riccarton campus), where accommodation will be available at very competitive rates for festival time. Social events will be arranged within the city centre, making VSTTE an unique cultural and scholarly event for 2010! INVITED SPEAKERS * Tom Ball (Microsoft Research, Redmond) * Gerwin Klein (National ICT Australia) * Matthew Parkinson (University of Cambridge) WORKSHOPS In addition to the main conference, VSTTE will host two workshops on August 19th:
[Haskell] Please check your dependencies on fgl
Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. As such, if your code uses fgl you should ensure that the specification of the package in your .cabal file has an explicit upper bound (or indeed just set fgl == 5.4.2.2) to avoid any problems when we release 6.0.0.0 (we're trying to avoid the problems that plagued KDE-4 by not claiming in the slightest that the initial few versions are intended for end users). I have already directly emailed the maintainers of any and all packages I could find on Hackage (using Roel van Dijk's wonderful reverse-dependency mirror at http://bifunctor.homelinux.net/~roel/hackage/packages/hackage.html), but just in case I've missed one or there's an as-yet-unreleased package somewhere in the works, here is the official heads up. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell] Re: [Haskell-cafe] Please check your dependencies on fgl
Oh, great, the email _did_ go out on the mailing lists (what with haskell.org being down I wasn't sure it would). Don Stewart d...@galois.com writes: ivan.miljenovic: Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. How about you give the library a different name then -- so as not to break all those programs? A complete rewrite with a new maintainer: fgl-awesome We considered giving it a new name (fgl', etc.) but figured that in the long term this wouldn't be advantagous. We feel that the situation is analogous to QuickCheck: when the new version came out most people kept using the old one until slowly the momentum shifted and more people started using the new version (without checking in depth, Roel's Hackage mirror reports QC-2.x now has 153 reverse dependencies as opposed to 127 reverse dependencies for QC-1.y). If we changed the name, then the emotional attachment that the Haskell community has to FGL being the de-facto graph library means that people would keep using the old version. Whilst we also face the possible problems of people not liking the old version and thus automatically dismissing the new version, I think this is a much more unlikely scenario. The overall philosophy is remaining the same: we're just updating the implementation (letting people pick the Node type rather than hard-coding it to Int, letting people constrain the label types and also providing more scope for optimisations). As such, the new version is incompatible with the old one; however, if you're only _using_ FGL (as opposed to making a new instance of the graph types), then the actual changes to using the new version should be minimal (especially if you're using it internally in which case you can hard-code the various types in and not have to worry about the type family usage at all). As I said, I've directly emailed the maintainers of the packages that have open-ended dependencies on FGL and thus would have compilation problems when we release the new version[s]; 7 out of 12 of those maintainers have already responded within less than 24 hours so I don't think this is likely to be a problem unless some new package is uploaded in the near future without proper ranged dependencies. So as to give you even more of a heads up, here are some more overall plans Thomas and I have for FGL: * FGL will still focus on inductive graphs; however the two current classes are being combined since it doesn't make much sense in general to have a graph that can be decomposed using match but can't be composed using (there might be specific cases where this is true such as considering the Cabal package dependency graph; however this is likely to be defined internally within some project so users should just be careful about how they use it to ensure they don't add arbitrary nodes/edges that don't make sense; note that the new Show and Read instances take advantage of this by using Contexts as the basis of this instance). * The ability to have proper Eq, Show and Read instances for graphs with pre-defined helper functions implementors can use (currently Data.Graph.Inductive.Tree has a pretty output for Show but no Read instance, and graphs cannot have equality due to overlapping instance problems). * Splitting the library up into the base classes + sample instances (the fgl package) and a separate fgl-algorithms package (analogous to Dan Doel's vector-algorithms; this will be comprised of what is currently in the Data.Graph.Inductive.Query.* modules as well as the Data.Graph.Analysis.Algorithms.* modules in my Graphalyze library. The Data.Graph.Inductive.Graphviz module will also be scrapped in favour of my graphviz library. * By default, fgl will ship with two default instances: the one currently in Data.Graph.Inductive.PatriciaTree and also a generic Map-based one that lets people choose their own Node type (i.e. the key type in the Map). Any other suitable instances that we can think of (e.g. Thomas has the beginnings of a vector-based one) we'll ship in separate packages (e.g. fgl-vector). If anyone has a good reason to object to any of these plans, we are willing to be persuaded out of them. This is why the 6.z series of fgl will be technology previews to slowly build up what FGL does and gauge the reaction of the Haskell community. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell-cafe] Span function
Can someone provide a hand calculation of: span ( 0) [-1, -2, -3, 0, 1, 2, -3, -4, -5]? I know the result is ([-1, -2, -3], [0, 1, 2, -3, -4, -5]), but the recursion flummoxes me. Here's the Prelude definition: mySpan :: (a - Bool) - [a] - ([a], [a])mySpan _ []= ([], [])mySpan p xs@(x:xs')| p x = (x:ys, zs)| otherwise= ([], xs) where (ys, zs) = mySpan p xs' Thanks. _ Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_1___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Removing alternate items from a list
What's the cleanest definition for a function f :: [a] - [a] that takes a list and returns the same list, with alternate items removed? e.g., f [0, 1, 2, 3, 4, 5] = [1,3,5]? _ The New Busy is not the old busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_3___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Stone age programming for space age hardware?
A few days ago, I watched a presentation by Gerard Holzmann on the development methodology and programming techniques used at JPL for writing the software for the next Mars mission. I found the talk entertaining and learned a few things. http://www.infoq.com/presentations/Scrub-Spin Among the arsenal of methods they use to ensure correctness is model checking for the algorithms used as well as rather restrictive coding standards. Well, model checking sounds good, real formal oomph. But the coding itself? For one thing, they're using C. On top of that, the coding standards prohibit dynamic memory allocation, recursion, and loops without explicit bounds; see [*] for more details. I was dumbfounded, although I have known all this. I have no personal experience with either embedded or real time software, but I've been aware that C still is the most popular language for that purpose and that coding standards are very restrictive. The real reason behind my surprise was, that I was wondering how more modern languages could make inroads into such an environment. Haskell without recursion and dynamic memory allocation? Hard to imagine. I have a hunch that the real restrictions of this kind of software are not concerned with fixed memory, iterations, whatever, but rather with guaranteed bounds. If that is indeed the case, how feasible would it be to prove relevant properties for systems programmed in Haskell? Michael [*] http://spinroot.com/gerard/pdf/Power_of_Ten.pdf -- Michael Schuerig mailto:mich...@schuerig.de http://www.schuerig.de/michael/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Problems with Haskell Platform
On Jun 4, 2010, at 23:04 , Don Stewart wrote: Build/does not build? That can be automated. Automated converters have a certain tendency to become confused and put files in unexpected places, etc. Usually this has less to do with the source than the destination; in particular, RPM sometimes makes some poor assumptions. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Reporting a problem with binary-0.5
Alexey Khudyakov alexey.sklad...@gmail.com writes: This issue was discussed on the list before. Get monad definition was changed in binary 0.5.0.2. It was made strict and evaluation of result of runGet is forced. This increased performance but broke programs which relies on lazyness to work. I just found a more detailed writeup by dons on http://donsbot.wordpress.com/2009/09/16/data-binary-performance-improvments-for-haskell-binary-parsing/ -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to Show an Operation?
On Friday, 4. June 2010 18:02:15 Daniel Fischer wrote: On Friday 04 June 2010 17:37:16, Martin Drautzburg wrote: Dear all, If I have a problem where I have to select from a set of operations, how would I print the result? Example: If I can chose from (x+y), (x*y), (x^2+y)... and I feed them all into my problem solver and it finds that (x*y) is right, how can I print that string? You'd have to pass the description string to the problem solver too. If it was previously solver :: Num a = Whatever - [a - a - a] - Result it would become for example solver :: Num a = Whatever - [(a - a - a, String)] - Result Thanks to Ozgur Akgun for his suggestion. However I really wanted a human readable name, but admittedly I haven't said so. About this one: The only thing I miss in this solution, is that the name is identified by its position in the Pair. In this case this is certainly not a problem. But anyways, I tried to give it a name, using record syntax. This worked well until I wanted to define a different set of operations, which should also be named. It turned out that the name function, which was implicitly created (using record syntax) cannot be used again. How should I work around that. I could use two different name function, but I don't like this. Would I have to define a typeclass namedFunction which all have a name function? I guess my mind is still a bit stuck in the OO world. -- Martin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] GHC Api typechecking
Hi, Just thought I'd follow up,
I implemented a VirtualFile target in the current head version of ghc just
to test, unfortunately unless I did something wrong It's not really that
much faster.
Most likely because in the scenario I'm using it in, the file would still be
in the disk cache, so I'd mostly get 100% cache hits and as it turns out,
the String approach is only about ~30ms faster than the File Based one.
Even worse when I put the disk under heavy load to get more cache misses,
the difference shrunk to ~22ms because Windows started doing more Fast Reads
and Writes. So while this might be useful for other means, It's not really
that much better in terms of performance.
Regards,
Phyx
-Original Message-
From: Thomas Schilling [mailto:nomin...@googlemail.com]
Sent: Sunday, April 18, 2010 18:21
To: Phyx
Cc: Gwern Branwen; haskell-cafe@haskell.org
Subject: Re: [Haskell-cafe] GHC Api typechecking
Looking at the code for GHC, it turns out that your use case is not
supported. It is not allowed to have in-memory-only files. If you specify
a buffer it will still try to find the module file on the disk, but it will
(or at least should) use the contents from the specified string buffer.
I've been thinking about changing the Finder (the part that maps module
names to source files and .hi files) to use a notion of a virtual file.
This way, the API client could define how and where data is stored.
On 18 April 2010 11:01, Phyx loneti...@gmail.com wrote:
Hi,
I checked out how Hint is doing it, but unfortunately they're calling
a function in the GHC api's interactive part to typecheck a single
statement, much like :t in ghci, So I can't use it to typecheck whole
modules.
I've tried working around not being able to construct a TargetId but ran
into another wall.
I can't find anyway to do dependency analysis on the in-memory target, so
the dependency graph would be empty which is ofcourse a big problem.
Does anyone know if Leksah uses the GHC api for typechecking? And if it
only gives type errors after you save a file?
