org.fife.ui.rsyntaxtextarea.modes

Class PlainTextTokenMaker

java.lang.Object

org.fife.ui.rsyntaxtextarea.AbstractJFlexTokenMaker

org.fife.ui.rsyntaxtextarea.modes.PlainTextTokenMaker

All Implemented Interfaces:

TokenMaker

public class PlainTextTokenMaker
extends AbstractJFlexTokenMaker

Scanner for plain text files. This implementation was created using JFlex 1.4.1; however, the generated file was modified for performance. Memory allocation needs to be almost completely removed to be competitive with the handwritten lexers (subclasses of AbstractTokenMaker), so this class has been modified so that Strings are never allocated (via yytext()), and the scanner never has to worry about refilling its buffer (needlessly copying chars around). We can achieve this because RText always scans exactly 1 line of tokens at a time, and hands the scanner this line as an array of characters (a Segment really). Since tokens contain pointers to char arrays instead of Strings holding their contents, there is no need for allocating new memory for Strings.

The actual algorithm generated for scanning has, of course, not been modified.

If you wish to regenerate this file yourself, keep in mind the following:

• The generated PlainTextTokenMaker.java file will contain two definitions of both zzRefill and yyreset. You should hand-delete the second of each definition (the ones generated by the lexer), as these generated methods modify the input buffer, which we'll never have to do.
• You should also change the declaration/definition of zzBuffer to NOT be initialized. This is a needless memory allocation for us since we will be pointing the array somewhere else anyway.
• You should NOT call yylex() on the generated scanner directly; rather, you should use getTokenList as you would with any other TokenMaker instance.

Version:

0.5

Author:

Robert Futrell

Field Summary

Fields

Modifier and Type	Field and Description
protected Token	currentToken Used in the creation of the linked list.
protected Token	firstToken The first token in the returned linked list.
protected Token	previousToken Used in the creation of the linked list.
static int	YYEOF This character denotes the end of file
static int	YYINITIAL lexical states

Fields inherited from class org.fife.ui.rsyntaxtextarea.AbstractJFlexTokenMaker

offsetShift, s, start

Constructor Summary

Constructors

Constructor and Description
PlainTextTokenMaker() Constructor.
PlainTextTokenMaker(InputStream in) Creates a new scanner.
PlainTextTokenMaker(Reader in) Creates a new scanner There is also a java.io.InputStream version of this constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	addNullToken() Adds a null token to the end of the current linked list of tokens.
void	addToken(char[] array, int start, int end, int tokenType, int startOffset) Adds the token specified to the current linked list of tokens.
void	addToken(char[] array, int start, int end, int tokenType, int startOffset, boolean hyperlink) Adds the token specified to the current linked list of tokens.
void	addToken(Segment segment, int start, int end, int tokenType, int startOffset) Adds the token specified to the current linked list of tokens.
boolean	getCurlyBracesDenoteCodeBlocks() Returns whether this programming language uses curly braces ('{' and '}') to denote code blocks.
int	getLastTokenTypeOnLine(Segment text, int initialTokenType) Always returns Token.NULL, as there are no multiline tokens in properties files.
String[]	getLineCommentStartAndEnd() Returns the text to place at the beginning and end of a line to "comment" it in a this programming language.
boolean	getMarkOccurrencesOfTokenType(int type) Always returns false, as you never want "mark occurrences" working in plain text files.
boolean	getShouldIndentNextLineAfter(Token token) The default implementation returns false always.
Token	getTokenList(Segment text, int initialTokenType, int startOffset) Returns the first token in the linked list of tokens generated from text.
protected void	resetTokenList() Deletes the linked list of tokens so we can begin anew.
void	setWhitespaceVisible(boolean visible, RSyntaxTextArea textArea) Sets whether tokens are generated that "show" whitespace.
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.
Token	yylex() Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
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

firstToken

protected Token firstToken

The first token in the returned linked list.

currentToken

protected Token currentToken

Used in the creation of the linked list.

previousToken

protected Token previousToken

Used in the creation of the linked list.

Constructor Detail

PlainTextTokenMaker

public PlainTextTokenMaker()

Constructor. This must be here because JFlex does not generate a no-parameter constructor.

PlainTextTokenMaker

public PlainTextTokenMaker(Reader in)

Creates a new scanner There is also a java.io.InputStream version of this constructor.

Parameters:

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

PlainTextTokenMaker

public PlainTextTokenMaker(InputStream in)

Creates a new scanner. There is also java.io.Reader version of this constructor.

