org.eclipse.jface.text.rules
Class RuleBasedScanner

java.lang.Object
  |
  +--org.eclipse.jface.text.rules.RuleBasedScanner

All Implemented Interfaces:

ICharacterScanner, ITokenScanner

Direct Known Subclasses:

BufferedRuleBasedScanner

public class RuleBasedScanner

extends Object

implements ICharacterScanner, ITokenScanner

A generic scanner which can be "programmed" with a sequence of rules. The scanner is used to get the next token by evaluating its rule in sequence until one is successful. If a rule returns a token which is undefined, the scanner will proceed to the next rule. Otherwise the token provided by the rule will be returned by the scanner. If no rule returned a defined token, this scanner returns a token which returns true when calling isOther, unless the end of the file is reached. In this case the token returns true when calling isEOF.

See Also:

IRule

Field Summary

protected int	fColumn
protected IToken	fDefaultReturnToken
protected char[][]	fDelimiters
protected IDocument	fDocument
protected int	fOffset
protected int	fRangeEnd
protected IRule[]	fRules
protected int	fTokenOffset
protected static int	UNDEFINED

Fields inherited from interface org.eclipse.jface.text.rules.ICharacterScanner

EOF

Constructor Summary

RuleBasedScanner()
Creates a new rule based scanner which does not have any rule.

Method Summary

int	getColumn() Returns the column of the character scanner.
char[][]	getLegalLineDelimiters() Provides rules access to the legal line delimiters.
int	getTokenLength() Returns the length of the last token read by this scanner.
int	getTokenOffset() Returns the offset of the last token read by this scanner.
IToken	nextToken() Returns the next token in the document.
int	read() Returns the next character or EOF if end of file has been reached
void	setDefaultReturnToken(IToken defaultReturnToken) Configures the scanner's default return token.
void	setRange(IDocument document, int offset, int length) Configures the scanner by providing access to the document range that should be scanned.
void	setRules(IRule[] rules) Configures the scanner with the given sequence of rules.
void	unread() Rewinds the scanner before the last read character.

Methods inherited from class java.lang.Object

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

Field Detail

fRules

protected IRule[] fRules

fDefaultReturnToken

protected IToken fDefaultReturnToken

fDocument

protected IDocument fDocument

fDelimiters

protected char[][] fDelimiters

fOffset

protected int fOffset

fRangeEnd

protected int fRangeEnd

fTokenOffset

protected int fTokenOffset

fColumn

protected int fColumn

UNDEFINED

protected static final int UNDEFINED

See Also:

Constant Field Values

Constructor Detail

RuleBasedScanner

public RuleBasedScanner()

Creates a new rule based scanner which does not have any rule.

Method Detail

setRules

public void setRules(IRule[] rules)

Configures the scanner with the given sequence of rules.

Parameters:

rules - the sequence of rules controlling this scanner

setDefaultReturnToken

public void setDefaultReturnToken(IToken defaultReturnToken)

Configures the scanner's default return token. This is the token which is returned when non of the rules fired and EOF has not been reached.

Since:

2.0

setRange

public void setRange(IDocument document,
                     int offset,
                     int length)

Description copied from interface: ITokenScanner

Configures the scanner by providing access to the document range that should be scanned.

Specified by:

setRange in interface ITokenScanner

Parameters:

document - the document to scan

offset - the offset of the document range to scan

length - the length of the document range to scan

getTokenOffset

public int getTokenOffset()

Description copied from interface: ITokenScanner

Returns the offset of the last token read by this scanner.

Specified by:

getTokenOffset in interface ITokenScanner

Returns:

the offset of the last token read by this scanner

getTokenLength

public int getTokenLength()

Description copied from interface: ITokenScanner

Returns the length of the last token read by this scanner.

Specified by:

getTokenLength in interface ITokenScanner

Returns:

the length of the last token read by this scanner

getColumn

public int getColumn()

Description copied from interface: ICharacterScanner

Returns the column of the character scanner.

Specified by:

getColumn in interface ICharacterScanner

Returns:

the column of the character scanner

getLegalLineDelimiters

public char[][] getLegalLineDelimiters()

Description copied from interface: ICharacterScanner

Provides rules access to the legal line delimiters.

Specified by:

getLegalLineDelimiters in interface ICharacterScanner

Returns:

the legal line delimiters

nextToken

public IToken nextToken()

Description copied from interface: ITokenScanner

Returns the next token in the document.

Specified by:

nextToken in interface ITokenScanner

Returns:

the next token in the document

read

public int read()

Description copied from interface: ICharacterScanner

Returns the next character or EOF if end of file has been reached

Specified by:

read in interface ICharacterScanner

Returns:

the next character or EOF

unread

public void unread()

Description copied from interface: ICharacterScanner

Rewinds the scanner before the last read character.

Specified by:

unread in interface ICharacterScanner