(starts-with? deq prefix)
  deq: a deque
  prefix: a deque
  returns a bool
F

Tests whether one deque is the prefix of another.

The deques must have the same type: two arrays, or two strings, but not an array and a string.

(prn (starts-with? "Zeus" "Ze")) ; prints #t
(prn (starts-with? "Zeus" ""))   ; prints #t
(prn (starts-with? "Zeus" "Zu")) ; prints #f
sort!
ends-with?