Write while loop equivalent in elixir

Questions & Help Questions
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5 
defmodule Demo do

  def while(pred, next, data) do
    case pred.(data) do
      true ->
        while(pred, next, next.(data))
      _ ->
        data
    end
  end

  def positive_non_zero?(i),
    do: i > 0

  def say_hello_once(i) do
    IO.puts("hello")
    i - 1
  end

  def demo1,
    do: while(&positive_non_zero?/1, &say_hello_once/1, 10)

  def demo2 do
    data = {1.01, [1.01, 1.02, 1.04]}

    p = fn {i,p} ->
      i in p
    end

    n = fn {last, p} ->
      i = last + 0.01
      IO.puts(i)
      {i, p}
    end

    while(p, n, data)
  end

end

IO.puts("# demo1")
IO.inspect(Demo.demo1())
IO.puts("# demo2")
IO.inspect(Demo.demo2())

$ elixir demo.exs
# demo1
hello
hello
hello
hello
hello
hello
hello
hello
hello
hello
0
# demo2
1.02
1.03
{1.03, [1.01, 1.02, 1.04]}
$

Refactoring: Replace Iteration with Recursion
Refactoring: Replace Recursion with Iteration

Recursion to Iteration Series
Recursion? We don’t need no stinking recursion!