org.h2.bnf

Class Bnf

java.lang.Object

org.h2.bnf.Bnf

public class Bnf
extends 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 and Description
Bnf()

Method Summary

Methods

Modifier and Type	Method and Description
static Bnf	getInstance(Reader csv) Create an instance using the grammar specified in the CSV file.
HashMap<String,String>	getNextTokenList(String query) Get the list of tokens that can follow.
RuleHead	getRuleHead(String title) Get the rule head for the given title.
static String	getRuleMapKey(String token) Convert convert ruleLink to rule_link.
ArrayList<RuleHead>	getStatements() Get the list of possible statements.
static StringTokenizer	getTokenizer(String s) Get the tokenizer for the given syntax.
void	linkStatements() Cross-link all statements with each other.
void	updateTopic(String topic, DbContextRule rule) Update a topic with a context specific rule.
void	visit(BnfVisitor visitor, 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, toString, wait, wait, wait

Constructor Detail

Bnf

public Bnf()

Method Detail

getInstance

public static Bnf getInstance(Reader csv)
                       throws SQLException,
                              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:

SQLException

IOException

visit

public void visit(BnfVisitor visitor,
         String s)

Parse the syntax and let the rule call the visitor.

Parameters:

visitor - the visitor

s - the syntax to parse

getRuleMapKey

public static String getRuleMapKey(String token)

Convert convert ruleLink to rule_link.

Parameters:

token - the token

Returns:

the rule map key

getRuleHead

public RuleHead getRuleHead(String title)

Get the rule head for the given title.

Parameters:

title - the title

Returns:

the rule head, or null

getNextTokenList

public HashMap<String,String> getNextTokenList(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(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 ArrayList<RuleHead> getStatements()

Get the list of possible statements.

Returns:

the list of statements

getTokenizer

public static StringTokenizer getTokenizer(String s)

Get the tokenizer for the given syntax.

Parameters:

s - the syntax

Returns:

the tokenizer