Context reduction stack overflow without undecidable instances
|Reported by:||guest||Owned by:|
|Keywords:||type family, termination||Cc:||oleg@…|
|Type of failure:||GHC rejects valid program||Difficulty:||Unknown|
|Test Case:||Blocked By:|
When using type families whose reduction surely terminates (and which are accepted without undecidable instances) GHC still seems to set the context stack reduction limit. See the included code.
The fixed limit on context stack size prevents us from doing type-level arithmetic on arbitrarily-sized type-level numerals.
If the context-size limit is applied whether undecidable instance
extension is used or not, one may wonder of the purpose of the
undecidable instance extension.
Change History (7)
Changed 3 years ago by guest
comment:5 Changed 4 months ago by nomeata
- Difficulty set to Unknown
- Resolution fixed deleted
- Status changed from closed to new