Re: pcase and minus-sign

[Joost Kremers <joostkremers@fastmail.fm>]

On Wed, Nov 30 2016, Andreas Röhler wrote:
> Hi,
>
> see code below. With numerical argument "1", first pattern is 
> matched as 
> expected.
>
> However without arg the minus is matched - the second pattern, 
> not the 
> default "_" at last.
>
> Any explanation?
>
> (defun foo (arg)
>    (interactive "P")
>    (pcase arg
>      (1 (message "%s" "ARG was `1'"))
>      (- (message "%s" "ARG was minus-sign"))
>      (_ (message "%s" "ARG not minus-sign"))))

Probably because - is a symbol and hence a variable. It works if 
you quote it:

(defun foo (arg)
  (interactive "P")
  (pcase arg
    (1 (message "%s" "ARG was `1'"))
    ('- (message "%s" "ARG was minus-sign"))
    (_ (message "%s" "ARG not minus-sign"))))



-- 
Joost Kremers
Life has its moments