Changeset 4226 for branches

Timestamp:

2016-06-04T18:37:30-07:00 (9 years ago)

Author:

Marek Rychlik

Message:

* empty log message *

File:

• branches/f4grobner/monom.lisp (modified) (1 diff)

branches/f4grobner/monom.lisp

@@ -536 +536 @@
 
 (defclass term (monom)
-  ((coeff :initarg :coeff :initform (error "Must specify coefficient.") :accessor term-coeff :type ring))
+  ((coeff :initarg :coeff :accessor term-coeff :type ring))
+  (:default-initargs :coeff 1)
   (:documentation "Implements a term, i.e. a product of a scalar
 and powers of some variables, such as 5*X^2*Y^3."))
 
+(defmethod initialize-instance :around ((self term) &rest initargs &key coeff)
+  "A convenience method. If a coefficient is an integer, wrap it in the INTEGER-RING object"
+  ;; Dispatch on supplied type of coefficient
+  (typecase coeff
+    (integer
+     (setf (getf initargs :coeff) (make-instance 'integer-ring :value coeff))))
+  ;; Now pass new initargs to the next method
+  (apply #'call-next-method (cons self initargs)))
+  
 (defmethod update-instance-for-different-class :after ((old monom) (new term) &key (coeff 1))
   "Converts OLD of class MONOM to a NEW of class TERM, initializing coefficient to COEFF."