Fmt.Big.mul: def of bend-kit-fmt@0.1.0.0
Import: import bend-kit-fmt@0.1.0.0/fmt.bend as Fmt
Lines 133-140 of bend-kit-fmt@0.1.0.0/fmt.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-fmt@0.1.0.0/fmt.bend&start_line=133&end_line=140

import Base

# m and c stay below 2^16, so a limb product fits a U32.
def Big.mul(a: List<&2, U32>, +m: U32, c: U32) -> List<&2, U32>:
  match a:
    case Nil{}:
      Nil{}
    case Con{x, xs}:
      +t = {U32.add(U32.mul(x, m), c) : U32}
      Con{U32.and(t, 65535), Big.mul(xs, m, U32.shrn(t, 16n))}

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.mul
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shrn