org.multijava.mjc
Class ParsingController.IndexedTokenBuffer

java.lang.Object
  org.multijava.mjc.ParsingController.IndexedTokenBuffer

Enclosing class:

ParsingController

class ParsingController.IndexedTokenBuffer

extends Object

This inner class buffers tokens of a nested language and allows selection and discarding of a subset of these buffered tokens based on a reference to an index token of the surrounding language.

Field Summary
private  LinkedList	indexTokens           A list of buffers containing index tokens of the surrounding language.
private  boolean	isBlocked           Indicates whether this is a blocked token buffer, to which new tokens or indices cannot be added.
private  boolean	startNewBuffer           Indicates whether a new buffer is required to store the next buffered token.
private  LinkedList	tokenBuffers           A list of token buffers.

 

Constructor Summary

ParsingController.IndexedTokenBuffer()           Creates a new empty token buffer.

ParsingController.IndexedTokenBuffer(LinkedList tokenBuffers)           Creates a blocked token buffer from the given list of token buffers.

 

Method Summary
private  void	addEOF()           Adds an end-of-file token to the end of the token buffer.
void	bufferToken(antlr.Token tok)           Adds the given token of the nested language to the buffer.
private  int	findIndexToken(antlr.Token index)           Returns the position in tokenBuffers of the last contiguous block of buffered tokens that comes before the given index token.
boolean	flushTokensBefore(antlr.Token index)           Discards all buffered tokens before the given index token.
boolean	hasNext()           Returns true if this buffer has additional tokens.
boolean	isBlocked()           Indicates whether this token buffer is blocked from accepting additinal tokens or indices.
antlr.Token	next()           Returns the next token from the buffer.
void	recordIndexToken(antlr.Token index)           Records the given index token.
ParsingController.FilteredTokenStream	streamForTokensBefore(antlr.Token index)           Returns a token stream that includes just the buffered tokens that came before the given index token.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

isBlocked

private boolean isBlocked

Indicates whether this is a blocked token buffer, to which new tokens or indices cannot be added.

startNewBuffer

private boolean startNewBuffer

Indicates whether a new buffer is required to store the next buffered token.

tokenBuffers

private LinkedList tokenBuffers

A list of token buffers. Each token buffer stored in this list contains a group of contiguous tokens from the original source text. Unless isBlocked, no token buffer stored in this list is empty.

indexTokens

private LinkedList indexTokens

A list of buffers containing index tokens of the surrounding language. Unless isBlocked, for all i, 0<=i

ParsingController.IndexedTokenBuffer

public ParsingController.IndexedTokenBuffer()

Creates a new empty token buffer.

ParsingController.IndexedTokenBuffer

public ParsingController.IndexedTokenBuffer(LinkedList tokenBuffers)

Creates a blocked token buffer from the given list of token buffers. A token buffer that is blocked does not accept new tokens or indices.

bufferToken

public void bufferToken(antlr.Token tok)
                 throws antlr.TokenStreamException

Adds the given token of the nested language to the buffer.

Throws:

antlr.TokenStreamException - if buffer is blocked

recordIndexToken

public void recordIndexToken(antlr.Token index)
                      throws antlr.TokenStreamException

Records the given index token.

Throws:

antlr.TokenStreamException - if buffer is blocked

streamForTokensBefore

public ParsingController.FilteredTokenStream streamForTokensBefore(antlr.Token index)
                                                            throws antlr.TokenStreamException

Returns a token stream that includes just the buffered tokens that came before the given index token. Removes those buffered tokens from this. If the index token is not recorded in this, then the stream returned will just contain an end-of-file token.

Throws:

antlr.TokenStreamException - if buffer is blocked

flushTokensBefore

public boolean flushTokensBefore(antlr.Token index)
                          throws antlr.TokenStreamException

Discards all buffered tokens before the given index token. If the index token is not recorded in this then no buffered tokens are discarded.

Returns:

true, iff some buffered tokens were discarded

Throws:

antlr.TokenStreamException - if buffer is blocked

isBlocked

public boolean isBlocked()

Indicates whether this token buffer is blocked from accepting additinal tokens or indices.

next

public antlr.Token next()

Returns the next token from the buffer.

hasNext

public boolean hasNext()

Returns true if this buffer has additional tokens. A buffer that is not blocked may return false and then return true on subsequent calls if tokens are added to the buffer.

findIndexToken

private int findIndexToken(antlr.Token index)

Returns the position in tokenBuffers of the last contiguous block of buffered tokens that comes before the given index token. Returns -1 if the index token is not recorded in this.

addEOF

private void addEOF()

Adds an end-of-file token to the end of the token buffer. Should only be called on a blocked buffer.