ParserInterpreter

@uml A parser simulator that mimics what ANTLR's generated parser code does. A ParserATNSimulator is used to make predictions via adaptivePredict but this class moves a pointer through the ATN to simulate parsing. ParserATNSimulator just makes us efficient rather than having to backtrack, for example.

This properly creates parse trees even for left recursive rules.

We rely on the left recursive rule invocation and special predicate transitions to make left recursive rules work.

See TestParserInterpreter for examples.

class ParserInterpreter : Parser {

string grammarFileName;

DFA[] decisionToDFA;

PredictionContextCache sharedContextCache;

string[] tokenNames;

string[] ruleNames;

DList!ParentContextPair _parentContextStack;

int overrideDecision;

int overrideDecisionInputIndex;

int overrideDecisionAlt;

bool overrideDecisionReached;

InterpreterRuleContext overrideDecisionRoot;

InterpreterRuleContext rootContext;

this(string grammarFileName, string[] tokenNames, string[] ruleNames, ATN atn, TokenStream input);

this(string grammarFileName, Vocabulary vocabulary, string[] ruleNames, ATN atn, TokenStream input);

void reset();

ATN getATN();

string[] getTokenNames();

Vocabulary getVocabulary();

string[] getRuleNames();

string getGrammarFileName();

ParserRuleContext parse(int startRuleIndex);

void enterRecursionRule(ParserRuleContext localctx, int state, int ruleIndex, int precedence);

ATNState getATNState();

void visitState(ATNState p);

int visitDecisionState(DecisionState p);

InterpreterRuleContext createInterpreterRuleContext(ParserRuleContext parent, int invokingStateNumber, int ruleIndex);

void visitRuleStopState(ATNState p);

void addDecisionOverride(int decision, int tokenIndex, int forcedAlt);

InterpreterRuleContext getOverrideDecisionRoot();

void recover(RecognitionException e);

Token recoverInline();

InterpreterRuleContext getRootContext();

}

Constructors

this this(string grammarFileName, string[] tokenNames, string[] ruleNames, ATN atn, TokenStream input): @uml deprecated Use {@link #ParserInterpreter(String, Vocabulary, Collection, ATN, TokenStream)} instead.
this this(string grammarFileName, Vocabulary vocabulary, string[] ruleNames, ATN atn, TokenStream input): Undocumented in source.

Members

Functions

addDecisionOverride void addDecisionOverride(int decision, int tokenIndex, int forcedAlt): @uml Override this parser interpreters normal decision-making process at a particular decision and input token index. Instead of allowing the adaptive prediction mechanism to choose the first alternative within a block that leads to a successful parse, force it to take the alternative, 1..n for n alternatives.
createInterpreterRuleContext InterpreterRuleContext createInterpreterRuleContext(ParserRuleContext parent, int invokingStateNumber, int ruleIndex): @uml Provide simple "factory" for InterpreterRuleContext's.
enterRecursionRule void enterRecursionRule(ParserRuleContext localctx, int state, int ruleIndex, int precedence): @uml @override
getATN ATN getATN(): @uml @override
getATNState ATNState getATNState(): Undocumented in source. Be warned that the author may not have intended to support it.
getGrammarFileName string getGrammarFileName(): @uml @override
getOverrideDecisionRoot InterpreterRuleContext getOverrideDecisionRoot(): Undocumented in source. Be warned that the author may not have intended to support it.
getRootContext InterpreterRuleContext getRootContext(): @uml Return the root of the parse, which can be useful if the parser bails out. You still can access the top node. Note that, because of the way left recursive rules add children, it's possible that the root will not have any children if the start rule immediately called and left recursive rule that fails.
getRuleNames string[] getRuleNames(): @uml @override
getTokenNames string[] getTokenNames(): @uml @override
getVocabulary Vocabulary getVocabulary(): @uml @override
parse ParserRuleContext parse(int startRuleIndex): @uml Begin parsing at startRuleIndex
recover void recover(RecognitionException e): @uml Rely on the error handler for this parser but, if no tokens are consumed to recover, add an error node. Otherwise, nothing is seen in the parse tree.
recoverInline Token recoverInline(): Undocumented in source. Be warned that the author may not have intended to support it.
reset void reset(): @uml @override
visitDecisionState int visitDecisionState(DecisionState p): Undocumented in source. Be warned that the author may not have intended to support it.
visitRuleStopState void visitRuleStopState(ATNState p): Undocumented in source. Be warned that the author may not have intended to support it.
visitState void visitState(ATNState p): Undocumented in source. Be warned that the author may not have intended to support it.

