Benchmarking performance of slicing text in different formats/ways

benchmark.exs

# 1024 bytes long string
string = """
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis tempus iaculis erat. Cras orci enim, vulputate a elementum at, rutrum pulvinar sem. Donec gravida quam at lectus sagittis, eu facilisis felis scelerisque. Nulla quis leo quis ipsum sollicitudin pharetra. Interdum et malesuada fames ac ante ipsum primis in faucibus. Donec bibendum porttitor hendrerit. In hac habitasse platea dictumst.

Sed blandit massa ut lorem accumsan, ut suscipit erat aliquet. Ut vulputate sit amet ligula non auctor. Nullam pharetra vestibulum velit, lobortis ultrices ante blandit quis. Curabitur gravida fringilla enim non pulvinar. Vestibulum facilisis turpis ipsum, ac tempor magna varius at. Cras pulvinar mi in varius mattis. Curabitur viverra nibh est, eu consectetur magna euismod eget. Suspendisse potenti. Vestibulum hendrerit auctor dui id imperdiet. Quisque congue enim non eros lobortis, rhoncus aliquam lacus eleifend. Nam et malesuada mauris, et semper velit. Aenean volutpat cursus ornare. Cras aliquam hendrerit est nullam.
"""

charlist = String.to_charlist(string)

Benchee.run(%{
  "string" => fn ->
    String.slice(string, 500, 501)
  end,
  "charlist" => fn ->
    Enum.slice(charlist, 500, 501)
  end,
  "binary" => fn ->
    binary_part(string, 500, 1)
  end
})

results.txt

Operating System: macOS
CPU Information: Intel(R) Core(TM) i5-7360U CPU @ 2.30GHz
Number of Available Cores: 4
Available memory: 16 GB
Elixir 1.10.2
Erlang 22.2.8

Benchmark suite executing with the following configuration:
warmup: 2 s
time: 5 s
memory time: 0 ns
parallel: 1
inputs: none specified
Estimated total run time: 21 s

Benchmarking binary...
Benchmarking charlist...
Benchmarking string...

Name               ips        average  deviation         median         99th %
binary       6295.14 K       0.159 μs   ±774.35%           0 μs           1 μs
charlist      134.25 K        7.45 μs   ±432.53%           7 μs          15 μs
string         17.35 K       57.65 μs    ±37.55%          55 μs         107 μs

Comparison: 
binary       6295.14 K
charlist      134.25 K - 46.89x slower +7.29 μs
string         17.35 K - 362.94x slower +57.49 μs