Object-oriented implementations

[ghost]

Hi,

There seems to be a danger passing File around, by reference.

If I have the following

let file = try folder.file(named: "name.pdf")

And I pass it into the following function.

func store(_ file: File) throws

Moving forward, if I interact with this same File reference, it may no longer have a valid path. The store function above may perform moveItem, for example.

Idea 1

Perhaps we could create an alias?

Idea 2

Might it be worth making a distinction between a File that you know exists and a PotentialFile that hasn't been confirmed to exist? You see this kind of 'evaluate at last minute' mentality throughout Swift.

The same kind of mentality as

• A slice of a string or array
• Copy on write
• An optional has .some or .none

I suppose we would have to handle a change in state, in both directions.

• PotentialFile becoming File
• File becoming PotentialFile

Idea 3

Perhaps we could harness this API?

FileReferenceURL

Check Resource Is Reachable

[ghost]

Actually, could we just update the path on the File instance, from within the implementation of move.

[clayellis]

@rob-nash Not sure what you mean. Operations on File and Folder that would result in their underlying file system representation changing do in fact update their internal path (see: FileSystem.Item.move(to:)). And since File and Folder are classes, when passed by reference, a change in one code path would affect the reference in another.

Can you write a test showing the behavior you're trying to design around?

[ghost]

Just wrote a test and I couldn't reproduce the issue. Started looking at other reason why this might be happening and it turns out I'm running code on the wrong thread.

Thanks for helping me think 'outside of the box'.

Sorry for wasting time.

[clayellis]

Never a waste! Glad to help 👍