Anti-ignore?

Anti-ignore?

[Marcin Borkowski]

Hi all,

the `ignore' function accepts any number of arguments and returns nil.
Is there a `canonical' function which would accept any number of
arguments and return t?  (Note: I /can/ implement it myself;-), I'm just
curious whether this exists - I couldn't find it.)

TIA,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

RE: Anti-ignore?

[Drew Adams]

> the `ignore' function accepts any number of arguments and returns nil.
> Is there a `canonical' function which would accept any number of
> arguments and return t?  (Note: I /can/ implement it myself;-), I'm just
> curious whether this exists - I couldn't find it.)

Not that I'm aware of.

Re: Anti-ignore?

[Pascal J. Bourguignon]

Marcin Borkowski <mbork@mbork.pl> writes:

> the `ignore' function accepts any number of arguments and returns nil.
> Is there a `canonical' function which would accept any number of
> arguments and return t?  (Note: I /can/ implement it myself;-), I'm just
> curious whether this exists - I couldn't find it.)

(funcall (constantly t) 'what 'ever) --> t

-- 
__Pascal Bourguignon__                 http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk

Re: Anti-ignore?

[Emanuel Berg]

"Pascal J. Bourguignon" <pjb@informatimago.com>
writes:

>> the `ignore' function accepts any number of
>> arguments and returns nil. Is there a `canonical'
>> function which would accept any number of arguments
>> and return t? (Note: I /can/ implement it
>> myself;-), I'm just curious whether this exists -
>> I couldn't find it.)
>
> (funcall (constantly t) 'what 'ever) --> t

That yields:

    (void-function constantly) in funcall

How about:

    (defun always-t (&rest args) t)

I suppose this can be useful when you are submitting
a function as an argument and you want it to be `t'.
You can't just submit `t' because it isn't a function.

-- 
underground experts united
http://user.it.uu.se/~embe8573

Re: Anti-ignore?

[Pascal J. Bourguignon]

Emanuel Berg <embe8573@student.uu.se> writes:

> "Pascal J. Bourguignon" <pjb@informatimago.com>
> writes:
>
>>> the `ignore' function accepts any number of
>>> arguments and returns nil. Is there a `canonical'
>>> function which would accept any number of arguments
>>> and return t? (Note: I /can/ implement it
>>> myself;-), I'm just curious whether this exists -
>>> I couldn't find it.)
>>
>> (funcall (constantly t) 'what 'ever) --> t
>
> That yields:
>
>     (void-function constantly) in funcall
>
> How about:

Indeed, you are missing this function; it's in pjb-emacs.el

;; with lexical-binding:t of course:
(defun constantly (value)
  (lambda (&rest arguments)
    (declare (ignore arguments))
    value))

-- 
__Pascal Bourguignon__                 http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk

Re: Anti-ignore?

[Nicolas Richard]

Marcin Borkowski <mbork@mbork.pl> writes:
> the `ignore' function accepts any number of arguments and returns nil.
> Is there a `canonical' function which would accept any number of
> arguments and return t?  (Note: I /can/ implement it myself;-), I'm just
> curious whether this exists - I couldn't find it.)

FWIW I once had the great idea of doing

(fset nil (lambda (&rest _) nil))
(fset t (lambda (&rest _) t))

but that didn't work quite as I wanted...

-- 
Nico.