ch.ethz.mxquery.iterators
Class GroupByIndexIterator

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

All Implemented Interfaces:

XDMIterator, Traversable

public final class GroupByIndexIterator
extends Iterator

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

GroupByIndexIterator(Context ctx, FFLWORIterator flwor, QName sourceQName, QName targetQName, XDMIterator[] bySources, QName[] byTargets, XDMIterator[] lets, XDMIterator where, QueryLocation location)
Creates a new group by iterator which applies an index for the values to group for

GroupByIndexIterator(Context ctx, QName sourceQName, QName targetQName, XDMIterator[] bySources, QName[] byTargets, XDMIterator[] lets, XDMIterator where, QueryLocation location)

Method Summary

void	init() The complete grouping according to values is done during the init.
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	setFLWOR(FFLWORIterator flwor)
void	setResettable(boolean r) Set this Iterator (and its subiterators) resetable.

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, isExprParameter, isOpen, isResettable, removePredicates, reset, setConstModePreserve, setLoc, setOrderByExpr, setParam, setReturnExpr, setSubIters, setSubIters, setSubIters, setWhereExpr, traverse, traverseIteratorTree

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupByIndexIterator

public GroupByIndexIterator(Context ctx,
                            QName sourceQName,
                            QName targetQName,
                            XDMIterator[] bySources,
                            QName[] byTargets,
                            XDMIterator[] lets,
                            XDMIterator where,
                            QueryLocation location)
                     throws MXQueryException

Throws:

MXQueryException

GroupByIndexIterator

public GroupByIndexIterator(Context ctx,
                            FFLWORIterator flwor,
                            QName sourceQName,
                            QName targetQName,
                            XDMIterator[] bySources,
                            QName[] byTargets,
                            XDMIterator[] lets,
                            XDMIterator where,
                            QueryLocation location)
                     throws MXQueryException

Creates a new group by iterator which applies an index for the values to group for

Parameters:

flwor -

sourceQName -

targetQName -

bySources -

byTargets -

lets -

where -

Throws:

MXQueryException

Method Detail

setFLWOR

public void setFLWOR(FFLWORIterator flwor)

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

init

public void init()
          throws MXQueryException

The complete grouping according to values is done during the init.

Throws:

MXQueryException

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