diff options
Diffstat (limited to 'compiler/GHC/Tc/Solver.hs')
| -rw-r--r-- | compiler/GHC/Tc/Solver.hs | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/compiler/GHC/Tc/Solver.hs b/compiler/GHC/Tc/Solver.hs index 3ae3836624..6f783a6182 100644 --- a/compiler/GHC/Tc/Solver.hs +++ b/compiler/GHC/Tc/Solver.hs @@ -438,7 +438,7 @@ Our solution is this: We re-emit the implication rather than reporting the errors right now, -so that the error mesages are improved by other solving and defaulting. +so that the error messages are improved by other solving and defaulting. e.g. we prefer Cannot match 'Type->Type' with 'Type' to Cannot match 'Type->Type' with 'TYPE r0' @@ -1013,7 +1013,7 @@ We could do more than once but we'd have to have /some/ limit: in the the recursive case, we would go on forever in the common case where the constraints /are/ satisfiable (#10592 comment:12!). -For stratightforard situations without type functions the try_harder +For straightforward situations without type functions the try_harder step does nothing. Note [tcNormalise] @@ -1668,13 +1668,13 @@ We will ultimately quantify f over (Eq a, C a, <diff>), where At least for single functions we would like to quantify f over precisely the same theta as <quant-theta>, so that we get to take the short-cut path in GHC.Tc.Gen.Bind.mkExport, and avoid calling -tcSubTypeSigma for impedence matching. Why avoid? Because it falls +tcSubTypeSigma for impedance matching. Why avoid? Because it falls over for ambiguous types (#20921). We can get precisely the same theta by using the same algorithm, findInferredDiff. -All of this goes wrong if we have (a) mutual recursion, (b) mutiple +All of this goes wrong if we have (a) mutual recursion, (b) multiple partial type signatures, (c) with different constraints, and (d) ambiguous types. Something like f :: forall a. Eq a => F a -> _ @@ -1848,7 +1848,7 @@ defaultTyVarsAndSimplify rhs_tclvl mono_tvs candidates -- NB: only pass 'DefaultKindVars' when we know we're dealing with a kind variable. tv - -- this common case (no inferred contraints) should be fast + -- this common case (no inferred constraints) should be fast simplify_cand [] = return [] -- see Note [Unconditionally resimplify constraints when quantifying] simplify_cand candidates |