I shouldn't have to modify PrelNames since I kept GHC.Integer.Type, no? Or does PrelNames have to contain the name of the module that originally defined the type? Looking in the .hi file in question (the one for GHC.Integer.Type) I can see both the export of Integer(..) and the import of Integer(..) from GHC.Integer.GMP.Types. On Thu, Aug 18, 2011 at 6:10 PM, Simon Peyton-Jones wrote:

My guess is that you have not updated compiler/prelude/PrelNames, which contains wired-in knowledge of which modules certain functions and data types live in.  Check the ones you've moved!

S

| -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users- | bounces@haskell.org] On Behalf Of Johan Tibell | Sent: 18 August 2011 15:45 | To: glasgow-haskell-users | Subject: Can't find interface-file declaration for type constructor or class integer- | gmp:GHC.Integer.Type.Integer | | I'm trying to refactor the integer-gmp package to fix the breakage | explained in #5384. During the refactoring I | | * moved GHC.Integer.Type to GHC.Integer.GMP.Type, and | * added a new GHC.Integer.Type module that re-exports parts of the | interface now exposed by GHC.Integer.GMP.Type | | The content of GHC.Integer.Type is just: | | {-# LANGUAGE NoImplicitPrelude #-} | {-# OPTIONS_HADDOCK hide #-} | | -- If you change the module name or the export list you must update | -- compiler/prelude/PrelNames.lhs. | module GHC.Integer.Type ( |       Integer(..) |     , plusInteger |     , timesInteger |     , smallInteger |     , integerToWord |     , integerToInt |     , minusInteger |     , negateInteger |     , eqInteger |     , neqInteger |     , absInteger |     , signumInteger |     , leInteger |     , gtInteger |     , ltInteger |     , geInteger |     , compareInteger |     , gcdInteger |     , lcmInteger |     , andInteger |     , orInteger |     , xorInteger |     , complementInteger |     , shiftLInteger |     , shiftRInteger |     ) where | | import GHC.Integer.GMP.Type | | GHC doesn't seem to like this at all. It can no longer find the | GHC.Integer.Type.Integer type: | | $ "inplace/bin/ghc-stage1"   -H64m -O -fasm    -package-name | base-4.4.0.0 -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-0.3.0.0 -package rts-1.0 | -package-name base -XHaskell98 -XCPP -O -dcore-lint | -no-user-package-conf -rtsopts     -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/./Data/Maybe.hs -o | libraries/base/dist-install/build/Data/Maybe.o | | libraries/base/Data/Maybe.hs:70:13: |     Can't find interface-file declaration for type constructor or | class integer-gmp:GHC.Integer.Type.Integer |       Probable cause: bug in .hi-boot file, or inconsistent .hi file |       Use -ddump-if-trace to get an idea of which file caused the error |     When deriving the instance for (Eq (Maybe a)) | | Here's the -ddump-if-trace log: | | $ "inplace/bin/ghc-stage1"   -H64m -O -fasm    -package-name | base-4.4.0.0 -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-0.3.0.0 -package rts-1.0 | -package-name base -XHaskell98 -XCPP -O -dcore-lint | -no-user-package-conf -rtsopts     -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/./Data/Maybe.hs -o | libraries/base/dist-install/build/Data/Maybe.o -ddump-if-trace | FYI: cannont read old interface file: |     libraries/base/dist-install/build/Data/Maybe.hi: openBinaryFile: | does not exist (No such file or directory) | Considering whether to load base:GHC.Base | Reading interface for base:GHC.Base; |     reason: GHC.Base is directly imported | readIFace libraries/base/dist-install/build/GHC/Base.hi | updating EPS_ | Considering whether to load ghc-prim:GHC.Generics | Reading interface for ghc-prim:GHC.Generics; |     reason: GHC.Generics is directly imported | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist- | install/build/GHC/Generics.hi | updating EPS_ | updating EPS_ | Considering whether to load base:GHC.Base {- SYSTEM -} | loadHiBootInterface base:Data.Maybe | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | Reading interface for ghc-prim:GHC.Types; |     reason: Checking fixity for : | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist- | install/build/GHC/Types.hi | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | Starting fork { Declaration for Monad | Loading decl for GHC.Base.Monad | updating EPS_ | buildClass | buildClass GHC.Base.T:Monad | } ending fork Declaration for Monad | Starting fork { Declaration for Functor | Loading decl for GHC.Base.Functor | updating EPS_ | buildClass | buildClass GHC.Base.T:Functor | } ending fork Declaration for Functor | tcImportDecl