ch.ethz.mxquery.model
Class Iterator

java.lang.Object
  ch.ethz.mxquery.model.Iterator

All Implemented Interfaces:

XDMIterator, Traversable

Direct Known Subclasses:

BlockDeclIterator, CurrentBasedIterator, FTContainsIterator, GroupByIndexIterator, ResultDataIterator, RewriteExpression, TokenBasedIterator, TokenSequenceIterator, UpdateIterator, Window, WrapperIterator, XDMImportAdapter

public abstract class Iterator
extends java.lang.Object
implements XDMIterator

Field Summary

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

Iterator(Context ctx, int minExpected, XDMIterator[] subIters, QueryLocation location)

Iterator(Context ctx, QueryLocation location)

Iterator(Context ctx, XDMIterator[] subIters, int expected, QueryLocation location)

Iterator(Context ctx, XDMIterator[] subIters, QueryLocation location)

Method Summary

void	addPredicates(Iterator[] predIters)
void	close(boolean restartable) Frees the state of the iterator and all subiterators.
XDMIterator	copy(Context parentIterContext, XQStaticContext prevParentIterContext, boolean copyContext, java.util.Vector nestedPredCtxStack) Copies the Iterator.
static int[]	copyInts(int[] ints)
static XDMIterator[]	copyIterators(Context context, XDMIterator[] iters, java.util.Vector nestedPredCtxStack)
static QName[]	copyQNames(QName[] qnames)
static java.lang.String[]	copyStrings(java.lang.String[] strings)
static TypeInfo[]	copyTypeInfos(TypeInfo[] infos)
XDMIterator[]	getAllSubIters()
java.util.Vector	getAllSubItersRecursive()
Context	getContext() Retrieve the (unified) context of this iterators, carrying both dynamic and static information
int	getExpressionCategoryType(boolean scripting) Get and (check) the expression category type, as defined in the XQSF draft Expression categories are: SIMPLE, UPDATING, SEQUENTIAL, VACUOUS If the categories are incompatible, the related exception is thrown The check is only done when requested by calling this function The implementation covers the common case (simple expressions, no checking) and needs to be overwritten for checking and also by updating, sequential and vacuous expressions
QueryLocation	getLoc() Get the location in the XQuery source where this operator comes from
PendingUpdateList	getPendingUpdateList() Returns the complete Pending Update List (PUL) of this iterator.
Iterator[]	getPredicates()
TypeInfo	getStaticType() Return the return type if it can be statically determined
XDMIterator[]	getSubIters()
boolean	hasPredicates()
boolean	isConstModePreserve()
boolean	isExprParameter(int valueToCheck, boolean recursive) Optimization check
boolean	isOpen()
boolean	isResettable() Retrieve if this iterator is resetable
void	removePredicates()
void	reset() Resets the Iterator to its original state, without discarding expensive state
void	setConstModePreserve(boolean constModePreserve)
void	setContext(Context context, boolean recursive) Assigns a context for this iterator (and possibly for its subIterators), replacing the existing context
void	setLoc(QueryLocation loc) Set the location in the XQuery source where this operator comes from
void	setOrderByExpr(XDMIterator orderByExpr)
void	setParam(java.lang.String name, java.lang.String value)
void	setResettable(boolean r) Set this Iterator (and its subiterators) resetable.
void	setReturnExpr(XDMIterator retExpr)
void	setSubIters(java.util.Vector subIt)
void	setSubIters(XDMIterator subIt)
void	setSubIters(XDMIterator[] subIt)
void	setWhereExpr(XDMIterator whereExpr)
KXmlSerializer	traverse(KXmlSerializer serializer)
KXmlSerializer	traverseIteratorTree(KXmlSerializer serializer)

Methods inherited from class java.lang.Object

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

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

next

Constructor Detail

Iterator

public Iterator(Context ctx,
                QueryLocation location)

Iterator

public Iterator(Context ctx,
                int minExpected,
                XDMIterator[] subIters,
                QueryLocation location)
         throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

Iterator

public Iterator(Context ctx,
                XDMIterator[] subIters,
                int expected,
                QueryLocation location)
         throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

Iterator

public Iterator(Context ctx,
                XDMIterator[] subIters,
                QueryLocation location)

Method Detail

addPredicates

public void addPredicates(Iterator[] predIters)

getPredicates

public Iterator[] getPredicates()

removePredicates

public void removePredicates()

hasPredicates

public boolean hasPredicates()

setContext

public void setContext(Context context,
                       boolean recursive)
                throws MXQueryException

Description copied from interface: XDMIterator

Assigns a context for this iterator (and possibly for its subIterators), replacing the existing context

Specified by:

setContext in interface XDMIterator

Parameters:

context - the context to assign

recursive - true perform the assignment also subiteratos, false only replace on the current iterator

Throws:

MXQueryException

setSubIters

public void setSubIters(java.util.Vector subIt)

setSubIters

public void setSubIters(XDMIterator[] subIt)
                 throws MXQueryException

Specified by:

setSubIters in interface XDMIterator

Throws:

MXQueryException

setSubIters

public void setSubIters(XDMIterator subIt)

Specified by:

setSubIters in interface XDMIterator

getSubIters

public XDMIterator[] getSubIters()
                          throws MXQueryException

Specified by:

getSubIters in interface XDMIterator

Throws:

