Bendtorch.hcat: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/main.bend as Bendtorch
Lines 2725-2729 of bendtorch@1.3.0.0/main.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/main.bend&start_line=2725&end_line=2729

import Base

# the two halves back as one list, in order (what the laws attn_par_fwd and attn_par_bwd compare the trees with)
def hcat(-A: Type, h: Halves<A>) -> List<&1, A>:
  match h:
    case Halves{l, r}:
      List.append(&1, A, l, r)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/main.bend&name=Halves