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Diffstat (limited to 'compiler/GHC/Tc/Solver/Equality.hs')
| -rw-r--r-- | compiler/GHC/Tc/Solver/Equality.hs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/compiler/GHC/Tc/Solver/Equality.hs b/compiler/GHC/Tc/Solver/Equality.hs index 9b068e18e6..bdc15f4510 100644 --- a/compiler/GHC/Tc/Solver/Equality.hs +++ b/compiler/GHC/Tc/Solver/Equality.hs @@ -1843,6 +1843,9 @@ Wrinkles: and unifying alpha effectively promotes this wanted to a given. Doing so means we lose track of the rewriter set associated with the wanted. + In short: we must not have a co_hole in a Given, and unification + effectively makes a Given + On the other hand, w is perfectly suitable for rewriting, because of the way we carefully track rewriter sets. |