> I suspect it can be done with no change to the core pcase code by
> rewriting
>
>     (pcase-defmacro \` (qpat)
>
> so it does the recursion on its own (e.g. instead of expanding `(A . B)
> to a pattern which contains `A and `B).  Then at any level if it notices
> that no `,` was found during the recursion it can just use `equal`.

The patch below does that.
For that ERC test, the resulting code is still very heavily nested, of
course, but ... less so.


        Stefan