add regex::Match len method

[gabenodarse]

Describe your feature request

Match (regex::Match) represents a group match and has 4 methods, start, end, range, and as_str. While those methods are sufficient, I think len should be added. The reason simply is that I would prefer to use start + len rather than end, because I can't tell immediately if end refers to the last character or the 1 + the last character (it refers to 1 + the last character).

For instance, if I'm replacing a match m from original sting original_str, I would use:

original_str.replace_range(m.start() .. m.start() + m.len(), "foo")

rather than

original_str.replace_range(m.start()..m.end(), "foo")

I'm sure there are other instances where developers would prefer to use a len method, instances that make more sense than mine.

[BurntSushi]

I know you said it, but the end of a range refers to the offset immediately following the last byte in the matched range. This is idiomatic and ubiquitous in the Rust ecosystem. I do not think a len method should be added for your use case because I consider using m.start() + m.len() to be quite odd given that m.end() exists. It's also potentially more costly, depending on whether the compiler optimizes it correctly or not.

Another idea here might be to add a range method that returns a std::ops::Range.

[gabenodarse]

Thank you for the response. That end() refers to 1 after the last byte is what I would expect, but I had not seen (enough) similar functions to be confident of that. It is good to know that it is idiomatic and ubiquitous.