OpenEuphoria

Re: 3.0.3

• Posted by CChris <christian.cuvier at agriculture.gouv.fr> May 12, 2007
• 717 views

Derek Parnell wrote:
> 
> Jeremy Peterson wrote:
> > 
> > Juergen Luethje wrote:
> > > 
> > > Helo Rob,
> > > 
> > > maybe you can add something like the following to 'misc.e':
> > > }}}
<eucode>
> > > global constant
> > >    FALSE = 0,
> > >    TRUE  = not FALSE
> > > 
> > > global type boolean (object x)
> > >    if integer(x) then
> > >       return x = FALSE or x = TRUE
> > >    else
> > >       return FALSE
> > >    end if
> > > end type
> > > </eucode>
{{{

> > > 
> > > I think it would be pretty useful.
> > > 
> > > Regards,
> > >    Juergen
> > 
> > Why not just
> > 
> > TRUE = 1 
> 
> Because it removes implementation dependancies.
> 
> It is generally accepted that when the concept 'FALSE' is implemented as an
> integer, the value zero is used. However, there are quite a few different
> implementations
> of 'TRUE', some use 1, some -1, and some use every non-zero value. By defining
> 'TRUE' as 'not FALSE' it will work with any implementation.
> 
> 
> Alsoh due to a quirk in the way that short-circuit IF evaluations work, it can
> be made to execute faster when the conditions are separated out ...
> 
> }}}
<eucode>
> global constant
>    FALSE = 0,
>    TRUE  = not FALSE
> 
> global type boolean (object x)
>    if not integer(x) then return FALSE end if
>    if x = FALSE return TRUE end if
>    if x = TRUE  return TRUE end if
>    return FALSE
> end type
> </eucode>
{{{

> 
> -- 
> Derek Parnell
> Melbourne, Australia
> Skype name: derek.j.parnell

Isn't

global constant
FALSE = 0,
TRUE = not FALSE

global type boolean(integer x)
return x = x = TRUE
end type

even faster?

CChris