Re: [TCLCORE] TIP #347: Add 'string is bignum' to the 'string is' Subcommand

[Daniel A. S. <da...@ca...>]

On Wed, Feb 11, 2009 at 22:37, Daniel A. Steffen
<da...@ca...> wrote:
> sure, my point was that [string is double] accepts all bignums,
> including those that cannot fit into a C double without loss of
> precision, or even those bigger than DBL_MAX...

leading to things like this:

% set x [expr {10**400}]
10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
% string is double $x
1
% expr {double($x)}
Inf

from the manpage text, I would not have expected an overflowing double
to be acceptable:

              double      Any of the valid forms for a  double  in  Tcl,  with
                          optional   surrounding   whitespace.    In  case  of
                          under/overflow in the value, 0 is returned  and  the
                          varname will contain -1.