On Wed, Aug 21, 2019 at 10:52:57AM -0400, George Neuner wrote: > > I don't like the idea of compulsory 'else' - for 'cond' or 'case' or > 'match' or ... > > 'Else' isn't needed if all input cases are covered, but in almost all > real world uses, the compiler is not able to prove the 'else' is > unneeded so as to prevent emitting code for it. And depending on how > the compiler structures the tests (cond is simple, case less so), > adding 'else' into the mix may increase execution time as well.
What about treating a missing 'else' as a run-time error if and only if control gets that far. That would require code that intends nothing to be done to have an explicit 'else' saying so. Except for notation, this would seem to meet your demands for semantic expressibility. -- hendrik -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/20190821150121.u46ng3uogxxg5v6s%40topoi.pooq.com.