GHC.Classes.Eq | Need decl for GHC.Classes.Eq | Considering whether to load ghc-prim:GHC.Classes {- SYSTEM -} | Reading interface for ghc-prim:GHC.Classes; |     reason: Need decl for GHC.Classes.Eq | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist- | install/build/GHC/Classes.hi | updating EPS_ | Starting fork { Declaration for Eq | Loading decl for GHC.Classes.Eq | updating EPS_ | buildClass | buildClass GHC.Classes.T:Eq | } ending fork Declaration for Eq | Starting fork { Declaration for Ord | Loading decl for GHC.Classes.Ord | updating EPS_ | buildClass | buildClass GHC.Classes.T:Ord | } ending fork Declaration for Ord | Starting fork { Declaration for Generic | Loading decl for GHC.Generics.Generic | updating EPS_ | buildClass | buildClass GHC.Generics.T:Generic | } ending fork Declaration for Generic | Starting fork { Declaration for D1 | Loading decl for GHC.Generics.D1 | updating EPS_ | } ending fork Declaration for D1 | Starting fork { Declaration for C1 | Loading decl for GHC.Generics.C1 | updating EPS_ | } ending fork Declaration for C1 | Starting fork { Declaration for S1 | Loading decl for GHC.Generics.S1 | updating EPS_ | } ending fork Declaration for S1 | Starting fork { Declaration for NoSelector | Loading decl for GHC.Generics.NoSelector | updating EPS_ | tcIfaceDecl4 GHC.Generics.NoSelector | } ending fork Declaration for NoSelector | Starting fork { Declaration for Rec0 | Loading decl for GHC.Generics.Rec0 | updating EPS_ | } ending fork Declaration for Rec0 | Starting fork { Declaration for Par0 | Loading decl for GHC.Generics.Par0 | updating EPS_ | } ending fork Declaration for Par0 | Starting fork { Declaration for U1 | Loading decl for GHC.Generics.U1 | updating EPS_ | tcIfaceDecl4 GHC.Generics.U1 | } ending fork Declaration for U1 | Starting fork { Declaration for V1 | Loading decl for GHC.Generics.V1 | updating EPS_ | tcIfaceDecl4 GHC.Generics.V1 | } ending fork Declaration for V1 | Starting fork { Declaration for :+: | Loading decl for GHC.Generics.:+: | updating EPS_ | tcIfaceDecl4 GHC.Generics.:+: | } ending fork Declaration for :+: | Starting fork { Declaration for :*: | Loading decl for GHC.Generics.:*: | updating EPS_ | tcIfaceDecl4 GHC.Generics.:*: | } ending fork Declaration for :*: | Starting fork { Declaration for Datatype | Loading decl for GHC.Generics.Datatype | updating EPS_ | buildClass | buildClass GHC.Generics.T:Datatype | } ending fork Declaration for Datatype | Starting fork { Declaration for Constructor | Loading decl for GHC.Generics.Constructor | updating EPS_ | buildClass | buildClass GHC.Generics.T:Constructor | } ending fork Declaration for Constructor | Starting fork { Declaration for Selector | Loading decl for GHC.Generics.Selector | updating EPS_ | buildClass | mkNewTyConRhs GHC.Generics.NTCo:T:Selector | buildClass GHC.Generics.T:Selector | } ending fork Declaration for Selector | Starting fork { Dict fun GHC.Classes.$fEq[] | Starting fork { Declaration for $fEq[] | Loading decl for GHC.Classes.$fEq[] | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEq[] | } ending fork Dict fun GHC.Classes.$fEq[] | Starting fork { Dict fun GHC.Classes.$fEqOrdering | Starting fork { Declaration for $fEqOrdering | Loading decl for GHC.Classes.$fEqOrdering | updating EPS_ | Need decl for GHC.Ordering.Ordering | Considering whether to load ghc-prim:GHC.Ordering {- SYSTEM -} | Reading interface for ghc-prim:GHC.Ordering; |     reason: Need decl for GHC.Ordering.Ordering | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist- | install/build/GHC/Ordering.hi | updating EPS_ | } ending fork Declaration for $fEqOrdering | } ending fork Dict fun GHC.Classes.$fEqOrdering | Starting fork { Declaration for Ordering | Loading decl for GHC.Ordering.Ordering | updating EPS_ | tcIfaceDecl4 GHC.Ordering.Ordering | } ending fork Declaration for Ordering | Starting fork { Dict fun GHC.Classes.$fEqInt | Starting fork { Declaration for $fEqInt | Loading decl for GHC.Classes.$fEqInt | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEqInt | } ending fork Dict fun GHC.Classes.$fEqInt | Starting fork { Dict fun GHC.Classes.$fEqFloat | Starting fork { Declaration for $fEqFloat | Loading decl for GHC.Classes.$fEqFloat | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEqFloat | } ending fork Dict fun GHC.Classes.$fEqFloat | Starting fork { Dict fun GHC.Classes.$fEqFixity | Starting fork { Declaration for $fEqFixity | Loading decl for GHC.Classes.$fEqFixity | updating EPS_ | } ending fork Declaration for $fEqFixity | } ending fork Dict fun GHC.Classes.