Package com.yahoo.prelude.query

Class NonReducibleCompositeItem

java.lang.Object

com.yahoo.prelude.query.Item

com.yahoo.prelude.query.CompositeItem

com.yahoo.prelude.query.NonReducibleCompositeItem

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

SameElementItem, WeakAndItem

public abstract class NonReducibleCompositeItem
extends CompositeItem

A composite item which specifies semantics which are not maintained if an instance with a single child is replaced by the single child. Most composites, like AND and OR, are reducible as e.g (AND a) is semantically equal to (a). This type functions as a marker type for query rewriters and returns empty when a single child is attempted extracted.

Author:

bratseth

Nested Class Summary

Nested classes/interfaces inherited from class com.yahoo.prelude.query.Item

Item.ItemCreator, Item.ItemType

Field Summary

Fields inherited from class com.yahoo.prelude.query.Item

connectedBacklink, connectedItem, connectivity, DEFAULT_WEIGHT, documentFrequency, explicitSignificance, significance, uniqueID

Constructor Summary

Constructors

Constructor	Description
NonReducibleCompositeItem()

Method Summary

Modifier and Type	Method	Description
final Optional<Item>	extractSingleChild()	Returns the single child of this, if this can be omitted without changes to recall semantics.

Methods inherited from class com.yahoo.prelude.query.CompositeItem

acceptsItemsOfType, adding, addItem, addItem, appendBodyString, clone, disclose, encode, encodeThis, encodingArity, ensureNotInSubtree, equals, getItem, getItemCount, getItemIndex, getItemIterator, getTermCount, hashCode, isLocked, items, lock, removeItem, removeItem, setIndexName, setItem, shouldParenthesize

Methods inherited from class com.yahoo.prelude.query.Item

addAnnotation, appendHeadingString, getAnnotation, getBytes, getCode, getCreator, getItemType, getLabel, getLanguage, getName, getParent, getWeight, hasAnnotation, hasConnectivityBackLink, hasPrefixMatchSemantics, hasUniqueID, isFilter, isFromSpecialToken, isProtected, isRanked, isRoot, putBytes, putString, setCreator, setFilter, setFromSpecialToken, setHasUniqueID, setLabel, setLanguage, setParent, setPositionData, setProtected, setRanked, setWeight, toString, usePositionData

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

NonReducibleCompositeItem

public NonReducibleCompositeItem()

Method Details

extractSingleChild

public final Optional<Item> extractSingleChild()

Description copied from class: CompositeItem

Returns the single child of this, if this can be omitted without changes to recall semantics.

Overrides:

extractSingleChild in class CompositeItem