Breakpoint properties and conditions

Peter Muraya · Post by **Peter Muraya** » 11 Sep 2015 5:36

Hi,
I was looking for a way of specifying a condition for stopping at a breakpoint when I opened its properties. I found 2 fields: comment and action.
The comment is the text that appears when you hover over the breakpoint marker; has anybody found this to be useful?
What about action? What is it intended for? What do I type in there?
Is it possible to specify a break condition at all?

Post by **Thomas Linder Puls** » 11 Sep 2015 9:07

Comment also appears in the breakpoint window, where it may be more relevant.

The action field is a non-documented and unsupported feature.

Ferenc Nagy · Post by **Ferenc Nagy** » 14 Sep 2015 5:07

The action field is a non-documented and unsupported feature.

Does it work at all?
Is it really non-documented?

Post by **Thomas Linder Puls** » 14 Sep 2015 11:22

Ferenc Nagy wrote:Does it work at all?

Yes, but it is unsupported.

Ferenc Nagy wrote:Is it really non-documented?

Yes.

Peter Muraya · Post by **Peter Muraya** » 23 Sep 2015 17:37

Thomas,
The first attachment shows a point in the code where I want to break and observe certain variables under some condition. The problem is that very often I have to Debug Run very many times before I get to the condition of interest (and that is tiresome). I solve this by doing what is illustrated in the 2nd attachment: adding an if statement and breaking on the desired condition. This happens so often (and sometimes I forget to remove the extra code after debugging) that I wish conditional breaking was supported. Is there an alternative to my approach? Is it likely that future versions of Prolog will support conditional breakpoints?

Post by **Thomas Linder Puls** » 23 Sep 2015 19:04

See Debugging tips: nothing.

Peter Muraya · Post by **Peter Muraya** » 24 Sep 2015 5:13

Thanks Thomas.
I see; with core::nothing(...) my concerns are sufficiently addressed.

Harrison Pratt · Post by **Harrison Pratt** » 24 Sep 2015 21:45

Thanks, Thomas, and thanks also to Peter for starting this thread. There will be dancing in the streets!

Peter Muraya · Post by **Peter Muraya** » 25 Sep 2015 10:07

Thank you Harrison.
When I got this response from Thomas, I searched this forum for further tips on debugging. I found 2 that I think are very useful.

The first one was Run in Window which allows me to see outputs without having to always include a readchar()=_ as in this sample:-

Code: Select all

run() :-
         X= array2M{integer}::newAtomic(2,2),
         I = X:get(0,0),
         stdio::write(I).,
         stdio::readChar()=_.

The second one was a way of navigating the code while not running it (in a way I was not aware of): Go to Position on Clipboard.. Thomas has a video that explains it very well.

Post by **Thomas Linder Puls** » 25 Sep 2015 13:15

The mentioned video is on youtube: Dump Demo - Visual Prolog 7.3 - IDE demonstration.

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