BTW, here is something I didn't expect:
`M-: 0.0e+NaN' returns -0.0e+NaN
`M-: -0.0e+NaN' returns 0.0e+NaN
The reader seems to flip the (irrelevant) sign.
I fixed that. Thanks.
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Drew Adams wrote:
Does anyone know that these are not equivalent:
(equal 0.0e+NaN) <=?=> (and (numberp x) (/= x x))
That is, are there any objects equal to 0.0e+NaN that are not NaN?
They are equivalent. internal_equal contains:
case Lisp_Float:
{
double d1, d2;
(equal 0.0e+NaN) <=?=> (and (numberp x) (/= x x))
That is, are there any objects equal to 0.0e+NaN that are not NaN?
They are equivalent. internal_equal contains:
...
/* If d is a NaN, then d != d. Two NaNs should be `equal' even
though they are no
> I didn't say above that (/0.0 0.0) should give `arith-error'.
Well, you seemed to: you complained that it did so in previous
versions.
No, I said "fair enough" to that change in behavior. I did not suggest it
was a bug. My question was about numberp's behavior:
> I suggested th
> From: "Drew Adams" <[EMAIL PROTECTED]>
> Date: Fri, 24 Jun 2005 13:26:23 -0700
>
> I didn't say above that (/0.0 0.0) should give `arith-error'.
Well, you seemed to: you complained that it did so in previous
versions.
> I suggested
> that perhaps `numberp' should return nil for a NaN argument,
Drew Adams wrote:
That doesn't tell me how to test if `foobar' is a NaN. See my previous
email: I knew I could test `(equal foo 0.0e+Nan)', but I thought I would
need to test against all of the possible NaN values.
The GNU C library has an isnan macro. From Lisp you could do:
(defun
Drew Adams wrote on 24 Jun 2005 22:26:23 +0200:
> That doesn't tell me how to test if `foobar' is a NaN. See my previous
> email: I knew I could test `(equal foo 0.0e+Nan)', but I thought I would
> need to test against all of the possible NaN values.
You just need to test (= foobar foobar)
--
> (numberp (/0.0 0.0)) returns t. That seems like a bug to me.
Maybe it is, maybe it isn't. (elisp)Arithmetic Operations says:
If you divide an integer by 0, an `arith-error' error is signaled.
(*Note Errors::.) Floating point division by zero returns either
i
Still following up on my own post:
(condition-case nil (setq foo (/ 0.0 0.0)) (arith-error nil))
In older versions of Emacs (at least prior to April 2005 CVS),
this would evaluate to nil. Now, it evaluates to -0.0NaN.
I can modify the code like so:
(and (condition-case nil (setq foo (/ 0
> From: "Drew Adams" <[EMAIL PROTECTED]>
> Date: Fri, 24 Jun 2005 12:33:53 -0700
>
> (condition-case nil (setq foo (/ 0.0 0.0)) (arith-error nil))
> In older versions of Emacs (at least prior to April 2005 CVS),
> this would evaluate to nil. Now, it evaluates to -0.0NaN.
> I can m
Consider this:
(condition-case nil (setq foo (/ 0.0 0.0)) (arith-error nil))
In older versions of Emacs (at least prior to April 2005 CVS), this would
evaluate to nil. Now, it evaluates to -0.0NaN (on Windows, at least), which
breaks the encompassing code (which tests the above expression for non
I said this:
(condition-case nil (setq foo (/ 0.0 0.0)) (arith-error nil))
In older versions of Emacs (at least prior to April 2005 CVS),
this would evaluate to nil. Now, it evaluates to -0.0NaN.
I can modify the code like so:
(and (condition-case nil (setq foo (/ 0.0 0.0)) (a
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