Test whether a delimited string contains a specific element
Integer_Type is_list_element (String_Type list, String_Type elem, Integer_Type delim)
The is_list_element function may be used to determine whether
or not a delimited list of strings, list, contains the element
elem. If elem is not an element of list, the function
will return zero, otherwise, it returns 1 plus the matching element
number.
The expression
is_list_element ("element 0, element 1, element 2", "0,", ' ');
returns 2 since "0," is element number one of the list
(numbered from zero).
extract_element, is_substr, create_delimited_string