diff options
| author | Sebastian Graf <sebastian.graf@kit.edu> | 2020-01-17 17:16:04 +0100 |
|---|---|---|
| committer | Sebastian Graf <sebastian.graf@kit.edu> | 2020-01-29 15:24:16 +0100 |
| commit | c9eec9f6dba2596bc94eb78237a64cd06fd270cc (patch) | |
| tree | 4a25d1027618fba8b5071b2a9a032312c5c893d1 /compiler/simplCore/SimplUtils.lhs | |
| parent | 97d0b0a367e4c6a52a17c3299439ac7de129da24 (diff) | |
| download | haskell-wip/T17703.tar.gz | |
PmCheck: Record type constraints arising from existentials in `PmCoreCt`swip/T17703
In #17703 (a follow-up of !2192), we established that contrary to my
belief, type constraints arising from existentials in code like
```hs
data Ex where Ex :: a -> Ex
f _ | let x = Ex @Int 15 = case x of Ex -> ...
```
are in fact useful.
This commit makes a number of refactorings and improvements to comments,
but fundamentally changes `addCoreCt.core_expr` to record the type
constraint `a ~ Int` in addition to `x ~ Ex @a y` and `y ~ 15`.
Fixes #17703.
Diffstat (limited to 'compiler/simplCore/SimplUtils.lhs')
0 files changed, 0 insertions, 0 deletions