Variables

_parentContextStack DList!ParentContextPair _parentContextStack;: @uml This stack corresponds to the _parentctx, _parentState pair of locals that would exist on call stack frames with a recursive descent parser; in the generated function for a left-recursive rule you'd see:
atn ATN atn;: Undocumented in source.
decisionToDFA DFA[] decisionToDFA;: @uml not shared like it is for generated parsers
grammarFileName string grammarFileName;: Undocumented in source.
overrideDecision int overrideDecision;: @uml We need a map from (decision,inputIndex)->forced alt for computing ambiguous parse trees. For now, we allow exactly one override.
overrideDecisionAlt int overrideDecisionAlt;: Undocumented in source.
overrideDecisionInputIndex int overrideDecisionInputIndex;: Undocumented in source.
overrideDecisionReached bool overrideDecisionReached;: @uml latch and only override once; error might trigger infinite loop
overrideDecisionRoot InterpreterRuleContext overrideDecisionRoot;: @uml What is the current context when we override a decisions? This tellsus what the root of the parse tree is when using override for an ambiguity/lookahead check.
rootContext InterpreterRuleContext rootContext;: Undocumented in source.
ruleNames string[] ruleNames;: Undocumented in source.
sharedContextCache PredictionContextCache sharedContextCache;: Undocumented in source.
tokenNames string[] tokenNames;: Undocumented in source.

