add may-reverse-and-cut

1 files changed, 9 insertions, 3 deletions

diff --git a/plus-inc.lisp b/plus-inc.lisp
index 3d85b11..cabc2d3 100644
--- a/plus-inc.lisp
+++ b/plus-inc.lisp
@@ -12,6 +12,12 @@
 (defun may-reverse (number)
   "If units is placed on the end, reverse; else keep it."
   (if *number-units-at-beginning*
+      number
+      (reverse number)))
+
+(defun may-reverse-and-cut (number)
+  "If units is placed on the end, reverse; else keep it. Also cuts unecessary digits."
+  (if *number-units-at-beginning*
       (reverse (cut-digits (reverse number)))
       (reverse (cut-digits number))))
 
@@ -82,12 +88,12 @@
 
 (defun plus (numerals a b)
   "Given a list of a numeral system and 2 lists of symbols, it returns the list of it's sum."
-  (may-reverse (plus-args-list numerals (may-reverse a) (may-reverse b))))
+  (may-reverse (plus-args-list numerals (may-reverse-and-cut a) (may-reverse-and-cut b))))
 
 (defun plus-decimal (&rest args)
   "Given decimal numbers, it returns the symbol it's sum."
-  (nth-value 0 (implode (may-reverse (reduce (lambda (a b) (plus-args-list '(|0| |1| |2| |3| |4| |5| |6| |7| |8| |9|) a b)) (mapcar #'may-reverse (mapcar #'explode args)))))))
+  (nth-value 0 (implode (may-reverse (reduce (lambda (a b) (plus-args-list '(|0| |1| |2| |3| |4| |5| |6| |7| |8| |9|) a b)) (mapcar #'may-reverse-and-cut (mapcar #'explode args)))))))
 
 (defun plus-earth (&rest args)
   "Give earthal numbers, it returns it's sum."
-  (symbol-to-number (nth-value 0 (implode (may-reverse (reduce (lambda (a b) (plus-args-list '(|1| |2| |3| |4| |5|) a b)) (mapcar #'may-reverse (mapcar #'explode args))))))))
+  (symbol-to-number (nth-value 0 (implode (may-reverse (reduce (lambda (a b) (plus-args-list '(|1| |2| |3| |4| |5|) a b)) (mapcar #'may-reverse-and-cut (mapcar #'explode args))))))))