Re: pcase and minus-sign

[Andreas Röhler]

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.

>