Examples with UnbufferedTokenStream org.antlr.v4.runtime.UnbufferedTokenStream used on opensource projects

Example 1 with UnbufferedTokenStream

use of org.antlr.v4.runtime.UnbufferedTokenStream in project pinot by linkedin.

the class Pql2Compiler method compileToBrokerRequest.

@Override
public BrokerRequest compileToBrokerRequest(String expression) throws Pql2CompilationException {
    try {
        //
        CharStream charStream = new ANTLRInputStream(expression);
        PQL2Lexer lexer = new PQL2Lexer(charStream);
        lexer.setTokenFactory(new CommonTokenFactory(true));
        TokenStream tokenStream = new UnbufferedTokenStream<CommonToken>(lexer);
        PQL2Parser parser = new PQL2Parser(tokenStream);
        parser.setErrorHandler(new BailErrorStrategy());
        // Parse
        ParseTree parseTree = parser.root();
        ParseTreeWalker walker = new ParseTreeWalker();
        Pql2AstListener listener = new Pql2AstListener(expression);
        walker.walk(listener, parseTree);
        AstNode rootNode = listener.getRootNode();
        BrokerRequest brokerRequest = new BrokerRequest();
        rootNode.updateBrokerRequest(brokerRequest);
        return brokerRequest;
    } catch (Pql2CompilationException e) {
        throw e;
    } catch (Exception e) {
        throw new Pql2CompilationException(e.getMessage());
    }
}

Example 2 with UnbufferedTokenStream

use of org.antlr.v4.runtime.UnbufferedTokenStream in project pinot by linkedin.

the class Pql2Compiler method compileToExpressionTree.

@Override
public TransformExpressionTree compileToExpressionTree(String expression) {
    CharStream charStream = new ANTLRInputStream(expression);
    PQL2Lexer lexer = new PQL2Lexer(charStream);
    lexer.setTokenFactory(new CommonTokenFactory(true));
    TokenStream tokenStream = new UnbufferedTokenStream<CommonToken>(lexer);
    PQL2Parser parser = new PQL2Parser(tokenStream);
    parser.setErrorHandler(new BailErrorStrategy());
    // Parse
    ParseTree parseTree = parser.expression();
    ParseTreeWalker walker = new ParseTreeWalker();
    Pql2AstListener listener = new Pql2AstListener(expression);
    walker.walk(listener, parseTree);
    final AstNode rootNode = listener.getRootNode();
    return TransformExpressionTree.buildTree(rootNode);
}

Example 3 with UnbufferedTokenStream

use of org.antlr.v4.runtime.UnbufferedTokenStream in project antlr4 by antlr.

the class TestUnbufferedTokenStream method testLookahead.

@Test
public void testLookahead() throws Exception {
    LexerGrammar g = new LexerGrammar("lexer grammar t;\n" + "ID : 'a'..'z'+;\n" + "INT : '0'..'9'+;\n" + "SEMI : ';';\n" + "ASSIGN : '=';\n" + "PLUS : '+';\n" + "MULT : '*';\n" + "WS : ' '+;\n");
    // Tokens: 012345678901234567
    // Input:  x = 302;
    CharStream input = new ANTLRInputStream(new StringReader("x = 302;"));
    LexerInterpreter lexEngine = g.createLexerInterpreter(input);
    TokenStream tokens = new UnbufferedTokenStream<Token>(lexEngine);
    assertEquals("x", tokens.LT(1).getText());
    assertEquals(" ", tokens.LT(2).getText());
    assertEquals("=", tokens.LT(3).getText());
    assertEquals(" ", tokens.LT(4).getText());
    assertEquals("302", tokens.LT(5).getText());
    assertEquals(";", tokens.LT(6).getText());
}

Example 4 with UnbufferedTokenStream

use of org.antlr.v4.runtime.UnbufferedTokenStream in project Alpha by alpha-asp.

the class Main method parseVisit.

public static ParsedProgram parseVisit(ANTLRInputStream is) throws IOException {
    /*
		// In order to require less memory: use unbuffered streams and avoid constructing a full parse tree.
		ASPCore2Lexer lexer = new ASPCore2Lexer(new UnbufferedCharStream(is));
		lexer.setTokenFactory(new CommonTokenFactory(true));
		final ASPCore2Parser parser = new ASPCore2Parser(new UnbufferedTokenStream<>(lexer));
		parser.setBuildParseTree(false);
		*/
    CommonTokenStream tokens = new CommonTokenStream(new ASPCore2Lexer(is));
    final ASPCore2Parser parser = new ASPCore2Parser(tokens);
    // Try SLL parsing mode (faster but may terminate incorrectly).
    parser.getInterpreter().setPredictionMode(PredictionMode.SLL);
    parser.removeErrorListeners();
    parser.setErrorHandler(new BailErrorStrategy());
    final CustomErrorListener errorListener = new CustomErrorListener(is.getSourceName());
    ASPCore2Parser.ProgramContext programContext;
    try {
        // Parse program
        programContext = parser.program();
    } catch (ParseCancellationException e) {
        // retry with LL parser and DefaultErrorStrategy printing errors to console.
        if (e.getCause() instanceof RecognitionException) {
            tokens.reset();
            parser.addErrorListener(errorListener);
            parser.setErrorHandler(new DefaultErrorStrategy());
            parser.getInterpreter().setPredictionMode(PredictionMode.LL);
            // Re-run parse.
            programContext = parser.program();
        } else {
            throw e;
        }
    }
    // is attempted) and the user will only see the first error encountered.
    if (errorListener.getRecognitionException() != null) {
        throw errorListener.getRecognitionException();
    }
    // Construct internal program representation.
    ParsedTreeVisitor visitor = new ParsedTreeVisitor();
    return (ParsedProgram) visitor.visitProgram(programContext);
}