Sigv4.ent: def of bend-kit-sigv4@0.11.0.1
Import: import bend-kit-sigv4@0.11.0.1/sigv4.bend as Sigv4
Lines 630-637 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=630&end_line=637

import Base

# The five XML entities and &#NN; / &#xHH;. None for any other.
def ent(+e: String) -> Maybe<&2, U32>:
  Bool.pick(Maybe<&2, U32>, String.eq(e, "lt"), Some{60},
    Bool.pick(Maybe<&2, U32>, String.eq(e, "gt"), Some{62},
      Bool.pick(Maybe<&2, U32>, String.eq(e, "amp"), Some{38},
        Bool.pick(Maybe<&2, U32>, String.eq(e, "quot"), Some{34},
          Bool.pick(Maybe<&2, U32>, String.eq(e, "apos"), Some{39},
            Bool.pick(Maybe<&2, U32>, Bool.and(String.starts_with(e, "#"), Nat.is_lt(1n, String.length(e))), ent.num(String.drop(e, 1n)), None{}))))))

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.pick
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.drop
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.eq
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.starts_with
  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=ent.num