On Sun, Jul 20, 2014 at 5:02 AM, קוראל אלימלך <coral2...@gmail.com> wrote: > Hey :) > How the arguments are passed in racket? > by value/ reference/name? > > If u can add an example it will b good :) > Thank U ! >
I suspect two different things are being conflated here: 1. the reduction semantics of the language 2. the question of whether or not data is copied at procedure-call boundaries. For (1), Racket's reduction strategy is call-by-value. As Jos Koot has demonstrated, in a procedure-call expression: (fn-expr argn-expr...) all of the sub-expressions will be reduced (that is, evaluated) to values before the function is applied. For (2), Racket does not copy data at procedure-call boundaries. If you pass a mutable struct, the callee is able to make changes to it that are visible to the caller. This is unlike in C, where you would need to pass a pointer to a struct in order to allow the callee to operate on the same instance as the caller. Unfortunately, "call-by-X" terminology is used to refer to both things and usually in ways that make matters far more confusing than they need be. See, e.g., [http://en.wikipedia.org/wiki/Evaluation_strategy], which is just awful. -Jon ____________________ Racket Users list: http://lists.racket-lang.org/users
