Hey Igor,

like that a lot 🙂 So you have to define „meta“ in the same environment as your desired „x“ to pull it in. Great idea and pretty much around the corner 🙂

Cheers,
Lars

Hi Konrad,
I don’t know if Power Query supports deep references, similar to other functional languages (like r with <<- assignment operator). But I do have a workaround for this.
Use the metadata tags
[a = [x=1, y=Value.Metadata(@a)[x], z=1+y] meta [x=x], b = 3, x = 4]
How meta is that 🙂 ?
I have a couple more examples If you're interested:
https://gist.github.com/Hugoberry/67c6b786a95d23f664918ace51011f67
Cheers,
Igor

Hi Konrad,

I wasn’t able to access the outer x from inside the record a. I am not sure this is possible at all. But you can do the following: Wrap the record in a let expression and assign it to a variable („P“ in my example):

let
P = [a = [x=1, y=P[x], z=1+y], b = 3, x = 4]
in
P[a][y]

I want P[a][y] to be 4 (from the outer x) instead of 1 (from the inner x). Unfortunately this expression throws an error, because P is not part of it’s own environment. BUT you can add a @ to P:

let
P = [a = [x=1, y=@P[x], z=1+y], b = 3, x = 4]
in
P

The @ allows recursion, which in this example means to be able to call the record from inside the record itself. I learnd this from Igor Cotruta. If you want to dive deeper into it, take a look at chapter 6.3 in the Power Query language specification.

Thanks to Igor for adding recursion to this topic and thanks to you, Konrad, for beeing interested in this blog post 🙂

Cheers,
Lars

Thanks Igor. That also applies to your posts. There will come more soon.

Cheers,
Lars