Goofing with Elixir Lang

Goofing with Elixir

##
## Define an .ex file that is compiled with elixirc
##
defmodule Hack do
  def reverse_list([h|t], acc // []) do
    Hack.reverse_list(t, List.concat([h], acc))
  end

  def reverse_list([], acc) do
    acc
  end

  def sum([h|t], acc) do
    sum(t, h + acc)
  end

  def sum([], acc) do
    acc
  end
end

##
## compile: elixirc reverse-list.ex
## start iex in same dir as the .beam
##
## iex(1)> Hack.reverse_list [1,2,3]
## [3, 2, 1]
##

##
## Now define a .exs (script file)
##

defmodule Hack do
  def reverse_list([h|t], acc) do
    Hack.reverse_list(t, List.concat([h], acc))
  end

  def reverse_list([], acc) do
    acc
  end

  def sum([h|t], acc) do
    sum(t, h + acc)
  end

  def sum([], acc) do
    acc
  end
end

x = Hack.reverse_list [1,2,3], []
IO.puts "#{is_list x}"
IO.puts "The length of x is #{length x}"
IO.puts "#{x}"

theSum = Enum.reduce(x, 0, fn(x, acc) -> x + acc end)
IO.puts "The sum of the invisible list is #{theSum}"

y = Hack.sum [1,2,3], 0
IO.puts "The result is #{y}"

##
## Save this and run it using:
## elixir reverse-list.exs
##
## the output of script is:
## >> true
## >> The length of x is 3
## >> 
## >> The sum of the invisible list is 6
## >> The result is 6

## The question is... why am i not seeing the list in stdout yet i am seeing that it's a list, it has length 3 and sum of 6
## confused!