[Haskell] Haskell Weekly News: Issue 113 - April 13, 2009

--- Haskell Weekly News http://sequence.complete.org/hwn/20090413 Issue 113 - April 13, 2009 --- Welcome to issue 113 of HWN, a newsletter covering

[Haskell] Re: seeking papers with good examples of the use of GADTs

I am hoping some of you may have suggestions about other papers that would be good tutorials in the use of GADTs. Norman Norman, This is very much in a state of flux but it may be worth taking a look at http://code.haskell.org/asn1/ASNTYPE.lhs. There's also

Re: [Haskell] Haskell Weekly News: Issue 113 - April 13, 2009

: --- Haskell Weekly News http://sequence.complete.org/hwn/20090413 Issue 113 - April 13, 2009 --- Welcome to issue 113 of HWN, a newsletter covering developments in the [1]Haskell community

[Haskell] deriving Show for GADT?

I've got a fairly large GADT for which I wished to use deriving (Show) but I got a mysterious error message: Exp.hs:13:11: Can't make a derived instance of `Show (Exp a)' (`Exp' has non-Haskell-98 constructor(s)) In the data type declaration for `Exp' This is from GHC. Does

Re: [Haskell] deriving Show for GADT?

Unfortunately, this isn't supported at present. --Ben On 14 Apr 2009, at 05:28, Norman Ramsey wrote: I've got a fairly large GADT for which I wished to use deriving (Show) but I got a mysterious error message: Exp.hs:13:11: Can't make a derived instance of `Show (Exp a)' (`Exp' has

Re: [GHC] #3162: Windows users can't compile time package

#3162: Windows users can't compile time package -+-- Reporter: NeilMitchell |Owner: Type: bug | Status: closed Priority: normal|

Re: [GHC] #3153: Panic on syntactically wrong LANGUAGE pragma

#3153: Panic on syntactically wrong LANGUAGE pragma ---+ Reporter: b_jonas |Owner: igloo Type: bug | Status: new Priority: normal |Milestone:

Re: [GHC] #2353: GHC inliner doesn't

#2353: GHC inliner doesn't -+-- Reporter: guest |Owner: Type: bug | Status: new Priority: normal|Milestone: 6.12

Re: [GHC] #2362: allow full import syntax in GHCi

#2362: allow full import syntax in GHCi -+-- Reporter: Isaac Dupree |Owner: Type: feature request | Status: new Priority: high |

Re: [GHC] #2365: Warn about suspicious flags in OPTIONS_GHC pragmas

#2365: Warn about suspicious flags in OPTIONS_GHC pragmas -+-- Reporter: igloo |Owner: Type: feature request | Status: new Priority: normal

Re: [GHC] #2370: num009 fails on OS X 10.5?

#2370: num009 fails on OS X 10.5? ---+ Reporter: batterseapower |Owner: Type: bug | Status: new Priority: normal |Milestone: 6.12

Re: [GHC] #2374: MutableByteArray# is slower than Addr#

#2374: MutableByteArray# is slower than Addr# --+- Reporter: dolio |Owner: Type: bug| Status: new Priority: normal |Milestone:

Re: [GHC] #2387: Optimizer misses unboxing opportunity

#2387: Optimizer misses unboxing opportunity -+-- Reporter: dolio |Owner: Type: run-time performance bug | Status: new Priority: normal

Re: [GHC] #2395: Pattern match(es) are overlapped warning with a single view pattern (ghc 6.9.20080606)

#2395: Pattern match(es) are overlapped warning with a single view pattern (ghc 6.9.20080606) -+-- Reporter: rwbarton |Owner: Type: bug | Status: new

Re: [GHC] #2396: Default class method not inlined

#2396: Default class method not inlined -+-- Reporter: sedillard |Owner: Type: run-time performance bug | Status: new Priority: normal

Re: [GHC] #2416: Optimization defeated by merging module into main

#2416: Optimization defeated by merging module into main ---+ Reporter: sedillard |Owner: Type: bug | Status: new Priority: normal |

Re: [GHC] #2422: Unrelated instance foils optimizer

#2422: Unrelated instance foils optimizer --+- Reporter: sedillard |Owner: Type: bug| Status: new Priority: normal |Milestone: 6.12 branch Component:

Re: [GHC] #2428: bad error message for multiple modules in the same file

#2428: bad error message for multiple modules in the same file -+-- Reporter: Isaac Dupree |Owner: Type: bug | Status: new Priority: normal

Re: [GHC] #2436: Bad warning when exporting data families

#2436: Bad warning when exporting data families -+-- Reporter: rl|Owner: chak Type: bug | Status: new Priority: normal|

