• Simon Peyton Jones's avatar
    Give lookupGRE_Name a better API · 3e0af469
    Simon Peyton Jones authored
    lookupGRE_Name should return either zero or one GREs, never
    several. This is a consequence of INVARIANT 1 on GlobalRdrEnv.
    
    So it's better if it returns a Maybe; the panic on multiple results
    is put in one place, instead of being scattered or ignored.
    
    Just refactoring, no change in behaviour
    3e0af469
RnPat.hs 33.5 KB