10 Jun
2015
10 Jun
'15
9 a.m.
An idea. Could the new desugaring be the same as for normal functions with a missing case? Code that uses fail would have to add the constraint still, but code that really didn't want to use fail would 1) get a warning about an incomplete pattern match and 2) get a runtime error for the failed pattern match produced by GHC. Is there anything I'm not thinking of here why this wouldn't work?