* is there an existing negate function ?
@ 2009-03-09 23:38 Mike Mattie
2009-03-10 0:22 ` Juanma Barranquero
2009-03-10 6:36 ` Drew Adams
0 siblings, 2 replies; 3+ messages in thread
From: Mike Mattie @ 2009-03-09 23:38 UTC (permalink / raw)
To: help-gnu-emacs
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is there an existing negate function ? something like this
that I have no found ?
(defun negate ( value )
"negate VALUE
Invert the boolean sense of VALUE
0 -> 1
1 -> 0
"
(if value
nil
t))
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: is there an existing negate function ?
2009-03-09 23:38 is there an existing negate function ? Mike Mattie
@ 2009-03-10 0:22 ` Juanma Barranquero
2009-03-10 6:36 ` Drew Adams
1 sibling, 0 replies; 3+ messages in thread
From: Juanma Barranquero @ 2009-03-10 0:22 UTC (permalink / raw)
To: Mike Mattie; +Cc: help-gnu-emacs
> is there an existing negate function ? something like this
> that I have no found ?
>
> (defun negate ( value )
> (if value
> nil
> t))
`null' (or its alias, `not').
Juanma
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: is there an existing negate function ?
2009-03-09 23:38 is there an existing negate function ? Mike Mattie
2009-03-10 0:22 ` Juanma Barranquero
@ 2009-03-10 6:36 ` Drew Adams
1 sibling, 0 replies; 3+ messages in thread
From: Drew Adams @ 2009-03-10 6:36 UTC (permalink / raw)
To: 'Mike Mattie', help-gnu-emacs
> is there an existing negate function ? something like this
> that I have no found ?
>
> (defun negate ( value )
> "negate VALUE - Invert the boolean sense of VALUE
> 0 -> 1
> 1 -> 0"
> (if value nil t))
I'll bite. ;-)
Is `not' (aka `null') what you mean?
(not nil) -> t
(not 'non-nil) -> nil
^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-03-09 23:38 is there an existing negate function ? Mike Mattie
2009-03-10 0:22 ` Juanma Barranquero
2009-03-10 6:36 ` Drew Adams
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