Interaction between ORF and record pattern synonyms needs to be resolved.

Currently the two extensions do not work well together. When defining a record pattern synonym all field names must be distinct even with the extension turned on.

Trac metadata

Trac field	Value
Version	7.10.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	agundry
Operating system
Architecture

mentioned in issue #11227 (closed)

changed weight to 5

added Tbug Trac import labels

Trac metadata

Trac field	Value
Version	7.10.3 → 7.11

assigned to @adamgundry

I'll try to take another look at this soon.

(Sadly I didn't spot this ticket earlier, because I need to be CCd as adamgundry rather than agundry.)

Trac metadata

Trac field	Value
CC	agundry →

It turns out that trying to make use of duplicate fields belonging to pattern synonyms triggers a find_tycon panic, similar to #9975 (closed).

Trac metadata

Trac field	Value
Related	- → #9975 (closed)

The panic was actually caused by the combination of pattern synonyms and DisambiguateRecordFields or RecordWildCards, without needing DuplicateRecordFields. See #11283 (closed).

The more general question of the interaction of DuplicateRecordFields and record pattern synonyms looks like it will be rather intricate. At the moment, record pattern synonym constructors and fields are not distinguished by the Avail or Parent types, but constructors and fields will need to be handled differently. This will require significant refactoring.

We need to track the pattern synonym to which a field belongs, so that we can disambiguate fields properly. This doesn't even require DuplicateRecordFields: merely using DisambiguateRecordFields fails when the constructor is a record pattern synonym. However, the pattern synonym isn't a "parent" for the field in the same way that a datatype is. And pattern synonyms have the added complexity of being able to be associated with arbitrary parent datatypes.

In addition, once DuplicateRecordFields is involved we need to keep track of the FieldLabelString separately from the Name when representing fields (e.g. in AvailTC or FldParent).

I'm not going to be able to address this in the near future.

Trac metadata

Trac field	Value
Related	#9975 (closed) → #9975 (closed), #11283 (closed)

mentioned in commit 4f69203d

mentioned in issue #12061 (closed)

mentioned in issue #12130 (closed)

mentioned in issue #14630 (closed)

added OverloadedRecordFields PatternSynonyms records labels

added Pnormal label

marked this issue as related to #17176 (closed)

mentioned in issue #17176 (closed)

unassigned @adamgundry

mentioned in issue #18452 (closed)