| Safe Haskell | None |
|---|---|
| Language | GHC2021 |
GHC.Tc.Solver.Rewrite
Synopsis
- rewrite :: CtEvidence -> TcType -> TcS (Reduction, RewriterSet)
- rewriteForErrors :: CtEvidence -> TcType -> TcS (Reduction, RewriterSet)
- rewriteArgsNom :: CtEvidence -> TyCon -> [TcType] -> TcS (Reductions, RewriterSet)
- rewriteType :: CtLoc -> TcType -> TcS TcType
Documentation
rewrite :: CtEvidence -> TcType -> TcS (Reduction, RewriterSet) Source #
See Note [Rewriting].
If (xi, co, rewriters) <- rewrite mode ev ty, then co :: xi ~r ty
where r is the role in ev.
rewriters is the set of coercion holes that have been used to rewrite
See Note [Wanteds rewrite Wanteds] in GHC.Tc.Types.Constraint
rewriteForErrors :: CtEvidence -> TcType -> TcS (Reduction, RewriterSet) Source #
See Note [Rewriting]
rewriteForErrors is a variant of rewrite that rewrites
w.r.t. nominal equality only, as this is better than full rewriting
for error messages. (This was important when we flirted with rewriting
newtypes but perhaps less so now.)
rewriteArgsNom :: CtEvidence -> TyCon -> [TcType] -> TcS (Reductions, RewriterSet) Source #