The code I've been trying is
typeCheckStringOnly :: String - IO (ApiResults Bool)
typeCheckStringOnly contents = handleSourceError processErrors $
runGhc (Just libdir) $ do
buffer - liftIO $ stringToStringBuffer contents
clock - liftIO getClockTime
dflags - getSessionDynFlags
setSessionDynFlags dflags
let srcLoc = mkSrcLoc (mkFastString internal:string) 1 1
dynFlag = defaultDynFlags
state = mkPState buffer srcLoc dynFlag
parsed = unP Parser.parseModule state
pkgId = stringToPackageId internal
name = mkModuleName Unknown
mod' = mkModule pkgId name
location = ModLocation Nothing
summary = ModSummary mod' HsSrcFile location clock Nothing []
[] dynFlag Nothing
(\a-setSession $ a { hsc_mod_graph = [summary] }) = getSession
case parsed of
PFailed _ _ - return $ ApiOk False
POk newstate mdata - do let module' = ParsedModule summary
mdata
check - typecheckModule module'
return $ ApiOk True
this fails with a ghc panic
: panic! (the 'impossible' happened)
(GHC version 6.12.1 for i386-unknown-mingw32):
no package state yet: call GHC.setSessionDynFlags
Please report this as a GHC bug:
http://www.haskell.org/ghc/reportabug
:(
Cheers,
Phyx
-Original Message-
From: Gwern Branwen [mailto:gwe...@gmail.com]
Sent: Saturday, April 17, 2010 20:59
To: Phyx
Subject: Re: [Haskell-cafe] GHC Api typechecking
On Sat, Apr 17, 2010 at 1:49 PM, Phyx loneti...@gmail.com wrote:
Hi all, I was wondering if someone knows how to do the following:
Im looking to typecheck a string using the GHC Api, where I run into
problems is that I need to construct a Target, but the TargetId only
seem to reference physical files.
Ofcourse I can write the string to a file and typecheck that file,
but I would like to do it all in memory and avoid IO if possible.
Does anyone know if this is possible?
For the record Im trying to create the target as follows
createTarget :: String - IO Target
createTarget content =
do clock - getClockTime
buffer - stringToStringBuffer content
return $ Target { targetId = TargetModule (mkModuleName
string:internal) ß problem
, targetAllowObjCode = True
, targetContents = Just (buffer,clock)
}
typeCheckStringOnly :: String - IO (ApiResults Bool)
typeCheckStringOnly contents = handleSourceError processErrors $
runGhc (Just libdir) $ do
dflags - getSessionDynFlags
setSessionDynFlags dflags
target - liftIO $ createTarget contents
addTarget target
load LoadAllTargets
let modName = mkModuleName string:internal ß problem again,
dont know how to create the dependency graph then.
Re: [Haskell-cafe] Issue with connectTo function in network package
Perhaps it was only listening on IPv6 ? ::1 ? - jeremy On Thu, Jun 3, 2010 at 10:30 PM, aditya siram aditya.si...@gmail.comwrote: Hi all, I had an issue where using the connectTo [1] function would fail to connect to localhost if my wireless card was turned off. The moment I turned on my wireless connection it worked. But if I use connectTo with 127.0.0.1 [2] with my network off it works. I confirmed that localhost' resolves to 127.0.0.1 by pinging localhost from command line with the Internet off. Is this a bug in connectTo? -deech [1] connectTo localhost (PortNumber some_number) [2] connectTo 127.0.0.1 (PortNumber some_number) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Issue with connectTo function in network package
Great! If there is a wiki or FAQ page for networking with Haskell it
might be worth updating.
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
/etc/hosts is the file responsible for resolving 'localhost' hostname.
As you can see from it, there are two entries for localhost: one
contains IPv4 address (127.0.0.1) and another contains IPv6 address
(::1).
The behaviour you observe is kinda bug in connectTo function. Instead of
trying all of the addresses, this function just tries the first one.
Until it is fixed (I'm gonna write and send a patch soon), can you live
with this temporary hack? If for some reason the answer is no, you
have to use low-level functions from Network.Socket module for now.
* aditya siram aditya.si...@gmail.com [2010-06-04 14:15:47-0500]
Doing (1) solves my problem. What did I do and why did it work? Thanks
a lot for your help!
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
Confirm if any of the following solves the problem:
1. commenting out (by prepending putting hash sign '#' in the beginning
of the line) the following line in /etc/hosts:
::1 localhost ip6-localhost ip6-loopback
2. executing as root the following command:
rmmod ipv6
* aditya siram aditya.si...@gmail.com [2010-06-04 13:51:29-0500]
Here's my GHCI session (with my network card off):
Prelude Network Network.Socket connectTo localhost (PortNumber 3000)
*** Exception: connect: does not exist (Connection refused)
Prelude Network Network.Socket connectTo 127.0.0.1 (PortNumber 3000)
{handle: socket: 7}
The OS is Ubuntu (Lucid) Linux. The contents of /etc/hosts and
/etc/nsswitch.conf are:
cat /etc/nsswitch.conf
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed,
try:
# `info libc Name Service Switch' for information about this file.
passwd: compat
group: compat
shadow: compat
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
networks: files
protocols: db files
services: db files
ethers: db files
rpc:db files
netgroup: nis
cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 deech-mac-ubuntu
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
* aditya siram aditya.si...@gmail.com [2010-06-03 22:30:33-0500]
Hi all,
I had an issue where using the connectTo [1] function would fail to
connect to localhost if my wireless card was turned off. The
moment
I turned on my wireless connection it worked. But if I use connectTo
with 127.0.0.1 [2] with my network off it works.
I confirmed that localhost' resolves to 127.0.0.1 by pinging
localhost from command line with the Internet off.
Is this a bug in connectTo?
-deech
[1] connectTo localhost (PortNumber some_number)
[2] connectTo 127.0.0.1 (PortNumber some_number)
How exactly did it fail? Did it throw an exception? If so, what was
the
exception?
Which operating system did you observe that under?
If that was Linux, can you show the contents of the following files
on
that system:
/etc/nsswitch.conf
/etc/hosts
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Function to find a substring
If you want to use libs to make your life easier, maybe something along these lines? Prelude Data.List.Split Safe fmap length . headMay . split (onSublist asdf) $ blee blah asdf bloo Just 10 If they are big strings, it's probably faster to use bytestrings, or arrays of some kinds, rather than default List implementation of string. 2010/6/6 R J rj248...@hotmail.com: What's an elegant definition of a Haskell function that takes two strings and returns Nothing in case the first string isn't a substring of the first, or Just i, where i is the index number of the position within the first string where the second string begins? Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox. Learn more. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Problems with Haskell Platform
allbery: On Jun 4, 2010, at 23:04 , Don Stewart wrote: Build/does not build? That can be automated. Automated converters have a certain tendency to become confused and put files in unexpected places, etc. Usually this has less to do with the source than the destination; in particular, RPM sometimes makes some poor assumptions. -- Sounds like a problem with the converters. cabal2arch does no such thing. But we tightly control the environment. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Problems with Haskell Platform
allbery: On Jun 4, 2010, at 06:54 , Ivan Lazar Miljenovic wrote: Don Stewart d...@galois.com writes: However, we have tools for some distros that do this, and some distro tools support it directly (e.g. bauerbill --hackage on Arch Linux knows how to ask cabal2arch to translate the .cabal file). Contribut to yum to allow pulling from hackage, by calling cabal2yum? I don't know how it is in Arch, but for Gentoo we need to do a lot of QA'ing to make sure our ebuilds generated with hackport work properly (which is one reason why we don't churn ebuilds out as fast as you generate PKBUILDs). Part of the problem is probably that hackport isn't as polished as cabal2arch, but a few other concerns we need to take care of are: I don't think anyone just does a conversion and bodges it into the package system, regardless of distribution, package system, or conversion tool. (Or language; you don't do it with gems, eggs, or CPAN packages either.) The tool does the boring part of the job for you, but of course you want to edit metadata, test, etc. before setting it loose. Release engineering is not optional. Build/does not build? That can be automated. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Problems with Haskell Platform
ivan.miljenovic: Don Stewart d...@galois.com writes: allbery: Supposedly a future Cabal extension will be to, instead of installing, write out a package for a vendor packaging system (yum, apt, yast, what have you). Consider contributing to that effort. However, we have tools for some distros that do this, and some distro tools support it directly (e.g. bauerbill --hackage on Arch Linux knows how to ask cabal2arch to translate the .cabal file). Contribut to yum to allow pulling from hackage, by calling cabal2yum? In general, I think this is a bad idea. I don't know how it is in Arch, but for Gentoo we need to do a lot of QA'ing to make sure our ebuilds generated with hackport work properly The ones on Arch just work. I wonder what we're doing differently. cabal2arch knows a *lot* about Arch's package system. (which is one reason why we don't churn ebuilds out as fast as you generate PKBUILDs). Part of the problem is probably that hackport isn't as polished as cabal2arch, but a few other concerns we need to take care of are: -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Proposal: Sum type branches as extended types (as Type!Constructor)
Gabriel Riba wrote:
New proposal draft:
Proposal: Type supplement for constructor specific uses of sum types
Purpose: Avoid error clauses (runtime errors), exception control or Maybe
types in partially defined (constructor specific) functions on sum types.
As an example, with
data List a = Nil | Cons a (List a)
* Actual system, with runtime errors (as in GHC Data.List head) or
exception throwing or optional Maybe results.
hd :: List a - a
hd (Cons x _) - x
hd Nil - error error: hd: empty list -- error or exception throwing
* Proposed system extending types with a suffix @ Constructor or @
{Constructor1, Constructor2, ..}
hd :: List @ Cons a - a
hd (Cons x _) = x
The caller must do pattern matching before applying the constructor-specific
function.
Since the goal is to propagate case analysis information, the syntax
should reflect that. That is, there should be support for nested
patterns, e.g.,
cdar :: [...@{_:_:_} - a
cdar (_:x:_) = x
cadr :: [[...@{(_:_):_} - a
cadr ((_:xs):_) = xs
headFromJust :: [Maybe a...@{just _ : _} - a
...
The t...@cons syntax is a nice shorthand, but we need to express the
arguments to the data constructors in the extended syntax in order to
support nested patterns.
