Changes between Version 398 and Version 399 of TypeFunctionsStatus
- Oct 9, 2008 3:32:54 AM (6 years ago)
v398 v399 19 19 20 20 * Constraint simplification: 21 21 22 * #2102 (superclass equalities) 22 23 * 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.