• Richard Eisenberg's avatar
    Do not create nested quantified constraints · de32beff
    Richard Eisenberg authored
    Previously, we would accidentally make constraints like
    forall a. C a => forall b. D b => E a b c as we traversed
    superclasses. No longer!
    
    This patch also expands Note [Eagerly expand given superclasses]
    to work over quantified constraints; necessary for T16502b.
    
    Close #17202 and #16502.
    
    test cases: typecheck/should_compile/T{17202,16502{,b}}
    de32beff
TcValidity.hs 115 KB