Package org.h2.bnf

Class Bnf

  • public class Bnf
extends java.lang.Object
    This class can read a file that is similar to BNF (Backus-Naur form). It is made specially to support SQL grammar.

    • Constructor Summary

      Constructors 
      Constructor Description
      Bnf()  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addAlias​(java.lang.String name, java.lang.String replacement)
      Add an alias for a rule.
      private void addFixedRule​(java.lang.String name, int fixedType)  
      private RuleHead addRule​(java.lang.String topic, java.lang.String section, Rule rule)  
      static Bnf getInstance​(java.io.Reader csv)
      Create an instance using the grammar specified in the CSV file.
      java.util.HashMap<java.lang.String,​java.lang.String> getNextTokenList​(java.lang.String query)
      Get the list of tokens that can follow.
      RuleHead getRuleHead​(java.lang.String title)
      Get the rule head for the given title.
      static java.lang.String getRuleMapKey​(java.lang.String token)
      Convert convert ruleLink to rule_link.
      java.util.ArrayList<RuleHead> getStatements()
      Get the list of possible statements.
      static java.util.StringTokenizer getTokenizer​(java.lang.String s)
      Get the tokenizer for the given syntax.
      void linkStatements()
      Cross-link all statements with each other.
      private void parse​(java.io.Reader reader)  
      private RuleExtension parseExtension​(boolean compatibility)  
      private Rule parseList()  
      private Rule parseOr()  
      private Rule parseRule()  
      private Rule parseToken()  
      private void read()  
      static boolean startWithSpace​(java.lang.String s)
      Check whether the statement starts with a whitespace.
      private java.lang.String[] tokenize()  
      java.lang.String toString()  
      void updateTopic​(java.lang.String topic, DbContextRule rule)
      Update a topic with a context specific rule.
      void visit​(BnfVisitor visitor, java.lang.String s)
      Parse the syntax and let the rule call the visitor.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • ruleMap

        private final java.util.HashMap<java.lang.String,​RuleHead> ruleMap
        The rule map. The key is lowercase, and all spaces are replaces with underscore.

      • syntax

        private java.lang.String syntax

      • currentToken

        private java.lang.String currentToken

      • tokens

        private java.lang.String[] tokens

      • firstChar

        private char firstChar

      • index

        private int index

      • lastRepeat

        private Rule lastRepeat

      • statements

        private java.util.ArrayList<RuleHead> statements

      • currentTopic

        private java.lang.String currentTopic

    • Constructor Detail

      • Bnf

        public Bnf()

    • Method Detail

      • getInstance

        public static Bnf getInstance​(java.io.Reader csv)
                       throws java.sql.SQLException,
                              java.io.IOException
        Create an instance using the grammar specified in the CSV file.
        Parameters:
        csv - if not specified, the help.csv is used
        Returns:
        a new instance
        Throws:
        java.sql.SQLException - on failure
        java.io.IOException - on failure

      • addAlias

        public void addAlias​(java.lang.String name,
                     java.lang.String replacement)
        Add an alias for a rule.
        Parameters:
        name - for example "procedure"
        replacement - for example "@func@"

      • addFixedRule

        private void addFixedRule​(java.lang.String name,
                          int fixedType)

      • addRule

        private RuleHead addRule​(java.lang.String topic,
                         java.lang.String section,
                         Rule rule)

      • parse

        private void parse​(java.io.Reader reader)
            throws java.sql.SQLException,
                   java.io.IOException
        Throws:
        java.sql.SQLException
        java.io.IOException

      • visit

        public void visit​(BnfVisitor visitor,
                  java.lang.String s)
        Parse the syntax and let the rule call the visitor.
        Parameters:
        visitor - the visitor
        s - the syntax to parse

      • startWithSpace

        public static boolean startWithSpace​(java.lang.String s)
        Check whether the statement starts with a whitespace.
        Parameters:
        s - the statement
        Returns:
        if the statement is not empty and starts with a whitespace

      • getRuleMapKey

        public static java.lang.String getRuleMapKey​(java.lang.String token)
        Convert convert ruleLink to rule_link.
        Parameters:
        token - the token
        Returns:
        the rule map key

      • getRuleHead

        public RuleHead getRuleHead​(java.lang.String title)
        Get the rule head for the given title.
        Parameters:
        title - the title
        Returns:
        the rule head, or null

      • parseRule

        private Rule parseRule()

      • parseOr

        private Rule parseOr()

      • parseList

        private Rule parseList()

      • parseExtension

        private RuleExtension parseExtension​(boolean compatibility)

      • parseToken

        private Rule parseToken()

      • read

        private void read()

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • tokenize

        private java.lang.String[] tokenize()

      • getNextTokenList

        public java.util.HashMap<java.lang.String,​java.lang.String> getNextTokenList​(java.lang.String query)
        Get the list of tokens that can follow. This is the main autocomplete method. The returned map for the query 'S' may look like this: 
         key: 1#SELECT, value: ELECT
 key: 1#SET, value: ET
        Parameters:
        query - the start of the statement
        Returns:
        the map of possible token types / tokens

      • linkStatements

        public void linkStatements()
        Cross-link all statements with each other. This method is called after updating the topics.

      • updateTopic

        public void updateTopic​(java.lang.String topic,
                        DbContextRule rule)
        Update a topic with a context specific rule. This is used for autocomplete support.
        Parameters:
        topic - the topic
        rule - the database context rule

      • getStatements

        public java.util.ArrayList<RuleHead> getStatements()
        Get the list of possible statements.
        Returns:
        the list of statements

      • getTokenizer

        public static java.util.StringTokenizer getTokenizer​(java.lang.String s)
        Get the tokenizer for the given syntax.
        Parameters:
        s - the syntax
        Returns:
        the tokenizer