Re: [GHC] #3953: Misleading error message when quasiquoter not in scope
#3953: Misleading error message when quasiquoter not in scope ---+ Reporter: guest | Owner: Type: bug | Status: closed Priority: normal| Milestone: 6.14.1 Component: Compiler |Version: 6.12.1 Resolution: fixed | Keywords: Difficulty:| Os: Unknown/Multiple Testcase: quasiquotation/T3953 | Architecture: Unknown/Multiple Failure: None/Unknown | ---+ Changes (by igloo): * status: merge => closed * resolution: => fixed Comment: Merged. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3953#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] #3953: Misleading error message when quasiquoter not in scope
#3953: Misleading error message when quasiquoter not in scope
-+--
Reporter: guest |Owner:
Type: bug | Status: merge
Priority: normal|Milestone: 6.14.1
Component: Compiler | Version: 6.12.1
Keywords:| Difficulty:
Os: Unknown/Multiple | Testcase: quasiquotation/T3953
Architecture: Unknown/Multiple | Failure: None/Unknown
-+--
Changes (by simonpj):
* status: new => merge
* testcase: => quasiquotation/T3953
Comment:
Good point, thanks. Fixed by
{{{
Fri Apr 9 21:17:48 BST 2010 simo...@microsoft.com
* Fix Trac #3953: fail earlier when using a bogus quasiquoter
M ./compiler/typecheck/TcSplice.lhs -5 +7
}}}
Merge to 6.12.3.
Simon
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3953#comment:2>
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Re: [GHC] #3953: Misleading error message when quasiquoter not in scope (was: Misleading error message when quasiquoter not in scopennnnnnnnnn)
#3953: Misleading error message when quasiquoter not in scope -+-- Reporter: guest |Owner: Type: bug | Status: new Priority: normal|Milestone: 6.14.1 Component: Compiler | Version: 6.12.1 Keywords:| Difficulty: Os: Unknown/Multiple | Testcase: Architecture: Unknown/Multiple | Failure: None/Unknown -+-- Changes (by igloo): * milestone: => 6.14.1 Comment: Thanks for the report -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3953#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] #3953: Misleading error message when quasiquoter not in scopennnnnnnnnn
#3953: Misleading error message when quasiquoter not in scopenn
-+--
Reporter: guest | Owner:
Type: bug | Status: new
Priority: normal| Component: Compiler
Version: 6.12.1|Keywords:
Os: Unknown/Multiple |Testcase:
Architecture: Unknown/Multiple | Failure: None/Unknown
-+--
t.hs:
{{{
{-# LANGUAGE QuasiQuotes #-}
main = [$notDefinedHere| |]
}}}
ghc's output:
{{{
t.hs:2:7: Not in scope: `notDefinedHere'
t.hs:2:7:
GHC stage restriction: notDefinedHere
is used in a quasiquote, and must be imported, not defined locally
Failed, modules loaded: none.
}}}
The second message is wrong, since notDefinedHere isn't defined anywhere.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3953>
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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: closed Priority: normal|Milestone: 6.12 branch Component: libraries/base| Version: 6.6 Severity: normal| Resolution: invalid Keywords:| Difficulty: Easy (1 hr) Testcase:| Os: Unknown/Multiple Architecture: Unknown/Multiple | -+-- Changes (by igloo): * status: new => closed * resolution: => invalid Comment: diffarray is now in its own package. Ticket moved to here: http://trac.haskell.org/diffarray/ticket/1 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1259#comment:5> 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] #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 Priority: normal|Milestone: 6.12 branch Component: libraries/base| Version: 6.6 Severity: normal| Resolution: Keywords:| Difficulty: Easy (1 hr) Testcase:| Os: Unknown/Multiple Architecture: Unknown/Multiple | -+-- Changes (by igloo): * priority: low => normal * milestone: 6.10 branch => 6.12 branch Comment: Raising priority now that we have extensible exceptions. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1259#comment:4> 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] #2294: Misleading error message suggestion
#2294: Misleading error message suggestion
--+-
Reporter: NeilMitchell | Owner:
Type: bug | Status: closed
Priority: normal| Milestone:
Component: Compiler |Version: 6.8.2
Severity: normal| Resolution: fixed
Keywords:| Difficulty: Unknown
Testcase:| Architecture: Unknown
Os: Unknown |
--+-
Changes (by simonpj):
* status: new => closed
* difficulty: => Unknown
* resolution: => fixed
Comment:
I improved this a little while ago (HEAD only)
{{{
Foo1.hs:5:15:
Illegal operator `.' in type `forall a . (a -> a)'
Perhaps you intended to use -XRankNTypes or similar flag
}}}
I think this is what you were suggesting.
