XSLT and XQuery Serialization 4.0

10 Adaptive Output Method

The Adaptive output method serializes the input tree into a human readable form for the purposes of debugging query results. The intention of this is to allow any input value to be serialized without raising a serialization error. Sequence normalization is not performed for this output method.

Each item in the supplied sequence is serialized individually as follows, with an occurrence of the chosen item-separator between successive items.

• A JNode is serialized in the format jnode(K: V) where K is the adaptive serialization of the value of its ·selector· property V is the adaptive serialization of the value of its ·content· property.

  For example, the JNode selected by the expression jtree({ "a": [4, 5] })/a is serialized as jnode("a":[4,5]).

  A JNode is serialized as follows:

  • If the ·selector· property is absent (that is, for a parentless JNode), in the format jtree(V) where V is the adaptive serialization of the value of its ·content· property.

    For example, the JNode selected by the expression jtree({ "a": [4, 5] }) is serialized as jtree({"a":[4,5]}).

  • If the ·selector· property is present, then in the format jnode(K: V) where K is the adaptive serialization of the value of its ·selector· property and V is the adaptive serialization of the value of its ·content· property.

    For example, the JNode selected by the expression jtree({ "a": [4, 5] })/a is serialized as jnode("a":[4,5]).

• A document, element, text, comment, or processing instruction node is serialized using the XML output method described in 5 XML Output Method.

• An attribute or namespace node is serialized as if it had a containing element node. For example an attribute node might be serialized as the string xsi:type="xs:integer"; a namespace node might be serialized as xmlns:sns="http://example.com/sample-namespace".

  Note:

  This may result in output of QNames containing prefixes whose binding is not displayed.

• An atomic item^XP is serialized as follows:

  • An instance of xs:boolean is serialized as true() or false().

  • An instance of xs:string, xs:untypedAtomic or xs:anyURI is serialized by enclosing the value in double quotation marks and doubling any quotes within the value; or optionally by enclosing the value in apostrophes and doubling any apostrophes within the value. The resulting value is then serialized using the Text output method described in 8 Text Output Method.

    Note:

    The Text output method will apply character expansion and encoding rules to this string as specified by the serialization parameters.

  • An instance of xs:integer or xs:decimal is serialized by converting the value to a string using the fn:string function.

  • An instance of xs:double is serialized by applying the function format-number(?, '0.0##########################e0') using the following default decimal format properties:

    Decimal format

    Property name	Property value
    decimal-separator	U+002E (FULL STOP, PERIOD, .)
    exponent-separator	U+0065 (LATIN SMALL LETTER E, e)
    grouping-separator	U+002C (COMMA, ,)
    zero-digit	U+0030 (DIGIT ZERO, 0)
    digit	U+0023 (NUMBER SIGN, #)
    infinity	The string "INF"
    NaN	The string "NaN"
    minus-sign	U+002D (HYPHEN-MINUS, -)

  • An instance of xs:NOTATION is serialized as a URI-qualified name (that is, in the form Q{uri}local).

  • An instance of xs:QName is serialized with a # character, followed by:

    • the local name if the name is in no namespace, or

    • the URI-qualified name otherwise (Q{uri}local).

  • An atomic item of any other type is serialized using the syntax of a constructor function: xs:TYPE("VAL") where TYPE is the name of the primitive type, and VAL is the result of applying the fn:string() function. For example, xs:date("2015-07-17"). The resulting string is then serialized using the Text output method described in 8 Text Output Method.

• An array item is serialized using the syntax of a SquareArrayConstructor^XP, that is as [member, member, ... ]. The members, which in general are sequences, are serialized in the form (item, item, ...) where the items are serialized by applying these rules recursively. The items are separated by commas (not by the item-separator character). The enclosing parentheses are optional if the sequence has length one.

  Note:

  The serializer should avoid outputting the parentheses if it is able to determine the length of the sequence before serializing the first item; but it is allowed to output parentheses around a singleton if this avoids buffering data in memory.

• A map item is serialized using the syntax of a [XPath 4.0] section MapConstructor without the optional map keyword, that is in the format {key:value, key:value, ...}. The key/value pairs in the serialized output retain the entry order^DM of entries in the map. The key is serialized by applying the rules for serializing an atomic item. The values are serialized in the same way as the members of an array (see above).

• A function item is serialized to the representation name#A where fn:name is a representation of the function name and A is the arity. If the function name is in one of the namespaces http://www.w3.org/2005/xpath-functions, http://www.w3.org/2005/xpath-functions/math, http://www.w3.org/2005/xpath-functions/map, http://www.w3.org/2005/xpath-functions/array or http://www.w3.org/2001/XMLSchema, then the name is output as a lexical QName using the conventional prefix fn, math, map, array, or xs as appropriate; if it is in any other namespace or in no namespace, then the name is output as a URI-qualified name (that is, Q{uri}local). If the function is anonymous, name is replaced by the string (anonymous-function).

  Note:

  The following examples illustrate this rule:

  • fn:exists#1 is serialized as function fn:exists#1

  • Q{http://www.w3.org/2005/xpath-functions}exists#1 is serialized as fn:exists#1

  • function($a) { $a } is serialized as (anonymous-function)#1

  • math:pi#0 is serialized as math:pi#0

Character maps are applied (a) when nodes are serialized using the XML output method, and (b) to any value represented as a string enclosed in quotation marks.

Optionally, in all the above constructs, characters whose visual representation is ambiguous (for example tab or non-breaking-space) may be represented in the form of an XML numeric character reference (for example 	 or  )

If any value cannot be output because doing so would cause a serialization error, the behavior is implementation-defined.

If the output is sent to a destination that allows hyperlinks to be included in the generated text, then the serializer may include implementation-dependent hyperlinks to provide additional information for example:

• to allow the type of atomic items^XP to be ascertained.

• to allow the namespace binding of prefixes to be ascertained.

• to provide further information about the cause of error indicators.