For delimiting multiple alternatives, it's not clear that comma is the
best delimiter to use, especially since it could be the data constructor
for tuples. Perhaps using ; or | would be better. Unless there's a
syntactic reason for preferring braces over parentheses, perhaps we
should just use parentheses for symmetry with as-patterns.
Finally, there should also be support for negative patterns, i.e.,
propagation of the failure to match a pattern. One place this is useful
is for distinguishing 0 from other numbers, which allows removing the
error branches from functions like division. Sometimes we can't
enumerate all the positive patterns we want to allow, but it's easy to
express what should be disallowed.
To match case analysis we should allow for a conjunction of negative
patterns followed by a positive pattern. Or, if we want to incorporate
multiple positive patterns, then a conjunction of negative patterns
followed by a disjunction of positive patterns. (Disjunctive case
matching has been an independent proposal in the past, and there's
nothing prohibiting supporting it.)
Thus, if we use | to delimit disjunctions, to delimit conjunctions,
and \\ to separate the disjuncts from the conjuncts, given the following
case analysis:
case x : T of
p1 y1... - e1
p2 y2... - e2
_- eF
The variable x has type T outside of the case expression. Within the
branch e1 it is given the refinement type t...@{p1 _...} where variables
bound by the pattern are replaced with wildcards. In branch e2 it is
given the refinement type t...@{p2 _... \\ p1 _...}. This can be simplified
to t...@{p2 _...} if the head constructors of p2 and p1 are distinct. And
in the eF branch x would be given the refinement type t...@{_ \\ p1 _...
p2_...}.
If this semantics is too hard to implement, we could instead require the
use of as-patterns for introducing the refinements. The variable
introduced by @ in the as-pattern would be given the refinement type,
but the scrutinee would continue to have the unrefined type. This latter
semantics is common in dependently typed languages, but it's verbose and
ugly so it'd be nice to avoid it if we can.
Other notes:
Case matching on non-variable expressions would gain no extra support,
since we have no variable to associate the refinement information with
(unless as-patterns are used).
A refinement type t...@{p1} can always be weakened to t...@{p1 | p2}.
Similarly, a refinement type can always be weakened by erasing it.
For type inference, I'd suggest that functions which do not have rigid
signatures are treated the way they currently are; that is, all
refinement information is weakened away unless it is explicitly
requested or returned by a function's type signature. This could be
improved upon later, but seems like the most reasonable place to start.
One complication of trying to infer refinement types is that if we are
too liberal then we won't catch bugs arising from non-exhaustive pattern
matching.
Syntax-wise, there's no particular reason for distinguishing difference
from conjunctions under difference. That is, the type t...@{... \\ p1 p2}
could just as well be written t...@{... \\ p1 \\ p2}. And there's no need
for conjunctions under disjunction because we can unify the patterns to
get their intersection. Thus, it might be best to just have disjunction
and difference for simplicity.
--
Live well,
~wren
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to Show an Operation?
How should I work around that. I could use two different name function, but
I don't like this. Would I have to define a typeclass namedFunction which
all have a name function?
How about a named type:
data Named a = Named {
val_of :: a,
name_of :: String
}
You can put it in Functor and Applicative to get some nice syntax for
modifying the value.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] How to name a mapped function?
Hello all, I like some of the naming conventions in haskell quite a lot, like calling a list of something xs, or function which takes a function as a parameter ..By as in sortBy or groupBy. If I have a function, say compute whose last parameter is some value ... and I create another function, which applies compute to a list of values, how would I call this function? I was tempted to use all, but my original function already returns a list, so this would be misleading. Also note that the mapped version, does some additional things (remove duplicates), otherwise a new function would hardly be justified. -- Martin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Removing alternate items from a list
maybe this? map snd . filter (odd . fst) . zip [1,2..] $ [1,2,3,4,5] 2010/6/6 R J rj248...@hotmail.com: What's the cleanest definition for a function f :: [a] - [a] that takes a list and returns the same list, with alternate items removed? e.g., f [0, 1, 2, 3, 4, 5] = [1,3,5]? The New Busy is not the old busy. Search, chat and e-mail from your inbox. Get started. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] is there a way to prove the equivalence of these two implementations of (Prelude) break function?
Here's two implementations of break, a snappy one from the prelude, and a slow stupid stateful one. They are quickchecked to be identical. Is there a way to prove they are identical mathematically? What are the techniques involved? Or to transform one to the other? import Control.Monad.State import Test.QuickCheck tThis = take 5 . show . mybreak (400) $ [1..10^7] tPrel = take 5 . show . prelbreak (400) $ [1..10^7] prelbreak p xs = (takeWhile (not . p) xs,dropWhile (not . p) xs) -- fast, more or less as implemented in prelude iiuc mybreak p xs = evalState (brk p) ([],xs) -- stateful, slow brk p = do (notsat,remaining) - get case remaining of [] - return (notsat,remaining) (r:rs) - if p r then return (notsat,remaining) else do put (notsat++[r],rs) -- ++ is probaby a major reason brk p ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Please check your dependencies on fgl
Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. As such, if your code uses fgl you should ensure that the specification of the package in your .cabal file has an explicit upper bound (or indeed just set fgl == 5.4.2.2) to avoid any problems when we release 6.0.0.0 (we're trying to avoid the problems that plagued KDE-4 by not claiming in the slightest that the initial few versions are intended for end users). I have already directly emailed the maintainers of any and all packages I could find on Hackage (using Roel van Dijk's wonderful reverse-dependency mirror at http://bifunctor.homelinux.net/~roel/hackage/packages/hackage.html), but just in case I've missed one or there's an as-yet-unreleased package somewhere in the works, here is the official heads up. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Problems with Haskell Platform
On Jun 4, 2010, at 06:54 , Ivan Lazar Miljenovic wrote: Don Stewart d...@galois.com writes: However, we have tools for some distros that do this, and some distro tools support it directly (e.g. bauerbill --hackage on Arch Linux knows how to ask cabal2arch to translate the .cabal file). Contribut to yum to allow pulling from hackage, by calling cabal2yum? I don't know how it is in Arch, but for Gentoo we need to do a lot of QA'ing to make sure our ebuilds generated with hackport work properly (which is one reason why we don't churn ebuilds out as fast as you generate PKBUILDs). Part of the problem is probably that hackport isn't as polished as cabal2arch, but a few other concerns we need to take care of are: I don't think anyone just does a conversion and bodges it into the package system, regardless of distribution, package system, or conversion tool. (Or language; you don't do it with gems, eggs, or CPAN packages either.) The tool does the boring part of the job for you, but of course you want to edit metadata, test, etc. before setting it loose. Release engineering is not optional. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please check your dependencies on fgl
ivan.miljenovic: Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. How about you give the library a different name then -- so as not to break all those programs? A complete rewrite with a new maintainer: fgl-awesome -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Issue with connectTo function in network package
Yeah, that seems to be the issue. When I commented out the ::1.. line it worked. -deech On 6/4/10, Jeremy Shaw jer...@n-heptane.com wrote: Perhaps it was only listening on IPv6 ? ::1 ? - jeremy On Thu, Jun 3, 2010 at 10:30 PM, aditya siram aditya.si...@gmail.comwrote: Hi all, I had an issue where using the connectTo [1] function would fail to connect to localhost if my wireless card was turned off. The moment I turned on my wireless connection it worked. But if I use connectTo with 127.0.0.1 [2] with my network off it works. I confirmed that localhost' resolves to 127.0.0.1 by pinging localhost from command line with the Internet off. Is this a bug in connectTo? -deech [1] connectTo localhost (PortNumber some_number) [2] connectTo 127.0.0.1 (PortNumber some_number) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] HP/Cygwin and Curl
Hi, I am trying to install the curl 1.3.5 hackage on the latest Haskell Platform (2010.1.0.0) on Windows 7. I have installed lib-curl-devel (7.19.6-1) on CygWin but I can't use Cygwin as (apparently) every attempt to install a package ends like this: C:\Program Files\Haskell Platform\2010.1.0.0\lib\..\mingw\bin\windres: can't open temporary file `\/cca01252.irc': No such file or directory Using cabal-install with MSYS generally works. Can HP be used with Cygwin? I have yet to find a way of installing Curl so that the curl hackage will recognise it-does anybody know how to do this? (I couldn't find any explanation of how HP can be used with Cygwin or how to install Curl for use with the hackage. If anyone knows where I can get these that would be fine much appreciated; the Haskell.org outage is compounding this.) Thanks in advance! Vhris ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] How to set a GHC option for a single module and a specific version of GHC?
Hi,
I'm looking for a way to set a GHC compile option on a specific module
(not every module in the program) but only for a specific version of
GHC. Ideally within the confines of cabal, and in a portable way.
GHC provides the OPTIONS_GHC pragma, but it does not appear to provide
a way for the pragma to fire for specific versions of GHC. Also, I
can't use an #ifdef trick because File-header pragmas are read once
only, before pre-processing the file (e.g. with cpp).
Cabal provides conditional statements and a way to check the version
of GHC, but I can't see a way to get it to only use certain compiler
options for a particular module.
In summary, what I really want is a modified version of the OPTIONS_GHC pragma:
{-# OPTIONS_GHC ==6.12.1 ... #-}
or a way to tell cabal to use certain compiler options for a
particular module under certain conditions.
