Re: most-positive-float, most-negative-float coming up nil

[Jambunathan K]

Burton Samograd <address@hidden> writes:

> Version: "GNU Emacs 24.0.90.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1)
>  of 2011-10-07 on bsamograd-ubuntu"
>
> Just playing around with emacs lisp and I thought I would try the
> most-positive/most-negative variables to see numeric range. 
>
> most-positive-fixnum
> 2305843009213693951
> most-negative-fixnum
> -2305843009213693952
> most-positive-float
> nil
> most-negative-float
> nil
>
> Any reason why the float values are coming up nil?

M-: (info "(cl) Implementation Parameters")

Or

M-x info-display-manual RET cl RET
i most-positive-float

will land you in a page which has the following entry.

,----
|  -- Function: cl-float-limits
|      This function makes sure that the Common Lisp floating-point
|      parameters like `most-positive-float' have been initialized.
|      Until it is called, these parameters will be `nil'.  If this
|      version of Emacs does not support floats, the parameters will
|      remain `nil'.  If the parameters have already been initialized,
|      the function returns immediately.
| 
|      The algorithm makes assumptions that will be valid for most modern
|      machines, but will fail if the machine's arithmetic is extremely
|      unusual, e.g., decimal.
`----

>
> --
> Burton Samograd
>
>
>

--