org.basex.query.item

Class FItem

java.lang.Object

org.basex.data.ExprInfo

org.basex.query.expr.Expr

org.basex.query.item.Value

org.basex.query.item.Item

org.basex.query.item.FItem

All Implemented Interfaces:

java.lang.Iterable<Item>

Direct Known Subclasses:

FuncItem, Map

public abstract class FItem
extends Item

Abstract super class for function items.

Author:

BaseX Team 2005-12, BSD License, Leo Woerteler

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.expr.Expr

Expr.Use

Field Summary

Fields inherited from class org.basex.query.item.Item

UNDEF

Fields inherited from class org.basex.query.item.Value

type

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FItem(Type t) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
abstract int	arity() Number of arguments this function item takes.
abstract FItem	coerceTo(FuncType ft, QueryContext ctx, InputInfo ii) Coerces this function item to the given function type.
boolean	eq(InputInfo ii, Item it) Checks the items for equality.
abstract QNm	fName() Name of this function, null means anonymous function.
Item	invItem(QueryContext ctx, InputInfo ii, Value... args) Invokes this function item with the given arguments.
Iter	invIter(QueryContext ctx, InputInfo ii, Value... args) Invokes this function item with the given arguments.
abstract Value	invValue(QueryContext ctx, InputInfo ii, Value... args) Invokes this function item with the given arguments.
abstract void	plan(Serializer ser) Serializes the expression tree.
byte[]	string(InputInfo ii) Returns a string representation of the value.
java.lang.Object	toJava() Returns a Java representation of the value.

Methods inherited from class org.basex.query.item.Item

bool, comparable, dbl, dec, diff, ebv, equiv, flt, hash, homogenous, input, isItem, item, itemAt, iter, iterable, itr, score, score, serialize, size, test, type, writeTo, xdmInfo

Methods inherited from class org.basex.query.item.Value

cache, comp, count, data, description, info, isValue, iter, iterator, removable, remove, uses, value

Methods inherited from class org.basex.query.expr.Expr

addText, compEbv, hasFreeVars, indexAccessible, indexEquivalent, isEmpty, isFunction, isVacuous, markTailCalls, sameAs

Methods inherited from class org.basex.data.ExprInfo

toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FItem

protected FItem(Type t)

Constructor.

Parameters:

t - type

Method Detail

arity

public abstract int arity()

Number of arguments this function item takes.

Returns:

function arity

fName

public abstract QNm fName()

Name of this function, null means anonymous function.

Returns:

name or null

invValue

public abstract Value invValue(QueryContext ctx,
             InputInfo ii,
             Value... args)
                        throws QueryException

Invokes this function item with the given arguments.

Parameters:

ctx - query context

ii - input info

args - arguments

Returns:

resulting iterator

Throws:

QueryException - query exception

invIter

public Iter invIter(QueryContext ctx,
           InputInfo ii,
           Value... args)
             throws QueryException

Invokes this function item with the given arguments.

Parameters:

ctx - query context

ii - input info

args - arguments

Returns:

resulting iterator

Throws:

QueryException - query exception

invItem

public Item invItem(QueryContext ctx,
           InputInfo ii,
           Value... args)
             throws QueryException

Invokes this function item with the given arguments.

Parameters:

ctx - query context

ii - input info

args - arguments

Returns:

resulting item

Throws:

QueryException - query exception

coerceTo

public abstract FItem coerceTo(FuncType ft,
             QueryContext ctx,
             InputInfo ii)
                        throws QueryException

Coerces this function item to the given function type.

Parameters:

ft - function type

ctx - query context

ii - input info

Returns:

coerced item

Throws:

QueryException - query exception

string

public final byte[] string(InputInfo ii)
                    throws QueryException

Description copied from class: Item

Returns a string representation of the value.

Specified by:

string in class Item

Parameters:

ii - input info, use null if none is available

Returns:

string value

Throws:

QueryException - if the item can't be atomized

eq

public final boolean eq(InputInfo ii,
         Item it)
                 throws QueryException

Description copied from class: Item

Checks the items for equality.

Specified by:

eq in class Item

Parameters:

ii - input info

it - item to be compared

Returns:

result of check

Throws:

QueryException - query exception

toJava

public java.lang.Object toJava()
                        throws QueryException

Description copied from class: Value

Returns a Java representation of the value.

Specified by:

toJava in class Value

Returns:

Java object

Throws:

QueryException - query exception

plan

public abstract void plan(Serializer ser)
                   throws java.io.IOException

Description copied from class: ExprInfo

Serializes the expression tree.

Overrides:

plan in class Item

Parameters:

ser - serializer

Throws:

java.io.IOException - I/O exception