harumph arg parser

_expectations.md

I would expect to get

3 4 5 6
3 4 5 6

but the shifted parameters are still in place :-(

wwalker@serenity:~ ✓ $ ./a.sh 1 2 3 4 5 6
3 4 5 6
1 2 3 4 5 6

a.sh

#!/bin/bash

arg_parser(){
  shift
  shift

  POSITIONAL=()
  while [[ $# -gt 0 ]]
  do
    POSITIONAL+=("$1")
    shift
  done
  echo "${POSITIONAL[@]}"
  set -- "${POSITIONAL[@]}"
}

arg_parser "$@"
echo "$@"