Package com.yahoo.prelude.semantics

Class RuleBase

java.lang.Object
com.yahoo.prelude.semantics.RuleBase
public class RuleBase extends Object
A set of semantic production rules and named conditions used to analyze and rewrite queries
Author:
bratseth

  • Constructor Details

    • RuleBase

      public RuleBase(String name)
      Creates an empty rule base

  • Method Details

    • createFromFile

      public static RuleBase createFromFile(String ruleFile, String automataFile, com.yahoo.language.Linguistics linguistics) throws IOException, ParseException
      Creates a rule base from file
      Parameters:
      ruleFile - the rule file to read. The name of the file (minus path) becomes the rule base name.
      automataFile - the automata file, or null to not use an automata
      Throws:
      IOException - if there is a problem reading one of the files
      ParseException - if the rule file can not be parsed correctly
      RuleBaseException - if the rule file contains inconsistencies

    • createFromString

      public static RuleBase createFromString(String name, String ruleString, String automataFile, com.yahoo.language.Linguistics linguistics) throws IOException, ParseException
      Creates a rule base from a string
      Parameters:
      name - the name of the rule base
      ruleString - the rule string to read
      automataFile - the automata file, or null to not use an automata
      Throws:
      IOException - if there is a problem reading the automata file
      ParseException - if the rule file can not be parsed correctly
      RuleBaseException - if the rule file contains inconsistencies

    • include

      public void include(RuleBase include)

      Include another rule base into this. This transfers ownership of the given rule base - it can not be subsequently used for any purpose (including accessing).

      Each rule base will only be included by the first include directive enountered for that rule base.

    • addCondition

      public void addCondition(NamedCondition namedCondition)
      Adds a named condition which can be referenced by rules

    • includes

      public boolean includes(String ruleBaseName)
      Returns whether this rule base - directly or through other includes - includes the rule base with the given name

    • setName

      public void setName(String name)
      Sets the name of this rule base. If this rule base is given to a searcher, it must be removed before the name change, and then re-added

    • getName

      public String getName()
      Returns the name of this rule base. This is never null.

    • setAutomataFile

      public void setAutomataFile(String automataFile)
      Sets the name of the automata file to use as a source of condition matches. To reload the automata, call this again. This can be done safely at any point by any thread while this rule base is in use.
      Throws:
      IllegalArgumentException - if the file is not found

    • getAutomataFile

      public String getAutomataFile()
      Returns the name of the automata file used, or null if none

    • setDefault

      public void setDefault(boolean isDefault)
      Sets whether this base is default, the semantics of default is left to the application

    • isDefault

      public boolean isDefault()
      Returns whether this base is default, the semantics of default is left to the application

    • setPhraseMatcher

      public void setPhraseMatcher(PhraseMatcher matcher)
      Thread safely sets the phrase matcher to use in this, or null to not use a phrase matcher

    • getPhraseMatcher

      public PhraseMatcher getPhraseMatcher()
      Thread safely gets the phrase matcher to use in this

    • getSource

      public String getSource()
      The identifying name of the source of this rule base. The absolute file name if this came from a file.

    • setSource

      public void setSource(String source)
      Sets the name of the source of this rule base. If this came from a file, the source must be set to the absolute file name of the rule base

    • usesAutomata

      public boolean usesAutomata()
      Returns whether this uses a phrase matcher automata

    • addRule

      public void addRule(ProductionRule productionRule)

    • getCondition

      public NamedCondition getCondition(String name)
      Returns a named condition, or null if no condition with that name exists

    • initialize

      public void initialize()
      Call this when all rules are added, before any rule evaluation starts.
      Throws:
      RuleBaseException - if there is an inconsistency in the rule base.

    • analyze

      public String analyze(Query query, int traceLevel)
      Analyzes a query over this rule base
      Parameters:
      query - the query to analyze
      traceLevel - the level of tracing to add to the query
      Returns:
      the error caused by analyzing the query, or null if there was no error If there is an error, this query is destroyed (unusable)

    • matchAutomata

      protected void matchAutomata(Query query, int traceLevel)

    • annotatePhrase

      protected void annotatePhrase(PhraseMatcher.Phrase phrase, Query query, int traceLevel)

    • ruleIterator

      public ListIterator<ProductionRule> ruleIterator()
      Returns the rules in added order

    • rules

      public List<ProductionRule> rules()
      Returns the rules unmodifiable

    • conditionIterator

      public Iterator<NamedCondition> conditionIterator()
      Returns the named conditions in added order

    • equals

      public boolean equals(Object object)
      Returns true if the given object is a rule base having the same name as this
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • toContentString

      public String toContentString()
      Returns a string containing all the rules and conditions of this rule base in the form they will be evaluated, with all included rule bases inlined