;; The insertion sort method which sorts array of numbers only
(defun insertion-sort (arr)
  (loop for i from 1 to (1- (length arr)) do
        (let(
             (key (aref arr i))
             (j (1- i)))
        
             (loop while (and (> j -1) (< key (aref arr j))) do
                   
                   (setf (aref arr (1+ j)) (aref arr j))
                   (setq j (1- j)))
          (setf (aref arr (1+ j)) key)
           
          ))
        arr)

             
;; Generic insertion sort, which sorts arrays of any type using funcall.
;; lt and gt are lessthan and greaterthan functional parameters
;; call this function with (generic-insertion-sort #( "Ellie" "Mark" "Mariam" "Ali") #'string< ), in the debug window
            
  (defun generic-insertion-sort (arr lt)
  (loop for i from 1 to (1- (length arr)) do
        (let(
             (key (aref arr i))
             (j (1- i)))
        
             (loop while (and (> j -1) (funcall lt key (aref arr j))) do
                   
                   (setf (aref arr (1+ j)) (aref arr j))
                   (setq j (1- j)))
          (setf (aref arr (1+ j)) key)
           
          ))
        arr)