January 2014 - ghc-tickets

[GHC] #8599: Deriving in associated data families
by GHC 10 Jan '14

10 Jan '14

#8599: Deriving in associated data families ------------------------------------+------------------------------------- Reporter: mojojojo | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This code {{{ class Class a where data DF a data family DF' a instance (Eq (DF' a)) => Class a where newtype DF a = DF (DF' a) deriving (Eq) }}} fails with {{{ No instance for (Eq (DF' a)) arising from the 'deriving' clause of a data type declaration Possible fix: add an instance declaration for (Eq (DF' a)) or use a standalone 'deriving instance' declaration, so you can specify the instance context yourself When deriving the instance for (Eq (DF a)) }}} The following way it compiles fine, however {{{ class Class a where data DF a data family DF' a instance Class a where newtype DF a = DF (DF' a) deriving instance (Eq (DF' a)) => Eq (DF a) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8599> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8630: Kind inference fails to account for associated types
by GHC 10 Jan '14

10 Jan '14

#8630: Kind inference fails to account for associated types -------------------------------------------+------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.7 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- Consider this: {{{ {-# LANGUAGE PolyKinds, TypeFamilies, FlexibleInstances #-} class C a where type F a instance C a where type F a = a -> a }}} HEAD gives me {{{ Expected a type, but ‛a’ has kind ‛k’ In the type ‛a -> a’ In the type instance declaration for ‛F’ In the instance declaration for ‛C a’ }}} The problem is that the use of `(->)` in the RHS of the definition for the `F a` instance constrains `a` to be of kind `*`, but GHC does not propagate this information back to the instance head. This decision is in conflict with the behavior for ''class'' declarations (as opposed to ''instance'' declarations), where a type variable's use in the definition informs its kind in the head. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8630> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7942: aarch64 support in ghc
by GHC 10 Jan '14

10 Jan '14

#7942: aarch64 support in ghc --------------------------------------------+--------------------------- Reporter: jcapik | Owner: kgardas Type: feature request | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Linux | Architecture: arm Type of failure: GHC doesn't work at all | Difficulty: Unknown Test Case: | Blocked By: 7623 Blocking: | Related Tickets: --------------------------------------------+--------------------------- Comment (by carter): no, -fvia-C still works, i know (because i broke it accidentaly early fall) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7942#comment:20> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8660: unexpected parsing error, "in" is treated as reserved word in type class constraints
by GHC 10 Jan '14

10 Jan '14

#8660: unexpected parsing error, "in" is treated as reserved word in type class constraints -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Parser) | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- I'm amidst writing a nice ffi binding to BLAS for ghc 7.6 and newer, and I hit an bizarre parser error when i had the follwoing type for a function transpose {{{ transposeMatrix :: (in ~ (Transpose out) , out ~ (Transpose in) ) => Matrix in elem -> Matrix out elem transposeMatrix (RowMajorMatrix x y stride arr)= (ColMajorMatrix x y stride arr) transposeMatrix (ColMajorMatrix x y stride arr) =(RowMajorMatrix x y stride arr) }}} {{{ src/Numerical/OpenBLAS/MatrixTypes.hs:83:21: parse error on input ‛in’ Failed, modules loaded: none. }}} i hit this error in GHC head I built this week AND with ghc 7.6 i'm pretty sure "in" shouldn't be a reserved word in types! If i rename "in" to "inor" the parser error goes away. if this is valid behavior, it'd be hepful to get a more precise parser error like "encountered reserved word "in", expected a variable" attaching the full module for your pleasure thanks! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8660> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8622: Importing modules in .ghci file doesn't not work
by GHC 10 Jan '14

