for a nice speed increase (no strlen and only one pointer dereference)
try changing
for (i = 0; i < strlen (z); i++) {
to
const char *iter;
char ch;
for(iter=z; (ch=*iter); ++iter) {
and
if (i == 0) {
to
if(iter==z) {
and all the z[i] to ch.
On 5/15/05, Michael Evenson <[EMAIL PROTECTED]> wrote:
> This fixes the problem of negative numeric values. It does not however
> handle locale specific numbers (like using , as decimal separator) or for
> that matter, commas in the numbers. As I understand it, sqlite does not
> handle locale specific numbers in general.
>
> Mike
>
>
> /*
> ** Implementation of the isnumeric() function
> */
> static void isnumericFunc(sqlite3_context *context, int argc, sqlite3_value
> **argv)
> {
> int i;
> int nResult = 1;
>
> assert( argc==1 );
> switch( sqlite3_value_type(argv[0]) ){
> case SQLITE_INTEGER: {
> sqlite3_result_int(context, 1);
> break;
> }
> case SQLITE_FLOAT: {
> sqlite3_result_int(context, 1);
> break;
> }
> case SQLITE_NULL: {
> sqlite3_result_int(context, 0);
> break;
> }
> case SQLITE_TEXT: {
> int d = 0;
> const char *z = sqlite3_value_text(argv[0]);
> for (i = 0; i < strlen (z); i++) {
> if (!isdigit (z[i])) {
> /* the character is not a digit */
> if (i == 0) {
> /* allow - or + as the first character */
> if ((z[i] != '-') && (z[i] != '+') && (z[i] != '.')) {
> /* only +, - and . allowed as first non digit character */
> nResult = 0;
> if (z[i] == '.')
> d++;
> break;
> }
> }
> else {
> if ((d > 0) && (z[i] == '.')) {
> /* only . allowed as non digit character here */
> /* and only one of them in the string */
> nResult = 0;
> break;
> }
> else if (z[i] == '.')
> d++;
> }
> }
> }
> sqlite3_result_int(context, nResult);
> break;
> }
> default: {
> sqlite3_result_int(context, 0);
> break;
> }
> }
> }
>
> > -----Original Message-----
> > From: Wolfgang Rohdewald [mailto:[EMAIL PROTECTED]
> > Sent: Saturday, May 14, 2005 8:39 AM
> > To: [email protected]
> > Subject: Re: [sqlite] Convert and isnumeric function
> >
> > On Samstag 14 Mai 2005 00:31, Michael Evenson wrote:
> > > case SQLITE_TEXT: {
> > > const char *z = sqlite3_value_text(argv[0]);
> > > for (i = 0; i < strlen (z); i++) {
> > > if (!isdigit (z[i])) {
> > > nResult = 0;
> > > break;
> > > }
> >
> > this should return FALSE for -5, 1123.456.
> > In some locales, that might be written as 1'123,456 or
> > 1,123.456 or whatever.
> >
> > strtol()
> >
> > seems to what you need, see man strol()
> >
> > --
> > Wolfgang
> >
>
>
--
Cory Nelson
http://www.int64.org