MXQueryException

setReturnExpr

public void setReturnExpr(XDMIterator retExpr)

setOrderByExpr

public void setOrderByExpr(XDMIterator orderByExpr)

setWhereExpr

public void setWhereExpr(XDMIterator whereExpr)

setParam

public void setParam(java.lang.String name,
                     java.lang.String value)
              throws MXQueryException

Throws:

MXQueryException

getContext

public Context getContext()

Description copied from interface: XDMIterator

Retrieve the (unified) context of this iterators, carrying both dynamic and static information

Specified by:

getContext in interface XDMIterator

Returns:

a Context object

setResettable

public void setResettable(boolean r)
                   throws MXQueryException

Description copied from interface: XDMIterator

Set this Iterator (and its subiterators) resetable. Resetable iterators may require more space (trading buffered data against recomputation)

Specified by:

setResettable in interface XDMIterator

Parameters:

r - true make this iterator resetable, false make it not resetable

Throws:

MXQueryException

isResettable

public boolean isResettable()
                     throws MXQueryException

Description copied from interface: XDMIterator

Retrieve if this iterator is resetable

Specified by:

isResettable in interface XDMIterator

Returns:

true this iterator is resetable, false it is not

Throws:

MXQueryException

isExprParameter

public boolean isExprParameter(int valueToCheck,
                               boolean recursive)

Description copied from interface: XDMIterator

Optimization check

Specified by:

isExprParameter in interface XDMIterator

Returns:

if iterator fulfills the requested criteria

reset

public final void reset()
                 throws MXQueryException

Description copied from interface: XDMIterator

Resets the Iterator to its original state, without discarding expensive state

Specified by:

reset in interface XDMIterator

Throws:

MXQueryException

close

public final void close(boolean restartable)
                 throws MXQueryException

Description copied from interface: XDMIterator

Frees the state of the iterator and all subiterators.

Specified by:

close in interface XDMIterator

Parameters:

restartable - make the iterator restartable (otherwise the iterator will stay closed with additional next calls)

Throws:

MXQueryException

getStaticType

public TypeInfo getStaticType()

Description copied from interface: XDMIterator

Return the return type if it can be statically determined

Specified by:

getStaticType in interface XDMIterator

Returns:

a Type info carrying the most precise static type that could be determined. If no specific type could be determined, the type is ITEM*

getExpressionCategoryType

public int getExpressionCategoryType(boolean scripting)
                              throws MXQueryException

Description copied from interface: XDMIterator

Get and (check) the expression category type, as defined in the XQSF draft Expression categories are: SIMPLE, UPDATING, SEQUENTIAL, VACUOUS If the categories are incompatible, the related exception is thrown The check is only done when requested by calling this function The implementation covers the common case (simple expressions, no checking) and needs to be overwritten for checking and also by updating, sequential and vacuous expressions

Specified by:

getExpressionCategoryType in interface XDMIterator

Parameters:

scripting - TODO

Returns:

the most stringent expression type

Throws:

MXQueryException

getAllSubIters

public XDMIterator[] getAllSubIters()

Specified by:

getAllSubIters in interface XDMIterator

getAllSubItersRecursive

public java.util.Vector getAllSubItersRecursive()

Specified by:

getAllSubItersRecursive in interface XDMIterator

traverseIteratorTree

public KXmlSerializer traverseIteratorTree(KXmlSerializer serializer)
                                    throws java.lang.Exception

Specified by:

traverseIteratorTree in interface XDMIterator

Throws:

java.lang.Exception

traverse

public KXmlSerializer traverse(KXmlSerializer serializer)

Specified by:

traverse in interface Traversable

isOpen

public boolean isOpen()

Specified by:

isOpen in interface XDMIterator

getPendingUpdateList

public PendingUpdateList getPendingUpdateList()
                                       throws MXQueryException

Description copied from interface: XDMIterator

Returns the complete Pending Update List (PUL) of this iterator. Is null for non-updating expressions. Since the PUL is computed gradually (especially in a scripting environment, this function should only be called when the evaluation is complete. For scripting, this function also merges the PULs of the child iterators, so

Specified by:

getPendingUpdateList in interface XDMIterator

Returns:

pending update list

Throws:

MXQueryException

copy

public XDMIterator copy(Context parentIterContext,
                        XQStaticContext prevParentIterContext,
                        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

Parameters:

parentIterContext - The new parent context

prevParentIterContext - 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

copyIterators

public static XDMIterator[] copyIterators(Context context,
                                          XDMIterator[] iters,
                                          java.util.Vector nestedPredCtxStack)
                                   throws MXQueryException

Throws:

MXQueryException

copyStrings

public static java.lang.String[] copyStrings(java.lang.String[] strings)

copyInts

public static int[] copyInts(int[] ints)

copyTypeInfos

public static TypeInfo[] copyTypeInfos(TypeInfo[] infos)

copyQNames

public static QName[] copyQNames(QName[] qnames)

getLoc

public QueryLocation getLoc()

Description copied from interface: XDMIterator

Get the location in the XQuery source where this operator comes from

Specified by:

getLoc in interface XDMIterator

Returns:

the QueryLocation object representing the location

setLoc

public void setLoc(QueryLocation loc)

Description copied from interface: XDMIterator

Set the location in the XQuery source where this operator comes from

Specified by:

setLoc in interface XDMIterator

Parameters:

loc - the QueryLocation object representing the location

isConstModePreserve

public boolean isConstModePreserve()

Specified by:

isConstModePreserve in interface XDMIterator

setConstModePreserve

public void setConstModePreserve(boolean constModePreserve)

Specified by:

setConstModePreserve in interface XDMIterator