antlr

Class TokenStreamHiddenTokenFilter

public class TokenStreamHiddenTokenFilter extends TokenStreamBasicFilter implements TokenStream

This object filters a token stream coming from a lexer or another TokenStream so that only certain token channels get transmitted to the parser. Any of the channels can be filtered off as "hidden" channels whose tokens can be accessed from the parser.

Field Summary
protected CommonHiddenStreamToken	firstHidden
protected BitSet	hideMask
protected CommonHiddenStreamToken	lastHiddenToken track tail of hidden list emanating from previous monitored token
protected CommonHiddenStreamToken	nextMonitoredToken

Constructor Summary
	TokenStreamHiddenTokenFilter(TokenStream input)

Method Summary
protected void	consume()
BitSet	getDiscardMask()
CommonHiddenStreamToken	getHiddenAfter(CommonHiddenStreamToken t) Return a ptr to the hidden token appearing immediately after token t in the input stream.
CommonHiddenStreamToken	getHiddenBefore(CommonHiddenStreamToken t) Return a ptr to the hidden token appearing immediately before token t in the input stream.
BitSet	getHideMask()
CommonHiddenStreamToken	getInitialHiddenToken() Return the first hidden token if one appears before any monitored token.
void	hide(int m)
void	hide(BitSet mask)
protected CommonHiddenStreamToken	LA(int i)
Token	nextToken() Return the next monitored token.

Field Detail

firstHidden

protected CommonHiddenStreamToken firstHidden

hideMask

protected BitSet hideMask

lastHiddenToken

protected CommonHiddenStreamToken lastHiddenToken

track tail of hidden list emanating from previous monitored token

nextMonitoredToken

protected CommonHiddenStreamToken nextMonitoredToken

Constructor Detail

TokenStreamHiddenTokenFilter

public TokenStreamHiddenTokenFilter(TokenStream input)

Method Detail

consume

protected void consume()

getDiscardMask

public BitSet getDiscardMask()

getHiddenAfter

public CommonHiddenStreamToken getHiddenAfter(CommonHiddenStreamToken t)

Return a ptr to the hidden token appearing immediately after token t in the input stream.

getHiddenBefore

public CommonHiddenStreamToken getHiddenBefore(CommonHiddenStreamToken t)

Return a ptr to the hidden token appearing immediately before token t in the input stream.

getHideMask

public BitSet getHideMask()

getInitialHiddenToken

public CommonHiddenStreamToken getInitialHiddenToken()

Return the first hidden token if one appears before any monitored token.

hide

public void hide(int m)

hide

public void hide(BitSet mask)

LA

protected CommonHiddenStreamToken LA(int i)

nextToken

public Token nextToken()

Return the next monitored token. Test the token following the monitored token. If following is another monitored token, save it for the next invocation of nextToken (like a single lookahead token) and return it then. If following is unmonitored, nondiscarded (hidden) channel token, add it to the monitored token. Note: EOF must be a monitored Token.