Defs.dec: def of lawful-fields@0.1.1.0
Import: import lawful-fields@0.1.1.0/defs.bend as Defs
Lines 57-64 of lawful-fields@0.1.1.0/defs.bend: https://jend.leeeet.dev/read.txt?path=lawful-fields@0.1.1.0/defs.bend&start_line=57&end_line=64

import Base

# A decimal number: one or more digits (leading zeros allowed), nothing else;
# any size (framebender's Pos.read on text is the same function).
def dec(xs: List<&2, U32>) -> Maybe<&2, Nat>:
  match xs:
    case Nil{}:
      None{}
    case Con{x, t}:
      dec.go(Con{x, t}, Some{0n})

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/defs.bend&name=dec.go