Package org.terrier.querying.parser

Class SingleTermQuery

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    public class SingleTermQuery
extends Query
    Models a query of a single term. The single term queries can be of the forms:
    term
    +term
    -term
    field:term
    The term can be optionally followed by a weight, as shown below:
    term^weight
    +term^weight
    -term^weight
    field:term^weight
    where weight is a real number. If no weight is specified, then the default weight is 1.0.
    Author:
    Vassilis Plachouras
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      int required
      The optional required qualifier.

    • Constructor Summary

      Constructors 
      Constructor Description
      SingleTermQuery()
      An empty default constructor.
      SingleTermQuery​(java.lang.String t)
      Creates an instance of the class for the given query term.
      SingleTermQuery​(java.lang.String t, int r)
      Creates an instance of the class for the given query term that should be either required or not.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean applyTermPipeline​(TermPipelineAccessor tpa)
      Puts the query term in the given term pipeline, which is accessed through the given accessor object.
      java.lang.Object clone()
      Deep copy this Query object
      int getRequired()
      Indicates whether the query term is required, or it isn't required to appear in the retrieved documents.
      java.lang.String getTerm()
      Gets the query term.
      protected void getTerms​(java.util.List<Query> alist)
      Adds the query term in the given list of query terms.
      void getTermsOf​(java.lang.Class<? extends Query> c, java.util.List<Query> alist, boolean req)
      An empty method because the single term query cannot have children.
      double getWeight()
      Returns the weight of the query term.
      boolean obtainControls​(java.util.Set<java.lang.String> allowed, java.util.Map<java.lang.String,​java.lang.String> controls)
      This object cannot contain any controls, so this method will always return false.
      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 setRequired​(int r)
      Sets the value of the required switch.
      void setTerm​(java.lang.String t)
      Sets the string of the term.
      void setWeight​(double w)
      Sets the weight of the query term.
      java.lang.String toString()
      Returns a string representation of the query term.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • required

        public int required
        The optional required qualifier. It takes the values -1 that corresponds to '-', +1 that corresponds to '+' and 0 that corresponds to unspecified. The default value is 0

    • Constructor Detail

      • SingleTermQuery

        public SingleTermQuery()
        An empty default constructor.

      • SingleTermQuery

        public SingleTermQuery​(java.lang.String t)
        Creates an instance of the class for the given query term.
        Parameters:
        t - String one query term.

      • SingleTermQuery

        public SingleTermQuery​(java.lang.String t,
                       int r)
        Creates an instance of the class for the given query term that should be either required or not.
        Parameters:
        t - String one query term.
        r - int indicates whether the term is required or not.

    • Method Detail

      • clone

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

      • setRequired

        public void setRequired​(int r)
        Sets the value of the required switch.
        Parameters:
        r - int the value of the required switch.

      • setTerm

        public void setTerm​(java.lang.String t)
        Sets the string of the term.
        Parameters:
        t - String the query term.

      • getTerm

        public java.lang.String getTerm()
        Gets the query term.
        Returns:
        String the query term.

      • getRequired

        public int getRequired()
        Indicates whether the query term is required, or it isn't required to appear in the retrieved documents. A value of zero means that this has been left unspecified.
        Returns:
        int an indication of whether the query term should appear in the retrieved documents, or not.

      • toString

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

      • setWeight

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

      • getWeight

        public double getWeight()
        Returns the weight of the query term.
        Returns:
        double the weight of the query term.

      • applyTermPipeline

        public boolean applyTermPipeline​(TermPipelineAccessor tpa)
        Puts the query term in the given term pipeline, which is accessed through the given accessor object.
        Overrides:
        applyTermPipeline in class Query
        Parameters:
        tpa - TermPipelineAccessor the object that provides the 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 the query term in the given list of query terms.
        Overrides:
        getTerms in class Query
        Parameters:
        alist - ArrayList the array list that stores the query terms.

      • obtainControls

        public boolean obtainControls​(java.util.Set<java.lang.String> allowed,
                              java.util.Map<java.lang.String,​java.lang.String> controls)
        This object cannot contain any controls, so this method will always return false.
        Overrides:
        obtainControls in class Query
        Returns:
        false

      • getTermsOf

        public void getTermsOf​(java.lang.Class<? extends Query> c,
                       java.util.List<Query> alist,
                       boolean req)
        An empty method because the single term query cannot have children.
        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.

      • 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