Learning how to use the Prolog Command Line Debugger? Try this new overview!

I’m looking to replace the current command line debugger tutorial, with a new one that is more detailed and has a walkthrough. Try it out and let me know your feedback in this topic.

I’m especially interested in knowing how it worked for people that are new to the command line debugger, but all feedback is appreciated!


Thank you for explaining trace points vs. spy points vs. break points - I could never sort this out until now with your explanation! Sometimes it felt harder to understand the tracer than finding the bug in my code.


Great! That frustration is why I wrote it, it was very confusing to me as well.

If you have time, try out the new version of the graphical debugger overview too and let me know any feedback you have there as well. Kudos or suggestions are all appreciated, I want to know what works and what doesn’t. I want to make these tools as approachable as possible!

This is amazing! Well done @ericzinda

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This is a great tutorial. Maybe it should be included in the official documentation at https://www.swi-prolog.org/pldoc/man?section=debugoverview.

Thank you! Yes that is the plan.


Maybe I should first sync some of the Markdown differences to make your work easier :slight_smile: The tables and `name/arity` should not be too hard.

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Great, thanks! I’ll wait to submit the graphical debugger one until I get those changes.

I just read through the graphical debugger tutorial, I must say that you are quite talented in writing documentation; I am glad you are contributing it to SWI-Prolog.


Thank you! I’ve gotten a lot of value from SWI Prolog so I’m glad to be able to contribute.

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