chickadee » srfi-209 » enum<?

These predicates return #t if their arguments are enums whose ordinals are in increasing, decreasing, non-decreasing, and non-increasing order respectively, and #f otherwise. It is an error unless all of the arguments belong to the same enum type.

(enum<? (enum-ordinal->enum color 0) (enum-ordinal->enum color 1)) ⇒ #t

(enum>? (enum-ordinal->enum color 2) (enum-ordinal->enum color 1)) ⇒ #t

(enum>=? (enum-ordinal->enum color 2)
         (enum-ordinal->enum color 1)
         (enum-ordinal->enum color 1))
 ⇒ #t