Cheers,
Bernie.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: random-fu 0.1.0.0
James Andrew Cook wrote: In particular, functions such as 'uniform' and 'normal' which directly construct RVars are very useful in defining the rvar implementation of other types. I have been reluctant to drop the rvar function from the Distribution class because it is very useful to be able to define other Distribution instances in terms of these functions instead of the uglier explicit use of rvarT - e.g. rvarT StdUniform in place of just 'stdUniform'. Eventually I'll probably give up this particular objection – probably sooner rather than later now that you've made me think about it – but I'm presently in the state where I know it isn't right to have both (for some value of right) but I don't know yet what a better solution is, given my conflicting objectives (one of which is to refrain from changing everything at once, so users have a chance to keep up with the library's evolution). Oh I'm sure writing the rvar implementation is prettier. However, since clients have to define rvarT too, they can't escape the ugliness :) If RVar were a datatype, then I could imagine there being performance reasons for wanting to define them separately. However, since it isn't, it seems like having both methods in the class is just begging for code duplication and inconsistency bugs. Without the performance benefit, I can't see a reason for having both--- ---unless, perhaps, you have a way of deriving a definition of rvarT from rvar. If so, then there could be efficiency issues in the other direction. I could see some people just giving a pretty implementation of rvar and using the inefficient rvarT, whereas other people would put up with the ugly in order to have an efficient rvarT... (I haven't looked at the package to know if this is actually a possibility) Making the convenience functions mentioned above return RVarT seems natural, but when I tried it I found it made their usage require type annotations in many other places to fix the type of the underlying monad, and I have not yet decided whether it is worth all that. I may yet introduce separate RVarT-typed convenience functions as well, but I'm not sure I want to do that either. That's what I was going to propose :) You could define the RVarT versions, but then keep the RVar versions around for their restricted type. That would allow for moving rvar out of the class (eliminating possible code duplication bugs) and still allow for using uniformT, normalT, etc when defining rvarT. -- Live well, ~wren ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Removing alternate items from a list
i think explicit recursion is quite clean? f :: [a] - [a] f (x:y:zs) = x : f zs f x = x On 7 June 2010 19:42, Thomas Hartman tphya...@gmail.com wrote: maybe this? map snd . filter (odd . fst) . zip [1,2..] $ [1,2,3,4,5] 2010/6/6 R J rj248...@hotmail.com: What's the cleanest definition for a function f :: [a] - [a] that takes a list and returns the same list, with alternate items removed? e.g., f [0, 1, 2, 3, 4, 5] = [1,3,5]? The New Busy is not the old busy. Search, chat and e-mail from your inbox. Get started. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Ozgur Akgun ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Removing alternate items from a list
or, since you don't need to give a name to the second element of the list: f :: [a] - [a] f (x:_:xs) = x : f xs f x = x On 7 June 2010 20:11, Ozgur Akgun ozgurak...@gmail.com wrote: i think explicit recursion is quite clean? f :: [a] - [a] f (x:y:zs) = x : f zs f x = x On 7 June 2010 19:42, Thomas Hartman tphya...@gmail.com wrote: maybe this? map snd . filter (odd . fst) . zip [1,2..] $ [1,2,3,4,5] 2010/6/6 R J rj248...@hotmail.com: What's the cleanest definition for a function f :: [a] - [a] that takes a list and returns the same list, with alternate items removed? e.g., f [0, 1, 2, 3, 4, 5] = [1,3,5]? The New Busy is not the old busy. Search, chat and e-mail from your inbox. Get started. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Ozgur Akgun -- Ozgur Akgun ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HP/Cygwin and Curl
Hi Chris HP can be used fine with Cygwin. Where a library in the HP is a binding to a C library, the HP supplies the relevant C library as an *.a file, e.g libglu32.a and libglut32.a for OpenGL. Pure Haskell libraries will install fine under Cygwin as well. Bindings to additional C libraries like Curl are problematic, for one thing Cygwin static libraries have a different object format to MinGW ones. With effort and knowledge, FFI libraries/bindings can be made to work with Cygwin but I don't think anyone is looking at this systematically (and documenting their methods). Practically speaking using MinGW / MSYS to build and install bindings is the solution. Best wishes Stephen ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to name a mapped function?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Jun 6, 2010, at 14:22 , Martin Drautzburg wrote: If I have a function, say compute whose last parameter is some value ... and I create another function, which applies compute to a list of values, how would I call this function? The few cases of this in the standard Haskell libraries suggest mapCompute. - -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.10 (Darwin) iEYEARECAAYFAkwNSsIACgkQIn7hlCsL25XxQACfaUr8Jt31qDTGkvCeNhfs1L+q ir4AninhHrsxscmnsUl8cchh0DKRMN1m =dnbt -END PGP SIGNATURE- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to name a mapped function?
On Jun 6, 2010, at 11:22 AM, Martin Drautzburg wrote: If I have a function, say compute whose last parameter is some value ... and I create another function, which applies compute to a list of values, how would I call this function? computeF is my natural inclination. F is for Functor. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] HP/Cygwin and Curl
Thanks ever so much for your clear answer. I have no problem at all with using MSYS to build libraries that link to libraries built in Windows land--this seems entirely reasonable. Is this written down somewhere? I mean I really would like to RTFM! :-) Also, what's with C:\Program Files\Haskell Platform\2010.1.0.0\lib\..\mingw\bin\windres: can't open temporary file `\/cca01252.irc': No such file or directory Chris -Original Message- From: Stephen Tetley [mailto:stephen.tet...@gmail.com] Sent: 07 June 2010 20:19 To: Chris Dornan Cc: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] HP/Cygwin and Curl Hi Chris HP can be used fine with Cygwin. Where a library in the HP is a binding to a C library, the HP supplies the relevant C library as an *.a file, e.g libglu32.a and libglut32.a for OpenGL. Pure Haskell libraries will install fine under Cygwin as well. Bindings to additional C libraries like Curl are problematic, for one thing Cygwin static libraries have a different object format to MinGW ones. With effort and knowledge, FFI libraries/bindings can be made to work with Cygwin but I don't think anyone is looking at this systematically (and documenting their methods). Practically speaking using MinGW / MSYS to build and install bindings is the solution. Best wishes Stephen ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to name a mapped function?
If the function is changing the size of the list (e.g. by removing duplicates) a name implying 'mapping' might be misleading. Maybe something like /process/ or /normalize/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to Show an Operation?
If I have a problem where I have to select from a set of operations,
how
would I print the result?
Example: If I can chose from (x+y), (x*y), (x^2+y)...
and I feed them all into my problem solver
and it finds that (x*y) is right, how can I print that string?
As others have pointed out, you can't go from operation to representation,
but you can pair operations and expressions with their representations.
Unless your problem solver just tries out a list of known expressions,
you'll probably end up with a proper expression representation as an
algebraic datatype, and a way to bind the variables. However, if you
really only want arithmetic expressions and their values, you could
define your own instances of the classes defining those operations.
A small example of this approach can be found here:
http://community.haskell.org/~claus/misc/R.hs
It pairs up values with String representations of the expressions
that led to those values
data R a = R { rep:: String, val:: a }
and defines a Num instance for 'Num a = R a'
Then you can do things like (more examples in the source):
-- expressions at default type: show the value
*R foldl (+) 0 [1..4]
10
*R foldr (+) 0 [1..4]
10
-- expressions at 'R Int' types: show the representation
*R foldl (+) 0 [1..4]::R Int
0 + 1) + 2) + 3) + 4)
*R foldr (+) 0 [1..4]::R Int
(1 + (2 + (3 + (4 + 0
*R flip (foldr (+)) [1..4]::R Int-R Int
\x-(1 + (2 + (3 + (4 + x
*R flip (foldl (+)) [1..4]::R Int-R Int
\x-x + 1) + 2) + 3) + 4)
This approach does not easily scale to more complex expressions,
and the code was meant for small demonstrations only, but it might
give you some ideas.
Claus
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Issue with connectTo function in network package
Another way round -- it (the server) was only listening on IPv4 and the (Haskell) client only tried to connect via IPv6. The bug is described here (with a patch): http://trac.haskell.org/network/ticket/30 * Jeremy Shaw jer...@n-heptane.com [2010-06-04 16:57:38-0500] Perhaps it was only listening on IPv6 ? ::1 ? - jeremy On Thu, Jun 3, 2010 at 10:30 PM, aditya siram aditya.si...@gmail.comwrote: Hi all, I had an issue where using the connectTo [1] function would fail to connect to localhost if my wireless card was turned off. The moment I turned on my wireless connection it worked. But if I use connectTo with 127.0.0.1 [2] with my network off it works. I confirmed that localhost' resolves to 127.0.0.1 by pinging localhost from command line with the Internet off. Is this a bug in connectTo? -deech [1] connectTo localhost (PortNumber some_number) [2] connectTo 127.0.0.1 (PortNumber some_number) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Roman I. Cheplyaka :: http://ro-che.info/ Don't let school get in the way of your education. - Mark Twain ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HP/Cygwin and Curl
On 7 June 2010 20:44, Chris Dornan ch...@chrisdornan.com wrote: Also, what's with C:\Program Files\Haskell Platform\2010.1.0.0\lib\..\mingw\bin\windres: can't open temporary file `\/cca01252.irc': No such file or directory Hi Chris I don't know what's going on there, are you using the Windows CLI and then working with GHC's mingw? GHC (and thus the Haskell Platform) does ship with a minimal version of MinGW - includes files, static libraries, gcc, linker etc. - as GHC needs these pieces in its tool chain, and it means you can use GHC with the regular Windows CLI. For 'real work' though, you want to be using a full MSYS / MinGW installation and the MSYS Bash shell. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal -j
Hmmm. Now that I've had a chance to rewatch the video, I am enlightened. Nevertheless, I will confess that I wouldn't mind the idea of just doing an external parallelism wrapper, running multiple sessions of GHC rather than making GHC internally parallel. Hm. Louis Wasserman wasserman.lo...@gmail.com http://profiles.google.com/wasserman.louis On Thu, Jun 3, 2010 at 11:57 PM, Evan Laforge qdun...@gmail.com wrote: Something I wondered from watching that talk, rather than trying to make ghc run concurrently internally, can we just have --make, when faced with multiple possibilities, pick the first one without a 'ModuleName.working' file, create such a working file, and then go to? Then you can run 'ghc --make X.hs ; ghc --make X.hs ; ...'. In fact, isn't that what make -j already does? I could try it with the old style 'ghc -M' and pure makefile, but it turns out to be a lot of work to figure out what packages to include and tangle out the right .o files and whatnot, work that --make does for me. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to set a GHC option for a single module and a specific version of GHC?
