]> [...] > I was expecting "when" to be right distributive over "|". I find > OCaml's behaviour not very intuitive in such a situation. [...] The when construct introduces a guard to a pattern matching clause. This means that a when construct is global to the entire pattern of the clause it appears in; it means in particular that no when construct can be nested into a pattern and the question of its distributivity wrt any other construct is pointless. > Is there a good reason for this? Yes: simplicity, complexity invariants preservation for runtime pattern analysis decisions even in the presence of when clauses, easier understanding of the compiler warnings, simplicity and well-definedness semantics (in particular the desired invariance wrt the order of evaluation). > Cheers, > > Sébastien. Best regards, Pierre Weis INRIA, Projet Cristal, Pierre.Weis@inria.fr, http://pauillac.inria.fr/~weis/ ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners