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From: David Mark on 31 May 2010 10:44
On May 31, 5:12 am, Ry Nohryb <jo...(a)jorgechamorro.com> wrote:
> On May 30, 6:28 pm, Dr J R Stockton <reply1...(a)merlyn.demon.co.uk>
> wrote:
>
> > (...)
> > Opera 10.10, but not Opera 10.53 : Number.toString(radix) ignores
> > radix.
>
> There's a bug in Safaris also:
>

Also? It's been demonstrated that there is no such bug in Opera
10.10.
From: Ry Nohryb on 31 May 2010 10:55
On May 31, 4:14 pm, "Evertjan." <exjxw.hannivo...(a)interxnl.net> wrote:
> Ry Nohryb wrote on 31 mei 2010 in comp.lang.javascript:
>
> >  /* get the digits that are valid for this base */
> >   validDigits= "0123456789abcdefghijklmnopqrstuvwxyz".substr(0, base);
>
> nice!
>
> >   /* validate structure and contents of the input str : */
> >   /* ^ (optional) whitespace + (optional) a single char [-+] */
> >   /* + (non-optional) 1 or more validDigits + (optional) a point */
> >   /* + (optional) more validDigits + (optional) whitespace $ */
> >   n= "^\\s{0,}([-+]{0,1})(["+ validDigits+ "]{1,})[.]{0,1}(["+
> > validDigits+ "]{0,})\\s{0,}$";
>
> This would fail for 'pointfractions', like ".56ab" and "-.2"
>
> In short:
>
>  n='^\\s*([-+]?)(['+validDigits+']+)\\.?(['+validDigits+']?)\\s*$';
>
> However, to allow for such pointfractions would need something like this:
>
>  n1='^\\s*([-+]?)(['+validDigits+']+)\\.?(['+validDigits+']?)\\s*$';
>  n2='^\\s*([-+]?)()\\.(['+validDigits+']?)\\s*$';
>
>  n = n1 + '|' + n2
>
> or
>
>  n1 = '^\\s*([-+]?)'
>  n2a = '(['+validDigits+']+)\\.?'
>  n2b = '()\\.'
>  n3 = '(['+validDigits+']?)\\s*$';
>
>  n = n1 + '(?:' + n2a + '|' + n2b + ')' + n3
>
> not tested.

Hmmm, I think I just have to make that part optional in the regexp
({0,} instead of {1,}), and guard n[2] with || "0" in the call to
parseInt() :

String.prototype.toFP= function (base, n, r, w, div) {
//20100531 by jorge(a)jorgechamorro.com

/* check that base is in range and an integer */
if ((base < 2) || (base > 36) || (base % 1)) return NaN;

/* get the digits that are valid for this base */
validDigits= "0123456789abcdefghijklmnopqrstuvwxyz".substr(0, base);

/* validate structure and contents of the input str : */
/* ^ (optional) whitespace + (optional) a single char [-+] */
/* + (non-optional) 1 or more validDigits + (optional) a point */
/* + (optional) more validDigits + (optional) whitespace $ */
n= "^\\s{0,}([-+]{0,1})(["+ validDigits+ "]{0,})[.]{0,1}(["+
validDigits+ "]{0,})\\s{0,}$";

/* exec n on 'this' now, case-insensitively, and reuse n*/
if (!(n= new RegExp(n, "i").exec(this))) return NaN;

/* got captured : */
/* n[1]= sign, n[2]=integer part, n[3]= fractional part */

if (isFinite(r= parseInt(n[2] || "0", base)) && (w= n[3].length)) {
/* trim until div is finite */
while (!isFinite(div= Math.pow(base, w))) w--;
r+= parseInt(n[3].substr(0, w), base)/ div;
}

/* sign is one of "1" or "+1" or "-1" */
return (n[1]+ "1")* r;
};

"-.8".toFP(10)
--> -0.8
--
Jorge.
From: Stefan Weiss on 31 May 2010 11:16
On 31/05/10 16:55, Ry Nohryb wrote:
> On May 31, 4:14 pm, "Evertjan." <exjxw.hannivo...(a)interxnl.net> wrote:
>> This would fail for 'pointfractions', like ".56ab" and "-.2"
....
> Hmmm, I think I just have to make that part optional in the regexp
> ({0,} instead of {1,}), and guard n[2] with || "0" in the call to
> parseInt() :

Since you like short code:

{0,} is the same as *
{1,} is the same as +

:)


--
stefan
From: Evertjan. on 31 May 2010 12:54
Stefan Weiss wrote on 31 mei 2010 in comp.lang.javascript:

> Since you like short code:
>
> {0,} is the same as *
> {1,} is the same as +

and {0,1} is ?

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)
From: Ry Nohryb on 31 May 2010 13:07
On May 31, 5:16 pm, Stefan Weiss <krewech...(a)gmail.com> wrote:
>
> Since you like short code:
>
>   {0,} is the same as *
>   {1,} is the same as +
>
> :)

Yes, but, don't you find their -the regExps'- syntax sufficiently
confusing and unintelligible enough without the shortcuts ? Whose sick
mind invented such an ugly thing ? :-)
--
Jorge.
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