Matches are represented by the following dict structure:
match: String, what the regex matchedstart: Number, start position in the source of the matchend: Number, end position in the source of the matchgroups: List of String, the groups the regex matched. Can be empty if the regex didn’t have any group
Regular expression syntax (google/re2 wiki/Syntax)
Regular expressions are a notation for describing sets of character strings. When a particular string is in the set described by a regular expression, we often say that the regular expression matches the string.
