ch.ethz.mxquery.iterators.forseq
Class ForseqIterator

java.lang.Object
  ch.ethz.mxquery.model.Iterator
      ch.ethz.mxquery.model.TokenBasedIterator
          ch.ethz.mxquery.iterators.forseq.ForseqIterator

All Implemented Interfaces:

XDMIterator, Traversable

Direct Known Subclasses:

ForseqGeneralIterator, ForseqWindowIterator

public abstract class ForseqIterator
extends TokenBasedIterator

The main abstract class for FORSEQ. It basically contains a collection of helper methods

Field Summary

static int	GENERAL_WINDOW
static int	LANDMARK_WINDOW
static int	ORDER_MODE_END
static int	ORDER_MODE_ENDSTART
static int	ORDER_MODE_NONE
static int	SLIDING_WINDOW
static int	TUMBLING_WINDOW

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

Constructor Summary

ForseqIterator(Context ctx, int windowType, QName var, TypeInfo t, XDMIterator seq, int orderMode, QueryLocation location)
Every FORSEQ (Window and General) has those properties in common

Method Summary

XDMIterator	copy(Context parentIterContext, XQStaticContext newParentIterContext, boolean copyContext, java.util.Vector nestedPredCtxStack) Copies the Iterator.
QName	getForseqVariable() Returns the QName of the forseq variable
boolean	isParallelAccess()
Token	next() A skeleton for next.
void	setParallelAccess(boolean parallelAccess)

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

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

Methods inherited from class java.lang.Object

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

Field Detail

GENERAL_WINDOW

public static final int GENERAL_WINDOW

See Also:

Constant Field Values

TUMBLING_WINDOW

public static final int TUMBLING_WINDOW

See Also:

Constant Field Values

SLIDING_WINDOW

public static final int SLIDING_WINDOW

See Also:

Constant Field Values

LANDMARK_WINDOW

public static final int LANDMARK_WINDOW

See Also:

Constant Field Values

ORDER_MODE_NONE

public static final int ORDER_MODE_NONE

See Also:

Constant Field Values

ORDER_MODE_END

public static final int ORDER_MODE_END

See Also:

Constant Field Values

ORDER_MODE_ENDSTART

public static final int ORDER_MODE_ENDSTART

See Also:

Constant Field Values

Constructor Detail

ForseqIterator

public ForseqIterator(Context ctx,
                      int windowType,
                      QName var,
                      TypeInfo t,
                      XDMIterator seq,
                      int orderMode,
                      QueryLocation location)

Every FORSEQ (Window and General) has those properties in common

Parameters:

windowType -

var -

t -

seq -

Method Detail

next

public Token next()
           throws MXQueryException

A skeleton for next. It takes care, that init is called and that the windows are destroyed for the garbage collection

Specified by:

next in interface XDMIterator

Overrides:

next in class TokenBasedIterator

Returns:

The first call will give the type of first Token of the result, the second the second and so on. When the last token has been produced, the type of an END_SEQUENCE token will be returned

Throws:

MXQueryException

getForseqVariable

public QName getForseqVariable()

Returns the QName of the forseq variable

Returns:

The QName of the forseq variable

copy

public final XDMIterator copy(Context parentIterContext,
                              XQStaticContext newParentIterContext,
                              boolean copyContext,
                              java.util.Vector nestedPredCtxStack)
                       throws MXQueryException

Description copied from interface: XDMIterator

Copies the Iterator. The context is copied (if necessary) here. The subIterators are copied (if existing) here.

Specified by:

copy in interface XDMIterator

Overrides:

copy in class Iterator

Parameters:

parentIterContext - The new parent context

newParentIterContext - The previous context of the parent iterator

copyContext - Copy the context or use the parent context

nestedPredCtxStack - The Stack of nested predicate context, needed for nested rewritten predicates

Returns:

A copy of this Iterator

Throws:

MXQueryException

isParallelAccess

public boolean isParallelAccess()

setParallelAccess

public void setParallelAccess(boolean parallelAccess)