oracle.javatools.parser.diff
Class DiffLexer

java.lang.Object
  oracle.javatools.parser.AbstractLexer
      oracle.javatools.parser.diff.DiffLexer

All Implemented Interfaces:

DiffTokens, Lexer

public class DiffLexer
extends AbstractLexer
implements DiffTokens

The DiffLexer is an implementation of the Lexer interface for a *.diff or *.patch file.

Nested Class Summary

Nested classes/interfaces inherited from class oracle.javatools.parser.AbstractLexer

AbstractLexer.DefaultLexerToken

Field Summary

Fields inherited from class oracle.javatools.parser.AbstractLexer

currentPos, textBuffer

Fields inherited from interface oracle.javatools.parser.diff.DiffTokens

TK_ADDITION, TK_HEADER, TK_REMOVAL

Fields inherited from interface oracle.javatools.parser.Lexer

TK_EOF, TK_NOT_FOUND

Constructor Summary

DiffLexer()
Constructs a default PropertiesLexer with a starting position of 0.

Method Summary

void	backup() Unlexes the last found token.
int	lex(LexerToken lexedToken) Scans the text buffer at the current position and returns the token that was found.
void	setPosition(int offset) Sets the current lex (read) position to the given offset in the buffer.
static java.lang.String	tokenToString(int token) Utility routine to map the token to a string representation of the token (for debug printing.)
static java.lang.String	tokenToText(int token) Utility routine to map the token to the original text (if retrievable) of the token (for debug printing.)

Methods inherited from class oracle.javatools.parser.AbstractLexer

createLexerToken, getTextBuffer, setTextBuffer

Methods inherited from class java.lang.Object

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

Constructor Detail

DiffLexer

public DiffLexer()

Constructs a default PropertiesLexer with a starting position of 0. Clients must call setTextBuffer() to initialize the text buffer used for the Lexer. To start lexing from an offset other than 0, call setPosition().

Method Detail

lex

public int lex(LexerToken lexedToken)

Scans the text buffer at the current position and returns the token that was found. The token and offset information is also stored in the lexedToken instance passed in to the call.

Specified by:

lex in interface Lexer

Specified by:

lex in class AbstractLexer

Parameters:

lexedToken - the instance passed in where token info is stored

Returns:

the token that was found, same as calling lexedToken.getToken() (for convenience)

backup

public void backup()

Unlexes the last found token. The next call to lex() will return the last token and offset information found.

Specified by:

backup in interface Lexer

Specified by:

backup in class AbstractLexer

setPosition

public void setPosition(int offset)

Sets the current lex (read) position to the given offset in the buffer. It is the clients responsibility to ensure that this offset corresponds to the start of the line, otherwise, unexpected (and incorrect) results may occur.

Specified by:

setPosition in interface Lexer

Overrides:

setPosition in class AbstractLexer

Parameters:

offset - the offset for the next lex() operation.

tokenToString

public static java.lang.String tokenToString(int token)

Utility routine to map the token to a string representation of the token (for debug printing.)

Parameters:

token - the token to map

Returns:

a printable representation of the token

tokenToText

public static java.lang.String tokenToText(int token)

Utility routine to map the token to the original text (if retrievable) of the token (for debug printing.)

Parameters:

token - the token to map

Returns:

a printable representation of the token