Re: [GHC] #2440: Bad code with type families

#2440: Bad code with type families -+-- Reporter: rl|Owner: Type: run-time performance bug | Status: new Priority: normal

Re: [GHC] #2443: @EnableWin32DLLs@ in mk/config.mk

#2443: @EnableWin32DLLs@ in mk/config.mk -+-- Reporter: rurban|Owner: rurban Type: bug | Status: assigned Priority: normal|Milestone: 6.12

Re: [GHC] #2455: Building ticky-ticky profiling libraries doesn't work

#2455: Building ticky-ticky profiling libraries doesn't work -+-- Reporter: tim |Owner: tim Type: task | Status: new Priority: normal

Re: [GHC] #2466: Execution time mis-accounting

#2466: Execution time mis-accounting --+- Reporter: heatsink |Owner: Type: bug| Status: new Priority: normal |Milestone: 6.12 branch Component:

Re: [GHC] #2476: internal error: awaitEvent: descriptor out of range

#2476: internal error: awaitEvent: descriptor out of range ---+ Reporter: newsham |Owner: Type: bug | Status: new Priority: normal |

Re: [GHC] #2500: Unrecognised pragma complained about twice

#2500: Unrecognised pragma complained about twice -+-- Reporter: simonpj |Owner: Type: bug | Status: new Priority: normal|

Re: [GHC] #2507: quotation characters in error messages

#2507: quotation characters in error messages -+-- Reporter: Isaac Dupree |Owner: Type: feature request | Status: new Priority: normal|

Re: [GHC] #2514: Add/Expose Binary API that allows dumping of any GHC Binary instance

#2514: Add/Expose Binary API that allows dumping of any GHC Binary instance -+-- Reporter: nominolo |Owner: nominolo Type: feature request | Status: new

Re: [GHC] #2531: Prune duplicates in ghci history

#2531: Prune duplicates in ghci history -+-- Reporter: venkat|Owner: Type: feature request | Status: new Priority: normal|

Re: [GHC] #2986: :info printing instances often isn't wanted

#2986: :info printing instances often isn't wanted -+-- Reporter: Remi |Owner: Type: feature request | Status: new Priority: normal|

Re: [GHC] #2933: LDFLAGS ignored by build system

#2933: LDFLAGS ignored by build system -+-- Reporter: duncan|Owner: Type: bug | Status: new Priority: normal|Milestone: 6.12

Re: [GHC] #2924: createDirectory: permission denied

#2924: createDirectory: permission denied +--- Reporter: simonmar |Owner: Type: bug | Status: new Priority: normal |

Re: [GHC] #2921: __GLASGOW_HASKELL__ undefined

#2921: __GLASGOW_HASKELL__ undefined -+-- Reporter: guest |Owner: Type: bug | Status: closed Priority: normal|Milestone:

Re: [GHC] #2831: Floated error expressions get poor strictness, leaving bad arity

#2831: Floated error expressions get poor strictness, leaving bad arity -+-- Reporter: simonpj |Owner: Type: run-time performance bug | Status: new

Re: [GHC] #2828: TcTyFuns.uMeta: normalisation shouldn't allow x ~ x

#2828: TcTyFuns.uMeta: normalisation shouldn't allow x ~ x -+-- Reporter: pizza |Owner: chak Type: bug | Status: new Priority: normal|Milestone: 6.12 branch

Re: [GHC] #2805: Test ffi009(ghci) fails on PPC Mac OS X

#2805: Test ffi009(ghci) fails on PPC Mac OS X -+-- Reporter: thorkilnaur |Owner: Type: bug | Status: new Priority: normal|Milestone: 6.12 branch

Re: [GHC] #2791: Allow two versions of GHC to be installed simultaneously with the OS X installer

#2791: Allow two versions of GHC to be installed simultaneously with the OS X installer -+-- Reporter: igloo |Owner: Type: bug | Status: new

Re: [GHC] #2682: Keep going after failed search for module in current directory

#2682: Keep going after failed search for module in current directory -+-- Reporter: ajd |Owner: Type: bug | Status: new Priority:

Re: [GHC] #2677: Detection of TF instance conflict depends on instance order

#2677: Detection of TF instance conflict depends on instance order +--- Reporter: reinerp |Owner: chak Type: bug | Status: new

Re: [GHC] #2120: Arrays allow out-of-bounds indexes

#2120: Arrays allow out-of-bounds indexes --+- Reporter: amthrax|Owner: Type: bug| Status: new Priority: normal |

Re: [GHC] #2669: index out of range error message regression

#2669: index out of range error message regression -+-- Reporter: claus |Owner: Type: bug | Status: new Priority: normal|

