> On Mar 29, 2017, at 7:05 PM, Joe Groff <[email protected]> wrote:
>
> KeyPath objects themselves have properties, so key1 could be a member of
> KeyPath. This doesn't seem workable.
Yeah, someone pointed that out to me privately. One solution would be to make
it so that an uninterrupted chain of property and subscript references is
treated as constructing a key path, but parenthesizing ends the key path
construction and accesses its properties instead:
#keyPath(Person).friends[0].name // Key path to the
`name` property of a `Person`
(#keyPath(Person).friends[0]).name // Value of the `name` property
of a `WritableKeyPath<Person, Person>`
Optional chaining behaves the same way, and in practice it seems to work fine.
In practice, I'm not sure this would come up very often, because I don't think
you're likely to construct a key path and immediately start calling properties
on it. But it is a concern.
--
Brent Royal-Gordon
Architechies
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