org.jrubyparser.lexer
Class LexerSource

java.lang.Object
  org.jrubyparser.lexer.LexerSource

Direct Known Subclasses:

ReaderLexerSource

public abstract class LexerSource
extends Object

This class is what feeds the lexer. It is primarily a wrapper around a Reader that can unread() data back onto the source. Originally, I thought about using the PushBackReader to handle read/unread, but I realized that some extremely pathological case could overflow the pushback buffer. Better safe than sorry. I could have combined this implementation with a PushbackBuffer, but the added complexity did not seem worth it.

Field Summary

protected int	line
protected int	offset

Constructor Summary

protected

LexerSource(String sourceName, int line) Create our food-source for the lexer

Method Summary

abstract int	chompReadAhead()
String	getFilename() What file are we lexing?
int	getLine() What line are we at?
int	getOffset() The location of the last byte we read from the source.
SourcePosition	getPosition() Where is the reader within the source {filename,row}
SourcePosition	getPosition(SourcePosition startPosition, boolean inclusive) Where is the reader within the source {filename,row}
static LexerSource	getSource(String name, Reader content, ParserConfiguration configuration) Create a source.
abstract boolean	isANewLine()
abstract boolean	lastWasBeginOfLine()
abstract boolean	matchMarker(String marker, boolean indent, boolean withNewline) Match marker against input consumering lexer source as it goes...Unless it does not match then it reverts lexer source back to point when this method was invoked.
abstract boolean	peek(int c)
abstract int	read()
abstract String	readLineBytes()
abstract String	readUntil(char c)
abstract void	setIsANewLine(boolean nextCharIsOnANewLine)
abstract void	setOffset(int offset)
abstract int	skipUntil(int c)
abstract void	unread(int c)
abstract void	unreadMany(CharSequence line)
abstract boolean	wasBeginOfLine()

Methods inherited from class java.lang.Object

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

Field Detail

line

protected int line

offset

protected int offset

Constructor Detail

LexerSource

protected LexerSource(String sourceName,
                      int line)

Create our food-source for the lexer

Parameters:

sourceName - is the file we are reading

line - starting line number for source (used by eval)

Method Detail

getFilename

public String getFilename()

What file are we lexing?

Returns:

the files name

getLine

public int getLine()

What line are we at?

Returns:

the line number 0...line_size-1

getOffset

public int getOffset()

The location of the last byte we read from the source.

Returns:

current location of source

getPosition

public SourcePosition getPosition(SourcePosition startPosition,
                                  boolean inclusive)

Where is the reader within the source {filename,row}

Returns:

the current position

getPosition

public SourcePosition getPosition()

Where is the reader within the source {filename,row}

Returns:

the current position

getSource

public static LexerSource getSource(String name,
                                    Reader content,
                                    ParserConfiguration configuration)

Create a source.

Parameters:

name - the name of the source (e.g a filename: foo.rb)

content - the data of the source

Returns:

the new source

matchMarker

public abstract boolean matchMarker(String marker,
                                    boolean indent,
                                    boolean withNewline)
                             throws IOException

Match marker against input consumering lexer source as it goes...Unless it does not match then it reverts lexer source back to point when this method was invoked.

Parameters:

marker - to match against

indent - eat any leading whitespace

withNewline - includes a check that marker is followed by newline or EOF

Returns:

true if marker matches...false otherwise

Throws:

IOException - if an error occurred reading from underlying IO source

read

public abstract int read()
                  throws IOException

Throws:

IOException

readUntil

public abstract String readUntil(char c)
                          throws IOException

Throws:

IOException

readLineBytes

public abstract String readLineBytes()
                              throws IOException

Throws:

IOException

skipUntil

public abstract int skipUntil(int c)
                       throws IOException

Throws:

IOException

unread

public abstract void unread(int c)

unreadMany

public abstract void unreadMany(CharSequence line)

peek

public abstract boolean peek(int c)
                      throws IOException

Throws:

IOException

lastWasBeginOfLine

public abstract boolean lastWasBeginOfLine()

wasBeginOfLine

public abstract boolean wasBeginOfLine()

chompReadAhead

public abstract int chompReadAhead()

isANewLine

public abstract boolean isANewLine()

setIsANewLine

public abstract void setIsANewLine(boolean nextCharIsOnANewLine)

setOffset

public abstract void setOffset(int offset)