Re: [GHC] #2664: type family + data family + typeclass + type error causes GHC to diverge

#2664: type family + data family + typeclass + type error causes GHC to diverge -+-- Reporter: ryani |Owner: chak Type: bug | Status: new

Re: [GHC] #2642: Improve SpecConstr for join points

#2642: Improve SpecConstr for join points -+-- Reporter: simonpj |Owner: Type: run-time performance bug | Status: new Priority: normal

Re: [GHC] #2611: print022 fails

#2611: print022 fails -+-- Reporter: igloo |Owner: mnislaih Type: bug | Status: assigned Priority: normal|Milestone: 6.12 branch

Re: [GHC] #2598: Avoid excessive specialisation in SpecConstr

#2598: Avoid excessive specialisation in SpecConstr -+-- Reporter: simonpj |Owner: Type: feature request | Status: new Priority: normal|

Re: [GHC] #2561: Using ITstring !FastString in Lexer.x goes wrong (internal error: stg_ap_v_ret)

#2561: Using ITstring !FastString in Lexer.x goes wrong (internal error: stg_ap_v_ret) -+-- Reporter: igloo |Owner: Type: bug | Status: new

Re: [GHC] #2559: Haddock: Prelude docs are missing Bool, Int, Integer

#2559: Haddock: Prelude docs are missing Bool, Int, Integer -+-- Reporter: simonmar |Owner: Type: bug | Status: new Priority: normal

Re: [GHC] #2552: SCC annotation behavior differs between toplevel and non-toplevel

#2552: SCC annotation behavior differs between toplevel and non-toplevel --+- Reporter: Rauli |Owner: Type: bug| Status: new Priority: normal

Re: [GHC] #2539: panic when using .o files from the wrong platform

#2539: panic when using .o files from the wrong platform -+-- Reporter: ajd |Owner: Type: bug | Status: new Priority: normal

Re: [GHC] #311: gmp's memory management

#311: gmp's memory management -+-- Reporter: as49 |Owner: Type: bug | Status: new Priority: low |Milestone: 6.12

Re: [GHC] #2881: Basic Fibonacci function using Word causes ghci to panic. - 6.10.1

#2881: Basic Fibonacci function using Word causes ghci to panic. - 6.10.1 -+-- Reporter: axman6|Owner: simonmar Type: bug | Status: new

Re: [GHC] #2275: Poor indication of type error location

#2275: Poor indication of type error location +--- Reporter: guest|Owner: Type: bug | Status: closed Priority: low

Re: [GHC] #2249: Undeclared variable in cmm reports as panic

#2249: Undeclared variable in cmm reports as panic ---+ Reporter: millenix|Owner: Type: bug | Status: new Priority: low |Milestone:

Re: [GHC] #2245: Numeric literal printed wrong in error message

#2245: Numeric literal printed wrong in error message -+-- Reporter: guest |Owner: Type: bug | Status: new Priority: low |Milestone: 6.12 branch

Re: [GHC] #2197: GHCi doesn't work when built with way=p

#2197: GHCi doesn't work when built with way=p -+-- Reporter: SamB |Owner: simonmar Type: bug | Status: new Priority: low |Milestone:

Re: [GHC] #2197: GHCi doesn't work when built with way=p

#2197: GHCi doesn't work when built with way=p -+-- Reporter: SamB |Owner: simonmar Type: bug | Status: new Priority: low |Milestone:

Re: [GHC] #1974: length foo doesn't work with -XOverloadedStrings

#1974: length foo doesn't work with -XOverloadedStrings -+-- Reporter: ganesh|Owner: Type: feature request | Status: new Priority: low

Re: [GHC] #1874: getDirectoryContents yields invalid argument instead of permission error

#1874: getDirectoryContents yields invalid argument instead of permission error -+-- Reporter: Orphi | Owner: Type: bug

Re: [GHC] #1826: unable to list source for exception thrown should never occur

#1826: unable to list source for exception thrown should never occur -+-- Reporter: guest |Owner: Type: feature request | Status: reopened Priority: low

Re: [GHC] #1799: Retain export-list order in ModIface, use it in :browse

#1799: Retain export-list order in ModIface, use it in :browse -+-- Reporter: guest |Owner: Type: bug | Status: new Priority: low

Re: [GHC] #1792: -ddump-minimal-imports breaks qualified imports (import...as)

#1792: -ddump-minimal-imports breaks qualified imports (import...as) -+-- Reporter: guest |Owner: Type: bug | Status: new Priority: low

Re: [GHC] #1666: -Werror aborts too early

#1666: -Werror aborts too early -+-- Reporter: simonmar |Owner: Type: bug | Status: new Priority: low |Milestone: 6.12

