Write `var0, var1, var2, ..., var10` in a buffer

Question

Most of the times there is no need to write manually many variables with the same name and a different index, like

var0, var1, var2, var3, ..., var9

because one can use arrays, vectors or whatever the language offers.

Anyway, I just needed to write manually ten variables as shown above. What is the fastest way to do it with emacs?

I guess that the fastest way is to write some elisp code. I tried doing it with this code

(setq i 0)
    (while (< i 10) (print (format "var%d, " i)) (setq i (+ 1 i))

followed by (insert-last-message) defined here. It does not work (I get "(#o0, #x0, ?\C-@)").

What's wrong here? Is there any faster way?

Answer 1

The fastest way is to use the macro counter:

C-x( starts recording a macro
varF3,space inserts 0 as the initial value of the counter
M-1M-0 repeat the following 10 times
C-xe execute the macro

Answer 2

print will output to the echo area rather than putting stuff in your buffer. You're looking for insert and dotimes:

(dotimes (i 10) (insert (format "var%d, " i)))

(alternatively you can use keyboard macros for this)

Answer 3

I'd use a macro just as @choroba did (with F3 in place of C-x ( and F4 instead of C-x e, for brevity and to be able to easily specifying a non-zero starting number, as @DoMiNeLa10 mentioned), but if you want a possibly more ergonomic solution, there is abo-abo's tiny package. You'd type m0, 9|var%d into your buffer, and then execute tiny-expand and it would replace m0, 9|var%d with:

var0, var1, var2, var3, var4, var5, var6, var7, var8, var9

for you. (I used it just now to type that.)

Notice that the comma and space between 0 and 9 are used as a separator, that is, you don´t get an extra one at the end like you would with the most straightforward macro.

Answer 4

If you use lispy (https://github.com/abo-abo/lispy), you can do this:

1. Enter (s-join ", " (loop for i below 10 collect (format "var%s" i))) into your elisp buffer. At the end of the sexp, type xr which will evaluate and replace the sexp with a string in quotes. Type C-b to get the cursor on the last quote, then type C-u " to unquote the string.

alternatively, if you type the code @rpluim suggested, and type xr, it will also replace it with about the same thing, you just have to delete a nil and the last comma.

I am not sure it is faster than a macro counter, but since I like lispy, it is a nice solution for me.