String.slice_bytes() can be used to slice a String into a ByteArray,
similar to String.slice():

    'foo'.slice_bytes(start: 0, length: 2).to_string # => 'fo'

String.split() can be used to split a string into an Array of
substrings:

    'foo/bar/baz'.split('/') # => Array.new('foo', 'bar', 'baz')