I’ve decided to take on the masochistic task of getting my hands dirty with
NSRegularExpression. Here are some of my thoughts and findings:
– Regex is voodoo. What’s worse, it’s not even standardized. So all the tutorials on the web are not platform agnostic. I could use a recipe to match the things I’m interested in, but when creating an instance of
NSRegularExpression on iOS, it fails as “invalid pattern”.
– Because of this, you WILL become a test driven developer. 🙂
– Start with a simple regex pattern that detects PARTS of what you’re looking to match, then add complexity. This way you can see what part of your pattern is failing.
– Don’t use the Number Sign # as a matchable character. It is protected but not documented! Use \u0023 instead. e.g. “\\b
– When you map/inspect your NSTextCheckingResult objects, it should have the same number of ranges as you have capture groups. You use these to get more specific about which capture groups were involved in the match. (Provides more granularity/control). The NSTextCheckingResult.range represents the range in the text associated with that one result!
– NSRegularExpression really doesn’t deal well with the hash symbol (sharps).
I ultimately reached a solution, but it never felt entirely ‘correct’ despite finding a way to produce the correct results.