Changes between Version 307 and Version 308 of TypeFunctionsStatus
- Apr 3, 2008 3:15:29 AM (7 years ago)
v307 v308 51 51 2. check that the ... can be unified with t1..tn 52 52 If (1) succeeds but (2) fails, the alternative is in accessible. Of course, (2) might fail "later" by generating a constraint that later can't be satisfied, and we won't report that well, but we'd get a good message in the common fails-fast case. We could even improve the message from (1) to say: "Constructor C is from data type T, but a pattern of type s is expected. 53 53 54 0. Implementing FDs by TFs: 54 55 * Step 1: Replace the existing improvement machinery for FDs by code that generates explicit equalities from the two FD rules. Then, all improvement is by normalisation of equalities, which hopefully allows us to simplify `TcSimplify.reduceContext`.