The shortest solution is

for line in String.split(input, ")"), do: Code.string_to_quoted!(line <> ")")

NimbleParsec is not regex. It’s not “searching” through your input.

A parser works by going though the input string front → end and at each step you need to define what can be matched next. In your example you tell it to match either "validate" or "sanitize". It starts from the front, finds "sanitize" and then the next char is (, which matches neither of your expected values, so parsing halts.

NimbleParsec — NimbleParsec v1.3.1 has an example of something similar, parsing things wrapped in " instead of parenthesis.

With NimbleParsec, you create rules for the things you want to parse and then define a parser, e.g parsing a gmail-like search string. Should be pretty straight forward to parse your text format.

  ...

  field =
    choice([
      string("message:") |> replace(:message),
      string("user:") |> replace(:user),
      string("ip:") |> replace(:ip)
    ])
    |> ignore(optional(whitespace))

  param =
    repeat(
      lookahead_not(concat(optional(whitespace), choice([field, value_field, time_field])))
      |> optional(whitespace)
      |> utf8_string([not: ?\s], min: 1)
    )
    |> ignore(choice([whitespace, eos()]))
    |> post_traverse(:join)

  ...

  defparsec :parse_search_string,
            ignore(optional(whitespace))
            |> times(
              choice([
                concat(field, param),
                value_field_param,
                time_field
              ])
              |> post_traverse(:group)
              |> ignore(optional(whitespace)),
              

NimbleParsec is okay for this task. You can handroll the parser yourself, since it is pretty simple parser with only two different states.

I think he means using lex/yacc, in theory it should be very easy and pretty versatile implementation.