ch.ethz.mxquery.iterators
Class FFLWORIterator

java.lang.Object
  ch.ethz.mxquery.model.Iterator
      ch.ethz.mxquery.model.CurrentBasedIterator
          ch.ethz.mxquery.iterators.FFLWORIterator

All Implemented Interfaces:

XDMIterator, Traversable

Direct Known Subclasses:

PFFLWORIterator

public class FFLWORIterator
extends CurrentBasedIterator

Nested Class Summary

class

FFLWORIterator.CFAdapter This Adapter is needed to enable break and continue during return-materialization in order by.

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

FFLWORIterator(Context ctx, XDMIterator[] subIters, XDMIterator whereExpr, OrderByIterator orderByExpr, XDMIterator returnExpr, QueryLocation location)

Method Summary

XDMIterator	copy(Context parentIterContext, XQStaticContext newParentIterContext, boolean copyContext, java.util.Vector nestedPredCtxStack) Copies the Iterator.
boolean	doNextBinding() Starts the binding.
XDMIterator[]	getAllSubIters()
XDMIterator	getOrderByExpr()
XDMIterator	getReturnExpr()
TypeInfo	getStaticType() Return the return type if it can be statically determined
XDMIterator[]	getSubIters()
XDMIterator	getWhereExpr()
Token	next() Produces the next XDM token This method typically implements the base functionality of an Iterator and computes the value of the next token.
void	setContext(Context context, boolean recursive) Assigns a context for this iterator (and possibly for its subIterators), replacing the existing context
void	setOrderByExpr(OrderByIterator oExpr)
void	setResettable(boolean r) Set this Iterator (and its subiterators) resetable.
void	setReturnExpr(XDMIterator retExpr)
void	setWhereExpr(XDMIterator wExpr)
KXmlSerializer	traverseIteratorTree(KXmlSerializer serializer)

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

addPredicates, close, copyInts, copyIterators, copyQNames, copyStrings, copyTypeInfos, getAllSubItersRecursive, getContext, getExpressionCategoryType, getLoc, getPendingUpdateList, getPredicates, hasPredicates, isConstModePreserve, isExprParameter, isOpen, isResettable, removePredicates, reset, setConstModePreserve, setLoc, setOrderByExpr, setParam, setSubIters, setSubIters, setSubIters, traverse

Methods inherited from class java.lang.Object

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

Constructor Detail

FFLWORIterator

public FFLWORIterator(Context ctx,
                      XDMIterator[] subIters,
                      XDMIterator whereExpr,
                      OrderByIterator orderByExpr,
                      XDMIterator returnExpr,
                      QueryLocation location)
               throws MXQueryException

Throws:

MXQueryException

Method Detail

setReturnExpr

public void setReturnExpr(XDMIterator retExpr)

Overrides:

setReturnExpr in class Iterator

setWhereExpr

public void setWhereExpr(XDMIterator wExpr)

Overrides:

setWhereExpr in class Iterator

setOrderByExpr

public void setOrderByExpr(OrderByIterator oExpr)

next

public Token next()
           throws MXQueryException

Description copied from interface: XDMIterator

Produces the next XDM token This method typically implements the base functionality of an Iterator and computes the value of the next token.

Returns:

The XDM token representing the next fragment of the XDM instance

Throws:

MXQueryException

doNextBinding

public boolean doNextBinding()
                      throws MXQueryException

Starts the binding. Returns true if successful otherwise false (means the last binding was done)

Returns:

can the next binding be performed

Throws:

MXQueryException

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

Overrides:

setContext in class Iterator

Parameters:

context - the context to assign

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

Throws:

MXQueryException

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

Overrides:

setResettable in class Iterator

Parameters:

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

Throws:

MXQueryException

getSubIters

public XDMIterator[] getSubIters()

Specified by:

getSubIters in interface XDMIterator

Overrides:

getSubIters in class Iterator

getAllSubIters

public XDMIterator[] getAllSubIters()

Specified by:

getAllSubIters in interface XDMIterator

Overrides:

getAllSubIters in class Iterator

getOrderByExpr

public XDMIterator getOrderByExpr()

getReturnExpr

public XDMIterator getReturnExpr()

getWhereExpr

public XDMIterator getWhereExpr()

traverseIteratorTree

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

Specified by:

traverseIteratorTree in interface XDMIterator

Overrides:

traverseIteratorTree in class Iterator

Throws:

java.lang.Exception

copy

public 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

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

Overrides:

getStaticType in class Iterator

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*