Jeremy Maitin-Shepard a écrit :
Obviously actual timing data would be useful, but it seems that in some cases these techniques might result in increased compilation time, which is at least as serious a problem as the error messages.
Indeed. The idea, in order to provide better error messages, is to test whether all the expressions you're going to evaluate are going to lead to errors. Then, if they don't, you evaluate said expressions. However, this basically ends up doing the same thing twice (or worse, checking the expressions are valid may be more costly than actually instanciating them) as far as the compiler is concerned. Therefore I think the solution is to provide a compiler debug mode in which we do this testing, and one where we don't.