Simon
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[GHC] #2294: Misleading error message suggestion
#2294: Misleading error message suggestion
-+--
Reporter: NeilMitchell | Owner:
Type: bug | Status: new
Priority: normal| Component: Compiler
Version: 6.8.2 |Severity: normal
Keywords:|Testcase:
Architecture: Unknown | Os: Unknown
-+--
Given a rank-2 type, such as:
{{{
id :: forall a . a -> a
id x = x
}}}
The compiler complains:
{{{
Uniplate.hs:3:15:
Illegal operator `.' in type `forall a . (a -> a)'
(Use -XTypeOperators to allow operators in types)
}}}
Of course, people using {{{`.'}}} in a type signature are much more likely
to be aiming for {{{Rank2Types}}} - so perhaps in this one type operator
the suggestion should be towards rank-2 types.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2294>
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Re: [GHC] #2126: Misleading error message for newtype with no constructors
#2126: Misleading error message for newtype with no constructors -+-- Reporter: tim | Owner: igloo Type: merge| Status: closed Priority: normal | Milestone: Component: Compiler (Type checker) |Version: 6.8.1 Severity: trivial | Resolution: fixed Keywords: | Difficulty: Unknown Testcase: T2126| Architecture: Unknown Os: Unknown | -+-- Changes (by igloo): * status: new => closed * resolution: => fixed Comment: Merged -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2126#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] #2126: Misleading error message for newtype with no constructors
#2126: Misleading error message for newtype with no constructors
-+--
Reporter: tim | Owner: igloo
Type: merge| Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) |Version: 6.8.1
Severity: trivial | Resolution:
Keywords: | Difficulty: Unknown
Testcase: T2126| Architecture: Unknown
Os: Unknown |
-+--
Changes (by simonpj):
* testcase: => T2126
* difficulty: => Unknown
* type: bug => merge
* owner: => igloo
Comment:
Good point. Fixed by
{{{
Wed Feb 27 08:32:02 PST 2008 [EMAIL PROTECTED]
* Fix Trac #2126: re-order tests (easy)
}}}
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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2126#comment:1>
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[GHC] #2126: Misleading error message for newtype with no constructors
#2126: Misleading error message for newtype with no constructors
+---
Reporter: tim | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler (Type checker)
Version: 6.8.1|Severity: trivial
Keywords: |Testcase:
Architecture: Unknown | Os: Unknown
+---
Further adventures in error message pedantry! If I compile this module:
{{{
module Foo where
newtype X
}}}
I get:
{{{
$ ghc -c Foo.hs
Foo.hs:3:0:
`X' has no constructors (-XEmptyDataDecls permits this)
In the newtype declaration for `X'
}}}
Naively, I do what it suggests:
{{{
$ ghc -c Foo.hs -XEmptyDataDecls
Foo.hs:3:0:
A newtype must have exactly one constructor, but `X' has none
In the newtype declaration for `X'
}}}
It would be better to just print the second error message even when the
user doesn't pass {{{-XEmptyDataDecls}}}, and not lead them down a maze of
twisty little passages...
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2126>
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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
Priority: low |Milestone: 6.10
Component: libraries/base | Version: 6.6
Severity: normal | Resolution:
Keywords: | Difficulty: Easy (1 hr)
Os: Unknown | Testcase:
Architecture: Multiple|
---+
Changes (by igloo):
* milestone: => 6.10
Old description:
> Prelude> :m + Data.Array.Diff
> Prelude Data.Array.Diff> :t array
> array :: (Ix i, IArray a e) => (i, i) -> [(i, e)] -> a i e
> Prelude Data.Array.Diff> array (1,1) [] :: DiffArray Int Int
> array (1,1) [(1,*** Exception: MArray: undefined array element
>
> Since DiffArray isn't a MArray(it implements IArray), this is misleading.
> It should either say IArray or better DiffArray: undefined array element.
New description:
{{{
Prelude> :m + Data.Array.Diff
Prelude Data.Array.Diff> :t array
array :: (Ix i, IArray a e) => (i, i) -> [(i, e)] -> a i e
Prelude Data.Array.Diff> array (1,1) [] :: DiffArray Int Int
array (1,1) [(1,*** Exception: MArray: undefined array element
}}}
Since DiffArray isn't a MArray(it implements IArray), this is misleading.
