Core.first: def of bend-schema-lib@0.4.1.0
Import: import bend-schema-lib@0.4.1.0/core.bend as Core
Lines 766-772 of bend-schema-lib@0.4.1.0/core.bend: https://jend.leeeet.dev/read.txt?path=bend-schema-lib@0.4.1.0/core.bend&start_line=766&end_line=772

import Base

# The first of two: the second counts only when the first found nothing.
def first(m: Maybe<&2, Err>, n: Maybe<&2, Err>) -> Maybe<&2, Err>:
  match m:
    case None{}:
      n
    case Some{e}:
      Some{e}

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=bend-schema-lib@0.4.1.0/core.bend&name=Err