XQuery uses “smiley faces” to begin and end comments. This cheerful notation was originally suggested by Jeni Tennison. Here is an example of a comment:
(: Thanks, Jeni! :)
Note that XQuery comments are comments found in a query. XML documents may also have comments, like the comment found in an earlier example:
<!— document order —>
XQuery comments do not create XML comments—XQuery has a constructor for this purpose, which is discussed later in the section on constructors.
XQuery supports three kinds of numeric literals. Any number may begin with an optional + or – sign. A number that has only digits is an integer, a number containing only digits and a single decimal point is a decimal, and any valid floating-point ...