Re: RPG read loops

[James Rich <james@xxxxxxxxxxx>]

On Tue, 1 Feb 2005, Paul Morgan wrote:

> You could code your own procedure:
>
> P ReadMore     B
> D ReadMore     PR       N
> /Free
>  Return Not %Eof(FileToRead);
> /End-Free
> P ReadMore      E
>
> Then your read loop would be:
>
> Read FileToRead;
> DoW ReadMore();
>  // do something
>  Read FileToRead;
> EndDo;

But this doesn't do what was asked.  The example was:

> > DoW  %read(FileToRead)
> > .....
> > EndDo

The read is done when the dow is evaluated.  Using your approach above 
doesn't gain you anything.  But doing the read *at the time of the DOW 
evaluation* is very nice as it 1. reduces the number of lines and 2. makes 
clear under what conditions the loop continues.  Some psuedo-code to 
implement this might look like:

P readmyfile      B
D readmyfile      PR
C          read  myfile
           return %EOF
P readmyfile      E

For this to work %EOF would have to be off on a successful read.  Then you 
could code what was asked for:

dow (readmyfile <> %EOF)

James Rich

It's not the software that's free; it's you.
        - billyskank on Groklaw