On 5 June 2010 09:28, Bernie Pope florbit...@gmail.com wrote: Hi, I'm looking for a way to set a GHC compile option on a specific module (not every module in the program) but only for a specific version of GHC. Ideally within the confines of cabal, and in a portable way. GHC provides the OPTIONS_GHC pragma, but it does not appear to provide a way for the pragma to fire for specific versions of GHC. Also, I can't use an #ifdef trick because File-header pragmas are read once only, before pre-processing the file (e.g. with cpp). Not that it helps you immediately, but this is now fixed: http://hackage.haskell.org/trac/ghc/ticket/3457 I'm not sure which release will include the fix. Duncan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] HP/Cygwin and Curl
Thanks Stephen--that was related to my original question, about using HP with Cygwin. The answer seems to be No!--you must use MSYS (for real work). Or am I just being very slow? (I probably am--sorry!) Chris -Original Message- From: Stephen Tetley [mailto:stephen.tet...@gmail.com] Sent: 07 June 2010 21:09 To: Chris Dornan Cc: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] HP/Cygwin and Curl On 7 June 2010 20:44, Chris Dornan ch...@chrisdornan.com wrote: Also, what's with C:\Program Files\Haskell Platform\2010.1.0.0\lib\..\mingw\bin\windres: can't open temporary file `\/cca01252.irc': No such file or directory Hi Chris I don't know what's going on there, are you using the Windows CLI and then working with GHC's mingw? GHC (and thus the Haskell Platform) does ship with a minimal version of MinGW - includes files, static libraries, gcc, linker etc. - as GHC needs these pieces in its tool chain, and it means you can use GHC with the regular Windows CLI. For 'real work' though, you want to be using a full MSYS / MinGW installation and the MSYS Bash shell. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Issue with connectTo function in network package
Here's my GHCI session (with my network card off):
Prelude Network Network.Socket connectTo localhost (PortNumber 3000)
*** Exception: connect: does not exist (Connection refused)
Prelude Network Network.Socket connectTo 127.0.0.1 (PortNumber 3000)
{handle: socket: 7}
The OS is Ubuntu (Lucid) Linux. The contents of /etc/hosts and
/etc/nsswitch.conf are:
cat /etc/nsswitch.conf
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc Name Service Switch' for information about this file.
passwd: compat
group: compat
shadow: compat
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
networks: files
protocols: db files
services: db files
ethers: db files
rpc:db files
netgroup: nis
cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 deech-mac-ubuntu
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
* aditya siram aditya.si...@gmail.com [2010-06-03 22:30:33-0500]
Hi all,
I had an issue where using the connectTo [1] function would fail to
connect to localhost if my wireless card was turned off. The moment
I turned on my wireless connection it worked. But if I use connectTo
with 127.0.0.1 [2] with my network off it works.
I confirmed that localhost' resolves to 127.0.0.1 by pinging
localhost from command line with the Internet off.
Is this a bug in connectTo?
-deech
[1] connectTo localhost (PortNumber some_number)
[2] connectTo 127.0.0.1 (PortNumber some_number)
How exactly did it fail? Did it throw an exception? If so, what was the
exception?
Which operating system did you observe that under?
If that was Linux, can you show the contents of the following files on
that system:
/etc/nsswitch.conf
/etc/hosts
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haddock on HP failing
Hi, I am trying to use Haddock on the Haskell Platform 2010.1.0.0 and getting haddock.exe: can't find a package database at E:\ghc\ghc-6.12.1\lib\package.conf.d I have tried uninstalling and re-installing HP (just in case) to no avail. Has anybody else seen this? Chris ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to name a mapped function?
Martin Drautzburg martin.drautzb...@web.de writes: If I have a function, say compute whose last parameter is some value ... and I create another function, which applies compute to a list of values, how would I call this function? If I understand you correctly, and it's not simply map . compute (which I'd leave just like that), I would name the function that works on the full data set (i.e. list) 'compute' and a sub-function working on a single element 'compute1'. -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HP/Cygwin and Curl
On Mon, 07 Jun 2010 21:44:13 +0200, Chris Dornan ch...@chrisdornan.com wrote: Thanks ever so much for your clear answer. I have no problem at all with using MSYS to build libraries that link to libraries built in Windows land--this seems entirely reasonable. Is this written down somewhere? I mean I really would like to RTFM! :-) Some information can be found at: http://www.haskell.org/haskellwiki/Windows#Tools_for_compilation (improvements are welcome) Regards, Henk-Jan van Tuyl -- http://Van.Tuyl.eu/ http://members.chello.nl/hjgtuyl/tourdemonad.html -- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Problems with threading?
While working on the Shootout, I noticed the following benchmarks: http://shootout.alioth.debian.org/u64/program.php?test=chameneosreduxlang=ghcid=3 http://shootout.alioth.debian.org/u64/program.php?test=chameneosreduxlang=ghcid=3 http://shootout.alioth.debian.org/u64q/program.php?test=chameneosreduxlang=ghcid=3 The same program becomes almost 4 times slower when compiled with --threaded and run with +RTS -N5 -- even though the multi-core benchmark really only ever uses one processor. Other languages seem to have found a way of arranging these threads in a way such that parallelism actually happens, but as it stands, compiling this benchmark without --threaded actually makes Haskell competitive against the genuinely parallel alternatives in other languages...which is unusual by itself. I wanted to throw this out for people to discuss, because I'd like to see it improved. As it stands, I'm going to submit a version which asks not to be compiled with --threaded (and has a few other improvements). http://shootout.alioth.debian.org/u64q/program.php?test=chameneosreduxlang=ghcid=3 Louis Wasserman wasserman.lo...@gmail.com http://profiles.google.com/wasserman.louis ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Problems with threading?
wasserman.louis: While working on the Shootout, I noticed the following benchmarks: http://shootout.alioth.debian.org/u64/program.php?test=chameneosreduxlang=ghc; id=3 http://shootout.alioth.debian.org/u64q/program.php?test=chameneosreduxlang= ghcid=3 The same program becomes almost 4 times slower when compiled with --threaded and run with +RTS -N5 -- even though the multi-core benchmark really only ever uses one processor. Using -N5 sounds suspicious. There are only 4 cores on the machine. Other languages seem to have found a way of arranging these threads in a way such that parallelism actually happens, but as it stands, compiling this benchmark without --threaded actually makes Haskell competitive against the genuinely parallel alternatives in other languages...which is unusual by itself. I wanted to throw this out for people to discuss, because I'd like to see it improved. As it stands, I'm going to submit a version which asks not to be compiled with --threaded (and has a few other improvements). What parallelization did you try? Is it a good algorithm? -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Issue with connectTo function in network package
Doing (1) solves my problem. What did I do and why did it work? Thanks
a lot for your help!
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
Confirm if any of the following solves the problem:
1. commenting out (by prepending putting hash sign '#' in the beginning
of the line) the following line in /etc/hosts:
::1 localhost ip6-localhost ip6-loopback
2. executing as root the following command:
rmmod ipv6
* aditya siram aditya.si...@gmail.com [2010-06-04 13:51:29-0500]
Here's my GHCI session (with my network card off):
Prelude Network Network.Socket connectTo localhost (PortNumber 3000)
*** Exception: connect: does not exist (Connection refused)
Prelude Network Network.Socket connectTo 127.0.0.1 (PortNumber 3000)
{handle: socket: 7}
The OS is Ubuntu (Lucid) Linux. The contents of /etc/hosts and
/etc/nsswitch.conf are:
cat /etc/nsswitch.conf
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed,
try:
# `info libc Name Service Switch' for information about this file.
passwd: compat
group: compat
shadow: compat
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
networks: files
protocols: db files
services: db files
ethers: db files
rpc:db files
netgroup: nis
cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 deech-mac-ubuntu
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
-deech
On 6/4/10, Roman Cheplyaka r...@ro-che.info wrote:
* aditya siram aditya.si...@gmail.com [2010-06-03 22:30:33-0500]
Hi all,
I had an issue where using the connectTo [1] function would fail to
connect to localhost if my wireless card was turned off. The moment
I turned on my wireless connection it worked. But if I use connectTo
with 127.0.0.1 [2] with my network off it works.
I confirmed that localhost' resolves to 127.0.0.1 by pinging
localhost from command line with the Internet off.
Is this a bug in connectTo?
-deech
[1] connectTo localhost (PortNumber some_number)
[2] connectTo 127.0.0.1 (PortNumber some_number)
How exactly did it fail? Did it throw an exception? If so, what was the
exception?
Which operating system did you observe that under?
If that was Linux, can you show the contents of the following files on
that system:
/etc/nsswitch.conf
/etc/hosts
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
Roman I. Cheplyaka :: http://ro-che.info/
Don't let school get in the way of your education. - Mark Twain
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Span function
R J wrote:
Can someone provide a hand calculation of:
span ( 0) [-1, -2, -3, 0, 1, 2, -3, -4, -5]?
I know the result is ([-1, -2, -3], [0, 1, 2, -3, -4, -5]), but the recursion
flummoxes me.
Here's the Prelude definition:
First, let's simplify the definition.
span _ [] = ([], [])
span p xs@(x:xs')
| p x = (x:ys, zs)
| otherwise = ([], xs)
where
(ys, zs) = span p xs'
===
span _ [] = ([], [])
span p xs@(x:xs')
| p x = let (ys, zs) = span p xs' in (x:ys, zs)
| otherwise = ([], xs)
===
span p xs =
case xs of
[] - ([], [])
(x:xs') -
if p x
then let (ys, zs) = span p xs' in (x:ys, zs)
else ([], xs)
And finally we can pretty up that recursive call (possibly changing
strictness, but otherwise keeping the same meaning).
span = \p xs -
case xs of
[] - ([], [])
(x:xs') -
if p x
then first (x:) (span p xs')
else ([], xs)
And now, the reduction:
span ( 0) (-1:-2:-3:0:1:2:-3:-4:-5:[])
== {delta: unfold the definition of span}
(\ p xs -
case xs of
[] - ([], [])
(x:xs') -
if p x
then first (x:) (span p xs')
else ([], xs)) ( 0) (-1:-2:-3:0:1:2:-3:-4:-5:[])
== {beta: reduction of application}
(let p = ( 0) in \ xs -
case xs of
[] - ([], [])
(x:xs') -
if p x
then first (x:) (span p xs')
else ([], xs)) (-1:-2:-3:0:1:2:-3:-4:-5:[])
N.B. this next step isn't entirely accurate in Haskell since it looses
sharing.
