September 2017 Update

Task/Empty-string/Ol/empty-string.ol

@@ -0,0 +1,17 @@
+; define the empty string
+(define empty-string "")
+
+; three simplest tests for 'the-string emptiness
+(if (or
+      (string-eq? the-string "")
+      (string=?   the-string "")
+      (eq? (string-length the-string) 0))
+   (print "the-string is empty")
+
+; four simplest tests for 'the-string not emptiness
+(if (or
+      (not (string-eq? the-string ""))
+      (not (string=?   the-string ""))
+      (not (eq? (string-length the-string) 0))
+      (less? 0 (string-length the-string)))
+   (print "the-string is NOT empty))