net.sf.saxon.s9api.streams

Class Predicates

java.lang.Object

net.sf.saxon.s9api.streams.Predicates

public class Predicates
extends java.lang.Object

This non-instantiable class provides a number of useful implementations of the Predicate interface, designed for use when navigating streams of XDM items.

Constructor Summary

Constructors

Constructor and Description
Predicates()

Method Summary

Modifier and Type	Method and Description
static java.util.function.Predicate<XdmNode>	attributeEq(java.lang.String local, java.lang.String value) Obtain a predicate that tests whether an item is an element node with a given attribute (whose name is in no namespace) whose string value is equal to a given value
static <T extends XdmItem> java.util.function.Predicate<XdmItem>	empty(Step<T> step) Obtain a predicate that tests whether a supplied Step delivers an empty result
static <T extends XdmItem> java.util.function.Predicate<XdmItem>	eq(Step<T> step, java.lang.String value) Obtain a predicate that tests whether there is some item in the result of applying a step, whose string value is equal to a given string.
static java.util.function.Predicate<XdmItem>	eq(java.lang.String value) Obtain a predicate that tests whether the result of applying the XPath string() function to an item is equal to a given string
static java.util.function.Predicate<XdmAtomicValue>	eq(XdmAtomicValue value) Obtain a predicate that tests whether an atomic value compares equal to a supplied atomic value of a comparable type
static <T extends XdmItem> java.util.function.Predicate<XdmItem>	every(Step<T> step, java.util.function.Predicate<? super XdmItem> condition) Obtain a predicate that tests whether every item in the result of applying a step satisfies the supplied condition.
static <T extends XdmItem> java.util.function.Predicate<XdmItem>	exists(Step<T> step) Obtain a predicate that tests whether a supplied Step delivers a non-empty result
static java.util.function.Predicate<XdmNode>	hasAttribute(java.lang.String local) Obtain a predicate that tests whether an item is an element node with a given attribute (whose name is in no namespace)
static java.util.function.Predicate<XdmNode>	hasLocalName(java.lang.String localName) Obtain a predicate that tests whether an item is a node with a given local name, irrespective of the namespace
static java.util.function.Predicate<? super XdmNode>	hasName(java.lang.String uri, java.lang.String localName) Obtain a predicate that tests whether an item is a node with a given namespace URI and local name
static java.util.function.Predicate<XdmNode>	hasNamespace(java.lang.String uri) Obtain a predicate that tests whether an item is a node with a given namespace URI
static java.util.function.Predicate<XdmItem>	hasType(ItemType type) Obtain a predicate that tests whether an item matches a given item type
static java.util.function.Predicate<XdmItem>	isArray() A predicate to test whether an item is an XDM array
static java.util.function.Predicate<XdmItem>	isAtomic() A predicate to test whether an item is an atomic value
static java.util.function.Predicate<XdmItem>	isAttribute() A predicate to test whether an item is an attribute node
static java.util.function.Predicate<XdmItem>	isComment() A predicate to test whether an item is a comment node
static java.util.function.Predicate<XdmItem>	isDocument() A predicate to test whether an item is a document node
static java.util.function.Predicate<XdmItem>	isElement() A predicate to test whether an item is an element node
static java.util.function.Predicate<XdmItem>	isFunction() A predicate to test whether an item is a function value (this includes maps and arrays)
static java.util.function.Predicate<XdmItem>	isMap() A predicate to test whether an item is an XDM map
static java.util.function.Predicate<XdmItem>	isNamespace() A predicate to test whether an item is a namespace node
static java.util.function.Predicate<XdmItem>	isNode() A predicate to test whether an item is a node
static java.util.function.Predicate<XdmItem>	isProcessingInstruction() A predicate to test whether an item is a processing instruction node
static java.util.function.Predicate<XdmItem>	isText() A predicate to test whether an item is a text node
static java.util.function.Predicate<XdmItem>	matchesRegex(java.lang.String regex) Obtain a predicate that tests whether the result of applying the XPath string() function to an item matches a given regular expression
static <T> java.util.function.Predicate<T>	not(java.util.function.Predicate<T> condition) Return a Predicate that is the negation of a supplied Predicate
static <T extends XdmItem> java.util.function.Predicate<XdmItem>	some(Step<T> step, java.util.function.Predicate<? super T> condition) Obtain a predicate that tests whether there is some item in the result of applying a step that satisfies the supplied condition.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Predicates

public Predicates()