$fEqFixity | Starting fork { Declaration for Fixity | Loading decl for GHC.Generics.Fixity | updating EPS_ | tcIfaceDecl4 GHC.Generics.Fixity | } ending fork Declaration for Fixity | Starting fork { Dict fun GHC.Classes.$fEqDouble | Starting fork { Declaration for $fEqDouble | Loading decl for GHC.Classes.$fEqDouble | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEqDouble | } ending fork Dict fun GHC.Classes.$fEqDouble | Starting fork { Dict fun GHC.Classes.$fEqChar | Starting fork { Declaration for $fEqChar | Loading decl for GHC.Classes.$fEqChar | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEqChar | } ending fork Dict fun GHC.Classes.$fEqChar | Starting fork { Dict fun GHC.Classes.$fEqBool | Starting fork { Declaration for $fEqBool | Loading decl for GHC.Classes.$fEqBool | updating EPS_ | Considering whether to load ghc-prim:GHC.Types {- SYSTEM -} | } ending fork Declaration for $fEqBool | } ending fork Dict fun GHC.Classes.$fEqBool | Starting fork { Dict fun GHC.Classes.$fEqAssociativity | Starting fork { Declaration for $fEqAssociativity | Loading decl for GHC.Classes.$fEqAssociativity | updating EPS_ | } ending fork Declaration for $fEqAssociativity | } ending fork Dict fun GHC.Classes.$fEqAssociativity | Starting fork { Declaration for Associativity | Loading decl for GHC.Generics.Associativity | updating EPS_ | tcIfaceDecl4 GHC.Generics.Associativity | } ending fork Declaration for Associativity | Starting fork { Dict fun GHC.Classes.$fEqArity | Starting fork { Declaration for $fEqArity | Loading decl for GHC.Classes.$fEqArity | updating EPS_ | } ending fork Declaration for $fEqArity | } ending fork Dict fun GHC.Classes.$fEqArity | Starting fork { Declaration for Arity | Loading decl for GHC.Generics.Arity | updating EPS_ | tcIfaceDecl4 GHC.Generics.Arity | } ending fork Declaration for Arity | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | Reading interface for ghc-prim:GHC.Tuple; |     reason: Need home interface for wired-in thing (,,,,,,,,,,,,,,) | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist- | install/build/GHC/Tuple.hi | updating EPS_ | } ending fork Declaration for $fEq(,,,,,,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,,) | Starting fork { Declaration for $fEq(,,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,,) | Starting fork { Declaration for $fEq(,,,,,) | Loading decl for GHC.Classes.$fEq(,,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,,) | Starting fork { Declaration for $fEq(,,,,) | Loading decl for GHC.Classes.$fEq(,,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,,) | Starting fork { Declaration for $fEq(,,,) | Loading decl for GHC.Classes.$fEq(,,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,,) | } ending fork Dict fun GHC.Classes.$fEq(,,,) | Starting fork { Dict fun GHC.Classes.$fEq(,,) | Starting fork { Declaration for $fEq(,,) | Loading decl for GHC.Classes.$fEq(,,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,,) | } ending fork Dict fun GHC.Classes.$fEq(,,) | Starting fork { Dict fun GHC.Classes.$fEq(,) | Starting fork { Declaration for $fEq(,) | Loading decl for GHC.Classes.$fEq(,) | updating EPS_ | Considering whether to load ghc-prim:GHC.Tuple {- SYSTEM -} | } ending fork Declaration for $fEq(,) | } ending fork Dict fun GHC.Classes.$fEq(,) | Starting fork { Dict fun GHC.Classes.$fEq() | Starting fork { Declaration for $fEq() | Loading decl for GHC.Classes.$fEq() | updating EPS_ | Considering whether to load ghc-prim:GHC.Unit {- SYSTEM -} | Reading interface for ghc-prim:GHC.Unit; |     reason: Need home interface for wired-in thing () | readIFace /usr/local/google/src/ghc/libraries/ghc-prim/dist-install/build/GHC/Unit.hi | updating EPS_ | } ending fork Declaration for $fEq() | } ending fork Dict fun GHC.Classes.$fEq() | tcImportDecl GHC.Integer.Type.Integer | Need decl for GHC.Integer.Type.Integer | Considering whether to load integer-gmp:GHC.Integer.Type {- SYSTEM -} | Reading interface for integer-gmp:GHC.Integer.Type; |     reason: Need decl for GHC.Integer.Type.Integer | readIFace /usr/local/google/src/ghc/libraries/integer-gmp/dist- | install/build/GHC/Integer/Type.hi | updating EPS_ | | libraries/base/Data/Maybe.hs:70:13: |     Can't find interface-file declaration for type constructor or | class integer-gmp:GHC.Integer.Type.Integer |       Probable cause: bug in .hi-boot file, or inconsistent .hi file |       Use -ddump-if-trace to get an idea of which file caused the error |     When deriving the instance for (Eq (Maybe a)) | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

