November 2015 - ghc-tickets

[GHC] #10900: Suggestions for improvement of the PatternSynonyms chapter in the User's Guide
by GHC 20 Nov '15

20 Nov '15

#10900: Suggestions for improvement of the PatternSynonyms chapter in the User's Guide -------------------------------------+------------------------------------- Reporter: thomie | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: | Version: 7.10.2 Documentation | Keywords: | Operating System: Unknown/Multiple PatternSynonms | Architecture: | Type of failure: Documentation Unknown/Multiple | bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- I read the chapter on PatternSynonyms recently. Seems like a very useful feature! Here are my notes, in the same spirit as #10140. == 7.3.9 == * This section starts with a nice example of how pattern synonyms can make some code much clearer. No problems sofar. > Note that in this example, the pattern synonyms Int and Arrow can also be > used as expressions (they are bidirectional). * How can a pattern (synonym) possibly be used as an expression. They seem such different concepts. You say "bidirectional", but what are the directions? You mentioned "constructor-like" before, maybe it's something like that? * This could use an example. * Is `Arrow Int Int` an example of using a pattern synonym as an expression? * What about `pattern Maybe t`, can it also be used as an expression? Why is this not mentioned? What is it doing there anyway, it's not used in either of the functions `collectArgs`, `isInt` and `isIntEndo`. > This is not necessarily the case: unidirectional pattern synonyms can also be > declared with the following syntax * Ok. > We can give an explicit inversion of a pattern synonym using the > following syntax * What does inverting a pattern synonym mean? * You mentioned unidirectional and bidirectional pattern synonyms. Can I invert both? {{{ pattern Head x <- x:xs where Head x = [x] }}} * Weird syntax. But what does it //do//? (I'm very confused now) == 7.3.9.1 == > Either prefix or infix syntax can be used. * I have no idea what this refers to. > For implicitly bidirectional pattern synonyms * This is the first time you mention the word "implicit". > For unidirectional and explicitly-bidirectional pattern synonyms * Ok, now it's getting clear. There seem to be 3 types of pattern synonyms. I wish you had said this earlier. (goes back to read from the beginning: ok I guess the first time you mentioned bidirectional patttern synonyms, they were the implicit ones, and the "explicit inversion" stuff with the weird syntax are the explicit ones.) == 7.3.9.2 == {{{ import Data.Maybe( pattern Just ) }}} * This doesn't compile. It turns out I need the PatternSynonyms extension in the importing module, even though you said in the beginning "it is required for defining them, but //not// for using them". * I later found #10653, so that explains it. Maybe mention that ticket. == 7.3.9.3 == > In the common case where CReq is empty, (), it can be omitted altogether. * Why is it more common for CReq to empty than for CProv to be empty? * What if CProv is empty, but CReq isn't? * What if both are empty, can they both be omitted? > so function f is rejected because the type signature is Maybe a * I tried this example, and f is not rejected at all. **Bug**? == 7.3.9.4 == > A pattern synonym occurrence in a pattern is evaluated by first matching > against the pattern synonym itself, and then on the argument patterns. * Should be "against the //rhs// of the pattern synonym" I think. * This is tricky stuff. Why is pattern synonym semantics not just defined as 'textual substitution'? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10900> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 9

[GHC] Batch modify: #11086, #11087, #11088, #11089, #11090
by GHC 19 Nov '15

19 Nov '15

Batch modification to #11086, #11087, #11088, #11089, #11090 by thomie: Action: resolve Comment: Duplicate of #11091, possibly from form resubmission. -- Tickets URL: <http://ghc.haskell.org/trac/ghc/query?id=11086%2C11087%2C11088%2C11089%2C11…> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

[GHC] #11110: GHCi documentation says ":show packages" gives a list of packages currently loaded
by GHC 19 Nov '15

19 Nov '15

#11110: GHCi documentation says ":show packages" gives a list of packages currently loaded -------------------------------------+------------------------------------- Reporter: massysett | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- GHC manual section 2.7, "GHCi commands", says that ":show packages" shows a list of packages currently loaded. When I run ":show packages" I never get such a list. All I get are package flags, which will report what packages are actually loaded only if GHCi was invoked with "-hide-all- packages". I do not know if the documentation is inaccurate, if GHCi is not doing something it should, or if I am not understanding what it means to "show a list of packages currently loaded". -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11110> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #11074: invalid fixup in runtime linker
by GHC 19 Nov '15

