How to get the path matching with the dot path syntax ?

Hi, I would like to know if it would be possible, when working with arrays, to get the path that matched with the condition.

const data = { a: [{ b: 1 }, { b: 2 }] };

const result = sift({ "a.b": 1 }, data);
// --> a[0].b

Would it be feasible with a custom operator or is there a place where I can grab that info ?

Thank you

[crcn]

Closing this for now since @stalniy seems to have a good fix.

[stalniy]

Hi @J3m5

In terms of ucast, you need:

• MongoQueryParser - implemented in @ucast/mongo
• operators from JsInterpreter - implemented in @ucast/js
• custom js interpreter with logic to aggregate matching path instead of aggregating resulting value.

If you want to learn more, start from here

This is not something I plan to add ucast at least for now, because its main goal is to translate conditions from language to another (e.g., mongo query -> SQL, query string -> Mongo query, etc)

Details: theoretically it’s possible to do. Currently, @ucast/mongo provides a MongoQueryParser class, which you can use to parse any mongo query into AST (a tree of objects, you can think of it as something similar to XML tree). Having these objects, you can iterate over them to “interpret” them in anyway you need (e.g., XML can be interpreted as RSS, data transfer object or HTML).

So, during iteration you can use operator interpreters from @ucast/js (e.g., $lt, $gt, $in, $eq`, etc) to get boolean result, also you need to aggregate path down the tree. As soon as operator returns true for your desired case, just stop iteration and return aggregated path.