Method Detail

isNode

public static java.util.function.Predicate<XdmItem> isNode()

A predicate to test whether an item is a node

Returns:

a predicate that returns true if given an item that is a node

isElement

public static java.util.function.Predicate<XdmItem> isElement()

A predicate to test whether an item is an element node

Returns:

a predicate that returns true if given an item that is an element node

isAttribute

public static java.util.function.Predicate<XdmItem> isAttribute()

A predicate to test whether an item is an attribute node

Returns:

a predicate that returns true if given an item that is an attribute node

isText

public static java.util.function.Predicate<XdmItem> isText()

A predicate to test whether an item is a text node

Returns:

a predicate that returns true if given an item that is a text node

isComment

public static java.util.function.Predicate<XdmItem> isComment()

A predicate to test whether an item is a comment node

Returns:

a predicate that returns true if given an item that is a comment node

isProcessingInstruction

public static java.util.function.Predicate<XdmItem> isProcessingInstruction()

A predicate to test whether an item is a processing instruction node

Returns:

a predicate that returns true if given an item that is a processing instruction node

isDocument

public static java.util.function.Predicate<XdmItem> isDocument()

A predicate to test whether an item is a document node

Returns:

a predicate that returns true if given an item that is a document node

isNamespace

public static java.util.function.Predicate<XdmItem> isNamespace()

A predicate to test whether an item is a namespace node

Returns:

a predicate that returns true if given an item that is a namespace node

isAtomic

public static java.util.function.Predicate<XdmItem> isAtomic()

A predicate to test whether an item is an atomic value

Note: to test for a specific type of atomic value, use a predicate such as hasType(ItemType.XS_INTEGER)

Returns:

a predicate that returns true if given an item that is an atomic value.

isFunction

public static java.util.function.Predicate<XdmItem> isFunction()

A predicate to test whether an item is a function value (this includes maps and arrays)

Returns:

a predicate that returns true if given an item that is a function, including maps and arrays

isMap

public static java.util.function.Predicate<XdmItem> isMap()

A predicate to test whether an item is an XDM map

Returns:

a predicate that returns true if given an item that is a map

isArray

public static java.util.function.Predicate<XdmItem> isArray()

A predicate to test whether an item is an XDM array

Returns:

a predicate that returns true if given an item that is an array

empty

public static <T extends XdmItem> java.util.function.Predicate<XdmItem> empty(Step<T> step)

Obtain a predicate that tests whether a supplied Step delivers an empty result

Parameters:

step - a step to be applied to the item being tested

Returns:

a predicate that returns true if the supplied step returns an empty result. For example empty(attribute("id") is a predicate that returns true for a node that has no "id" attribute. Similarly CHILD.where(empty(child(IS_ELEMENT))) is a step that selects child elements having no element children.

not

public static <T> java.util.function.Predicate<T> not(java.util.function.Predicate<T> condition)

Return a Predicate that is the negation of a supplied Predicate

Type Parameters:

T - The type of object to which the predicate is applicable

Parameters:

condition - the supplied predicate

Returns:

a Predicate that matches an item if and only if the supplied Predicate does not match the item.

exists

public static <T extends XdmItem> java.util.function.Predicate<XdmItem> exists(Step<T> step)

Obtain a predicate that tests whether a supplied Step delivers a non-empty result

Parameters:

step - a step to be applied to the item being tested

Returns:

a predicate that returns true if the step returns a non-empty result. For example exists(attribute("id") is a predicate that returns true for a node that has an "id" attribute. So CHILD.where(exists(attribute("id")) is a step that selects child elements having an "id" attribute.

hasName

public static java.util.function.Predicate<? super XdmNode> hasName(java.lang.String uri,
                                                                    java.lang.String localName)

Obtain a predicate that tests whether an item is a node with a given namespace URI and local name

Parameters:

uri - the required namespace URI: supply a zero-length string to indicate the null namespace

localName - the required local name

Returns:

a predicate that returns true if and only if the supplied item is a node with the given namespace URI and local name

hasLocalName

public static java.util.function.Predicate<XdmNode> hasLocalName(java.lang.String localName)

Obtain a predicate that tests whether an item is a node with a given local name, irrespective of the namespace

Parameters:

localName - the required local name. If a zero-length string is supplied, the predicate will match nodes having no name (for example, comments and text nodes)

Returns:

a predicate that returns true if and only if the supplied item is a node with the given local name, irrespective of the namespace

hasNamespace

public static java.util.function.Predicate<XdmNode> hasNamespace(java.lang.String uri)

