I picked up used copies of the two regex books recommended in the help file under “Regular Expressions”. I see both of them for less than $10 each “used” on ebay which seems reasonable. I have dived into regular expressions on a few occasions and managed to come up with some rather complex formulas. Unfortunately I don’t use them often and it requires some extensive relearning with each new attempt. I don’t know if I’ll ever use them with any regularity so as to become proficient. I am glad I picked up these volumes just to have them on hand.
As far as web sites with some really good tutorials and examples I find the https://www.regular-expressions.info site very informative and it certainly helped me get a grasp of the basics. I think the Panorama X version of regular expressions is pretty generic and covers most common implementations.
Wikipedia provides information about the various flavors of RegEx.
Panorama uses the ICU regex engine, which is an open source project that is part of the Unicode consortium. Apple has included the ICU engine as part of it’s operating systems for close to a decade, so this engine is in very wide use.
The Wikipedia table has detailed charts about which RegEx engines support which features. I’ve never run into any of these issues myself, but I tend not to use advanced RegEx features like lookahead/lookbehind. When a task gets that complicated I generally start hand coding the solution myself (perhaps with subcomponents implemented in regular expressions).
All this said, regular expressions can be a fantastic tool, I do use them regularly and am very pleased they are now included in Panorama. I have a RegEx debugging program that I bought on the Mac App Store called RegExRx, which has great built in help menus. When I need a regular expression, I usually just fire up that program, put in some test data, and start using the menus to build up the expression.
Last year I did an introductory talk about regular expressions at the MacTech Conference. I think the it went very well, I got very positive feedback. It was recorded and is available on YouTube. I’ve never mentioned it before, because unfortunately, they messed up recording the video, and part of the screen is cut off, making it very difficult to follow. However, here is the link if you want to take a peek.
Jim, that’s all awesome, thanks so much! I feel much better about diving in. Just picked up the RegExRx from the app store, so thanks for the suggestion. And I’ll be checking out that Youtube link later tonight.