Internal abbreviation marker, marks abbreviations with an underscore behind. Useful if 'parsing_option' 1 is needed, but some abbreviations need 'parsing_option' 2.
Specific case converter shortcuts
Internal helper to test the design rules for any string and setting of 'to_any_case()'
Internal function that replaces regex matches with underscores
Internal helper for "lower_upper", "upper_lower". This helper returns a logical vector with TRUE for the first and every second string of those which contain an alphabetic character
Internal helper to replace special characters.
General case conversion
Internal parser, which is relevant for preprocessing, parsing and parsing options