indexed?

tests whether the provided forms are indexed sequences

If all forms evaluate to a valid sequence that can be accessed by index, then this function will return #t (true). The first non-indexed sequence will result in the function returning #f (false).

An Example

(indexed? '(1 2 3 4) [5 6 7 8])

This example will return #t (true).

Like most predicates, this function can also be negated by prepending the ! character. This means that all the provided forms must not be valid indexed sequences.

(!indexed? "hello" 99)

This example will return #f (false) because strings are indexed sequences.