package ecaml

Exactly s matches exactly the string s (e.g., '.' only matches '.')

Pattern s interprets s as a regexp (e.g., '.' matches any character)

Matches zero characters, but only where the point is.

Text matched by Submatch can be retrieved using Regexp.Last_match.text_exn ~subexp:index.

index is the number of parentheses to the left of this submatch in the regexp pattern.

Text matched by Submatch_n can be retrieved using Regexp.Last_match.text_exn ~subexp:index.

index must be at least the number of parentheses left of this submatch in the regexp pattern. If index is greater, it will shadow the submatch that would have been assigned that index. If index is less, then it is an error to use the resulting regexp.