10 Jan '14

#8622: Importing modules in .ghci file doesn't not work ----------------------------------+--------------------------------- Reporter: m4dc4p | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------- When attempting to import a module in the .ghci file, GHCi does not seem to use the search path. Define a module names "Macros.hs": {{{ module Macros where hello :: String -> IO String hello msg = return ("putStrLn " ++ show msg) }}} Now, in the same directory, create a .ghci file: {{{ import Macros :def hello hello }}} Run GHCi from that same directory, and you get an error: {{{ $ ghci GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. <no location info>: Could not find module `Macros' It is not a module in the current program, or in any known package. <interactive>:1:25: Not in scope: `hello' }}} It seems that GHCi should be able to find "Macros.hs", compile it, and all me to use it in defining macros. Adding the current directory (relative or absolute) to the search path (using -i) doesn't help. Why do I want to do this? I want to define GHCi macros in a separate module (that is not related to my program) and import them, rather than defining them directly in the .ghci file. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8622> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7942: aarch64 support in ghc
by GHC 10 Jan '14

10 Jan '14

#7942: aarch64 support in ghc --------------------------------------------+--------------------------- Reporter: jcapik | Owner: kgardas Type: feature request | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Linux | Architecture: arm Type of failure: GHC doesn't work at all | Difficulty: Unknown Test Case: | Blocked By: 7623 Blocking: | Related Tickets: --------------------------------------------+--------------------------- Comment (by kgardas): @carter: but -fvia-C is no longer supported, at least, https://ghc.haskell.org/trac/ghc/wiki/Building/Porting suggests that. So LLVM is the only way for AArch64 as we do not have NCG ready for this platform... -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7942#comment:19> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #393: functions without implementations
by GHC 10 Jan '14

10 Jan '14

#393: functions without implementations -------------------------------------+------------------------------------- Reporter: c_maeder | Owner: simonpj Type: feature request | Status: new Priority: normal | Milestone: _|_ Component: Compiler (Type | Version: None checker) | Keywords: Resolution: None | Architecture: Unknown/Multiple Operating System: Unknown/Multiple | Difficulty: Moderate (less Type of failure: None/Unknown | than a day) Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------- Comment (by jgallag8): Simonpj - Thanks very much for the advice. If I need more pointers, I'll let you know once I have become a little more familiar with the code base. Simonmar - Do you suggest the two be handled together? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/393#comment:18> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5791: Defer other kinds of errors until runtime, not just type errors
by GHC 10 Jan '14

10 Jan '14

#5791: Defer other kinds of errors until runtime, not just type errors -------------------------------------+------------------------------------ Reporter: simonmar | Owner: Type: task | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler | Version: 7.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: #5778 #393 -------------------------------------+------------------------------------ Changes (by nomeata): * related: 5778 => #5778 #393 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5791#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #393: functions without implementations
by GHC 10 Jan '14

10 Jan '14

#393: functions without implementations -------------------------------------+------------------------------------- Reporter: c_maeder | Owner: simonpj Type: feature request | Status: new Priority: normal | Milestone: _|_ Component: Compiler (Type | Version: None checker) | Keywords: Resolution: None | Architecture: Unknown/Multiple Operating System: Unknown/Multiple | Difficulty: Moderate (less Type of failure: None/Unknown | than a day) Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------- Comment (by simonmar): For what it's worth, this is part of #5791 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/393#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #393: functions without implementations
by GHC 10 Jan '14

10 Jan '14

#393: functions without implementations -------------------------------------+------------------------------------- Reporter: c_maeder | Owner: simonpj Type: feature request | Status: new Priority: normal | Milestone: _|_ Component: Compiler (Type | Version: None checker) | Keywords: Resolution: None | Architecture: Unknown/Multiple Operating System: Unknown/Multiple | Difficulty: Moderate (less Type of failure: None/Unknown | than a day) Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------- Comment (by simonpj): I suggest * A language extension flag `-XUndefinedFunctions` or something * In the renamer you'll have to arrange to create a binder for a signature that lacks a corresponding binding; and give an warning (rather than an error) for such signatures. * I suggest that you actually add the definition `f = error "Missing definition for f"` (or whatever) in the desugarer. GHC generally tries NOT to mess with the source code until desugaring, so that you can always show exactly what the user wrote. Happy to discuss when you get a bit further Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/393#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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