Changes between Version 408 and Version 409 of TypeFunctionsStatus
- Oct 21, 2008 12:16:16 PM (8 years ago)
v408 v409 21 21 * Constraint simplification: 22 22 * #2664 (typechecker diverges; actually, it's after Tc9, probably during zonking) 23 * #2102 & 2715 (superclass equalities) 23 * #2102 & 2715 (superclass equalities) 24 24 * To fix superclass equalities (specifically getting the coercion evidence), we could introduce a kind of typelet just for evidence. In fact, re-use `HsBind.VarBind` and make its right-hand side a specially data structure describing evidence construction, instead of being a general `HsExpr`. That evidence construction generation can have a case for extracting superclass constraints. The desugarer than has to generate the case expression bringing the equality in scope from that. 25 25 * What about filtering the `EqInst`s in `TcSimplify.addSCs`. We need them, don't we? But they give rise to `Var`s, not `Id`s, and we haven't got selectors.