如何使用多个定界符在ruby'split'中定界？

Question

I have the following code. My intend is to be able to parse the last full sentence in a string of sentences:

string = "something for nothing.  'nothing for free.'"
string.split(/!|\.|\.'|\?/)
=> ["something for nothing", "  'nothing for free", "'"]

I would like to be able to do array.last and get the last sentence, whether it ends in '!', '?', '.', or the end of a quote like, ." or .'

But when I try to include a combination, as above, it doesn't treat the .' part as a single delimiter.

Answer 1

As I can see, there are two spaces between the sentences. So just split on them, instead of using a regex, which is not needed here at all.

puts string.split("  ").last #=> 'nothing for free.'

If punctuation is guaranteed, then you can use the rex

puts string.split(/(?<=[.?!]("|'|))\s+/).last

The regex /(?<=[.?!]("|'|\\s))\\s+/ uses lookbehind and splits on the space after . or ? or ! + " or ' or space.

Answer 2

string = "something for nothing.  'nothing for free.'. Something for free? '...Everything for FREE!!!!!!...' "

string.split(/\b?\.\s|\?\s|\!\s/)

=> ["something for nothing", " 'nothing for free.'", "Something for free", "'...Everything for FREE!!!!!!...' "]