On Thu, Aug 18, 2011 at 7:07 PM, Simon Peyton-Jones wrote:

| I shouldn't have to modify PrelNames since I kept GHC.Integer.Type, | no? Or does PrelNames have to contain the name of the module that | originally defined the type?

Yes, exactly!

This causes some trouble though, as the module named in PrelNames must exist in both in integer-gmp and integer-simple i.e. it must be some generic name like GHC.Integer.Type rather than a name containing e.g. GMP. I could keep the data type definition where it is (GHC.Integer.Type) but then I would have a hard time exporting it from e.g. GHC.Integer.GMP.Internals without undoing Ian's patch which removed the slightly odd GHC.Integer -> GHC.Integer.GMP.Internals -> GHC.Integer.Type module dependency in integer-gmp.

On Thu, Aug 18, 2011 at 7:32 PM, Daniel Fischer wrote:

On Thursday 18 August 2011, 19:13:45, Johan Tibell wrote:

...

On Thu, Aug 18, 2011 at 7:07 PM, Simon Peyton-Jones

wrote:

...

| I shouldn't have to modify PrelNames since I kept GHC.Integer.Type, | no? Or does PrelNames have to contain the name of the module that | originally defined the type?

Yes, exactly!

This causes some trouble though, as the module named in PrelNames must exist in both in integer-gmp and integer-simple i.e. it must be some generic name like GHC.Integer.Type

GHC.Integer.Impl.Type ?

The problem is that we wan't to export the GMP specific constructors under something like GHC.Integer.GMP.Something, but that introduces a conceptually weird (according to Ian's patch) module dependency.

