Fields.digits.go: def of lawful-fields@0.1.1.0
Import: import lawful-fields@0.1.1.0/fields.bend as Fields
Lines 74-81 of lawful-fields@0.1.1.0/fields.bend: https://jend.leeeet.dev/read.txt?path=lawful-fields@0.1.1.0/fields.bend&start_line=74&end_line=81

import Base
import lawful-bytes@0.1.1.0/defs.bend as D
import lawful-bytes@0.1.1.0/bytes.bend as B

# r holds byte j; ok says every byte so far was a digit.
def digits.go(n: Nat, r: D.Bytes & U32, +j: U32, ok: Bool) -> D.Bytes & Bool:
  match n:
    case 0n:
      digits.out(ok, r)
    case 1n+m:
      (b, +x) = r
      digits.go(m, B.at(b, (j + 1 : U32)), (j + 1 : U32), ok && (U32.is_ge(x, 48) && U32.is_le(x, 57)))

Uses (12):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  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.is_ge
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_le
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/bytes.bend&name=at
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=Bytes
  https://jend.leeeet.dev/definition.txt?path=lawful-fields@0.1.1.0/fields.bend&name=digits.out