[goldenCeasar]

A question, would you interpret this as rank polymorphism?

  schema do
    input do
      array :regions do
        float :tax_rate
        array :offices do
          float :col_adjustment
          array :employees do
            float :salary
            float :rating
          end
        end
      end
    end

    trait :high_performer, input.regions.offices.employees.rating > 4.5
    
    value :bonus do
      on high_performer, input.regions.offices.employees.salary * 0.25
      base input.regions.offices.employees.salary * 0.10
    end
    
    value :final_pay,
      (input.regions.offices.employees.salary + bonus * input.regions.offices.col_adjustment) *
      (1 - input.regions.tax_rate)
  end

  result = schema.from(nested_data)[:final_pay]
  # => [[[91_000, 63_700], [58_500]], [[71_225]]]

[CraigJPerry]

I think i'm misunderstanding, rank is explicit throughout this example but i'm not familiar with this syntax (ruby maybe?) but whatever the case i don't see the rank polymorphism.

If i'm reading the syntax correctly, this would translate in kdb/q to a raze (flatten) on the 3 dimensions (regions, offices, employees). Probably more likely to be expressed as a converge but in either case, the calculations here are not possible in a rank polymorphic way.

[goldenCeasar]

The broadcasting handles the rank differences automatically. When bonus (at employee level) multiplies with col_adjustment (at office level), each employee's bonus gets their office's adjustment applied, no flattening or manual reshaping. The structure [[[91_000, 63_700], [58_500]], [[71_225]]] was preserved.

This is from a Ruby DSL I'm working on (Kumi). Probably the broadcasting semantics are very different from traditional rank operators in q/APL?

Edit: I realized that I missed the input structure:

  Region 0: Office 0 has 2 employees, Office 1 has 1 employee
  Region 1: Office 0 has 1 employee

[npalli]

I didn't downvote but was utterly puzzled with your example. After your response below, it occurs to me that you are confusing Employee rank (a business concept) with Array rank a mathematical concept. Either that or it is very strange explanation for rank polymorphism.