| %notin% | notin helper function. Opposite of 'in' function. | 
| assign_to_R_env | Add variable to R environment (in contrast to system environment). | 
| check_if_unique_rows | Takes a data.table dataset and checks if for each unique element in a specified column there is exaclty one row. | 
| cleanup_old_logfile | Archives the current logfile and creates a new blank one. | 
| clean_path_name | Clean paths to surely have a tailing slash or not. | 
| clear | Clean the console and environment-variables. | 
| close_all_connections | Unset/close all open connections. | 
| dt_row_to_string | Get the content of a data.table row in print-ready format. | 
| equals2 | Robust compare two elements and return true if both elements are the same. False otherwise. No 'NA' or 'NULL'. | 
| feedback | Function to feedback messages either to the user and/or to the console and to the logfile. | 
| feedback_get_formatted_string | Format the feedback string | 
| feedback_to_console | Print to the console. Internal use only. | 
| feedback_to_logfile | Add to the logfile. Internal use. | 
| feedback_to_logjs | Feedback to the gui/browser-console with logjs. Internal use. | 
| feedback_to_ui | Feedback to the user with a modal. Internal use. | 
| file_lines_to_list | Read in lines from a file and store it in a list. | 
| firstup | Converts the first letter of the input string to uppercase. | 
| format_posixct | Formats a given POSIXct timestamp without the need of manually specifing format parameters. | 
| get_config | Reads a config yaml file and return the value for a given key. | 
| get_current_timestamp | Quickly get the current time stamp without the need to handle format-options etc. | 
| is.empty | Check for empty/'NA'/'NULL'/'NaN'/etc. values. | 
| is_date_format | Checks if a string matches a given date format. | 
| log_get_current_options | Get the current settings for the logging function as list. | 
| log_get_default_options | Get the default settings for the logging function as list. | 
| log_internal_test | Internal function for debugging only. | 
| log_map_type_to_loggertype | Get the logger type from the type string (the argument of the 'feedback()' function) | 
| log_remove_options | Remove all log-related options from 'options()'. | 
| log_set_defaults | Set default options for all log-functions | 
| number_to_position | Converts an integer number to its "verbal position". 1 -> "1st", 2 -> "2nd", 3 -> "3rd", 4 -> "4th", ... | 
| paste2 | Normal 'paste' function with additional 'collapse_last' argument. | 
| paste_pct_sum | Get the percentage of two values pretty formatted. | 
| pretty_timestamp | Quickly get a pretty timestamp without need to handle format-options etc. | 
| rep2 | Repeat something with the ability to also collapse the output. | 
| robust_round | Round numbers without problems. | 
| setdiff_all | Get the difference of two vectors in both directions. | 
| setenv2 | Assign variables to the system environment. | 
| setenv_file | Set all variables of a '.env' file to the system environment. | 
| string_replacements | Clean string with a given set of replacements. | 
| time_diff_print | Calculate time difference of two timestamps, round the value and return a string with suiting unit. | 
| trim.space | Trim Spaces of a string. | 
| vgsub | Vectorised string replacement. |