Yes, this is a common way to do this. Usually to get the non-mutating behavior you need to make a copy first anyway. (Some languages just do so implicitly and don't allow anything else.) Sometimes, as Kristoffer mentions, there might be a way to construct a new object directly instead of copying and mutating.
> On Aug 22, 2015, at 4:21 PM, Kristoffer Carlsson <kcarlsso...@gmail.com> > wrote: > > What do you mean copying the object is inefficient? Do you mean that it is > cheaper to build it from scratch than to start with the copy? > >> On Saturday, August 22, 2015 at 9:51:48 PM UTC+2, Timothée Poisot wrote: >> Hi, >> >> I caught myself wondering about the "correct" way to use function and >> function! -- or rather, how other people deal with this. >> >> Let's say I have a simple function that operates on an array, and I >> want a version to modify the original object, and one that doesn't. >> >> Is this the correct way of doing it? >> >> ~~~ >> function baz!(x) >> # Do things on x >> end >> >> function baz(x) >> y = copy(x) >> baz!(y) >> end >> ~~~ >> >> This allows to reuse the code of baz!, but copying the object IS >> inefficient. How do you usually deal with this situation? >> >> t