19 Nov '15

#11074: invalid fixup in runtime linker -------------------------------------+------------------------------------- Reporter: Qinka | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: invalid fixup | Operating System: Windows in runtime linker | Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I don't know what was happened, while I was trying to use PostgreSQL. And the following is what is displayed. {{{ Prelude Database.PostgreSQL.LibPQ Data.ByteString.Internal> connectdb "d" <interactive>: internal error: checkProddableBlock: invalid fixup in runtime linker: 000000000bec00e8 (GHC version 7.10.2 for x86_64_unknown_mingw32) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. }}} PS: I try to install some kinds of PostgreSQL's packages. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11074> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

Re: [GHC] #7660: warning: conflicting types when compiling via-C
by GHC 19 Nov '15

19 Nov '15

#7660: warning: conflicting types when compiling via-C -------------------------------------+------------------------------------- Reporter: singpolyma | Owner: hvr Type: bug | Status: patch Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: warning Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1506 Wiki Page: | -------------------------------------+------------------------------------- Changes (by hvr): * status: new => patch * differential: => Phab:D1506 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7660#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #7660: warning: conflicting types when compiling via-C
by GHC 19 Nov '15

19 Nov '15

#7660: warning: conflicting types when compiling via-C -------------------------------------+------------------------------------- Reporter: singpolyma | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: warning Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by hvr): * owner: => hvr -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7660#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #7660: warning: conflicting types when compiling via-C
by GHC 19 Nov '15

19 Nov '15

#7660: warning: conflicting types when compiling via-C -------------------------------------+------------------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: warning Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by hvr): Here's a minimal C fragment extracted from such a `.hc` file which triggers this warning: {{{#!c typedef void *(*(*StgFunPtr)(void))(void); extern StgFunPtr strlen(); }}} If the main purpose of this is to get a pointer to primitives such as `strlen`, then we can use `-fno-builtin` to fix this warning (works w/ clang & gcc). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7660#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

[GHC] #11073: GHC ASSERT when compiling Data.Sequences in the mono-traversable-0.10.0
by GHC 19 Nov '15

19 Nov '15

#11073: GHC ASSERT when compiling Data.Sequences in the mono-traversable-0.10.0 --------------------------------+--------------------------------------- Reporter: highfly | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Linux Architecture: arm | Type of failure: Compile-time crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------+--------------------------------------- GHC reports : {{{ [4 of 7] Compiling Data.Sequences ( src/Data/Sequences.hs, dist/build/Data/Sequences.o ) *** Parser: *** Renamer/typechecker: *** Deleting temp files: Deleting: /tmp/ghc12990_0/ghc_35.ll /tmp/ghc12990_0/ghc_1.hscpp Warning: deleting non-existent /tmp/ghc12990_0/ghc_35.ll *** Deleting temp dirs: Deleting: /tmp/ghc12990_0 ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for arm-unknown-linux): ASSERT failed! file compiler/typecheck/TcEvidence.hs line 597 Sym cobox_a2uDU Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11073> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2

[GHC] #11050: [bug] ModOrigin: hidden module redefined
by GHC 19 Nov '15

19 Nov '15

#11050: [bug] ModOrigin: hidden module redefined -------------------------------------+------------------------------------- Reporter: codeonwort | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.3 Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs 1 import Haste 2 import Haste.DOM 3 import Haste.Graphics.Canvas 4 import Control.Monad 5 6 mkCanvas width height = do 7 canvas <- newElem "canvas" 8 setProp canvas "width" $ show width 9 setProp canvas "height" $ show height 10 let conf = [("display", "block"), ("border", "1px solid black"), ("margin", "0px auto 0 aut o"), ("backgroundColor", "black")] 11 mapM_ (\(style, value) -> setStyle canvas style value) conf 12 return canvas 13 14 picture = fill $ rect (0, 0) (600, 600) 15 16 main = do 17 canv <- mkCanvas 600 600 18 addChild canv documentBody 19 Just canv <- getCanvas canv 20 render canv picture }}} ------------------------------------------------------------------------ hello.hs:18:3: Warning:hastec: hastec: panic! (the 'impossible' happened) (GHC version 7.10.2 for x86_64-unknown-linux): ModOrigin: hidden module redefined Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug ------------------------------------------------------------------------ I was following the tutorial on http://ifeanyi.co/posts/client-side- haskell/ and got this bug. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11050> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #11071: The "Not in scope" error is misleading
by GHC 19 Nov '15

19 Nov '15

#11071: The "Not in scope" error is misleading -------------------------------------+------------------------------------- Reporter: mojojojo | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- E.g., if I have something like `Maybe.maybeToList` in a module, which does not have such an import, I get the following error: Not in scope: ‘Maybe.maybeToList’ Which leads the user to conclude that the `Maybe` namespace does not contain the `maybeToList` element, instead of informing that the `Maybe` namespace is not imported altogether instead. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11071> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 18