Is there any similarities between AWK and APL?

i dont think so

the syntax is kinda like C unless you are talking about something else

@Adám Thanks - and you are right, this solution is definitely the most readable yet. I've updated my answer on Code Golf Stack Exchange accordingly.

Is it possible for an inner dfn to access the ⍵ of an outer dfn, or is this something I shouldn't do / a sign that I need to refactor my code?

I was attempting to write a function that draws a hollow square of #s (codegolf.stackexchange.com/questions/98866/…) and this is all I could come up with:

      {' #'[∘.{⍬≢⍺⍵∩0 (n-1)}⍨⍳n←⍵]}5
#####
#   #
#   #
#   #
#####

you assign the outer ⍵ to a variable, and read that

So, like n←⍵ in my example?

yeah

nothing better than it in general

you can sometimes pass it as an arg or an operand, but that's rather ugly in most cases

I see, thanks!

(That was ⎕IO←0, for ⎕IO←1 it would look something like {' #'[1+∘.{⍬≢⍺ ⍵∩1 n}⍨⍳n←⍵]} I think)

⎕←{∘.∨⍨1⍵∊⍨⍳⍵}5

@dzaima
1 1 1 1 1
1 0 0 0 1
1 0 0 0 1
1 0 0 0 1
1 1 1 1 1

The ⍬≢⍺ ⍵∩1 n part really didn't feel right

That doesn't just feel like a great solution in the context of code golf but also a great solution in general. I wonder how often the shortest solution also happens to be the best one in APL, at least for small problems like this