Inherited Members

From Parser

TraceListener class TraceListener: TODO add class description
TrimToSizeListener class TrimToSizeListener: TODO add class description
_errHandler ANTLRErrorStrategy _errHandler;: Undocumented in source.
_input TokenStream _input;: Undocumented in source.
_precedenceStack IntegerStack _precedenceStack;: Undocumented in source.
ctx_ ParserRuleContext ctx_;: @uml The {@link ParserRuleContext} object for the currently executing rule. This is always non-null during the parsing process. @read @write
_buildParseTrees bool _buildParseTrees;: @uml Specifies whether or not the parser should construct a parse tree during the parsing process. The default value is {@code true}.
_tracer TraceListener _tracer;: Undocumented in source.
_parseListeners ParseTreeListener[] _parseListeners;: @uml The list of {@link ParseTreeListener} listeners registered to receive events during the parse.
matchedEOF bool matchedEOF;: @uml Indicates parser has match()ed EOF token. See {@link #exitRule()}.
reset void reset(): @uml reset the parser's state
match Token match(int ttype): @uml Match current input symbol against {@code ttype}. If the symbol type matches, {@link ANTLRErrorStrategy#reportMatch} and {@link #consume} are called to complete the match process.
matchWildcard Token matchWildcard(): @uml Match current input symbol as a wildcard. If the symbol type matches (i.e. has a value greater than 0), {@link ANTLRErrorStrategy#reportMatch} and {@link #consume} are called to complete the match process.
setBuildParseTree void setBuildParseTree(bool buildParseTrees): @uml Track the {@link ParserRuleContext} objects during the parse and hook them up using the {@link ParserRuleContext#children} list so that it forms a parse tree. The {@link ParserRuleContext} returned from the start rule represents the root of the parse tree.
getBuildParseTree bool getBuildParseTree(): @uml Gets whether or not a complete parse tree will be constructed while parsing. This property is {@code true} for a newly constructed parser.
setTrimParseTree void setTrimParseTree(bool trimParseTrees): @uml Trim the internal lists of the parse tree during parsing to conserve memory. This property is set to {@code false} by default for a newly constructed parser.
getTrimParseTree bool getTrimParseTree(): @uml The @return {@code true} if the {@link ParserRuleContext#children} list is trimed using the default {@link Parser.TrimToSizeListener} during the parse process.
getParseListeners ParseTreeListener[] getParseListeners(): Undocumented in source. Be warned that the author may not have intended to support it.
addParseListener void addParseListener(ParseTreeListener listener): @uml Registers {@code listener} to receive events during the parsing process.
removeParseListener void removeParseListener(ParseTreeListener listener): Undocumented in source. Be warned that the author may not have intended to support it.
removeParseListeners void removeParseListeners(): @uml Remove all parse listeners.
triggerEnterRuleEvent void triggerEnterRuleEvent(): @uml Notify any parse listeners of an enter rule event.
triggerExitRuleEvent void triggerExitRuleEvent(): @uml Notify any parse listeners of an exit rule event.
tokenFactory TokenFactory!CommonToken tokenFactory(): @uml @override
tokenFactory void tokenFactory(TokenFactory!CommonToken factory): Tell our token source and error strategy about a new way to create tokens. @uml @override
getATNWithBypassAlts ATN getATNWithBypassAlts(): @uml The ATN with bypass alternatives is expensive to create so we create it lazily.
compileParseTreePattern ParseTreePattern compileParseTreePattern(string pattern, int patternRuleIndex): Undocumented in source. Be warned that the author may not have intended to support it.
compileParseTreePattern ParseTreePattern compileParseTreePattern(string pattern, int patternRuleIndex, Lexer lexer): @uml The same as {@link #compileParseTreePattern(String, int)} but specify a {@link Lexer} rather than trying to deduce it from this parser.
getErrorHandler auto getErrorHandler(): Undocumented in source. Be warned that the author may not have intended to support it.
setErrorHandler void setErrorHandler(ANTLRErrorStrategy handler): Undocumented in source. Be warned that the author may not have intended to support it.
getInputStream TokenStream getInputStream(): @uml @override
setInputStream void setInputStream(IntStream input): @uml @override
getTokenStream TokenStream getTokenStream(): Undocumented in source. Be warned that the author may not have intended to support it.
setTokenStream void setTokenStream(TokenStream input): @uml Set the token stream and reset the parser.
getCurrentToken Token getCurrentToken(): @uml Match needs to return the current input symbol, which gets put into the label for the associated token ref; e.g., x=ID.
notifyErrorListeners void notifyErrorListeners(string msg): @uml @final
notifyErrorListeners void notifyErrorListeners(Token offendingToken, string msg, RecognitionException e): Undocumented in source. Be warned that the author may not have intended to support it.
consume Token consume(): @uml Consume and return the {@linkplain #getCurrentToken current symbol}.
addContextToParseTree void addContextToParseTree(): Undocumented in source. Be warned that the author may not have intended to support it.
enterRule void enterRule(ParserRuleContext localctx, int state, int ruleIndex): Undocumented in source. Be warned that the author may not have intended to support it.
exitRule void exitRule(): Undocumented in source. Be warned that the author may not have intended to support it.
enterOuterAlt void enterOuterAlt(ParserRuleContext localctx, int altNum): Undocumented in source. Be warned that the author may not have intended to support it.
getPrecedence int getPrecedence(): @uml Get the precedence level for the top-most precedence rule.
enterRecursionRule void enterRecursionRule(ParserRuleContext localctx, int ruleIndex): @uml . @deprecated Use {@link #enterRecursionRule(ParserRuleContext, int, int, int)} instead.
enterRecursionRule void enterRecursionRule(ParserRuleContext localctx, int state, int ruleIndex, int precedence): Undocumented in source. Be warned that the author may not have intended to support it.
pushNewRecursionContext void pushNewRecursionContext(ParserRuleContext localctx, int state, int ruleIndex): @uml Like {@link #enterRule} but for recursive rules. Make the current context the child of the incoming localctx.
unrollRecursionContexts void unrollRecursionContexts(ParserRuleContext _parentctx): Undocumented in source. Be warned that the author may not have intended to support it.
getInvokingContext ParserRuleContext getInvokingContext(int ruleIndex): Undocumented in source. Be warned that the author may not have intended to support it.
precpred bool precpred(InterfaceRuleContext localctx, int precedence): @uml @override
inContext bool inContext(string context): Undocumented in source. Be warned that the author may not have intended to support it.
isExpectedToken bool isExpectedToken(int symbol): @uml Checks whether or not {@code symbol} can follow the current state in the ATN. The behavior of this method is equivalent to the following, but is implemented such that the complete context-sensitive follow set does not need to be explicitly constructed.
isMatchedEOF bool isMatchedEOF(): Undocumented in source. Be warned that the author may not have intended to support it.
getExpectedTokens IntervalSet getExpectedTokens(): @uml Computes the set of input symbols which could follow the current parser state and context, as given by {@link #getState} and {@link #getContext}, espectively.
getExpectedTokensWithinCurrentRule IntervalSet getExpectedTokensWithinCurrentRule(): Undocumented in source. Be warned that the author may not have intended to support it.
getRuleIndex int getRuleIndex(string ruleName): @uml Get a rule's index (i.e., {@code RULE_ruleName} field) or -1 if not found.
getRuleContext ParserRuleContext getRuleContext(): Undocumented in source. Be warned that the author may not have intended to support it.
getRuleInvocationStack string[] getRuleInvocationStack(): @uml Return List<String> of the rule names in your parser instance leading up to a call to the current rule. You could override if you want more details such as the file/line info of where in the ATN a rule is invoked.
getRuleInvocationStack string[] getRuleInvocationStack(RuleContext p): Undocumented in source. Be warned that the author may not have intended to support it.
getDFAStrings string[] getDFAStrings(): @uml For debugging and other purposes.
dumpDFA void dumpDFA(): @uml For debugging and other purposes.
getSourceName string getSourceName(): Undocumented in source. Be warned that the author may not have intended to support it.
getParseInfo ParseInfo getParseInfo(): @uml @override
setProfile void setProfile(bool profile): Undocumented in source. Be warned that the author may not have intended to support it.
setTrace void setTrace(bool trace): Undocumented in source. Be warned that the author may not have intended to support it.
isTrace bool isTrace(): @uml Gets whether a {@link TraceListener} is registered as a parse listener for the parser.
ctx ParserRuleContext ctx(): Undocumented in source. Be warned that the author may not have intended to support it.
ctx void ctx(ParserRuleContext ctx): Undocumented in source. Be warned that the author may not have intended to support it.
numberOfSyntaxErrors int numberOfSyntaxErrors(): Undocumented in source. Be warned that the author may not have intended to support it.

Meta

Source

See Implementation

antlr v4 runtime ParserInterpreter aliases

classes

ParserInterpreter