Is there a way to tweak Common Lisp dotimes macro so that it does not start from zero but from a different number, such as 1?

Question

I am using Emacs, Slime, and SBCL.

The default use of dotimes is:

CL-USER> (defun my-dotimes (n)
           (dotimes (i n)
             (format t "~s ~%" i)))

Which generates:

CL-USER> (my-dotimes 10)
0 
1 
2 
3 
4 
5 
6 
7 
8 
9 
NIL

I wish the function could start counting from one. I can change it with:

CL-USER> (defun my-new-dotimes (n)
           (dotimes (i (- n 1))
             (format t "~s ~%" (+ i 1))))
MY-NEW-DOTIMES
CL-USER> (my-new-dotimes 10)
1 
2 
3 
4 
5 
6 
7 
8 
9 
NIL

But, it does not feel like an elegant solution.

The official documentation mentions a declare possibility. But I am not sure how to use it.

Is there a better way to do this?

Answer 1

CL-USER 15 > (defmacro dotimes-start ((var n start
                                       &optional (result nil))
                                      &body body)
               `(loop for ,var from ,start
                      repeat ,n
                      do (progn ,@body)
                      finally (return ,result)))
DOTIMES-START

CL-USER 16 > (dotimes-start (i 10 2) (print i))

2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
NIL

CL-USER 17 > (let ((s 0))
               (dotimes-start (i 10 3 s)
                 (incf s (sin i))))
-1.8761432