Re: [GHC] #1532: Implicit parameters are not available in breakpoints

#1532: Implicit parameters are not available in breakpoints -+-- Reporter: mnislaih |Owner: Type: feature request | Status: new Priority: low

Re: [GHC] #1381: Add terminateStmt to GHC as a library

#1381: Add terminateStmt to GHC as a library -+-- Reporter: guest |Owner: Type: feature request | Status: new Priority: low |

Re: [GHC] #437: Recompilation check should include flags

#437: Recompilation check should include flags -+-- Reporter: simonpj |Owner: Type: bug | Status: new Priority: low |

Re: [GHC] #670: External Core is broken

#670: External Core is broken -+-- Reporter: KirstenChevalier |Owner: tim Type: bug | Status: assigned Priority: low |Milestone: 6.12

Re: [GHC] #1259: Accessing undefined value in DiffArray returns misleading error message

#1259: Accessing undefined value in DiffArray returns misleading error message -+-- Reporter: guest |Owner: Type: bug | Status: new

Re: [GHC] #714: Inconsistency between handling functional dependencies in class and signature constraints

#714: Inconsistency between handling functional dependencies in class and signature constraints +--- Reporter: claus.rei...@talk21.com |Owner: simonpj Type: bug |

Re: [GHC] #698: GHC's internal memory allocator never releases memory back to the OS

#698: GHC's internal memory allocator never releases memory back to the OS -+-- Reporter: guest |Owner: igloo Type: bug | Status: new

Re: [GHC] #2211: Installing latest GHC-6.8.2 stable: pwd with floating point exception

#2211: Installing latest GHC-6.8.2 stable: pwd with floating point exception -+-- Reporter: guest |Owner: Type: bug | Status: reopened

Re: [GHC] #3003: Happy does not reject pragmas

#3003: Happy does not reject pragmas -+-- Reporter: SamB |Owner: Type: bug | Status: new Priority: normal|Milestone:

Re: [GHC] #3005: Normalize fully-applied type functions prior to display

#3005: Normalize fully-applied type functions prior to display -+-- Reporter: dmcclean |Owner: chak Type: feature request | Status: new Priority: normal

Re: [GHC] #3005: Normalize fully-applied type functions prior to display

#3005: Normalize fully-applied type functions prior to display -+-- Reporter: dmcclean |Owner: chak Type: feature request | Status: new Priority: normal

Re: [GHC] #3007: GHC seems to ignore the package name of modules imported with {#- SOURCE #-}

#3007: GHC seems to ignore the package name of modules imported with {#- SOURCE #-} ---+ Reporter: jeltsch |Owner: Type: bug | Status: new Priority: normal

Re: [GHC] #3011: ASSERT failed: file typecheck/TcMType.lhs line 526 t_a32G{tv}

#3011: ASSERT failed: file typecheck/TcMType.lhs line 526 t_a32G{tv} +--- Reporter: batterseapower |Owner: Type: bug | Status: new

Re: [GHC] #3012: A little deriving for GADTs

#3012: A little deriving for GADTs -+-- Reporter: guest |Owner: Type: feature request | Status: new Priority: normal|Milestone:

Re: [GHC] #3008: Strange behavior when using newtyped version of IO monad in FFI import declarations

#3008: Strange behavior when using newtyped version of IO monad in FFI import declarations ---+ Reporter: waern |Owner: Type: bug | Status: new

Re: [GHC] #3013: New simple GADT feature

#3013: New simple GADT feature -+-- Reporter: guest |Owner: Type: feature request | Status: new Priority: normal|Milestone: 6.12.1

Re: [GHC] #3015: Building packages using ghc (6.8.2) results in inconsistent error assembler messages

#3015: Building packages using ghc (6.8.2) results in inconsistent error assembler messages ---+ Reporter: akrohit |Owner: Type: bug | Status: new Priority:

where is ghcautoconf.h, DerivedConstants.h and GHCConstants.h

following wiki to make an unregistered build of ghc 6.6.1 on openbsd-powerpc-current target = powerpc_unknown_openbsd host= x86_64_unknown_linux with ghc-6.10.2 Copy T/includes/ghcautoconf.h, T/includes/DerivedConstants.h, and T/includes/GHCConstants.h to H/includes. Note that we are

[Haskell-cafe] Re: Types and hashes of hashes, trouble for a Java-programmer...

John Smith smithsno...@gmail.com wrote: Yes, I see. Good points in both answers, but I still would like to see how to do it with the mutable hash, if possible... test = do h - H.new (==) id h1 - H.new (==) id H.insert h 3 h1 H.insert h1 1 1000 inner - H.lookup h 3 case