jaitools.jiffle.parser
Class MultiChannelTokenStream

java.lang.Object
  org.antlr.runtime.BufferedTokenStream
      jaitools.jiffle.parser.MultiChannelTokenStream

All Implemented Interfaces:

org.antlr.runtime.IntStream, org.antlr.runtime.TokenStream

public final class MultiChannelTokenStream
extends org.antlr.runtime.BufferedTokenStream

A TokenStream that can work with multiple active channels. Adapted from ANTLR's CommonTokenStream class.

Since:

1.1

Version:

$Id: MultiChannelTokenStream.java 1389 2011-02-11 08:54:11Z michael.bedward $

Author:

Michael Bedward

Field Summary

protected List<Integer>

activeChannels The List of active channel indices.

Fields inherited from class org.antlr.runtime.BufferedTokenStream

lastMarker, p, range, tokens, tokenSource

Constructor Summary

MultiChannelTokenStream(org.antlr.runtime.TokenSource tokenSource)
Creates a new stream with the default ANTLR channel active.

MultiChannelTokenStream(org.antlr.runtime.TokenSource tokenSource, int[] channels)
Creates a new stream with the given channels active.

Method Summary

void	addActiveChannel(int channelNum) Adds a channel to those active.
void	consume()
boolean	isActiveChannel(int channelNum) Tests if a channel is active.
protected org.antlr.runtime.Token	LB(int k) Looks backwards for the kth token on any of the active channels.
org.antlr.runtime.Token	LT(int k) Looks forwards for the kth token on any of the active channels.
void	removeActiveChannel(int channelNum) Removes a channel from those active.
void	removeAllActiveChannels() Removes all active channels.
void	setTokenSource(org.antlr.runtime.TokenSource tokenSource)
protected void	setup() Positions the stream at the first token on an active channel.
protected int	skipOffTokenChannels(int pos) Gets the index of the next token on an active channel, starting from pos.
protected int	skipOffTokenChannelsReverse(int pos) Gets the index of the next token on an active channel, starting from pos and scanning backwards.

Methods inherited from class org.antlr.runtime.BufferedTokenStream

fetch, fill, get, get, getSourceName, getTokens, getTokens, getTokens, getTokens, getTokens, getTokenSource, index, LA, mark, range, release, reset, rewind, rewind, seek, size, sync, toString, toString, toString

Methods inherited from class java.lang.Object

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

Field Detail

activeChannels

protected final List<Integer> activeChannels

The List of active channel indices. These should all be positive and less than 99 (used by ANTLR to flag its hidden token channel).

Constructor Detail

MultiChannelTokenStream

public MultiChannelTokenStream(org.antlr.runtime.TokenSource tokenSource)

Creates a new stream with the default ANTLR channel active.

Parameters:

tokenSource - a lexer

MultiChannelTokenStream

public MultiChannelTokenStream(org.antlr.runtime.TokenSource tokenSource,
                               int[] channels)

Creates a new stream with the given channels active.

Parameters:

tokenSource - a lexer

channels - active channel indices

Method Detail

consume

public void consume()

Specified by:

consume in interface org.antlr.runtime.IntStream

Overrides:

consume in class org.antlr.runtime.BufferedTokenStream

LB

protected org.antlr.runtime.Token LB(int k)

Looks backwards for the kth token on any of the active channels.

Overrides:

LB in class org.antlr.runtime.BufferedTokenStream

Parameters:

k - number of active-channel tokens to scan over

Returns:

the token

LT

public org.antlr.runtime.Token LT(int k)

Looks forwards for the kth token on any of the active channels.

Specified by:

LT in interface org.antlr.runtime.TokenStream

Overrides:

LT in class org.antlr.runtime.BufferedTokenStream

Parameters:

k - number of active-channel tokens to scan over

Returns:

the token

skipOffTokenChannels

protected int skipOffTokenChannels(int pos)

Gets the index of the next token on an active channel, starting from pos.

Parameters:

pos - start token index

Returns:

the token index

skipOffTokenChannelsReverse

protected int skipOffTokenChannelsReverse(int pos)

Gets the index of the next token on an active channel, starting from pos and scanning backwards.

Parameters:

pos - start token index

Returns:

the token index

setup

protected void setup()

Positions the stream at the first token on an active channel.

Overrides:

setup in class org.antlr.runtime.BufferedTokenStream

setTokenSource

public void setTokenSource(org.antlr.runtime.TokenSource tokenSource)

Overrides:

setTokenSource in class org.antlr.runtime.BufferedTokenStream

addActiveChannel

public void addActiveChannel(int channelNum)

Adds a channel to those active.

Parameters:

channelNum - the channel to add

removeActiveChannel

public void removeActiveChannel(int channelNum)

Removes a channel from those active. It is safe to call this method speculatively.

Parameters:

channelNum - the channel to remove

isActiveChannel

public boolean isActiveChannel(int channelNum)

Tests if a channel is active.

Parameters:

channelNum - the channel to test

Returns:

true if the channel is active; false otherwise

removeAllActiveChannels

public void removeAllActiveChannels()

Removes all active channels.