class RBS::Locator

def find_in_decl(pos, decl:, array:)
  if test_loc(pos, location: decl.location)
    array.unshift(decl)
    case decl
    when AST::Declarations::Class
      decl.type_params.each do |param|
        find_in_type_param(pos, type_param: param, array: array) and return true
      end
      if super_class = decl.super_class
        if test_loc(pos, location: super_class.location)
          array.unshift(super_class)
          find_in_loc(pos, array: array, location: super_class.location)
          return true
        end
      end
      decl.each_decl do |decl_|
        find_in_decl(pos, decl: decl_, array: array) and return true
      end
      decl.each_member do |member|
        find_in_member(pos, array: array, member: member) and return true
      end
    when AST::Declarations::Module
      decl.type_params.each do |param|
        find_in_type_param(pos, type_param: param, array: array) and return true
      end
      decl.self_types.each do |self_type|
        if test_loc(pos, location: self_type.location)
          array.unshift(self_type)
          find_in_loc(pos, array: array, location: self_type.location)
          return true
        end
      end
      decl.each_decl do |decl_|
        find_in_decl(pos, decl: decl_, array: array) and return true
      end
      decl.each_member do |member|
        find_in_member(pos, array: array, member: member) and return true
      end
    when AST::Declarations::Interface
      decl.type_params.each do |param|
        find_in_type_param(pos, type_param: param, array: array) and return true
      end
      decl.members.each do |member|
        find_in_member(pos, array: array, member: member) and return true
      end
    when AST::Declarations::Constant, AST::Declarations::Global
      find_in_type(pos, array: array, type: decl.type) and return true
    when AST::Declarations::TypeAlias
      find_in_type(pos, array: array, type: decl.type) and return true
    end
    find_in_loc(pos, location: decl.location, array: array)
    true
  else
    false
  end
end