It should either say IArray or better DiffArray: undefined array element.
Comment:
I think the right way to fix this is to wait until we have extensible
exceptions, so MArray throws a structured exception. DiffArray can then
s/MArray/DiffArray/ without having to duplicate all the checks.
As such, it's probably something for 6.10.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1259>
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[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 Priority: low | Milestone: Component: libraries/base | Version: 6.6 Severity: normal |Keywords: Difficulty: Easy (1 hr) |Testcase: Architecture: Multiple| Os: Unknown ---+ Prelude> :m + Data.Array.Diff Prelude Data.Array.Diff> :t array array :: (Ix i, IArray a e) => (i, i) -> [(i, e)] -> a i e Prelude Data.Array.Diff> array (1,1) [] :: DiffArray Int Int array (1,1) [(1,*** Exception: MArray: undefined array element Since DiffArray isn't a MArray(it implements IArray), this is misleading. It should either say IArray or better DiffArray: undefined array element. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1259> 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] #1237: misleading error message from cabal when versions differ
#1237: misleading error message from cabal when versions differ -+-- Reporter: guest| Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: None |Version: 6.7 Severity: minor| Resolution: invalid Keywords: | Difficulty: Unknown Testcase: | Architecture: Unknown Os: Unknown | -+-- Changes (by igloo): * resolution: => invalid * status: new => closed Comment: I've opened a bug for this on the Cabal trac: http://hackage.haskell.org/trac/hackage/ticket/120 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1237> 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] #1237: misleading error message from cabal when versions differ
#1237: misleading error message from cabal when versions differ +--- Reporter: guest| Owner: Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 6.7 Severity: minor|Keywords: Difficulty: Unknown |Testcase: Architecture: Unknown | Os: Unknown +--- Using cabal, I do './Setup.hs configure', './Setup.hs build', and 'sudo ./Setup.hs install'. Unfortunately, root's $PATH pointed to a different GHC (6.7 at some point, and not 6.4.2 which I was using), which resulted in the error message: Setup.hs: error reading ./.setup-config; run "setup configure" command? Of course, there was nothing wrong with .setup-config, so I spent some time investigating permissions, before int-e suggested that the search path was at fault. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1237> 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: Misleading error message
Turns out I'd already fixed this in my copy (still, alas, uncommitted). The error message is a bit better than before. Foo.hs:4: All of the type variable(s) in the constraint `C a' are already in scope At least one must be universally quantified here In the type signature for `op' | -Original Message- | From: Ralf Hinze [mailto:[EMAIL PROTECTED]] | Sent: 24 February 2000 13:21 | To: [EMAIL PROTECTED] | Subject: Misleading error message | | | The following error message might be a bit misleading ;-) | | None of the type variable(s) in the constraint `C a' | appears in the type `a -> b' | In the type signature for `op' | | Here is the source | | > class C a where | > op :: (C a) => a -> b | | which is not legal Haskell 98 (cf page 45: "the cx_i may not | constrain u"). | | BTW Hugs 98 silently accepts the program. | | Cheers, Ralf |
Misleading error message
The following error message might be a bit misleading ;-) None of the type variable(s) in the constraint `C a' appears in the type `a -> b' In the type signature for `op' Here is the source > class C a where > op :: (C a) => a -> b which is not legal Haskell 98 (cf page 45: "the cx_i may not constrain u"). BTW Hugs 98 silently accepts the program. Cheers, Ralf
Re: Misleading error message
Simon, > Thanks for the suggestion. Is this better? Yes, definitely. Thanks very much. So, you also suppressed the modules names (`PrelBase' etc)? That's also a good idea, I think, especially to avoid confusing new users. Manuel > Foo.hs:8: > Couldn't match the type `()' against `[aVG]' > Expected: () > Inferred: [aVG] > In the second argument of `:', namely `()' > In a "case" branch: [] -> 1 : () > > Foo.hs:3: > Couldn't match the type `(aVR, aVU)' against `[aVZ]' > Expected: [aVZ] > Inferred: (aVQ, aVT) > In the scrutinee of a case expression: [] > In the case expression: case [] of (a, b) -> 1 > In a pattern binding: test = case [] of (a, b) -> 1 > > > > I just encountered a misleading errors message produced > > during type checking of `case' expressions. Given the > > malformed program > > > > test = case [] of > >(a, b) -> 1 > > > > > > test2 = case [] of > >[] -> 1:() > > > > I get the following error messages > > > > bug.hs:8: Couldn't match the type `PrelBase.