polyglot.parse

Class Lexer_c

java.lang.Object

polyglot.parse.Lexer_c

All Implemented Interfaces:

Lexer

public class Lexer_c
extends java.lang.Object
implements Lexer

Field Summary

Fields

Modifier and Type	Field and Description
static int	CHARACTER
static int	END_OF_LINE_COMMENT
static int	STRING
static int	TRADITIONAL_COMMENT
static int	YYEOF This character denotes the end of file
static int	YYINITIAL lexical states

Constructor Summary

Constructors

Constructor and Description
Lexer_c(java.io.Reader in) Creates a new scanner
Lexer_c(java.io.Reader reader, FileSource file, ErrorQueue eq)

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	file() The file being scanned, for use in constructing diagnostic messages.
protected void	init_keywords()
Token	nextToken() Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
java.lang.String	path() The path to the file being scanned, for use in constructing diagnostic messages.
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(java.io.Reader reader) Resets the scanner to read from a new input stream.
int	yystate() Returns the current lexical state.
java.lang.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

STRING

public static final int STRING

See Also:

Constant Field Values

CHARACTER

public static final int CHARACTER

See Also:

Constant Field Values

TRADITIONAL_COMMENT

public static final int TRADITIONAL_COMMENT

See Also:

Constant Field Values

END_OF_LINE_COMMENT

public static final int END_OF_LINE_COMMENT

See Also:

Constant Field Values

Constructor Detail

Lexer_c

public Lexer_c(java.io.Reader reader,
       FileSource file,
       ErrorQueue eq)

Lexer_c

public Lexer_c(java.io.Reader in)

Creates a new scanner

Parameters:

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

Method Detail

init_keywords

protected void init_keywords()

file

public java.lang.String file()

Description copied from interface: Lexer

The file being scanned, for use in constructing diagnostic messages.

Specified by:

file in interface Lexer

path

public java.lang.String path()

Description copied from interface: Lexer

The path to the file being scanned, for use in constructing diagnostic messages.

Specified by:

path in interface Lexer

yyclose

public final void yyclose()
                   throws java.io.IOException

Closes the input stream.

Throws:

java.io.IOException

yyreset

public final void yyreset(java.io.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 java.lang.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()!

nextToken

public Token nextToken()
                throws java.io.IOException

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

Specified by:

nextToken in interface Lexer

Returns:

the next token

Throws:

java.io.IOException - if any I/O-Error occurs