alt Hacker NewsI believe this is the regular syntax for a set of characters (between "[" and "]"), but the caret symbol ("^") is negation when used inside the set. Therefore, it is simply the negation of an empty set of characters.
I believe this is the regular syntax for a set of characters (between "[" and "]"), but the caret symbol ("^") is negation when used inside the set. Therefore, it is simply the negation of an empty set of characters.