Package org.terrier.querying.parser

Class MultiTermQuery

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    Direct Known Subclasses:
    DisjunctiveQuery, ExplicitMultiTermQuery, PhraseQuery, SegmentQuery
    public class MultiTermQuery
extends Query
    Represents a query consisting of more than one terms or other sub-queries, qualified with field, requirement or phrase operators.
    Author:
    Vassilis Plachouras, Craig Macdonald
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected java.lang.String prefix  
      protected java.lang.String suffix  
      protected java.util.ArrayList<Query> v
      A list for holding the sub-queries.

    • Constructor Summary

      Constructors 
      Constructor Description
      MultiTermQuery()
      A default constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(java.lang.String term)
      Adds a single query term to the query.
      void add​(Query query)
      Adds a subquery to this query.
      void apply​(Query.ForEachQueryNode processor)
      Apply the specified processor to this node.
      boolean applyTermPipeline​(TermPipelineAccessor tpa)
      Applies the given term pipeline to the query terms and sub-queries that construct this query.
      java.lang.Object clone()
      Deep copy this Query object
      int getNumberOfTerms()
      Returns the number of terms, or subqueries.
      protected void getTerms​(java.util.List<Query> alist)
      Adds all the subqueries and single-term queries to a given array list.
      void getTermsOf​(java.lang.Class<? extends Query> c, java.util.List<Query> alist, boolean req)
      Returns all the query terms, in subqueries that are instances of a given class
      void obtainAllOf​(java.lang.Class<? extends Query> c, java.util.List<Query> a)
      Returns all the queries of the specified class
      boolean obtainControls​(java.util.Set<java.lang.String> allowed, java.util.Map<java.lang.String,​java.lang.String> controls)
      Checks all child objects to see if they are FieldQuery objects, they are each called to see if the are controls.
      void obtainQueryTerms​(MatchingQueryTerms terms, java.lang.String field, java.lang.Boolean required, java.lang.Double weight)  
      void obtainQueryTerms​(Query.QueryTermsParameter parameters)  
      java.lang.String parseTree()
      Returns the parse tree for the query as a string
      void replace​(Query childNode, Query replacement)
      Replace query node
      void setWeight​(double w)
      Sets the weight of the disjunctive "term".
      java.lang.String toString()
      Returns a string representation of the query.

      • Methods inherited from class org.terrier.querying.parser.Query

        setChild

      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • prefix

        protected java.lang.String prefix

      • suffix

        protected java.lang.String suffix

      • v

        protected java.util.ArrayList<Query> v
        A list for holding the sub-queries. A LinkedList is ideal as we have no need to access numbered sub-query elements of the query - only be able to iterate throught them.

    • Constructor Detail

      • MultiTermQuery

        public MultiTermQuery()
        A default constructor.

    • Method Detail

      • setWeight

        public void setWeight​(double w)
        Sets the weight of the disjunctive "term".
        Parameters:
        w - double the weight of the disjunctive "term".

      • getNumberOfTerms

        public int getNumberOfTerms()
        Returns the number of terms, or subqueries.
        Returns:
        int the number of terms, or subqueries of this query.

      • clone

        public java.lang.Object clone()
        Deep copy this Query object
        Overrides:
        clone in class Query

      • add

        public void add​(java.lang.String term)
        Adds a single query term to the query.
        Parameters:
        term - String the query term.

      • add

        public void add​(Query query)
        Adds a subquery to this query.
        Parameters:
        query - Query a subquery.

      • toString

        public java.lang.String toString()
        Returns a string representation of the query.
        Specified by:
        toString in class Query
        Returns:
        String the string of this query.

      • applyTermPipeline

        public boolean applyTermPipeline​(TermPipelineAccessor tpa)
        Applies the given term pipeline to the query terms and sub-queries that construct this query.
        Overrides:
        applyTermPipeline in class Query
        Parameters:
        tpa - TermPipelineAccessor the object that gives access to a term pipeline.
        Returns:
        boolean true if the query is not empty, otherwise returns false.

      • obtainQueryTerms

        public void obtainQueryTerms​(MatchingQueryTerms terms,
                             java.lang.String field,
                             java.lang.Boolean required,
                             java.lang.Double weight)
        Specified by:
        obtainQueryTerms in class Query

      • getTerms

        protected void getTerms​(java.util.List<Query> alist)
        Adds all the subqueries and single-term queries to a given array list.
        Overrides:
        getTerms in class Query
        Parameters:
        alist - ArrayList the array list in which all the query terms and sub-queries are stored.

      • obtainControls

        public boolean obtainControls​(java.util.Set<java.lang.String> allowed,
                              java.util.Map<java.lang.String,​java.lang.String> controls)
        Checks all child objects to see if they are FieldQuery objects, they are each called to see if the are controls. Child objects which return true are removed from the tree. If all child objects return true then this object is also considered dead, and should be removed.
        Overrides:
        obtainControls in class Query
        Parameters:
        allowed - The HashSet of control names that are allowed to be set.
        controls - The Hashtable into which child objects much add found controls
        Returns:
        true if this object should be considered dead (no longer part of the query), false otherwise.

      • getTermsOf

        public void getTermsOf​(java.lang.Class<? extends Query> c,
                       java.util.List<Query> alist,
                       boolean req)
        Returns all the query terms, in subqueries that are instances of a given class
        Specified by:
        getTermsOf in class Query
        Parameters:
        c - Class a class of queries.
        alist - ArrayList the list of query terms.
        req - boolean indicates whether the subqueries are required or not.

      • replace

        public void replace​(Query childNode,
                    Query replacement)
        Replace query node
        Parameters:
        childNode -
        replacement -

      • obtainAllOf

        public void obtainAllOf​(java.lang.Class<? extends Query> c,
                        java.util.List<Query> a)
        Description copied from class: Query
        Returns all the queries of the specified class
        Overrides:
        obtainAllOf in class Query

      • apply

        public void apply​(Query.ForEachQueryNode processor)
        Apply the specified processor to this node. If the processor allows, move to any children nodes.
        Overrides:
        apply in class Query
        Parameters:
        processor -

      • parseTree

        public java.lang.String parseTree()
        Description copied from class: Query
        Returns the parse tree for the query as a string
        Specified by:
        parseTree in class Query