Autocomplete when typing lens

[michaelKurowski]

I know that this solution is already based on a likely tricky implementation of free types, but is it possible to have autocomplete when typing lens directly inside a focusing generic i.e. Get?

Get<
  ['have', 'autocomplete', 'here', 'since', 'we', 'know', 'the', 'target', 'type'],
  MyType
>

That is if MyType already has MyType['have']['autocomplete']['here']... it could be autocompleted when using needle in the Get generic.

[geoffreytools]

Hi,

The only way I can imagine implementing this would be to create a type definition from Haystack with a union of every possible path. This would likely tank performance.

However, if I implement type checking on Lens as mentioned in #1 then you could trigger suggestions for valid paths by typing a wrong path.

type Model = { a: number, b: [ {c: number}, {d: number} ] }
type Query = Lens<['b', unknown], Model>
//                ~~~~~~~~~~~~~
// Type '["b", unknown]' does not satisfy the constraint '["b", 0] | ["b", 1]'

I would not need to go deeper than one level after 'b'

[geoffreytools]

Hum I actually tried a dummy interface with an exhaustive union of paths and you wouldn't get auto-completion with this. You would get suggestions in a very noisy tooltip but not an interactive list, at least in VS Code. I don't think this is something under my control.

Programming with a whole would be a little more helpful: you can start with Lens<[''], Model>, be prompted to try ['a' | 'b'], then Lens<['b', ''], Model>, be prompted to try ["b", 0 | 1], etc.

[michaelKurowski]

Hi,
it is a bit suboptimal in comparison to the autocomplete, but it's a big QoL improvement. When using this feature then by definition you operate on complex objects and any form of a hint as you type is very helpful. Thanks!

[geoffreytools]

You may be interested in FindPaths for quickly coming up with a path. It's been added to the latest version. I updated the readme.