== {zeta: reduction of let-binding}
(\ xs -
case xs of
[] - ([], [])
(x:xs') -
if ( 0) x
then first (x:) (span ( 0) xs')
else ([], xs)) (-1:-2:-3:0:1:2:-3:-4:-5:[])
== {beta, zeta}
case (-1:-2:-3:0:1:2:-3:-4:-5:[]) of
[] - ([], [])
(x:xs') -
if ( 0) x
then first (x:) (span ( 0) xs')
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
== {iota: reduction of case matching}
let x = -1
xs' = (-2:-3:0:1:2:-3:-4:-5:[])
in
if ( 0) x
then first (x:) (span ( 0) xs')
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
== {zeta, zeta}
if ( 0) (-1)
then first (-1:) (span ( 0) (-2:-3:0:1:2:-3:-4:-5:[]))
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
== {beta}
if -1 0
then first (-1:) (span ( 0) (-2:-3:0:1:2:-3:-4:-5:[]))
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
Just to be pedantic :)
== {delta}
if -1 # 0
then first (-1:) (span ( 0) (-2:-3:0:1:2:-3:-4:-5:[]))
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
== {primitive}
if True
then first (-1:) (span ( 0) (-2:-3:0:1:2:-3:-4:-5:[]))
else ([], (-1:-2:-3:0:1:2:-3:-4:-5:[])))
== {iota}
first (-1:) (span ( 0) (-2:-3:0:1:2:-3:-4:-5:[]))
We'll ignore that `first` and evaluate under it for clarity, even though
this isn't accurate for Haskell's call-by-need strategy. Technically
we'd unfold the definition of `first`, do beta/zeta reduction, and then
do the following since we'd need to evaluate the scrutinee of the case
match. I'll go a bit faster now since it's the same.
== {delta, beta, beta, iota, zeta, zeta, beta, delta, primitive, iota}
first (-1:) (first (-2:) (span ( 0) [-3,0,1,2,-3,-4,-5]))
== {delta, beta, beta, iota, zeta, zeta, beta, delta, primitive, iota}
first (-1:) (first (-2:) (first (-3:) (span ( 0) [0,1,2,-3,-4,-5])))
Now things are a little different, so we'll slow down.
== {delta, beta, beta}
first (-1:) (first (-2:) (first (-3:) (
case [0,1,2,-3,-4,-5] of
[] - ([], [])
(x:xs') -
if ( 0) x
then first (x:) (span ( 0) xs')
else ([], [0,1,2,-3,-4,-5]) )))
== {iota, zeta, zeta, beta}
first (-1:) (first (-2:) (first (-3:) (
if 0 0
then first (0:) (span ( 0) [1,2,-3,-4,-5])
else ([], [0,1,2,-3,-4,-5]) )))
== {delta, primitive, iota}
first (-1:) (first (-2:) (first (-3:) ([], [0,1,2,-3,-4,-5])))
Now for those `first`s. Again, with pure call-by-need evaluation we'll
have already done most of this, and will have done it in reverse order.
For clarity we'll do it inside-out a la call-by-value. (Because of
strictness analysis, Haskell could perform a hybrid CBN/CBV strategy and
could actually follow this order if it determined that `first` was
strict in its second argument.)
== {delta}
first (-1:) (first (-2:) (
(\ f p - case p of (x,y) - (f x, y))
(-3:) ([], [0,1,2,-3,-4,-5])))
== {beta, zeta}
first (-1:) (first (-2:) (
(\ p - case p of (x,y) - ((-3:) x, y))
([], [0,1,2,-3,-4,-5])))
== {beta, zeta}
first (-1:) (first (-2:) (
case ([], [0,1,2,-3,-4,-5]) of (x,y) - ((-3:) x, y)))
== {iota, zeta,
Re: [Haskell-cafe] Please check your dependencies on fgl
Oh, great, the email _did_ go out on the mailing lists (what with haskell.org being down I wasn't sure it would). Don Stewart d...@galois.com writes: ivan.miljenovic: Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. How about you give the library a different name then -- so as not to break all those programs? A complete rewrite with a new maintainer: fgl-awesome We considered giving it a new name (fgl', etc.) but figured that in the long term this wouldn't be advantagous. We feel that the situation is analogous to QuickCheck: when the new version came out most people kept using the old one until slowly the momentum shifted and more people started using the new version (without checking in depth, Roel's Hackage mirror reports QC-2.x now has 153 reverse dependencies as opposed to 127 reverse dependencies for QC-1.y). If we changed the name, then the emotional attachment that the Haskell community has to FGL being the de-facto graph library means that people would keep using the old version. Whilst we also face the possible problems of people not liking the old version and thus automatically dismissing the new version, I think this is a much more unlikely scenario. The overall philosophy is remaining the same: we're just updating the implementation (letting people pick the Node type rather than hard-coding it to Int, letting people constrain the label types and also providing more scope for optimisations). As such, the new version is incompatible with the old one; however, if you're only _using_ FGL (as opposed to making a new instance of the graph types), then the actual changes to using the new version should be minimal (especially if you're using it internally in which case you can hard-code the various types in and not have to worry about the type family usage at all). As I said, I've directly emailed the maintainers of the packages that have open-ended dependencies on FGL and thus would have compilation problems when we release the new version[s]; 7 out of 12 of those maintainers have already responded within less than 24 hours so I don't think this is likely to be a problem unless some new package is uploaded in the near future without proper ranged dependencies. So as to give you even more of a heads up, here are some more overall plans Thomas and I have for FGL: * FGL will still focus on inductive graphs; however the two current classes are being combined since it doesn't make much sense in general to have a graph that can be decomposed using match but can't be composed using (there might be specific cases where this is true such as considering the Cabal package dependency graph; however this is likely to be defined internally within some project so users should just be careful about how they use it to ensure they don't add arbitrary nodes/edges that don't make sense; note that the new Show and Read instances take advantage of this by using Contexts as the basis of this instance). * The ability to have proper Eq, Show and Read instances for graphs with pre-defined helper functions implementors can use (currently Data.Graph.Inductive.Tree has a pretty output for Show but no Read instance, and graphs cannot have equality due to overlapping instance problems). * Splitting the library up into the base classes + sample instances (the fgl package) and a separate fgl-algorithms package (analogous to Dan Doel's vector-algorithms; this will be comprised of what is currently in the Data.Graph.Inductive.Query.* modules as well as the Data.Graph.Analysis.Algorithms.* modules in my Graphalyze library. The Data.Graph.Inductive.Graphviz module will also be scrapped in favour of my graphviz library. * By default, fgl will ship with two default instances: the one currently in Data.Graph.Inductive.PatriciaTree and also a generic Map-based one that lets people choose their own Node type (i.e. the key type in the Map). Any other suitable instances that we can think of (e.g. Thomas has the beginnings of a vector-based one) we'll ship in separate packages (e.g. fgl-vector). If anyone has a good reason to object to any of these plans, we are willing to be persuaded out of them. This is why the 6.z series of fgl will be technology previews to slowly build up what FGL does and gauge the reaction of the Haskell community. -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please check your dependencies on fgl
ivan.miljenovic: Oh, great, the email _did_ go out on the mailing lists (what with haskell.org being down I wasn't sure it would). Don Stewart d...@galois.com writes: ivan.miljenovic: Thomas Bereknyei are currently re-writing fgl (just about completely from scratch) and we plan to make an initial release to get feedback on the API in the next few weeks. However, I'm sending this email out now to warn people that I highly doubt any code that was written for the current version of fgl (http://hackage.haskell.org/package/fgl-5.4.2.2) will work with the new version. How about you give the library a different name then -- so as not to break all those programs? A complete rewrite with a new maintainer: fgl-awesome We considered giving it a new name (fgl', etc.) but figured that in the long term this wouldn't be advantagous. We feel that the situation is analogous to QuickCheck: when the new version came out most people kept using the old one until slowly the momentum shifted and more people started using the new version (without checking in depth, Roel's Hackage mirror reports QC-2.x now has 153 reverse dependencies as opposed to 127 reverse dependencies for QC-1.y). Just remember: you are now the maintainer of a package in the Haskell Platform, and that has some burden on ensuring stability and safety. API-breaking changes are fine, as long as well planned, and it may be up to 12 months before the HP can adopt an API changing release of a package. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haddock on HP failing
Chris Dornan ch...@chrisdornan.com writes: I am trying to use Haddock on the Haskell Platform 2010.1.0.0 and getting haddock.exe: can't find a package database at E:\ghc\ghc-6.12.1\lib\package.conf.d Where did you install GHC to (just checking...)? -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] After `readFile`, why cannot i `writeFile` ?
hitSSQ :: String - [Int] - IO () hitSSQ no hitNum = do let newNum = unwords $ [no] ++ map (\n - show n) hitNum hitNums - fmap lines $ readFile test.txt writeFile test.txt $ unlines $ hitNums ++ [newNum] *** Exception: test.txt: openFile: resource busy (file is locked) Sincerely! - e^(π⋅i) + 1 = 0 -- View this message in context: http://old.nabble.com/After-%60readFile%60%2C-why-cannot-i-%60writeFile%60tp28793133p28793133.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please check your dependencies on fgl
Don Stewart d...@galois.com writes:
ivan.miljenovic:
We considered giving it a new name (fgl', etc.) but figured that in the
long term this wouldn't be advantagous. We feel that the situation is
analogous to QuickCheck: when the new version came out most people kept
using the old one until slowly the momentum shifted and more people
started using the new version (without checking in depth, Roel's Hackage
mirror reports QC-2.x now has 153 reverse dependencies as opposed to 127
reverse dependencies for QC-1.y).
Just remember: you are now the maintainer of a package in the Haskell
Platform, and that has some burden on ensuring stability and safety.
API-breaking changes are fine, as long as well planned, and it may be up
to 12 months before the HP can adopt an API changing release of a
package.
Oh, we know that: we envisage it being a few months before anyone starts
using the new version of FGL.
One change I might make in a released version before then is if I'm
successful during AusHack in writing at least a start towards the
generic graph classes, we might make a 5.x release of fgl that has the
instances of the generic classes and then port at least graphviz over to
using the new generic classes. I realise that these changes as well
won't necessarily go into the HP straight away, but it should help
improve cross-library usage down the track.
off-topic
I was discussing the state of the graph libraries with Edward Kmett
yesterday, and here's what I said as what I envisage happening over the
next year or so:
* The generic graph classes will form a base library for accessing and
using graphs. It won't define any graph types itself, but will serve
as a base compatability layer between libraries. The focus of this
will be a class I'm currently calling GraphLike which let's you access
the vertices and edges of any type that matches the formal definition
of a graph that it's a set of vertices V and a set of edges E such
that forall e \in E, there exists two vertices v1, v2 \in V (not
neccessarily distinct) such that there are two mappings source e =
v1 and target e = v2 (or whatever you want to call them) between
each edge and the set of vertices.
