Method `longest_match`

[symil]

There is is_match that checks if there is a match for the given string, there is shortest_match that checks if there is a match and returns the length of the shortest match, but no method that checks if there is a match and returns the length of the longest match.

Re-using the shortest_match example, we would have:

let text = "aaaaa";
let pos = Regex::new(r"a+").unwrap().longest_match(text);
assert_eq!(pos, Some(5));

[BurntSushi]

That's what find does.

(Well, technically find is "leftmost-first" or "preference-order." This crate doesn't implement POSIX "leftmost longest" semantics.)

[BurntSushi]

And note also that shortest_match is perhaps not the best name: #747

[symil]

I was confused about what shortest_match did, sorry. I thought it stopped if the first character of the string didn't match the regex (and I thought the same about is_match). I suggest to change the example of shortest_match and have text be "baaaa" to illustrate that it's not the case. That would help clear the confusion for noobs like me who just discovered the crate.

Again sorry for the useless issue and thanks for the precision.