Elixirの対話モードでErlangライブラリの動作を確認してみた

# 概要
Elixirの対話モードでErlangライブラリの動作を確認してみました。以下のページを参考にしました。

https://dev.to/gumi/elixir-22-erlang-2492

# 対話モードで実行
以下のコマンドを実行しました。
```
$ iex
Erlang/OTP 24 [erts-12.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit]

Interactive Elixir (1.12.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> String.to_charlist("π")
[960]
iex(2)> :binary.bin_to_list("π")
[207, 128]
iex(3)> :io.format("Pi is approximately given by:~10.3f~n", [:math.pi])
Pi is approximately given by:     3.142
:ok
iex(4)> to_string :io_lib.format("Pi is approximately given by:~10.3f~n", [:math.pi])
"Pi is approximately given by:     3.142\n"
iex(5)> :io.format("円周率πは約~10.3f~n", [:math.pi])
åå¨çÏã¯ç´
              3.142
:ok
iex(6)> to_string :io_lib.format("円周率πは約:~10.3f~n", [:math.pi])
<<195, 165, 194, 134, 194, 134, 195, 165, 194, 145, 194, 168, 195, 167, 194,
  142, 194, 135, 195, 143, 194, 128, 195, 163, 194, 129, 194, 175, 195, 167,
  194, 180, 194, 132, 58, 32, 32, 32, 32, 32, 51, 46, 49, 52, 50, 10>>
iex(7)> Base.encode16(:crypto.hash(:sha256, "Elixir"))
"3315715A7A3AD57428298676C5AE465DADA38D951BDFAC9348A8A31E9C7401CB"
iex(8)> def application do
...(8)> [extra_applications: [:crypto]]
...(8)> end
** (ArgumentError) cannot invoke def/2 outside module
    (elixir 1.12.2) lib/kernel.ex:5963: Kernel.assert_module_scope/3
    (elixir 1.12.2) lib/kernel.ex:4699: Kernel.define/4
    (elixir 1.12.2) expanding macro: Kernel.def/2
    iex:8: (file)
iex(8)> digraph = :digraph.new()
{:digraph, #Reference<0.1816867024.1547042817.255620>,
 #Reference<0.1816867024.1547042817.255621>,
 #Reference<0.1816867024.1547042817.255622>, true}
iex(9)> coords = [{0.0, 0.0}, {3.0, 0.0}, {3.0, 4.0}]
[{0.0, 0.0}, {3.0, 0.0}, {3.0, 4.0}]
iex(10)> [v0, v1, v2] = (for c <- coords, do: :digraph.add_vertex(digraph, 
...(10)> c))
[{0.0, 0.0}, {3.0, 0.0}, {3.0, 4.0}]
iex(11)> :digraph.add_edge(digraph, v0, v1)
[:"$e" | 0]
iex(12)> :digraph.add_edge(digraph, v1, v2)
[:"$e" | 1]
iex(13)> :digraph.add_edge(digraph, v0, v2)
[:"$e" | 2]
iex(14)> :digraph.get_short_path(digraph, v0, v2)
[{0.0, 0.0}, {3.0, 4.0}]
iex(15)> table = :ets.new(:ets_test, [])
#Reference<0.1816867024.1547042817.255689>
iex(16)> :ets.insert(table, {"China", 1_390_080_000})
true
iex(17)> :ets.insert(table, {"USA", 325_890_000})
true
iex(18)> :ets.insert(table, {"Japan", 126_750_000})
true
iex(19)> :ets.i(table)
<1   > {<<"Japan">>,126750000}
<2   > {<<"USA">>,325890000}
<3   > {<<"China">>,1390080000}
EOT  (q)uit (p)Digits (k)ill /Regexp -->
EOT  (q)uit (p)Digits (k)ill /Regexp -->q
:ok
iex(20)> deg_to_rad = :math.pi() / 180
0.017453292519943295
iex(21)> sin = :math.sin(60 * deg_to_rad)
0.8660254037844386
iex(22)> sqrt_3 = :math.sqrt(3)
1.7320508075688772
iex(23)> sin == sqrt_3 / 2
true
iex(24)> :math.atan2(sqrt_3, 1) / deg_to_rad
59.99999999999999
iex(25)> x = :math.exp(10)
22026.465794806718
iex(26)> :math.log(x)
10.0
iex(27)> q = :queue.new
{[], []}
iex(28)> q = :queue.in("A", q)
{["A"], []}
iex(29)> q = :queue.in("B", q)
{["B"], ["A"]}
iex(30)> {value, q} = :queue.out(q)
{{:value, "A"}, {[], ["B"]}}
iex(31)> value
{:value, "A"}
iex(32)> {value, q} = :queue.out(q)
{{:value, "B"}, {[], []}}
iex(33)> value
{:value, "B"}
iex(34)> {value, q} = :queue.out(q)
{:empty, {[], []}}
iex(35)> value
:empty
iex(36)> :rand.uniform()
0.869295279706314
iex(37)> _ = :rand.seed(:exs1024, {123, 123534, 345345})
{%{
   jump: #Function<12.92093067/1 in :rand."-fun.exs1024_jump/1-">,
   max: 18446744073709551615,
   next: #Function<11.92093067/1 in :rand."-fun.exs1024_next/1-">,
   type: :exs1024
 },
 {[1777391367797874666, 1964529382746821925, 7996041688159811731,
   16797603918550466679, 13239206057622895956, 2190120427146910527,
   18292739386017762693, 7995684206500985125, 1619687243448614582,
   961993414031414042, 10239938031393579756, 12249841489256032092,
   1457887945073169212, 16031477380367994289, 12526413104181201380,
   16202025130717851397], []}}
iex(38)> :rand.uniform()
0.5820506340260994
iex(39)> :rand.uniform(6)
6
iex(40)> :zip.foldl(fn _, _, _, acc -> acc + 1 end, 0, :binary.bin_to_list("samples.zip"))
{:error, :enoent}
iex(41)> song = "
...(41)> The snow glows white on the mountain tonight
...(41)> Not a footprint to be seen
...(41)> A kingdom of isolation
...(41)> And it looks like I'm the queen"
"\nThe snow glows white on the mountain tonight\nNot a footprint to be seen\nA kingdom of isolation\nAnd it looks like I'm the queen"
iex(42)> compressed = :zlib.compress(song)<<120, 156, 29, 204, 49, 14, 195, 48, 12, 67, 209, 221, 167, 224, 214, 115, 116,
...(42)>   236, 210, 169, 23, 112, 16, 197, 22, 108, 139, 77, 172, 192, 215, 175, 208,
...(42)>   145, 15, 248, 76, 159, 42, 152, 198, 133, 210, 185, 38, 86, 85, 23, 208, 224,
...(42)>   ...>>
** (SyntaxError) iex:42:34: syntax error before: '<<'

iex(42)> byte_size(song)
127
iex(43)> byte_size(compressed)
** (CompileError) iex:43: undefined function compressed/0
    (stdlib 3.17) lists.erl:1358: :lists.mapfoldl/3
iex(43)> :zlib.uncompress(compressed)
** (CompileError) iex:43: undefined function compressed/0
    (stdlib 3.17) lists.erl:1358: :lists.mapfoldl/3
iex(43)> 
```

# まとめ
何かの役に立てばと。