Package org.antlr.runtime
Interface TokenStream
- All Superinterfaces:
IntStream
- All Known Implementing Classes:
CommonTokenStream
,DebugTokenStream
,TokenRewriteStream
A stream of tokens accessing tokens from a TokenSource
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Method Summary
Modifier and TypeMethodDescriptionget
(int i) Get a token at an absolute index i; 0..n-1.Where is this stream pulling tokens from? This is not the name, but the object that provides Token objects.LT
(int k) Get Token at current input pointer + i ahead where i=1 is next Token.toString
(int start, int stop) Return the text of all tokens from start to stop, inclusive.Because the user is not required to use a token with an index stored in it, we must provide a means for two token objects themselves to indicate the start/end location.
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Method Details
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LT
Get Token at current input pointer + i ahead where i=1 is next Token. i<0 indicates tokens in the past. So -1 is previous token and -2 is two tokens ago. LT(0) is undefined. For i>=n, return Token.EOFToken. Return null for LT(0) and any index that results in an absolute address that is negative. -
get
Get a token at an absolute index i; 0..n-1. This is really only needed for profiling and debugging and token stream rewriting. If you don't want to buffer up tokens, then this method makes no sense for you. Naturally you can't use the rewrite stream feature. I believe DebugTokenStream can easily be altered to not use this method, removing the dependency. -
getTokenSource
TokenSource getTokenSource()Where is this stream pulling tokens from? This is not the name, but the object that provides Token objects. -
toString
Return the text of all tokens from start to stop, inclusive. If the stream does not buffer all the tokens then it can just return "" or null; Users should not access $ruleLabel.text in an action of course in that case. -
toString
Because the user is not required to use a token with an index stored in it, we must provide a means for two token objects themselves to indicate the start/end location. Most often this will just delegate to the other toString(int,int). This is also parallel with the TreeNodeStream.toString(Object,Object).
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