Tensor.cat_bwd: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/tensor.bend as Tensor
Lines 620-623 of bendtorch@1.3.0.0/tensor.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/tensor.bend&start_line=620&end_line=623

import Base

def cat_bwd(+a: List<&2, Nat>, +b: List<&2, Nat>, +d: Nat, dz: Tensor<cat_shape(a, b, d)>) -> CatG<a, b, cat_shape(a, b, d)>:
  match dz:
    case Tensor{dd}:
      catg_b(a, b, d, gather_l(numel(a), 0, cat_map_a(a, b, d), Array.get(F32, dd, imap(cat_map_a(a, b, d), 0)), new(numel(a))))

Uses (13):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.get
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=CatG
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=Tensor
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=cat_map_a
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=cat_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=catg_b
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=gather_l
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=imap
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=new
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=numel