Since I am pulling most of my content from other sites such as Mahalo and Quora I thought I would pull back some of my more interesting HN comments.
Can anyone explain how this regex [- ~] matches ASCII characters?
It’s pretty simple. Assuming you know regex… Im going to assume you don’t since you are asking.
The bracket expression [ ] defines single characters to match, however you can have more then 1 character inside which all will match.
The – allows us to define the range. You can just as easily use [abc] but for long sequences such as [a-z] consider it short hand.
In this case [ -~] it means every character between and , which just happens to be all the ASCII printable characters (see chart in the article). The only bit you need to keep in mind is that is a character as well, and hence you can match on it.
You could rewrite the regex like so (note I haven’t escaped or anything in this so its probably not valid)
but that’s not quite as clever or neat.