Tail recursion in ruby

tail_recursion.rb

def factorial_tail(number)
  proc_fact = lambda do |acc, x|
    if x <= 0
      acc
    else
      proc_fact.call(x * acc, x - 1)
    end
  end
  return proc_fact.call(1, number)
end

puts "Factorial using tail recursion - #{factorial_tail(10)}"

def fibonacci_tail(n)
  fib_fact = lambda do |a,b,n|
    if n <= 1
      b
    else
      fib_fact.call(b, a + b, n -1)
    end
  end
  return fib_fact.call(0, 1, n)
end

puts "Fibonacci series using tail recusrion - #{fibonacci_tail(10)}"