A normal character, a character class, or a parenthesized regular expression.
atom :: = Char | charClass | ('(' regExp ')')
The following table shows valid atoms R and the description for their set of strings L(R).
Valid atoms R for normal characters c, character classes C, and regular expressions S | Set of strings L(R) |
---|---|
c | The single string consisting only of normal characters. |
C | All strings in L(C). |
(S) | All strings in L(S). |
XML Schema Regular Expressions | XML Schema Regular Expressions Reference Chart | Character Classes | Normal Character | Data Type Facets