Re: RPG Refactoring - removing GOTO - tips & techniques?

On Thu, Oct 12, 2017 at 2:07 PM, Buck Calabro <kc2hiz@xxxxxxxxx> wrote:

[Re: Option 1 - Transform GOTOs into LEAVEs in a DO loop]

This pattern is nice because when I go to add a new condition, the LEAVE
is automatic in my head due to the DO. So when I'm maintaining this a
year from now I'm unlikely to break it by adding new code. The downside
is that the DO triggers an expectation of a loop.

[Re: Option 2 - Transform GOTOs into EXSRs]

Although I've done this, I don't care for it. EXSR is hard-wired in my
head that the code will go there _and come back_ -- but it never does in
this case. The name @END_PROGRAM is a good hint about that though :-)

Charles wrote, in response to Kevin:

GOTO converted to LEAVSR only works if the GOTO is in a SR and
the going to the end of the SR.

Not the case here.

Ah, but it could be!

I can't say what Kevin's tooling does, but if you can wrap a chunk of
code in an artificial DO loop (so that you can use LEAVE), then you
could also (in principle) wrap that same chunk of code in a
subroutine, so that you can use LEAVESR.

Then leave setting the indicator and RETURN in the (syntactic) mainline.

So, something along the lines of

//syntactic mainline
exsr @MAIN;
parm12 = *in12;
return;
...
begsr @MAIN;
//semantic mainline part1
if something LEAVESR
//semantic mainline part2
if somethingelse LEAVESR
//semantic mainline part 3
endsr;

I realize it feels kind of radical to "move" so much code to "the
bottom". But it would be one way to get rid of the GOTOs without
introducing a loop.

John Y.