Basically, this class is an accessor class, so it will work for things
like package dependency graph in Cabal, etc. for graph-like types
which it might not make sense to add or change vertices and edges in
the graph. Whether there will also be a class for adding/removing
elements is currently up in the air, as this might not make sense for
all graph types. As such, those functions that don't need to edit
graphs (e.g. graphToDot in graphviz) will be able to just use these.
* The set of FGL libraries will form an initial to intermediary layer of
types. If your problem isn't large and the inductive nature is
applicable, then FGL will probably be your best bet.
* Edward's co-monadic graph library will be an intermediary to advanced
layer; it sounds quite interesting but might not be as easy to use due
to the types changing when you add a vertex, etc.
* fasta on #haskell{,-blah} has suggested that I read through the Boost
Graph Library documentation and consider writing a graph library based
upon that (and hints that he's once written a high-performance graph
library in Haskell on this model). As such, I'll have a look at this
down the track during my copious free time :s (Edward thinks it might
even fit in to his co-monadic approach, so we'll see).
What I'm after here is more sharing between graph types and libraries:
rather than defining something on just one specific graph type,
generalise it as much as you can (to avoid writing a new Graphviz
transformation library for every graph type for example).
/off-topic
--
Ivan Lazar Miljenovic
ivan.miljeno...@gmail.com
IvanMiljenovic.wordpress.com
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] After `readFile`, why cannot i `writeFile` ?
zaxis z_a...@163.com writes: hitSSQ :: String - [Int] - IO () hitSSQ no hitNum = do let newNum = unwords $ [no] ++ map (\n - show n) hitNum hitNums - fmap lines $ readFile test.txt writeFile test.txt $ unlines $ hitNums ++ [newNum] *** Exception: test.txt: openFile: resource busy (file is locked) You're currently reading the file; finish reading it and close it before you write over it (or else use WriteRead mode or whatever it's called and call openFile explicitly rather than using readFile and writeFile). -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Reminder: Deadline to submit talks on your commercial use of Haskell to CUFP in 7 days
This is a final call for speakers at CUFP 2010 -- the Commercial Users of FP Workshop, in Baltimore. CUFP is a chance for you to talk about your use of functional programming in a commercial setting -- and we'd love to see some Haskell speakers, given the recent spike in recruiting :-) You can see the fine videos from last year's CUFP on the all new CUFP site: http://cufp.org Time to stand up and be counted! -- Don 2010 Call for Presentations http://cufp.org Sponsored by SIGPLAN Co-located with ICFP 2010 Baltimore, MD USA Oct 1-2 Submission Deadline 15 June 2010 Functional programming languages have been a hot topic of academic research for over 35 years, and have seen an ever larger practical impact in settings ranging from tech startups to financial firms to biomedical research labs. At the same time, a vigorous community of practically-minding functional programmers has come into existence. CUFP is designed to serve this community. The annual CUFP workshop is a place where people can see how others are using functional programming to solve real world problems; where practitioners meet and collaborate; where language designers and users can share ideas about the future of their favorite language; and where one can learn practical techniques and approaches for putting functional programming to work. Giving a CUFP Talk If you have experience using functional languages in a practical setting, we invite you to submit a proposal to give a talk at the workshop. We're looking for two kinds of talks: Experience reports are typically 25 minutes long, and aim to inform participants about how functional programming plays out in real-world applications, focusing especially on lessons learned and insights gained. Experience reports don't need to be highly technical; reflections on the commercial, management, or software engineering aspects are, if anything, more important. You do not need to submit a paper! Technical talks are expected to be 30-45 minutes long, and should focus on teaching the audience something about a technical technique or methodology, from the point of view of someone who has seen it play out in practice. These talks could cover anything from techniques for building functional concurrent applications, to managing dynamic reconfigurations, to design recipes for using types effectively in large-scale applications. While these talks will often be based on a particular language, they should be accessible to a broad range of functional programmers. If you are interested in offering a talk, or nominating someone to do so, send an e-mail to francesco(at)erlang-consulting(dot)com or yminsky(at)janestreet(dot)com by 15 June 2010 with a short description of what you'd like to talk about or what you think your nominee should give a talk about. Such descriptions should be about one page long. There will be no published proceedings, as the meeting is intended to be more a discussion forum than a technical interchange. Program Committee Francesco Cesarini, Erlang Training and Consulting (Co-Chair) Tim Dysinger, Sonian Networks Alain Frisch, LexiFi Nick Gerakines, Chegg Adam Granicz, IntelliFactory Amanda Laucher Romain Lenglet, Google Japan Yaron Misky, Jane Street (Co-Chair) Mary Sheeran, Chalmers Don Stewart, Galois Dean Wampler, DRW Trading More information For more information on CUFP, including videos of presentations from previous years, take a look at the CUFP website at http://cufp.org. Note that presenters, like other attendees, will need to register for the event. Presentations will be video taped and presenters will be expected to sign an ACM copyright release form. Acceptance and rejection letters will be sent out by July 15th. Note that ICFP proper is on Sep. 27-29th.1G ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] is there a way to prove the equivalence of these two implementations of (Prelude) break function?
On Jun 5, 2010, at 8:10 PM, Thomas Hartman wrote: Is there a way to prove they are identical mathematically? What are the techniques involved? Or to transform one to the other? Typically, the easiest way to prove that functions f g are equivalent is to (1) show that their domains are the same, and (2) show that for every x in the domain, f x = g x. Usually, this amounts to comparing and understanding the function definitions, since each definition if a proof that the function relates a value x to f x, its image under f. So a proof that f = g is a proof that a characterization of f is the same as the characterization for g. For exposition, I'll do the analysis for the Prelude function. You might note how much like evaluating the function Generating the characterization for a caseful or stateful function requires quantifying over cases or states. Exercise left to the reader. prelbreak p xs = (takeWhile (not . p) xs,dropWhile (not . p) xs) We seek a characterization of prelbreak in the following terms: prelbreak is a function that accepts a proposition p and a list of x's, and returns a ... To that end, note that prelbreak is a product function. It returns a pair of images of p and xs, under the functions (\p xs - takeWhile (not . p) xs) and (\p xs - dropWhile (not . p) xs). takeWhile is kind of tricky to describe in English, since it depends on the intrinsic order of the xs. But in this case it returns the largest prefix of xs for which no x satisfies p. Dually, (\p xs - dropWhile (not . p) xs) returns the list complement (taken in xs) of the image of (\p xs - takeWhile (not . p) xs). (I guess this is a very high level characterization, especially since I didn't derive it from the function's definition. The level of detail you want in your proof is up to you) So, finally, prelbreak accepts a proposition p and a list xs, and returns a pair whose first element is the largest prefix of xs for which no x satisfies p, and whose second element is the complement of the first, taken in xs. To do it for mybreak, you would have to pick apart the semantics of evalState and brk, and recharacterize them. That could be a little trickier mathematically, or straight forward. It depends on how you end up quantifying over monadic actions. Either way, it will be a LOT like evaluating the code. (After all, the function definition is a proof that the function relates each x to f x) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] After `readFile`, why cannot i `writeFile` ?
readFile reads the file lazily so it isn't closed until the entire contents have been consumed. Try System.IO.Strict.readFile, which will read the entire file at once. zaxis z_a...@163.com writes: hitSSQ :: String - [Int] - IO () hitSSQ no hitNum = do let newNum = unwords $ [no] ++ map (\n - show n) hitNum hitNums - fmap lines $ readFile test.txt writeFile test.txt $ unlines $ hitNums ++ [newNum] *** Exception: test.txt: openFile: resource busy (file is locked) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] is there a way to prove the equivalence of these two implementations of (Prelude) break function?
On Jun 7, 2010, at 4:10 PM, Alexander Solla wrote: For exposition, I'll do the analysis for the Prelude function. You might note how much like evaluating the function Correction: You might note how much like evaluating the function generating the analysis is. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Removing alternate items from a list
alts :: [a] - [a] alts xs = map fst . filter snd $ zip xs (cycle [False, True]) Prelude alts [0, 1..5] [1,3, 5] On Sunday Jun 6, 2010, at 10:46 AM, R J wrote: What's the cleanest definition for a function f :: [a] - [a] that takes a list and returns the same list, with alternate items removed? e.g., f [0, 1, 2, 3, 4, 5] = [1,3,5]? The New Busy is not the old busy. Search, chat and e-mail from your inbox. Get started. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Issue with connectTo function in network package
On Jun 4, 2010, at 15:15 , aditya siram wrote: Doing (1) solves my problem. What did I do and why did it work? Thanks a lot for your help! Its the problem I pointed out; you are doing an IPv4 connect but localhost was resolving to an IPv6 address. This is annoyingly common on Linux. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Problems with threading?
--- On Mon, 6/7/10, Don Stewart d...@galois.com wrote: From: Don Stewart d...@galois.com Subject: Re: [Haskell-cafe] Problems with threading? To: Louis Wasserman wasserman.lo...@gmail.com Cc: Haskell Café List haskell-cafe@haskell.org Date: Monday, June 7, 2010, 2:50 PM wasserman.louis: While working on the Shootout, I noticed the following benchmarks: http://shootout.alioth.debian.org/u64/program.php?test=chameneosredux〈=ghc; id=3 http://shootout.alioth.debian.org/u64q/program.php?test=chameneosredux〈= ghcid=3 The same program becomes almost 4 times slower when compiled with --threaded and run with +RTS -N5 -- even though the multi-core benchmark really only ever uses one processor. Using -N5 sounds suspicious. There are only 4 cores on the machine. -N5 is likely to have been your orsuggestion for getting the most out of ghc 6.10.* :-) -snip- I wanted to throw this out for people to discuss, because I'd like to see it improved. As Louis has already mentioned this to me, I'll take the opportunity to sketch out a simple approach - 1) GHC programs compiled without -threaded and run without +RTS -N are already shown for x86 and x64 http://shootout.alioth.debian.org/u32/compare.php?lang=ghc http://shootout.alioth.debian.org/u64/compare.php?lang=ghc 2) For quad-core, the GHC programs will all be compiled with -threaded and all run with +RTS -N4 3) That seems to match the approach taken with Erlang, where all the programs on quad-core run with smp built into the vm, and all the programs on one core run without smp built into the vm. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Problems with threading?
igouy2: As Louis has already mentioned this to me, I'll take the opportunity to sketch out a simple approach - 1) GHC programs compiled without -threaded and run without +RTS -N are already shown for x86 and x64 http://shootout.alioth.debian.org/u32/compare.php?lang=ghc http://shootout.alioth.debian.org/u64/compare.php?lang=ghc 2) For quad-core, the GHC programs will all be compiled with -threaded and all run with +RTS -N4 3) That seems to match the approach taken with Erlang, where all the programs on quad-core run with smp built into the vm, and all the programs on one core run without smp built into the vm. Yep, that's fine. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Reporting a problem with binary-0.5
Ketil Malde wrote: There was a deliberate change in strictness in 0.5 making binary strict, which apparently speeds up GHC. Ah okay. I suppose that passes the buck to network-dns. Presumably it could be fixed fairly simply by requiring binary 0.5 (as you suggested). Ideally, though, the implementation of its infinite random list would be changed. This would avoid having a dependency on a package which is no longer current. Pete ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: haskell.org down?
