XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (807 page)

Comment (XML)

Markup in an XML document that is conventionally used to carry extraneous information that is not part of the document proper. Written between the delimiters

.

Comment Node (XPath)

A
node
in a
tree
representing an XML
comment
. The
string value
of the node is the text of the comment.

Complex Type (Schema)

A
schema type
that describes the structure of
elements
that may have
child
elements or
attributes
. If the type permits attributes but not child elements, it is referred to as a complex type with simple content.

Constructor Function (XPath)

A
function
that constructs an
atomic value
of a particular
type
. The function has the same name as the target
atomic type
, and always takes a single argument. A constructor function is created automatically for every
atomic type
, including user-defined atomic types. An example of a call on a constructor function is
xs:date(“2008-02-29”)
. The semantics of constructor functions are defined by reference to the rules for
cast
expressions.

Context Item (XPath)

The
item
currently being processed; part of the
dynamic context
. Certain XSLT instructions and XPath expressions place a new context item on the stack, and revert to the previous context item when the instruction or expression has been evaluated. The XSLT instructions

and

change the context item, as do the XPath expressions
E1/E2
and
E1[E2]
. The context item can be retrieved using the expression
.
.

Context Node (XPath)

If the
context item
is a
node
, then the context node is the same thing as the context item. If the context item is not a node, then the context node is undefined.

Context Position (XPath)

When a
sequence
of
items
is processed in an
expression
of the form
E1/E2
or
E1[E2]
, or by an

or

instruction
in XSLT, each item in the sequence in turn becomes the
context item
, and the context position identifies the position of the context item in the sequence being processed. The context position determines the value of the
position()
function, and is also used in evaluating a numeric
predicate
such as
[1]
.