on1 construct

[Doug Gwyn <gwyn>]

> I've started functions in the following way:
> 
> function ()
> {
>     static char first_time_in = TRUE;
> 
>     if (first_time_in)  {
>         first_time_in = FALSE;
> 	bla, bla, bla...
>     };
> 
>     etc...
> }
> 
> One contruct that I've always wanted to have is:
> 
> function ()
> {
>     on1  {
> 	bla, bla, bla...
>     };
> 
>     etc...
> }
> 
> I've been trying to define a macro to do this but haven't been succesful.

Try:

#define	on1	static long on1_flag = 0L; if ( on1_flag++ == 0L )

There are other tricks if you don't like this one.  Remember, the
condition inside the "if" parentheses can accomplish as many side
actions as desired.