These two parallel discussions are getting a bit confusing so I suggest we continue the discussion on the ticket. :) On Fri, Aug 19, 2011 at 12:39 AM, Simon Peyton-Jones wrote:

It's hard to know what Ian had in mind, but I'm sure he'll tell us when he gets back from holiday.

Meanwhile, yes, it is hard to reconcile * The wish to have multiple implementations of Integer * The wired-in knowledge that GHC has * The desire to have optimising rewrite rules in client libraries

I suggested one approach in the ticket earlier today; there might be others.  It might be good to figure out a good design before going much further into implementation.

Simon

|  -----Original Message----- |  From: Johan Tibell [mailto:johan.tibell@gmail.com] |  Sent: 18 August 2011 18:14 |  To: Simon Peyton-Jones |  Cc: glasgow-haskell-users |  Subject: Re: Can't find interface-file declaration for type constructor or class |  integer-gmp:GHC.Integer.Type.Integer | |  On Thu, Aug 18, 2011 at 7:07 PM, Simon Peyton-Jones |   wrote: |  > | I shouldn't have to modify PrelNames since I kept GHC.Integer.Type, |  > | no? Or does PrelNames have to contain the name of the module that |  > | originally defined the type? |  > |  > Yes, exactly! | |  This causes some trouble though, as the module named in PrelNames must |  exist in both in integer-gmp and integer-simple i.e. it must be some |  generic name like GHC.Integer.Type rather than a name containing e.g. |  GMP. I could keep the data type definition where it is |  (GHC.Integer.Type) but then I would have a hard time exporting it from |  e.g. GHC.Integer.GMP.Internals without undoing Ian's patch which |  removed the slightly odd GHC.Integer -> GHC.Integer.GMP.Internals -> |  GHC.Integer.Type module dependency in integer-gmp.

That sounds like another reason to keep things as they were. The benefits of moving things around are internal to the package while the downsides are external (breaking packages). On Fri, Aug 19, 2011 at 11:09 AM, Lennart Augustsson wrote:

Also beware that Typeable uses the original names of types, which means that moving basic types around totally wrecks backwards compatibility for those of us who use the type name for serialization etc.

  -- Lennart (iPhone)

On Aug 19, 2011, at 11:00, Johan Tibell wrote:

...

These two parallel discussions are getting a bit confusing so I suggest we continue the discussion on the ticket. :)

On Fri, Aug 19, 2011 at 12:39 AM, Simon Peyton-Jones wrote:

...

It's hard to know what Ian had in mind, but I'm sure he'll tell us when he gets back from holiday.

Meanwhile, yes, it is hard to reconcile * The wish to have multiple implementations of Integer * The wired-in knowledge that GHC has * The desire to have optimising rewrite rules in client libraries

I suggested one approach in the ticket earlier today; there might be others.  It might be good to figure out a good design before going much further into implementation.

Simon

|  -----Original Message----- |  From: Johan Tibell [mailto:johan.tibell@gmail.com] |  Sent: 18 August 2011 18:14 |  To: Simon Peyton-Jones |  Cc: glasgow-haskell-users |  Subject: Re: Can't find interface-file declaration for type constructor or class |  integer-gmp:GHC.Integer.Type.Integer | |  On Thu, Aug 18, 2011 at 7:07 PM, Simon Peyton-Jones |   wrote: |  > | I shouldn't have to modify PrelNames since I kept GHC.Integer.Type, |  > | no? Or does PrelNames have to contain the name of the module that |  > | originally defined the type? |  > |  > Yes, exactly! | |  This causes some trouble though, as the module named in PrelNames must |  exist in both in integer-gmp and integer-simple i.e. it must be some |  generic name like GHC.Integer.Type rather than a name containing e.g. |  GMP. I could keep the data type definition where it is |  (GHC.Integer.Type) but then I would have a hard time exporting it from |  e.g. GHC.Integer.GMP.Internals without undoing Ian's patch which |  removed the slightly odd GHC.Integer -> GHC.Integer.GMP.Internals -> |  GHC.Integer.Type module dependency in integer-gmp.

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