Re: Latest RPG Updates

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Oops, sorry... got my terms mixed up, I meant "overloaded prototype" 
rather than "candidate prototype".


On 10/8/2019 12:34 PM, Scott Klement wrote:
> Yeah, it mostly makes sense to me.   The one thing that seems weird is 
> the need for a return value on the prototype with the OVERLOAD keyword 
> (i.e. the "candidate prototype")   Since all of the prototypes have to 
> have the same return value (I think?) and the candidate prototype 
> doesn't need parameters coded, why does it have a return value coded?  
> That's weird to me.
>
>
> On 10/8/2019 12:32 PM, Vernon Hamberg wrote:
> > No need to presume - look at the article - it's pretty simple and 
> > elegant, as Barbara usually does things.
> >
> >
> >    *Overloaded prototypes*
> >
> > The OVERLOAD keyword defines a list of other prototypes that can be 
> > called using the name of the prototype with the OVERLOAD keyword. 
> > When the prototype with the OVERLOAD keyword is used in a call 
> > operation, the compiler uses the parameters specified for the call to 
> > determine which of the candidate prototypes listed in the OVERLOAD 
> > keyword to call.
> >
> > In the following example, FORMAT is defined with the OVERLOAD 
> > keyword. For the first call to FORMAT, the parameter has type Date, 
> > so FORMAT_DATE is called. For the second call to FORMAT, the 
> > parameter has type Time, so FORMAT_TIME is called. For the second 
> > call to FORMAT, the parameters have type Character, so FORMAT_MESSAGE 
> > is called.
> >
> >    DCL-PR format_date VARCHAR(100);
> >        dateParm DATE(*ISO) CONST;
> >    END-PR;
> >    DCL-PR format_time VARCHAR(100);
> >        timeParm TIME(*ISO) CONST;
> >    END-PR;
> >    DCL-PR format_message VARCHAR(100);
> >        msgid CHAR(7) CONST;
> >        replacement_text VARCHAR(100) CONST OPTIONS(*NOPASS);
> >    END-PR;
> >    DCL-PR format VARCHAR(100) OVERLOAD(format_time : format_date :
> >    format_message);
> >    DCL-S result varchar(50);
> >
> >    result = format(%date());              // 1
> >    result = format(%time());              // 2
> >    result = format('MSG0100' : filename); // 3
> >
> >
> >
> > On 10/8/2019 12:11 PM, Justin Taylor wrote:
> > > OVERLOAD!!!
> > >
> > > Presumably, the overload will be a prototype only without a 
> > > procedure.  How will that work with exported procedures?
> > >
> > > I assume you'll still be able to call the real procedures directly.  
> > > That would be less than ideal, but understandable.
> > >
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Jon Paris [mailto:jon.paris@xxxxxxxxxxxxxx]
> > > Sent: Tuesday, October 08, 2019 11:46 AM
> > > To: RPG programming on IBM i <rpg400-l@xxxxxxxxxxxxxxxxxx>
> > > Subject: Latest RPG Updates
> > >
> > > I see Barbara has posted this elsewhere but I know of many on this 
> > > list who have been waiting for procedure overloading. Yay!  It is 
> > > here ands I love it!
> > >
> > > Also (although not quite as requested) we now have "XML-FROM" in the 
> > > form of DATA-GEN which is kind of Open Access meets DATA-INTO (but 
> > > backwards).  You'll have to wait for meaningful examples of this one 
> > > but I'll be putting out an article on procedure overloading in a 
> > > couple fo weeks.
> > >
> > > Link to the basic details is here: 
> > > http://ibm.biz/fall_2019_rpg_enhancements 
> > > <http://ibm.biz/fall_2019_rpg_enhancements>
> > >
> > >
> > > Jon Paris