This regex matches a single one-line C-like string literal. The parsing rules are almost exactly the same as C string literals:

• A string literal can be surrounded by either single or double quotes, but they must match.
• In a double quoted string, single quotes can optionally not be preceded by a backslash. And vice versa.
• In a double quoted string, double quotes must be escaped. And vice versa.
• Backslashes themselves must be escaped.
• Any character but a newline, line-feed, or space can follow a backslash, so this regex can be used with any programming language.

The group <begin_quote> stores the quote character that the string literal is surrounded with.