antlr
Class TokenStreamHiddenTokenFilter

java.lang.Object
  antlr.TokenStreamBasicFilter
      antlr.TokenStreamHiddenTokenFilter

All Implemented Interfaces:

TokenStream

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.

Constructor Summary

TokenStreamHiddenTokenFilter(TokenStream input)

 

Method Summary
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(BitSet mask)
void	hide(int m)
Token	nextToken()           Return the next monitored token.

 

Methods inherited from class antlr.TokenStreamBasicFilter

discard, discard

 

Methods inherited from class java.lang.Object

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

 

Constructor Detail

TokenStreamHiddenTokenFilter

public TokenStreamHiddenTokenFilter(TokenStream input)

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)

nextToken

public Token nextToken()
                throws TokenStreamException

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.

Specified by:

nextToken in interface TokenStream

Overrides:

nextToken in class TokenStreamBasicFilter

Throws:

TokenStreamException