Package org.antlr.tool
Class Interpreter
java.lang.Object
org.antlr.tool.Interpreter
- All Implemented Interfaces:
TokenSource
The recognition interpreter/engine for grammars. Separated
out of Grammar as it's related, but technically not a Grammar function.
You create an interpreter for a grammar and an input stream. This object
can act as a TokenSource so that you can hook up two grammars (via
a CommonTokenStream) to lex/parse. Being a token source only makes sense
for a lexer grammar of course.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescription(package private) class
A lexer listener that just creates token objects as they are matched. -
Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionWhere are you getting tokens from? normally the implication will simply ask lexers input stream.Return a Token object from your input stream (usually a CharStream).void
parse
(String startRule, DebugEventListener actions, List<NFAState> visitedStates) protected void
parseEngine
(String startRule, NFAState start, NFAState stop, IntStream input, Stack<NFAState> ruleInvocationStack, DebugEventListener actions, List<NFAState> visitedStates) Fill a list of all NFA states visited during the parseint
Given an input stream, return the unique alternative predicted by matching the input.void
void
scan
(String startRule, DebugEventListener actions, List<NFAState> visitedStates) For a given input char stream, try to match against the NFA starting at startRule.
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Field Details
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grammar
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input
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Constructor Details
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Interpreter
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Method Details
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nextToken
Description copied from interface:TokenSource
Return a Token object from your input stream (usually a CharStream). Do not fail/return upon lexing error; keep chewing on the characters until you get a good one; errors are not passed through to the parser.- Specified by:
nextToken
in interfaceTokenSource
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scan
public void scan(String startRule, DebugEventListener actions, List<NFAState> visitedStates) throws RecognitionException For a given input char stream, try to match against the NFA starting at startRule. This is a deterministic parse even though it is using an NFA because it uses DFAs at each decision point to predict which alternative will succeed. This is exactly what the generated parser will do. This only does lexer grammars. Return the token type associated with the final rule end state.- Throws:
RecognitionException
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scan
- Throws:
RecognitionException
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scan
- Throws:
RecognitionException
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parse
public void parse(String startRule, DebugEventListener actions, List<NFAState> visitedStates) throws RecognitionException - Throws:
RecognitionException
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parse
- Throws:
RecognitionException
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parse
- Throws:
RecognitionException
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parseEngine
protected void parseEngine(String startRule, NFAState start, NFAState stop, IntStream input, Stack<NFAState> ruleInvocationStack, DebugEventListener actions, List<NFAState> visitedStates) throws RecognitionException Fill a list of all NFA states visited during the parse- Throws:
RecognitionException
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predict
Given an input stream, return the unique alternative predicted by matching the input. Upon error, return NFA.INVALID_ALT_NUMBER The first symbol of lookahead is presumed to be primed; that is, input.lookahead(1) must point at the input symbol you want to start predicting with. -
reportScanError
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getSourceName
Description copied from interface:TokenSource
Where are you getting tokens from? normally the implication will simply ask lexers input stream.- Specified by:
getSourceName
in interfaceTokenSource
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