Ozgur Akgun ozgurak...@gmail.com writes: http://downforeveryoneorjustme.com/www.haskell.org-- Ozgur Akgun Same problem here since two days ago. Apparently, the server just went back up. Anybody know what kept the server down for so long? -- Benjamin L. Russell -- Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/ Translator/Interpreter / Mobile: +011 81 80-3603-6725 Furuike ya, kawazu tobikomu mizu no oto. -- Matsuo Basho^ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Is www.haskell.org down?
Since yesterday, I have been unable to connect to www.haskell.org. Is the site down? -- Benjamin L. Russell -- Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/ Translator/Interpreter / Mobile: +011 81 80-3603-6725 Furuike ya, kawazu tobikomu mizu no oto. -- Matsuo Basho^ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Re: Re: Difference between div and /
On Thu, 2010-06-03 at 06:48 -0700, mo...@deepbondi.net wrote: On Thu, 3 Jun 2010, Maciej Piechotka wrote: Hmm. Thanks - however I fail to figure out how to do something like: generate a random number with normal distribution with average avg and standard deviation stdev. Unfortunately the package is restricted to discrete distributions so far. Shameless self-advertisement: The random-fu package (whimsically named, sorry) implements a modest variety of continuous distributions with what I believe to be a user-friendly and flexible interface. This thread inspired me to finish up and upload the 0.1 release (just announced on haskell-cafe as well). The public interface is slightly different from earlier releases and the haddock docs for the new one failed to build on hackage, but earlier versions have essentially the same end-user interface aside from some changes in the module export lists so if you'd like to get an idea of the basic spirit of the system you can browse the docs for the earlier releases. Alternatively, feel free to browse the source and steal some of the implementations (many of which were, in turn, translated from other sources such as wikipedia or the Numerical Recipes book). Unfortunately, the old documentation is much sparser and terser than the new documentation that failed to build, but if nothing else you can download and build the docs yourself for the new one. I build docs anyway ;). I discovered random-fu just before 0.1 release and it have nice, monadic interface :D I guess all it lacks is something to 'just' use IO without state etc. for fast typing in ghci - otherwise is IMHO perfect. Regards signature.asc Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Proposal filed to GHC, expecting supporters vote: Type supplement for constructor specific uses of sum types
Hi! I have filed a new proposal to GHC bugs/whishes process based on the previous discussion here. The proposal address is http://hackage.haskell.org/trac/ghc/ticket/4116#comment:2 ( I had some formatting problems with the first posting, so it is better read at comment:2) Voters admitted: GHC prioritizes bugs/features based on the length of supporters email list at the CC field of the ticket as explained here: http://hackage.haskell.org/trac/ghc/wiki/ReportABug#Ifalreadyreportedvoteforit You may add also any change proposal. Cheers. Gabriel ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Help with Bird problem 3.3.3
Hi, I'm just re-reading the book again, this time doing the exercises though :) Is there a site with solutions for the exercises? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: PDF generation?
On Tue, 2010-06-01 at 21:45 +0300, Yitzchak Gale wrote: I wrote: I have often generated PostScript from Haskell... Then you convert the PS to PDF using any of the nice utilities around for that Pierre-Etienne Meunier wrote: Isn't there a problem with non-type 1 vectorial fonts being rasterized during this conversion ? No. PDF is just a simplified, compressed encoding of PostScript. Unless there is some special reason to do so, why would a conversion utility go to the trouble of rasterizing fonts instead of just copying them in? Perhaps something like ImageMagick might do that; its internal format is a raster. Regards, Yitz PDF is not just simplified, compressed encoding of PostScript. Or at least - LaTeX have some features PDF-only. For example PDF can have hyper-links (both to local and external content). It can be scripted in JavaScript (don't ask me why) and can have form (OK. So I can fill them and print probably). Regards signature.asc Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: random-fu 0.1.0.0
On Jun 4, 2010, at 9:42 PM, wren ng thornton wrote: ---unless, perhaps, you have a way of deriving a definition of rvarT from rvar. If so, then there could be efficiency issues in the other direction. I could see some people just giving a pretty implementation of rvar and using the inefficient rvarT, whereas other people would put up with the ugly in order to have an efficient rvarT... (I haven't looked at the package to know if this is actually a possibility) This is precisely the present state of affairs, and I'm probably the worst offender. In fact, most of the distributions provided in the library just use the default implementation of rvarT, which as you guessed has a bit of a penalty associated. I've had it in the back of my mind for quite a while to revisit that design, it just hasn't been enough of a priority to actually do it. I've been having more fun mucking about in the numerical code :) Making the convenience functions mentioned above return RVarT seems natural, but when I tried it I found it made their usage require type annotations in many other places to fix the type of the underlying monad, and I have not yet decided whether it is worth all that. I may yet introduce separate RVarT-typed convenience functions as well, but I'm not sure I want to do that either. That's what I was going to propose :) You could define the RVarT versions, but then keep the RVar versions around for their restricted type. That would allow for moving rvar out of the class (eliminating possible code duplication bugs) and still allow for using uniformT, normalT, etc when defining rvarT. Yea, now that you put that in words, I like the idea and see that it wouldn't be as disruptive as I subliminally assumed. I'll probably get to it sooner rather than later - thanks! -- James___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: PDF generation?
On Jun 5, 2010, at 10:37 , Maciej Piechotka wrote:
PDF is not just simplified, compressed encoding of PostScript. Or at
least - LaTeX have some features PDF-only.
I think that has more to do with the fact that pdftex/pdflatex is
tightly integrated with a dvi converter that understands many PDF-
specific \special{}s.
--
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com
system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu
electrical and computer engineering, carnegie mellon universityKF8NH
PGP.sig
Description: This is a digitally signed message part
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: PDF generation?
On 6 June 2010 00:37, Maciej Piechotka uzytkown...@gmail.com wrote: PDF is not just simplified, compressed encoding of PostScript. Or at least - LaTeX have some features PDF-only. For example PDF can have hyper-links (both to local and external content). It can be scripted in JavaScript (don't ask me why) and can have form (OK. So I can fill them and print probably). The form stuff is also for online submission, and the javascript allows editing of what is possible. For example (requires Adobe Reader plugin, which I don't have and thus haven't seen it myself) this form (I believe) auto-fills in some details and saves a copy online, etc.: https://forms.australia.gov.au/forms/aec/Electoral%20enrolment/ Regards ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: PDF generation?
should have included this in previous... On Jun 5, 2010, at 10:37 , Maciej Piechotka wrote: For example PDF can have hyper-links (both to local and external content). It can be scripted in JavaScript (don't ask me why) and can have form (OK. So I can fill them and print probably). The only thing that stops PostScript from doing this is that it's almost always used with devices where neither feature is useful. Indeed, PostScript is fully network capable in theory; in practice I doubt many printers implement the entire I/O model. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] A question on existential types and Church encoding
In the new type, the parameter 'a' is misleading. It has no connection to the 'a's on the right of the equals sign. You might as well write: type CB = forall a. a - a - a On Tue, Jun 1, 2010 at 12:40 PM, Cory Knapp cory.m.kn...@gmail.com wrote: Ah! That makes sense. Which raises a new question: Is this type too general? Are there functions which are semantically non-boolean which fit in that type Actually, this type is *less* general, in that it has less members. Consider, what boolean is represented by this? q :: CB Int q = (+) Whereas the (forall a. a - a - a) must work on *any* type, so it has far less freedom to decide what to do, and therefore there are less possible implementations. In fact, if we treat all bottoms as equal, I believe these are all of the distinguishible implementations of this function: t a _ = a f _ a = a a1 = undefined a2 _ = undefined a3 _ _ = undefined a4 a b = seq b a a5 a b = seq a b a6 a = seq a (\_ - a) a7 a = seq a (\b - b) Without allowing bottoms, t and f are the only implementations. Here's some discriminators that are bottom if the passed in function is the first and not in the group of second: disc_t_f b = b undefined () disc_f_t b = b () undefined disc_6_t b = seq (b undefined) () disc_1_any b = seq b () disc_2_34567tf b = seq (b ()) () disc_3_4567tf b = seq (b () ()) () disc_4_6t b = b () undefined disc_5_f b = b undefined () disc_7_6 b = b () undefined disc_6_5 = seq (b undefined) () -- ryan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] After `readFile`, why cannot i `writeFile` ?
Bill Atkins-6 wrote: readFile reads the file lazily so it isn't closed until the entire contents have been consumed. Try System.IO.Strict.readFile, which will read the entire file at once. Yes, and i can use appendFile too. appendFile ssqHitNum.txt $ unwords $ [no] ++ map (\n - show n) hitNum ++ [\n] zaxis z_a...@163.com writes: hitSSQ :: String - [Int] - IO () hitSSQ no hitNum = do let newNum = unwords $ [no] ++ map (\n - show n) hitNum hitNums - fmap lines $ readFile test.txt writeFile test.txt $ unlines $ hitNums ++ [newNum] *** Exception: test.txt: openFile: resource busy (file is locked) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe - e^(π⋅i) + 1 = 0 -- View this message in context: http://old.nabble.com/After-%60readFile%60%2C-why-cannot-i-%60writeFile%60tp28793133p28812627.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
