0.25_regular_expressions_elements_regexp_sequence.js

// A regexp sequence contains one or more regexp factors. Each factor can optionally be
// followed by a quantifier that determines how many times the factor is allowed to
// appear. If there is no quantifier, then the factor will be matched one time.

// A regexp factor can be a character, a parenthesized group, a character class, or an
// escape sequence. All characters are treated literally except for the control characters
// and the special characters:
\ / [ ] ( ) { } ? + * | . ^ $
// which must be escaped with a \ prefix if they are to be matched literally. When in
// doubt, any special character can be given a \ prefix to make it literal. The \ prefix
// does not make letters or digits literal.
// An unescaped . matches any character except a line-ending character.
// An unescaped ^ matches the beginning of the text when the lastIndex property is
// zero. It can also match line-ending characters when the m flag is specified.
// An unescaped $ matches the end of the text. It can also match line-ending characters
// when the m flag is specified.