Parameters:

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

Method Detail

getLastTokenTypeOnLine

public int getLastTokenTypeOnLine(Segment text,
                         int initialTokenType)

Always returns Token.NULL, as there are no multiline tokens in properties files.

Specified by:

getLastTokenTypeOnLine in interface TokenMaker

Parameters:

text - The line of tokens to examine.

initialTokenType - The token type to start with (i.e., the value of getLastTokenTypeOnLine for the line before text).

Returns:

Token.NULL.

getLineCommentStartAndEnd

public String[] getLineCommentStartAndEnd()

Returns the text to place at the beginning and end of a line to "comment" it in a this programming language.

Specified by:

getLineCommentStartAndEnd in interface TokenMaker

Returns:

null, as there are no comments in plain text.

getMarkOccurrencesOfTokenType

public boolean getMarkOccurrencesOfTokenType(int type)

Always returns false, as you never want "mark occurrences" working in plain text files.

Specified by:

getMarkOccurrencesOfTokenType in interface TokenMaker

Parameters:

type - The token type.

Returns:

Whether tokens of this type should have "mark occurrences" enabled.

getTokenList

public Token getTokenList(Segment text,
                 int initialTokenType,
                 int startOffset)

Returns the first token in the linked list of tokens generated from text. This method must be implemented by subclasses so they can correctly implement syntax highlighting.

Parameters:

text - The text from which to get tokens.

initialTokenType - The token type we should start with.

startOffset - The offset into the document at which text starts.

Returns:

The first Token in a linked list representing the syntax highlighted text.

yyreset

public final void yyreset(Reader reader)
                   throws IOException

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 YY_INITIAL.

Parameters:

reader - the new input stream

Throws:

IOException

yyclose

public final void yyclose()
                   throws IOException

Closes the input stream.

Throws:

IOException

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()!

yylex

public Token yylex()
            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

addNullToken

public void addNullToken()

Adds a null token to the end of the current linked list of tokens. This should be put at the end of the linked list whenever the last token on the current line is NOT a multiline token.

Specified by:

addNullToken in interface TokenMaker

addToken

public void addToken(Segment segment,
            int start,
            int end,
            int tokenType,
            int startOffset)

Adds the token specified to the current linked list of tokens.

Parameters:

segment - Segment to get text from.

start - Start offset in segment of token.

end - End offset in segment of token.

tokenType - The token's type.

startOffset - The offset in the document at which this token occurs.

addToken

public void addToken(char[] array,
            int start,
            int end,
            int tokenType,
            int startOffset)

Adds the token specified to the current linked list of tokens.

Specified by:

addToken in interface TokenMaker

Parameters:

array - The character array.

start - The starting offset in the array.

end - The ending offset in the array.

tokenType - The token's type.

startOffset - The offset in the document at which this token occurs.

addToken

public void addToken(char[] array,
            int start,
            int end,
            int tokenType,
            int startOffset,
            boolean hyperlink)

Adds the token specified to the current linked list of tokens.

Parameters:

array - The character array.

start - The starting offset in the array.

end - The ending offset in the array.

tokenType - The token's type.

startOffset - The offset in the document at which this token occurs.

hyperlink - Whether this token is a hyperlink.

getCurlyBracesDenoteCodeBlocks

public boolean getCurlyBracesDenoteCodeBlocks()

Returns whether this programming language uses curly braces ('{' and '}') to denote code blocks.

The default implementation returns false; subclasses can override this method if necessary.

Specified by:

getCurlyBracesDenoteCodeBlocks in interface TokenMaker

Returns:

Whether curly braces denote code blocks.

getShouldIndentNextLineAfter

public boolean getShouldIndentNextLineAfter(Token token)

The default implementation returns false always. Languages that wish to better support auto-indentation can override this method.

Specified by:

getShouldIndentNextLineAfter in interface TokenMaker

Parameters:

token - The token the previous line ends with.

Returns:

Whether the next line should be indented.

resetTokenList

protected void resetTokenList()

Deletes the linked list of tokens so we can begin anew. This should never have to be called by the programmer, as it is automatically called whenever the user calls getLastTokenTypeOnLine or getTokenList.

setWhitespaceVisible

public void setWhitespaceVisible(boolean visible,
                        RSyntaxTextArea textArea)

Sets whether tokens are generated that "show" whitespace.

Specified by:

setWhitespaceVisible in interface TokenMaker

Parameters:

visible - Whether whitespace should be visible.