# create a function that generates an array of numbers
num_gen = proc do |count|
    (0...count).to_a
end

# create a function that generates an array of strings
string_gen = proc do |count|
    max = ('a'[0] + count).chr
    ('a'...max).to_a
end

# use the generators without knowing what they are
generators = [ num_gen, string_gen ]
generators.each do |gen|
    puts "[#{gen.call(5).join(', ')}]"
end