Re: Do-loop enigma with two variables

[Mike Gran]

On Friday, July 15, 2016 7:27 AM, Pierre Lairez <address@hidden> wrote:

>
>
>Dear guile users,
>
>When running the following loop:
>(do ((i 1 (+ 1 i))
>     (j 0 i))
>    ((> i 4) (newline))
>  (display (list i j)))
>
>I expect without hesitation to read
>(1 0)(2 1)(3 2)(4 3)
>
>To my surprise, I obtain
>(1 0)(2 2)(3 3)(4 4)


Yeah, I get the same in 2.0.11

I don't know the correct terminology

The "i" in (j 0 i) is a reference to

the "i" that is bound (+ 1 i).

You can prove this by running the following

(do ((i 1 (+ 1 i)) (j 0 (+ i 0)))
  ((> i 4) (newline))
  (display (list i j)))