OpenEuphoria

Re: recommendation

• Posted by George Walters <gwalters at sc.rr.com> Aug 29, 2001
• 450 views

thanks Derek. Interesting stuff...BTW were you able to unzip that file I
sent?

...george
----- Original Message -----
From: "Derek Parnell" <ddparnell at bigpond.com>
To: "EUforum" <EUforum at topica.com>
Subject: Re: recommendation


>
> Hi George,
> my general rule is that if a value is going to be used in arithmetic
> operations or numerical comparisions, then convert the text and store it
as
> a number. This is a *general* principle and there are always exceptions.
>
> For example, if you are really concerned about the speed of conversions,
you
> might store the value as both text and as a number and use either as
> appropriate at the time.
>
> Another example. Consider street addresses. Normally you would store these
> as text, but if your program had to sort addresses for some purpose, you
> might consider storing the house number as a separate numeric field so
that
> "12 Main Street" would sort after "1 Main Street".
>
> In my opinion, the Euphoria value() function is only suitable for very
> simple or specific situations. It is not a general purpose text-to-number
> conversion because it allows some malformed text to be converted and fails
> on some correctly formed text.
>
>   value("12 .10") ==> 12 (embedded space)
>   value("1.2.3")  ==> 1.2 (too many dots)
>   value("$12.10") ==> Fails, doesn't support currency symbols
>
>   value("#AF") ==> 175
>   value("#af") ==> Fails (only support upper case hex digits)
>   value("#123") ==> 291 (always assumes '#' means hex number follows)
>
>   value("1,210") ==> 1 (doesn't support thousand separator)
>
>   value("1.210") ==> 1.21 (doesn't support European thousand separator)
>   value("1,23") ==>1  (doesn't support European decimal separator)
>
>   value("2d")  ==> 2
>   value("2e")  ==> Fails (due to malformed "scientific" notation)
>   value("2f")  ==> 2
>
>   value("(1.23)") ==> Fails (doesn't support parenthesis for negative
> numbers)
>
>   value(" 1.23") ==> 1.23
>   value("-1.23") ==> -1.23
>   value("1.23-") ==> Fails (doesn't support trailing signs)
>
> A number of alternate routines have been developed by contributors to the
> Euphoria forum, so you might like to check them out before deciding to
> always use value().
>
> -----
> Derek.
>
> ----- Original Message -----
> From: "George Walters" <gwalters at sc.rr.com>
> To: "EUforum" <EUforum at topica.com>
> Sent: Thursday, August 30, 2001 2:55 AM
> Subject: recommendation
>
>
> > When writing/storing your data base records how is the best/your way of
> > dealing with numeric data. Do you save the records with the numbers
> > converted to strings and convert them back when read every time? Or do
you
> > write them as numbers and on editText entry convert those to strings
back
> > and forth from the file? I'm worried here about future ease of use in
> > reports and updates. On Theos Basic all this was handeled automatically
> > during I/O.
> >
> > ...george
> >
> >
>
>