ch.ethz.mxquery.bindings
Class WindowSequenceIterator

java.lang.Object
  ch.ethz.mxquery.model.Iterator
      ch.ethz.mxquery.model.Window
          ch.ethz.mxquery.bindings.WindowIterator
              ch.ethz.mxquery.bindings.WindowSequenceIterator

All Implemented Interfaces:

IndexIterator, XDMIterator, Traversable

public final class WindowSequenceIterator
extends WindowIterator

Window Iterators are only created by a WindowBuffer or by a existing WindowIterator. All window iterators operate on window buffer and have a defined range on this buffer.
Important definitions:
item: Is a item in a sequence
position: Position as in XQuery. First position is 1.
nodeId: Like Position but starting with 0
tokenId: Id of each token. Also starting with 0

Field Summary

Fields inherited from class ch.ethz.mxquery.model.Window

END_OF_STREAM_NODE, END_OF_STREAM_POSITION

Fields inherited from interface ch.ethz.mxquery.model.XDMIterator

EXPR_CATEGORY_SEQUENTIAL, EXPR_CATEGORY_SIMPLE, EXPR_CATEGORY_UPDATING, EXPR_CATEGORY_VACUOUS, EXPR_PARAM_CHEAPEVAL, EXPR_PARAM_VARIABLE, EXPR_PARAM_WINDOW, EXPR_PARAM_XDMGEN

Method Summary

java.lang.String	getAttributeType(int i)
Identifier	getId()
XDMIterator	getItem(int position) Returns the item on the given Position.
WindowBuffer	getMat()
Window	getNewEarlyParallelWindowInterface(int startPosition, WindowVariable[] startVars, VariableHolder[] startVarHolders, XDMIterator endExpr, WindowVariable[] endVars, VariableHolder[] endVarHolders)
Window	getNewEarlyWindowInterface(int startPosition, XDMIterator startExpr, WindowVariable[] startVars, VariableHolder[] startVarHolders, XDMIterator endExpr, WindowVariable[] endVars, VariableHolder[] endVarHolders)
Window	getNewItemWindow(IntegerList values) Returns a new iterator consisting of the given items in the integer list.
Window	getNewWindow(int startPosition, int endPosition) Returns a new window inside this window.
int	getPosition()
int	getStartNode() Returns the first node id of the window
boolean	hasItem(int position) Checks if the given position is availabe
boolean	hasNextItem() Checks if a next item exists.
boolean	isAttributeDefault(int i)
Token	next() xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Iterator standard methods xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
XDMIterator	nextItem() Returns the next item if exist

Methods inherited from class ch.ethz.mxquery.bindings.WindowIterator

destroyWindow, equals, getStore, getWindowId, hashCode, isWindowInUse, setContext, setWindowInUse

Methods inherited from class ch.ethz.mxquery.model.Window

getEndPosition, getNextWindowStartPosition, getUnderlyingWindow, increasePosition, isExprParameter, isWindow, jumpToNextAttribute, setPosition

Methods inherited from class ch.ethz.mxquery.model.Iterator

addPredicates, close, copy, copyInts, copyIterators, copyQNames, copyStrings, copyTypeInfos, getAllSubIters, getAllSubItersRecursive, getContext, getExpressionCategoryType, getLoc, getPendingUpdateList, getPredicates, getStaticType, getSubIters, hasPredicates, isConstModePreserve, isOpen, isResettable, removePredicates, reset, setConstModePreserve, setContext, setLoc, setOrderByExpr, setParam, setResettable, setReturnExpr, setSubIters, setSubIters, setSubIters, setWhereExpr, traverse, traverseIteratorTree

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Method Detail

hasItem

public boolean hasItem(int position)
                throws MXQueryException

Description copied from interface: IndexIterator

Checks if the given position is availabe

Parameters:

position - Position in the sequence (starting with 1)

Returns:

True if the next item is not end_sequence otherwise false

Throws:

MXQueryException

hasNextItem

public boolean hasNextItem()
                    throws MXQueryException

Checks if a next item exists. Especially used in for's or forseq's

Returns:

true if the next items exists

Throws:

MXQueryException

nextItem

public XDMIterator nextItem()
                     throws MXQueryException

Returns the next item if exist

Returns:

an iterator representing the next item, if it exists, otherwise an empty sequence iterator

Throws:

MXQueryException

getNewWindow

public Window getNewWindow(int startPosition,
                           int endPosition)

Returns a new window inside this window. Technically this window operates on the underlying buffer directly but it inherits the border of the current window

Specified by:

getNewWindow in class Window

Parameters:

startPosition - start position inside the current window

endPosition - end position inside the current window

Returns:

new window iterator

getNewEarlyWindowInterface

public Window getNewEarlyWindowInterface(int startPosition,
                                         XDMIterator startExpr,
                                         WindowVariable[] startVars,
                                         VariableHolder[] startVarHolders,
                                         XDMIterator endExpr,
                                         WindowVariable[] endVars,
                                         VariableHolder[] endVarHolders)

Overrides:

getNewEarlyWindowInterface in class Window

getNewEarlyParallelWindowInterface

public Window getNewEarlyParallelWindowInterface(int startPosition,
                                                 WindowVariable[] startVars,
                                                 VariableHolder[] startVarHolders,
                                                 XDMIterator endExpr,
                                                 WindowVariable[] endVars,
                                                 VariableHolder[] endVarHolders)

Overrides:

getNewEarlyParallelWindowInterface in class Window

getNewItemWindow

public Window getNewItemWindow(IntegerList values)

Description copied from class: Window

Returns a new iterator consisting of the given items in the integer list. If a position is outside the underlying sequence, the position is skipped.

Specified by:

getNewItemWindow in class Window

Parameters:

values - Each value in the integer list has to be a position

Returns:

a new Window for the given list of positions

next

public Token next()
           throws MXQueryException

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Iterator standard methods xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Returns:

The XDM token representing the next fragment of the XDM instance

Throws:

MXQueryException

getPosition

public int getPosition()

Specified by:

getPosition in class Window

getStartNode

public int getStartNode()

Description copied from class: Window

Returns the first node id of the window

Specified by:

getStartNode in class WindowIterator

Returns:

returns the first node id of this window

getItem

public XDMIterator getItem(int position)
                    throws MXQueryException

Description copied from interface: IndexIterator

Returns the item on the given Position. If the item is not evailabe, an empty sequence item is returned

Parameters:

position - Position in the sequence (starting with 1)

Returns:

Item or empty sequence iterator

Throws:

MXQueryException

getMat

public WindowBuffer getMat()

getAttributeType

public java.lang.String getAttributeType(int i)

isAttributeDefault

public boolean isAttributeDefault(int i)

getId

public Identifier getId()