Merge branch 'strings'

[jscl.git] / src / numbers.lisp

diff --git a/src/numbers.lisp b/src/numbers.lisp
index 342c12d..18d679c 100644 (file)
--- a/src/numbers.lisp
+++ b/src/numbers.lisp
@@ -16,6 +16,50 @@
 ;;;; Various numeric functions and constants
 
 ;; TODO: Use MACROLET when it exists
+(defmacro define-variadic-op (operator initial-value)
+  (let ((init-sym   (gensym))
+        (dolist-sym (gensym)))
+    `(defun ,operator (&rest args)
+       (let ((,init-sym ,initial-value))
+         (dolist (,dolist-sym args)
+           (setq ,init-sym (,operator ,init-sym ,dolist-sym)))
+         ,init-sym))))
+
+(define-variadic-op + 0)
+(define-variadic-op * 1)
+
+;; - and / work differently from the above macro.
+;; If only one arg is given, it negates it or takes its reciprocal.
+;; Otherwise all the other args are subtracted from or divided by it.
+;; TODO: Use MACROLET when it exists
+(defmacro define-sub-or-div (operator unary-form)
+  `(defun ,operator (x &rest args)
+     (cond
+       ((null args) ,unary-form)
+       (t (dolist (y args)
+            (setq x (,operator x y)))
+          x))))
+
+(define-sub-or-div - (-   x))
+(define-sub-or-div / (/ 1 x))
+
+(defun 1+ (x) (+ x 1))
+(defun 1- (x) (- x 1))
+
+(defun truncate (x &optional (y 1))
+  (floor (/ x y)))
+
+(defun integerp (x)
+  (and (numberp x) (= (floor x) x)))
+
+(defun floatp (x)
+  (and (numberp x) (not (integerp x))))
+
+(defun minusp (x) (< x 0))
+(defun zerop (x) (= x 0))
+(defun plusp (x) (< 0 x))
+
+;; TODO: Use MACROLET when it exists
 (defmacro defcomparison (operator)
   `(defun ,operator (x &rest args)
      (dolist (y args) 
@@ -26,8 +70,10 @@
 
 (defcomparison >)
 (defcomparison >=)
+(defcomparison =) 
 (defcomparison <)
 (defcomparison <=)
+(defcomparison /=)
 
 (defconstant pi 3.141592653589793)