On 25-Oct-2015 08:01, Nerve wrote:
Hello D community! First time poster, I'm utterly fascinated with this language's mix of features. It's powerful and expressive.There are just two conveniences I'd like to see out of D. The first is pattern matching, a functional construct which can unwrap tuples or other containers, usually evaluates to a value (in most languages), and which almost always idiomatically enforces the programmer to match over every possible case of a given type. While ML-inspired languages like F# and OCaml have some good pattern matching syntax, it's not syntax which would fit in to D; I suggest taking inspiration of Rusts's matching construct. match x { Some(7) => "Lucky number 7!", Some(_) => "No lucky number.", None => "No value found" }
I humbly believe that D may just add special re-write rule to the switch statement in order to allow user-defined switchable types. This goes along nicely with the trend - e.g. foreach statement works with anything having static range interfaces or opApply.
All in all we've seen a lot of examples of how it's done in the library but always somewhat cumbersome. The next big problem would be that switch is a statement not expression which limits use-cases of user-defined pattern matching.
-- Dmitry Olshansky
