[procedure] default-compare obj1 obj2

SRFI-67: compares its arguments by type using the ordering null < pair < boolean < char < string < symbol < number < vector < other.

Two objects of the same type type are compared as type-compare would, if there is such a procedure. The type null consists of the empty list '(). The effect of comparing two other objects or of comparing cyclic structures (made from lists or vectors) is unspecified. (Implementations are encouraged to add comparisons for other built-in types, e.g. records, regexps, etc.)