6.27.1 Predicates about strings

Function: list-of-strings? obj

Return #t if obj is null or a proper list of strings; otherwise return #f.

Function: list-of-nestrings? obj

Return #t if obj is null or a proper list of non–empty strings; otherwise return #f.

Function: string-empty? str

Return #t if the string str is empty, otherwise return #f. It is an error if str is not a string.

Function: empty-string? obj

Return #t if the obj is a string and it is empty, otherwise return #f.

Function: nestring? obj

Return #t if the obj is a string and it is non–empty, otherwise return #f.