types-characters -- r7rs Category character;character-alphabetic;character-alphabetic-upper-case;character-alphabetic-lower-case;character-numeric;character-whitespace;character-ascii;character-ascii-alphabetic;character-ascii-alphabetic-upper-case;character-ascii-alphabetic-lower-case;character-ascii-numeric;character-ascii-whitespace;code-point-unicode;code-point-ascii;