min, max

Fundamental.lisp

 ;; fundamental predefined Lisp functions
 ;(debug t)
 
+(defun max (&rest numargs)
+  "return the biggest of all (numeric) arguments"
+  (if (null (cdr numargs))
+      (car numargs)
+    (let ((a (car numargs))
+          (b (apply #'max (cdr numargs))))
+      (if (< a b)
+          b
+        a))))
+
+(defun min (&rest numargs)
+  "return the smallest of all (numeric) arguments"
+  (if (null (cdr numargs))
+      (car numargs)
+    (let ((a (car numargs))
+          (b (apply #'min (cdr numargs))))
+      (if (< a b)
+          a
+        b))))
+
 (defun apropos (match)
   (sort (filter #'(lambda (sym) (re-match match (symbol-name sym)))
                 (symbols))

TODO

@@ -6,7 +6,9 @@
 
   * more of alists
 
-  * min, max; floor ceiling, round
+  * floor, ceiling, round
+
+  + min, max
 
   + "isqrt", "return the integer square root of numeric ARG"
 

tests/037-minmax.lisp

+(testcmp "max 1" '(max) nil)
+(testcmp "max 2" '(max 3) 3)
+(testcmp "max 3" '(max 3 4 5 2 54 6 9 3 5 7) 54)
+(testcmp "max 4" '(max 3 -4 5 -2 54 -6 9 -3 5 -7) 54)
+
+(testcmp "min 1" '(min) nil)
+(testcmp "min 2" '(min 3) 3)
+(testcmp "min 3" '(min 3 4 5 2 54 6 9 3 5 7) 2)
+(testcmp "min 4" '(min 3 -4 5 -2 54 -6 9 -3 5 -7) -7)
+(testcmp "min 5" '(min 4 2 4 2 4 2 7 1 19) 1)