Re: pcase and minus-sign

["Andreas Röhler" <andreas.roehler@easy-emacs.de>]

On 02.12.2016 03:30, Stefan Monnier wrote:
>>>> But what make the char `a' so special WRT char `1'?:
>>>>
>>>> (defun foo (arg)
>>>> (interactive "P")
>>>> (pcase arg
>>>> (1 (message "%s" "ARG was `1'"))
>>>> (a (message "%s" "ARG was `a'"))
>>>> ('- (message "%s" "ARG was minus-sign"))
>>>> (_ (message "%s" "ARG not minus-sign"))))
>>> The same thing that makes it different in "normal" Lisp code. 1 is read as
>>> an integer, not as a symbol.
>> Thanks all again!
> BTW, the driving idea behind the shape of pcase patterns is more or less
> that a pattern PAT matches the value V if an expression PAT could
> evaluate to the value V.

Must confess some hardship of understanding. If an expression may 
evaluate to a certain value or not, that depends resp. may depend on the 
state at run-time. Can't see how that makes sense here.

>