code: @Override
      public void resolve(final ValueStack values) throws Exception
      {
          if (values.size() < 2)
              throw new Exception("missing operands for " + toString());
          try
          {
              final Object op2 = values.popWhatever();
              final Object op1 = values.popWhatever();
  
              if (op2 instanceof TokVariable) { throw new Exception("invalid assignment value: " + op2.toString()); }
  
              if (op1 instanceof TokVariable && !(op2 instanceof TokVariable))
              {
                  /*
                   * Assign the value on the right side of the assignment to the
                   * variable on the left.
                   */
                  Equ.getInstance().getSupport().assignVariable(((TokVariable) op1).getValue().toString(), op2);
                  /*
                   * leave the result (value of the assignment) on the stack.
                   */
                  values.push(op2);
                  return;
              }
  
              throw new Exception("invalid assignment target: " + op1.toString());
  
          } catch (final ParseException e)
          {
              e.fillInStackTrace();
              throw new Exception(toString() + "; " + e.getMessage(), e);
          }
      }
docs: {@inheritDoc}