Christopher Howard <ch.howard@zoho.com> writes:

> Hi, what does the underscore character mean in this debug output?
>
>    159:37  5 (delete ((3 . "c") (((2 . "b") (()) 1) (5 . "e") (()) 1)
> 2) 2)
>    163:49  4 (delete ((2 . "b") (()) 1) _)
>     152:9  3 (delete _ _)
>     86:11  2 (skew _)
>      64:6  1 (horizontal-left-link? _)
>     46:11  0 (left-tree _)
>
> Knowing the value of those parameters would be super helpful here, but
> for some reason they have been replaced by underscores.

My guess would be that those values are being garbage-collected. Since _
is the pattern for matching an arbitary value, it is used to denote a
garbage-collected value.