Core.is_null: def of yaml-for-bend@0.1.1.0
Import: import yaml-for-bend@0.1.1.0/core.bend as Core
Lines 28-29 of yaml-for-bend@0.1.1.0/core.bend: https://jend.leeeet.dev/read.txt?path=yaml-for-bend@0.1.1.0/core.bend&start_line=28&end_line=29

import Base

def is_null(+s: String) -> Bool:
  Bool.or(Bool.or(String.is_empty(s), String.eq(s, "~")), Bool.or(String.eq(s, "null"), Bool.or(String.eq(s, "Null"), String.eq(s, "NULL"))))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  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.is_empty