> On 19 Apr 2016, at 17:51, Vladimir.S <[email protected]> wrote:
>
> I.e. the question is *if we want/need to be able to pass array to existed
> variadic function*. Not about removing the variadic feature("removing" is
> offtop for this poposal, as I understand)
I’d say it’s on-topic, as removing variadic functions would eliminate the
problem entirely, so if it is considered a better alternative then there would
be no need to have an additional means of calling them with an array of
arguments.
Personally the way I see it comes down to variadic functions is this:
Pros:
Slightly cleaner syntax at call-site.
Possibly optimisations unavailable to Array passing?
Cons:
Doesn’t do anything that passing an array directly can’t.
Passing an array is actually slightly more flexible (can dynamically pass more
or less arguments as required at the call site).
Less explicit type at call site; gives the appearance of passing instance(s) of
Foo, rather than one instance of [Foo], can lead to ambiguity with overloaded
functions.
Extra syntax to support (enabling array passing would be more code required to
support this feature)
I’d also argue that variadic functions increase the learning curve, as the
first time you’re presented with one it isn’t necessarily clear what it does
unless you’ve encountered them before. Like I say it can be ambiguous at the
call-site in particular, as it doesn’t show that an array of [Foo] is being
passed as opposed to N instances of Foo (however many are in the call).
While I’ve used them in the past, I’ve never really felt that they simplify
anything enough to justify them, as it’s just two square brackets extra to pass
an array; this is extra noise sure, but clarifies what is actually happening.
So if variadic functions don’t have any other advantages, then it’s really just
a very minor piece of syntactic sugar that can lead to more confusion, less
explicit types in function calls, an extra piece of syntax to parse and handle
and possibly other features required to support it better (like the one being
inquired about). The only other argument I can think of for them is that many
other languages have them, but that’s not important to me vs cutting out cruft.
Short version; removing variadic functions would solve the problem of defining
overloads for both variadic and array types by only ever requiring the latter.
P.S- I’d also like to note that where possible people should be accepting
Sequences or Collections in their methods anyway rather than arrays
specifically, as it’s more flexible that way ;)
_______________________________________________
swift-evolution mailing list
[email protected]
https://lists.swift.org/mailman/listinfo/swift-evolution