Obtain a predicate that tests whether an item is a node with a given namespace URI

Parameters:

uri - the required namespace URI: supply a zero-length string to identify the null namespace

Returns:

a predicate that returns true if and only if the supplied item is a node with the given namespace URI. If a zero-length string is supplied, the predicate will also match nodes having no name, such as text and comment nodes, and nodes having a local name only, such as namespace and processing-instruction nodes.

hasAttribute

public static java.util.function.Predicate<XdmNode> hasAttribute(java.lang.String local)

Obtain a predicate that tests whether an item is an element node with a given attribute (whose name is in no namespace)

Parameters:

local - the required attribute name

Returns:

a predicate that returns true if and only if the supplied item is an element having an attribute with the given local name, in no namespace

attributeEq

public static java.util.function.Predicate<XdmNode> attributeEq(java.lang.String local,
                                                                java.lang.String value)

Obtain a predicate that tests whether an item is an element node with a given attribute (whose name is in no namespace) whose string value is equal to a given value

Parameters:

local - the required attribute name

value - the required attribute value

Returns:

a predicate that returns true if and only if the supplied item is an element having an attribute with the given local name, in no namespace, whose string value is equal to the given value

hasType

public static java.util.function.Predicate<XdmItem> hasType(ItemType type)

Obtain a predicate that tests whether an item matches a given item type

Parameters:

type - the required item type

Returns:

a predicate that returns true if and only if the supplied item matches the supplied item type. For example, hasType(ItemType.DATE_TIME) matches atomic values of type xs:dateTime.

some

public static <T extends XdmItem> java.util.function.Predicate<XdmItem> some(Step<T> step,
                                                                             java.util.function.Predicate<? super T> condition)

Obtain a predicate that tests whether there is some item in the result of applying a step that satisfies the supplied condition.

For example, some(CHILD, exists(attribute("foo")) matches an element if it has a child element with an attribute whose local name is "foo".

If the step returns an empty sequence the result will always be false.

Parameters:

step - the step to be evaluated

condition - the predicate to be applied to the items returned by the step

every

public static <T extends XdmItem> java.util.function.Predicate<XdmItem> every(Step<T> step,
                                                                              java.util.function.Predicate<? super XdmItem> condition)

Obtain a predicate that tests whether every item in the result of applying a step satisfies the supplied condition.

For example, every(CHILD, exists(attribute("foo")) matches an element if each of its child elements has an attribute whose local name is "foo".

If the step returns an empty sequence the result will always be true.

Parameters:

step - the step to be evaluated

condition - the predicate to be applied to the items returned by the step

eq

public static java.util.function.Predicate<XdmAtomicValue> eq(XdmAtomicValue value)

Obtain a predicate that tests whether an atomic value compares equal to a supplied atomic value of a comparable type

Parameters:

value - the atomic value to be compared with

Returns:

a Predicate which returns true when applied to a value that is equal to the supplied value under the "is-same-key" comparison rules. (These are the rules used to compare key values in an XDM map. The rules are chosen to be context-free, error-free, and transitive.)

eq

public static java.util.function.Predicate<XdmItem> eq(java.lang.String value)

Obtain a predicate that tests whether the result of applying the XPath string() function to an item is equal to a given string

Parameters:

value - the string being tested

Returns:

a Predicate which returns true if the string value of the item being tested is equal to the given string under Java comparison rules for comparing strings.

matchesRegex

public static java.util.function.Predicate<XdmItem> matchesRegex(java.lang.String regex)

Obtain a predicate that tests whether the result of applying the XPath string() function to an item matches a given regular expression

Parameters:

regex - the regular expression (this is a Java regular expression, not an XPath regular expression)

Returns:

a Predicate which returns true if the string value of the item being tested contains a substring that matches the given regular expression. To test the string in its entirety, use anchors "^" and "$" in the regular expression.

eq

public static <T extends XdmItem> java.util.function.Predicate<XdmItem> eq(Step<T> step,
                                                                           java.lang.String value)

Obtain a predicate that tests whether there is some item in the result of applying a step, whose string value is equal to a given string.

For example, eq(attribute("id"), "foo") matches an element if it has an "id" attribute whose value is "foo".

Parameters:

step - the step to be evaluated

value - the string to be compared against the items returned by the step

Returns:

a Predicate which returns true if some item selected by the step has as string value equal to the given string