Sigv4.hex: def of bend-kit-sigv4@0.11.0.1
Import: import bend-kit-sigv4@0.11.0.1/sigv4.bend as Sigv4
Lines 615-625 of bend-kit-sigv4@0.11.0.1/sigv4.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-sigv4@0.11.0.1/sigv4.bend&start_line=615&end_line=625

import Base

# ponytail: no overflow check; a reference past U+10FFFF wraps and decodes to junk rather than failing.
def hex(s: String, m: Maybe<&2, U32>) -> Maybe<&2, U32>:
  match s:
    case SNil{}:
      m
    case SCon{Chr{c}, t}:
      match m:
        case None{}:
          None{}
        case Some{acc}:
          hex(t, hex.step(hex.digit(c), acc))

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Char
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-kit-sigv4@0.11.0.1/sigv4.bend&name=hex.digit
  https://jend.leeeet.dev/definition.txt?path=bend-kit-sigv4@0.11.0.1/sigv4.bend&name=hex.step