Re: [racket-users] Re: Functional object-oriented programming

> On Feb 8, 2017, at 9:05 PM, Philip McGrath wrote: > Personally, I tend to end up defining helper functions to do functional > update (often with optional keyword arguments to address the > fields-that-stay-the-same issue). Generics in the sense of racket/generic can

Re: [racket-users] Re: Functional object-oriented programming

Note, though, that struct-copy needs to be given the type of the resulting structure statically, at compile time, and "the result of *struct-expr* can be an instance of a sub-type of *id*, but the resulting copy is an immediate instance of *id* (not the sub-type)." [1] If you have a complex

Re: [racket-users] Re: Functional object-oriented programming

Matthias, thanks for the confirmation that macros are the answer. Yes, mutation could be simpler. I'm learning more doing it functionally. Alex, thanks for pointing out struct-copy. I hadn't read that part of the Racket Guide yet. Would it be possible to write a macro that when invoked within

[racket-users] Re: Functional object-oriented programming

Structures support this style of updating: (struct foo (bar baz) #:transparent) (define one (foo "hello" 1)) ;; Copy all fields from "one" and update baz to 2 (define two (struct-copy foo one (baz 2))) They also have immutable fields by default. Best Regards, Alex. -- You