[swift-evolution] SE-0171: Reduce with inout

[Guillaume Lessard]

> https://github.com/apple/swift-evolution/blob/master/proposals/0171-reduce-with-inout.md
> 
> • What is your evaluation of the proposal?

I support this proposal. It is easy to inadvertently write inefficient algorithms with reduce, and this provides a built-in solution. The parameter label is decent, and it differentiates the overloads nicely; that helps with readability. I think that the straight overload case becomes less readable; that happens to reinforce the compiler performance concern.


> • Is the problem being addressed significant enough to warrant a change to Swift?

Yes. A lot of transformations can be implemented on top of ‘reduce’; this will help a class of those solutions be more efficient.

> • Does this proposal fit well with the feel and direction of Swift?

Yes. A functional algorithm that embraces mutation in the name of efficiency: so swifty.

> • How much effort did you put into your review? A glance, a quick reading, or an in-depth study?

Participated in discussion, experimented with the concept.

Guillaume Lessard