output.txt

Error in ./foo.cr:22: undefined method 'uid' for Nil (compile-time type is Rank?)

p list.by("foo").uid
                 ^~~

================================================================================

Nil trace:

  ./foo.cr:13

      def by(uid)
          ^~

  ./foo.cr:14

        @entries.find { |rank| rank.uid == uid }
                 ^~~~

  /opt/crystal/src/enumerable.cr:218

      def find(if_none = nil)


  /opt/crystal/src/enumerable.cr:222

        if_none
        ^~~~~~~

  /opt/crystal/src/enumerable.cr:218

      def find(if_none = nil)
                         ^

rank.cr

class Rank
  getter uid
  def initialize(@uid)
  end
end

class RankList
  @entries = [] of Rank
  def initialize(@entries)
    @entries
  end

  def by(uid)
    @entries.find { |rank| rank.uid == uid }
  end
end

list = RankList.new(
  [Rank.new("foo")]
)

p list.by("foo").uid
p list.by("bar").uid