Re: Ambiguous occurence error, despite use of DuplicateRecordFields (worked with ghc 8.10.7, not with 9.6.4)
Han Joosten <[email protected]>
| Newsgroups | gmane.comp.lang.haskell.cafe |
|---|---|
| Message-ID | <CAKzCsfjKFXV2f=bVdawDnLqg79n0NVkEK9E9Kq7O2FN_1-Oigg@mail.gmail.com> |
I figured out to go for the easy way, not to figure out all the (fancy?) language pragma's. I will just rewrite the broken bits. Not hard to do, mostly annoying and less concise. I use stack to build. That way I know exactly the versions that will be used for each and every dependency. Thanks for helping out! Han. Op di 9 apr 2024 om 15:01 schreef Tom Ellis < [email protected]>: > By the way, how are you compiling this? I tried > > $ cabal build -w ghc-9.6 > > on branch upgrade-ghc but I get a cabal resolver error. > > Tom > > > On Tue, Apr 09, 2024 at 01:17:47PM +0100, Tom Ellis wrote: > > I see, thanks. So it does look like my wild guess was correct. GHC > > will no longer disambiguate ambiguous field selectors. Perhaps you're > > supposed to use OverloadedRecordDot for this (I'm not sure, I don't > > use it myself). > > > > On Tue, Apr 09, 2024 at 01:57:48PM +0200, Han Joosten wrote: > > > The code can be found here: > > > > https://github.com/AmpersandTarski/Ampersand/blob/upgrade-ghc/src/Ampersand/Core/ParseTree.hs > > > > > > The idea is that I have several data definitions each with a field > named > > > `pos`. I have a class that conveniently gets that field from whatever > > > instance. This used to work, but now is broken: > > > > > > data Foo = Foo > > > { pos :: !Origin, > > > ... other fields > > > } > > > data Bar = Bar > > > { pos :: !Origin, > > > ... other fields > > > } > > > > > > class Traced a where > > > origin :: a -> Origin > > > > > > instance Traced Foo where > > > origin = pos > > > > > > instance Traced Bar where > > > origin = pos > > > > > > Of course I could rewrite the instance definitions something like > > > > > > instance Traced Foo where > > > origin (Foo{pos = p} = p > > > > > > Op di 9 apr 2024 om 12:38 schreef Tom Ellis < > > > [email protected]>: > > > > Would it be possible to produce a minimal example that demonstrates > > > > the problem? Or at the very least share the code? It's very hard to > > > > know where to start diagnosing. (Although perhaps someone else knows > > > > without having to see code.) > > > > > > > > At a wild guess, have you been hit by this? > > > > > > > > > As of GHC 9.4.1, selector names have to be entirely unambiguous > > > > > (under the usual name resolution rules), while for record updates, > > > > > there must be at most one datatype that has all the field names > > > > > being updated. > > > > > > > > > https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/duplicate_record_fields.html#extension-DuplicateRecordFields > > > > > > > > On Tue, Apr 09, 2024 at 12:18:14PM +0200, Han Joosten wrote: > > > > > Hi all, > > > > > > > > > > I am currently migrating a Haskell project that uses ghc 8.10.7 to > ghc > > > > > 9.6.4. > > > > > > > > > > Using the new version, I get errors like > > > > > > > > > > ~~~.haskell > > > > > Ambiguous occurrence ‘pos’ > > > > > It could refer to > > > > > either the field ‘pos’ of record ‘PClassify’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:1265:5 > > > > > or the field ‘pos’ of record ‘PPurpose’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:1186:5 > > > > > or the field ‘pos’ of record ‘P_ViewSegment’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:1129:5 > > > > > or the field ‘pos’ of record ‘P_ViewD’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:1080:5 > > > > > or the field ‘pos’ of record ‘P_IdentDf’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:1024:5 > > > > > or the field ‘pos’ of record ‘P_BoxItem’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:981:9 > > > > > or the field ‘pos’ of record ‘TemplateKeyValue’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:959:5 > > > > > or the field ‘pos’ of record ‘BoxHeader’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:947:5 > > > > > or the field ‘pos’ of record ‘P_SubIfc’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:934:9 > > > > > or the field ‘pos’ of record ‘P_Interface’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:899:5 > > > > > or the field ‘pos’ of record ‘P_Population’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:870:9 > > > > > or the field ‘pos’ of record ‘P_Rule’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:806:5 > > > > > or the field ‘pos’ of record ‘PairViewSegment’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:740:9 > > > > > or the field ‘pos’ of record ‘P_NamedRel’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:591:5 > > > > > or the field ‘pos’ of record ‘PAtomPair’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:467:5 > > > > > or the field ‘pos’ of record ‘Pragma’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:415:5 > > > > > or the field ‘pos’ of record ‘P_Relation’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:408:5 > > > > > or the field ‘pos’ of record ‘Representation’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:339:5 > > > > > or the field ‘pos’ of record ‘PConceptDef’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:268:5 > > > > > or the field ‘pos’ of record ‘P_Pattern’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:209:5 > > > > > or the field ‘pos’ of record ‘Role’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:185:5 > > > > > or the field ‘pos’ of record ‘P_RoleRule’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:172:5 > > > > > or the field ‘pos’ of record ‘P_Enforce’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:152:5 > > > > > or the field ‘pos’ of record ‘MetaData’, > > > > > defined at > > > > > > /workspaces/AmpersandNamespace/src/Ampersand/Core/ParseTree.hs:136:5 > > > > > > > > > > Previously, it was totally fine to have different data types each > have a > > > > > field with the same name, as long as you used > `DuplicateRecordFields` > > > > > > > > > > I have searched the migration documentation but I couldn't find > any clue > > > > on > > > > > why this has been changed or how to deal with it. I probably > missed it. > > > > > Any help is mostly appreciated! > > > > > > > > > > Thanks for reading > > > > > Cheers, > > > > > Han Joosten > > > > > > > > > _______________________________________________ > > > > > Haskell-Cafe mailing list > > > > > To (un)subscribe, modify options or view archives go to: > > > > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > > > > > Only members subscribed via the mailman list are allowed to post. > > > > > > > > _______________________________________________ > > > > Haskell-Cafe mailing list > > > > To (un)subscribe, modify options or view archives go to: > > > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > > > > Only members subscribed via the mailman list are allowed to post. > > > > > _______________________________________________ > > > Haskell-Cafe mailing list > > > To (un)subscribe, modify options or view archives go to: > > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > > > Only members subscribed via the mailman list are allowed to post. > > > > _______________________________________________ > > Haskell-Cafe mailing list > > To (un)subscribe, modify options or view archives go to: > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > > Only members subscribed via the mailman list are allowed to post. > _______________________________________________ > Haskell-Cafe mailing list > To (un)subscribe, modify options or view archives go to: > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe > Only members subscribed via the mailman list are allowed to post. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.