memory_instructions.txt

iex(38)> # input |> constructor |> show
nil
iex(39)> "Did you try turning it off and on again?"
"Did you try turning it off and on again?"
iex(40)> # input |> constructor |> erase |> show
nil
iex(41)> "D_d y__ tr_ turni__...."
"D_d y__ tr_ turni__...."
iex(42)> # input |> constructor |> erase |> erase |> show
nil
iex(43)> "D__ y__ _r_ tu_ni__...."
"D__ y__ _r_ tu_ni__...."
iex(44)> # input |> constructor |> erase |> erase |> erase |> show
nil
iex(45)> "___ ____ ____ _-__...." 
"___ ____ ____ _-__...."



===============

```
iex(47)> text = "Make my day."
"Make my day."
iex(48)> steps = 3
3
iex(49)> len = String.length text
12
iex(50)> text = "Make my day" 
"Make my day"
iex(51)> len = String.length text
11
iex(52)> chunk_size = 
...(52)>   ceil(length / steps)
error: undefined variable "length"
  iex:53

** (CompileError) cannot compile code (errors have been logged)

iex(52)> chunk_size =
...(52)> ceil(len / steps)   
4
iex(53)> 1..len |> Enum.chunk_every(chunk_size)
[[1, 2, 3, 4], [5, 6, 7, 8], ~c"\t\n\v"]
iex(54)> 1..len |> Enum.shuffle() |> Enum.chunk_every(chunk_size)
[[1, 2, 4, 7], [3, 5, 6, 10], ~c"\v\t\b"]
iex(55)> 1..len |> Enum.shuffle() |> Enum.chunk_every(chunk_size)
[[6, 11, 9, 2], [5, 8, 3, 4], [7, 1, 10]]
iex(56)> plan = 1..len |> Enum.shuffle() |> Enum.chunk_every(chunk_size)
[[5, 10, 11, 2], [1, 8, 7, 3], [6, 9, 4]]
iex(57)> acc = %{plan: plan, text: text}
%{text: "Make my day", plan: [[5, 10, 11, 2], [1, 8, 7, 3], [6, 9, 4]]}
iex(58)> text |> String.split
["Make", "my", "day"]
iex(59)> text |> String.split("\n")
["Make my day"]
iex(60)> text |> String.graphemes  
["M", "a", "k", "e", " ", "m", "y", " ", "d", "a", "y"]
iex(61)> text |> String.graphemes |> Enum.with_index
[
  {"M", 0},
  {"a", 1},
  {"k", 2},
  {"e", 3},
  {" ", 4},
  {"m", 5},
  {"y", 6},
  {" ", 7},
  {"d", 8},
  {"a", 9},
  {"y", 10}
]
iex(62)> text |> String.graphemes |> Enum.with_index(1)
[
  {"M", 1},
  {"a", 2},
  {"k", 3},
  {"e", 4},
  {" ", 5},
  {"m", 6},
  {"y", 7},
  {" ", 8},
  {"d", 9},
  {"a", 10},
  {"y", 11}
]
iex(63)> step = hd plan
[5, 10, 11, 2]
iex(64)> tuples = text |> String.graphemes |> Enum.with_index(1)
[
  {"M", 1},
  {"a", 2},
  {"k", 3},
  {"e", 4},
  {" ", 5},
  {"m", 6},
  {"y", 7},
  {" ", 8},
  {"d", 9},
  {"a", 10},
  {"y", 11}
]
iex(65)> Enum.map(tuples, fn {ch, i} -> 
...(65)>   cond do
...(65)>     i in step -> "_"
...(65)>     true -> ch
...(65)>   end
...(65)> end
...(65)> )
["M", "_", "k", "e", "_", "m", "y", " ", "d", "_", "_"]
iex(66)> Enum.join(v)
"M_ke_my d__"
iex(67)> 
```