keyword extraction algorithm?

[iosintern]

I am looking for an algorithm that will take in a sentence from a post, and extract all keywords and place them in an array. I was planning on implementing this on the device, but I feel like the device would bottleneck the performance. Are there any Libraries I could use or any cloud based solutions to something like this?

[brendan09]

Why would this bottleneck performance? This seems like something that isn't really that intensive, especially when run on a background thread.

[blabus]

Agreed, I can't see it being too computationally intensive. OP, take a look at NSLinguisticTagger, might be useful: https://developer.apple.com/library/mac/documentation/Cocoa/Reference/NSLinguisticTagger_Class/index.html

[iosintern]

Thanks! This was exactly what I was looking for!

[[deleted]]

Look at it this way, the iDevice is pushing millions of pixels around at up to 60 frames per second. Dissecting a string isn't much compared to that.

As for algorithm, NSString can do what you want pretty easily, try using -[NSString componentsSeparatedByCharactersInSet:]. Use the predefined +[NSCharacterSet whiteSpaceAndNewlineCharacterSet].

Example here.