[GRASS-dev] G_is_double()

GRASS GIS GRASS GIS developer
1

Hi all,

I would like to add to the GIS library (strings.c) new fns
G_is_double(char *str) and G_is_int(char *str). Any objections?

Martin

--
Martin Landa <landa.martin@gmail.com> * http://gama.fsv.cvut.cz/~landa *

2

Martin Landa wrote:

I would like to add to the GIS library (strings.c) new fns
G_is_double(char *str) and G_is_int(char *str). Any objections?

With what definition? E.g. does G_is_double() recognise numbers
without a point? Does it use the locale's decimal separator or always
a dot? Does G_is_int() recognise octal/hex? What about a leading "+"
sign?

Personally, I suggest leaving this to the modules. Otherwise,
whichever syntax you choose, code well tend to use the library
functions regardless of whether their syntax is appropriate for the
specific purpose.

--
Glynn Clements <glynn@gclements.plus.com>

3

Glynn,

2007/11/25, Glynn Clements <glynn@gclements.plus.com>:

> I would like to add to the GIS library (strings.c) new fns
> G_is_double(char *str) and G_is_int(char *str). Any objections?

With what definition? E.g. does G_is_double() recognise numbers
without a point? Does it use the locale's decimal separator or always
a dot? Does G_is_int() recognise octal/hex? What about a leading "+"
sign?

Personally, I suggest leaving this to the modules. Otherwise,
whichever syntax you choose, code well tend to use the library
functions regardless of whether their syntax is appropriate for the
specific purpose.

hm, I was thinking simply about

int G_is_double(char *str)
{
    char *tail;

    if (strtod (str, &tail),
  tail == str || *tail != '\0') {
  /* doesn't look like a number,
     or has extra characters after what looks to be a number */
  return 0;
    }

    return 1;
}

int G_is_int(char *str, int base)
{
    char *tail;

    if (strtol (str, &tail, base),
  tail == str || *tail != '\0') {
  /* doesn't look like a number,
     or has extra characters after what looks to be a number */
  return 0;
    }

    return 1;
}

Maybe doesn't make sense so much.

Martin

--
Martin Landa <landa.martin@gmail.com> * http://gama.fsv.cvut.cz/~landa *