()' against `[taQI]' > > Expected: `PrelBase.()' > > Inferred: `[taQI]' > > In a "case" branch: `PrelBase.[]' -> `1 PrelBase.: PrelBase.()' > > In the case expression > > `case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' > > In a pattern binding: > > `test2 > >= case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' > > > > bug.hs:4: Couldn't match the type > > `PrelBase.[]' against `PrelTup.(,) oaQW' > > Expected: `(taQV, taQY)' > > Inferred: `[taQR]' > > In a "case" branch: (`a', `b') -> `1' > > In the case expression `case PrelBase.[] of (a, b) -> 1' > > In a pattern binding: `test = case PrelBase.[] of (a, b) -> 1' > > > > The first one, referring to `test2', is nice, but the second > > one, referring to `test' is misleading. It suggest (at > > least to me) that the mistake actually is in the case > > branch, whereas it is *between* the case branch and the > > scrutinized expression. In the program where I originally > > encountered the problem, the actual error was a missing > > argument in the scrutinized expression (and the case branch > > was correct). This may put users (especially, unexperienced > > ones) on the wrong track during debugging... > > > > Manuel
Re: Misleading error message
Manuel: Thanks for the suggestion. Is this better? Simon Foo.hs:8: Couldn't match the type `()' against `[aVG]' Expected: () Inferred: [aVG] In the second argument of `:', namely `()' In a "case" branch: [] -> 1 : () Foo.hs:3: Couldn't match the type `(aVR, aVU)' against `[aVZ]' Expected: [aVZ] Inferred: (aVQ, aVT) In the scrutinee of a case expression: [] In the case expression: case [] of (a, b) -> 1 In a pattern binding: test = case [] of (a, b) -> 1 > I just encountered a misleading errors message produced > during type checking of `case' expressions. Given the > malformed program > > test = case [] of > (a, b) -> 1 > > > test2 = case [] of > [] -> 1:() > > I get the following error messages > > bug.hs:8: Couldn't match the type `PrelBase.()' against `[taQI]' > Expected: `PrelBase.()' > Inferred: `[taQI]' > In a "case" branch: `PrelBase.[]' -> `1 PrelBase.: PrelBase.()' > In the case expression > `case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' > In a pattern binding: > `test2 > = case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' > > bug.hs:4: Couldn't match the type > `PrelBase.[]' against `PrelTup.(,) oaQW' > Expected: `(taQV, taQY)' > Inferred: `[taQR]' > In a "case" branch: (`a', `b') -> `1' > In the case expression `case PrelBase.[] of (a, b) -> 1' > In a pattern binding: `test = case PrelBase.[] of (a, b) -> 1' > > The first one, referring to `test2', is nice, but the second > one, referring to `test' is misleading. It suggest (at > least to me) that the mistake actually is in the case > branch, whereas it is *between* the case branch and the > scrutinized expression. In the program where I originally > encountered the problem, the actual error was a missing > argument in the scrutinized expression (and the case branch > was correct). This may put users (especially, unexperienced > ones) on the wrong track during debugging... > > Manuel
Misleading error message
I just encountered a misleading errors message produced during type checking of `case' expressions. Given the malformed program test = case [] of (a, b) -> 1 test2 = case [] of [] -> 1:() I get the following error messages bug.hs:8: Couldn't match the type `PrelBase.()' against `[taQI]' Expected: `PrelBase.()' Inferred: `[taQI]' In a "case" branch: `PrelBase.[]' -> `1 PrelBase.: PrelBase.()' In the case expression `case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' In a pattern binding: `test2 = case PrelBase.[] of PrelBase.[] -> 1 PrelBase.: PrelBase.()' bug.hs:4: Couldn't match the type `PrelBase.[]' against `PrelTup.(,) oaQW' Expected: `(taQV, taQY)' Inferred: `[taQR]' In a "case" branch: (`a', `b') -> `1' In the case expression `case PrelBase.[] of (a, b) -> 1' In a pattern binding: `test = case PrelBase.[] of (a, b) -> 1' The first one, referring to `test2', is nice, but the second one, referring to `test' is misleading. It suggest (at least to me) that the mistake actually is in the case branch, whereas it is *between* the case branch and the scrutinized expression. In the program where I originally encountered the problem, the actual error was a missing argument in the scrutinized expression (and the case branch was correct). This may put users (especially, unexperienced ones) on the wrong track during debugging... Manuel
