infinite_enum.rb

my_enum = (1..5).lazy.map { |i| i == 3 ? raise(StandardError) : i }

safe_enum = Enumerator.new do |y|
  loop do
    begin
      y.yield my_enum.next
    rescue => e
      break if e.kind_of? StopIteration
    end
  end
end

safe_enum.take(100) # => [1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2]
# https://www.destroyallsoftware.com/talks/wat

my_enum = (1..5).lazy.map { |i| i == 3 ? raise(StandardError) : i }

safe_enum = Enumerator.new do |y|
  loop do
    begin
      y.yield my_enum.next
    rescue StopIteration
      break
    rescue
      y.yield my_enum.feed(nil)
    end
  end
end

safe_enum.take(100) #=> [1, 2, nil, 1, 2, nil, 1, 2, nil, 1, 2, ...]