net.ontopia.topicmaps.query.parser

Class TologLexer

java.lang.Object

net.ontopia.topicmaps.query.parser.TologLexer

All Implemented Interfaces:

antlr.TokenStream

public class TologLexer
extends Object
implements antlr.TokenStream

A tolog lexer, to be used with the Antlr-generated parser.

Field Summary

Fields

Modifier and Type	Field and Description
static int	COMMENT
static int	YYEOF This character denotes the end of file
static int	YYINITIAL lexical states

Constructor Summary

Constructors

Constructor and Description
TologLexer(Reader in) Creates a new scanner
TologLexer(Reader reader, TologOptions options)

Method Summary

Modifier and Type	Method and Description
TologOptions	getOptions()
int	getStartOfToken()
antlr.Token	nextToken()
antlr.Token	nextToken2() Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
void	yybegin(int newState) Enters a new lexical state
char	yycharat(int pos) Returns the character at position pos from the matched text.
void	yyclose() Closes the input stream.
int	yylength() Returns the length of the matched text region.
void	yypushback(int number) Pushes the specified amount of characters back into the input stream.
void	yyreset(Reader reader) Resets the scanner to read from a new input stream.
int	yystate() Returns the current lexical state.
String	yytext() Returns the text matched by the current regular expression.

Methods inherited from class java.lang.Object

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

Field Detail

YYEOF

public static final int YYEOF

This character denotes the end of file

See Also:

Constant Field Values

YYINITIAL

public static final int YYINITIAL

lexical states

See Also:

Constant Field Values

COMMENT

public static final int COMMENT

See Also:

Constant Field Values

Constructor Detail

TologLexer

public TologLexer(Reader reader,
                  TologOptions options)

TologLexer

public TologLexer(Reader in)

Creates a new scanner

Parameters:

in - the java.io.Reader to read input from.

Method Detail

getOptions

public TologOptions getOptions()

nextToken

public antlr.Token nextToken()

Specified by:

nextToken in interface antlr.TokenStream

getStartOfToken

public int getStartOfToken()

yyclose

public final void yyclose()
                   throws IOException

Closes the input stream.

Throws:

IOException

yyreset

public final void yyreset(Reader reader)

Resets the scanner to read from a new input stream. Does not close the old reader. All internal variables are reset, the old input stream cannot be reused (internal buffer is discarded and lost). Lexical state is set to ZZ_INITIAL. Internal scan buffer is resized down to its initial length, if it has grown.

Parameters:

reader - the new input stream

yystate

public final int yystate()

Returns the current lexical state.

yybegin

public final void yybegin(int newState)

Enters a new lexical state

Parameters:

newState - the new lexical state

yytext

public final String yytext()

Returns the text matched by the current regular expression.

yycharat

public final char yycharat(int pos)

Returns the character at position pos from the matched text. It is equivalent to yytext().charAt(pos), but faster

Parameters:

pos - the position of the character to fetch. A value from 0 to yylength()-1.

Returns:

the character at position pos

yylength

public final int yylength()

Returns the length of the matched text region.

yypushback

public void yypushback(int number)

Pushes the specified amount of characters back into the input stream. They will be read again by then next call of the scanning method

Parameters:

number - the number of characters to be read again. This number must not be greater than yylength()!

nextToken2

public antlr.Token nextToken2()
                       throws IOException

Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.

Returns:

the next token

Throws:

IOException - if any I/O-Error occurs