Package org.jacop.util.fsm

Class RegularExpressionParser

java.lang.Object

org.jacop.util.fsm.RegularExpressionParser

public class RegularExpressionParser
extends Object

Instances of this class parse the word combination little language.

Version:

4.10

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	RegularExpressionParser.Concatination
class	RegularExpressionParser.Expression	It creates an abstract class expression which specifies basic methods of the expression.
class	RegularExpressionParser.Literal	It specifies a simple literal.
(package private) class	RegularExpressionParser.Star
(package private) class	RegularExpressionParser.Sum
static class	RegularExpressionParser.SyntaxException	SyntaxException raised if not regular expression is being parsed.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	Concatenation	The constant denoting concatenation expression.
static final int	Expression	Constant denoting an expression.
private LexicalAnalyzer	lexer
static final int	Literal	The constant denoting simple literal.
static final int	Star	The constant denoting star expression.
static final int	Sum	The constant denoting sum expression.
private int	token

Constructor Summary

Constructors

Constructor	Description
RegularExpressionParser(StringReader input)	It constructs a parser of the regular expression.

Method Summary

Modifier and Type	Method	Description
private void	expect(int t)	Complain if the current token is not the specified kind of token.
RegularExpressionParser.Expression	parse(boolean parseOneNext)	This method parses an expression that it reads from a given input stream.
private String	tokenName(int t)

Methods inherited from class java.lang.Object

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

Field Details

lexer

private LexicalAnalyzer lexer

token

private int token

Expression

public static final int Expression

Constant denoting an expression.

See Also:

• Constant Field Values

Literal

public static final int Literal

The constant denoting simple literal.

See Also:

• Constant Field Values

Concatenation

public static final int Concatenation

The constant denoting concatenation expression.

See Also:

• Constant Field Values

Star

public static final int Star

The constant denoting star expression.

See Also:

• Constant Field Values

Sum

public static final int Sum

The constant denoting sum expression.

See Also:

• Constant Field Values

Constructor Details

RegularExpressionParser

public RegularExpressionParser(StringReader input)
                        throws RegularExpressionParser.SyntaxException

It constructs a parser of the regular expression.

Parameters:

input - string reader containing the regular expression.

Throws:

RegularExpressionParser.SyntaxException - if first token is neither word or left parenthesis.

Method Details

parse

public RegularExpressionParser.Expression parse(boolean parseOneNext)
                                         throws RegularExpressionParser.SyntaxException

This method parses an expression that it reads from a given input stream.

Parameters:

parseOneNext - if parsing should parse only one item.

Returns:

An expression that is the root of the parse tree produced by the parser.

Throws:

RegularExpressionParser.SyntaxException - execption rised when syntax is not followed

expect

private void expect(int t)
             throws RegularExpressionParser.SyntaxException

Complain if the current token is not the specified kind of token.

Parameters:

t - The type of token that is expected.

Throws:

RegularExpressionParser.SyntaxException

tokenName

private String tokenName(int t)