In general is it ok to loop if statements with goto under else?

Question

So I have a task to be done which is to program the robot (AUBO) to pick different objects and place them in a certain order (Point A, B, C, D). I'm using some vision system known as pim60. So if an object is detected it will go and pick and the rest of the program are waypoints to drop products. The first problem is I want it to go to the next waypoint to drop the and the second thing is, the next drop point cannot be skipped until an object is detected for that drop point.

In my own code, I wrote a rather lengthy program like this.

::LoopA::
script_common_interface("SICKCamera","takePhoto")
script_common_interface("SICKCamera","getResult")
Located = script_common_interface("SICKCamera","partLocated")
if(Located == 1) then
.
.
.
Drop at position A
else 
goto LoopA
end

::LoopB::
script_common_interface("SICKCamera","takePhoto")
script_common_interface("SICKCamera","getResult")
Located = script_common_interface("SICKCamera","partLocated")
if(Located == 1) then
.
.
.
Drop at position B
else 
goto LoopB
end

::LoopC::
script_common_interface("SICKCamera","takePhoto")
script_common_interface("SICKCamera","getResult")
Located = script_common_interface("SICKCamera","partLocated")
if(Located == 1) then
.
.
.
Drop at position C
else 
goto LoopC
end

::LoopD::
script_common_interface("SICKCamera","takePhoto")
script_common_interface("SICKCamera","getResult")
Located = script_common_interface("SICKCamera","partLocated")
if(Located == 1) then
.
.
.
Drop at position D
else 
goto LoopD
end

There is no error and the program runs as expected. However, I'm wondering if there is any better way to do it.

What language are you programming the robot in? It doesn't appear to be Lua. — Jack Taylor, Jun 14 '19 at 11:40
My noobish program makes it appear so. And I had posted incorrect stuff after not touching the code for some time. — TheNooblet, Jun 14 '19 at 13:05
I've just planned to turn the common occurring lines such as commands sending to the external vision system, extracting of object location and intermediate waypoints into a function I suppose this would make the code neater. — TheNooblet, Jun 14 '19 at 13:11
what is the difference between each position? is it just the code in the if statement? — Nifim, Jun 14 '19 at 16:47
Yes it is only just within the if statements containing different drop points. — TheNooblet, Jun 15 '19 at 03:20

maxy · Accepted Answer · 2019-06-14T16:53:02.587

1

The only generally accepted use-case for goto is error handling, e.g. to jump forward to the cleanup code. But even for that it usually can and should be avoided.

You can probably do something like this:

-- loop B
repeat
  take photo, etc.
  located = ...
until(located == 1)

Drop at position B

Also, if you're repeating the same code three times, you should extract it into a function, and maybe give the position as a parameter. Or at least put the whole thing into a for loop.

edited Jun 14 '19 at 16:53

answered Jun 14 '19 at 16:41

maxy

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The question is tag with Lua as it's language, might not have been when you started writing your answer – Nifim Jun 14 '19 at 16:44
fair point, fixed that; the question seemed rather a general programming question – maxy Jun 14 '19 at 16:54
Either way, this has been a lot of help for a guy that did less of my own due diligence and came straight asking. THANKS VERY MUCH! – TheNooblet Jun 15 '19 at 03:07

In general is it ok to loop if statements with goto under else?

1 Answers1