regex can be very difficult for a human to read and to comprehend. That is why,
like any good code, a good regular expression must be well formatted and documented.
Here are some guidelines when formatting and documenting your regex:
1. Keep each line under 80 characters, horizontal scrolling reduces readability.
2. Break long patterns into multiple lines, usually after a space or a line break.
3. Indent bracers to help think in the right scope.
4. Format complicated OR patterns into multiple blocks like a case statement.
5. Comment your regex on what it does, don't just translate it into English.
Bad example: Comment that translates the regex into English.
Good example: Comment that explains the purpose of the pattern.
Bad Example: Pray you never have to modify this regex.
Good Example: Now it make sense!