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

Example 1 with LexerInterpreter

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

the class TestBufferedTokenStream method testCompleteBufferAfterConsuming.

@Test
public void testCompleteBufferAfterConsuming() 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 = 3 * 0 + 2 * 0;
    CharStream input = new ANTLRInputStream("x = 3 * 0 + 2 * 0;");
    LexerInterpreter lexEngine = g.createLexerInterpreter(input);
    TokenStream tokens = createTokenStream(lexEngine);
    Token t = tokens.LT(1);
    while (t.getType() != Token.EOF) {
        tokens.consume();
        t = tokens.LT(1);
    }
    String result = tokens.getText();
    String expecting = "x = 3 * 0 + 2 * 0;";
    assertEquals(expecting, result);
}

Example 2 with LexerInterpreter

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

the class TestBufferedTokenStream method test2ndToken.

@Test
public void test2ndToken() 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 = 3 * 0 + 2 * 0;
    CharStream input = new ANTLRInputStream("x = 3 * 0 + 2 * 0;");
    LexerInterpreter lexEngine = g.createLexerInterpreter(input);
    TokenStream tokens = createTokenStream(lexEngine);
    String result = tokens.LT(2).getText();
    String expecting = " ";
    assertEquals(expecting, result);
}

Example 3 with LexerInterpreter

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

the class TestBufferedTokenStream method testLookback.

@Test
public void testLookback() 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 = 3 * 0 + 2 * 0;
    CharStream input = new ANTLRInputStream("x = 3 * 0 + 2 * 0;");
    LexerInterpreter lexEngine = g.createLexerInterpreter(input);
    TokenStream tokens = createTokenStream(lexEngine);
    // get x into buffer
    tokens.consume();
    Token t = tokens.LT(-1);
    assertEquals("x", t.getText());
    tokens.consume();
    // consume '='
    tokens.consume();
    t = tokens.LT(-3);
    assertEquals("x", t.getText());
    t = tokens.LT(-2);
    assertEquals(" ", t.getText());
    t = tokens.LT(-1);
    assertEquals("=", t.getText());
}

Example 4 with LexerInterpreter

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

the class TestBufferedTokenStream method testFirstToken.

@Test
public void testFirstToken() 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 = 3 * 0 + 2 * 0;
    CharStream input = new ANTLRInputStream("x = 3 * 0 + 2 * 0;");
    LexerInterpreter lexEngine = g.createLexerInterpreter(input);
    TokenStream tokens = createTokenStream(lexEngine);
    String result = tokens.LT(1).getText();
    String expecting = "x";
    assertEquals(expecting, result);
}

Example 5 with LexerInterpreter

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

the class TestAmbigParseTrees method testAmbiguousTrees.

public void testAmbiguousTrees(LexerGrammar lg, Grammar g, String startRule, String input, int decision, String expectedAmbigAlts, String overallTree, String[] expectedParseTrees) {
    InterpreterTreeTextProvider nodeTextProvider = new InterpreterTreeTextProvider(g.getRuleNames());
    LexerInterpreter lexEngine = lg.createLexerInterpreter(new ANTLRInputStream(input));
    CommonTokenStream tokens = new CommonTokenStream(lexEngine);
    final GrammarParserInterpreter parser = g.createGrammarParserInterpreter(tokens);
    parser.setProfile(true);
    parser.getInterpreter().setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);
    // PARSE
    int ruleIndex = g.rules.get(startRule).index;
    ParserRuleContext parseTree = parser.parse(ruleIndex);
    assertEquals(overallTree, Trees.toStringTree(parseTree, nodeTextProvider));
    System.out.println();
    DecisionInfo[] decisionInfo = parser.getParseInfo().getDecisionInfo();
    List<AmbiguityInfo> ambiguities = decisionInfo[decision].ambiguities;
    assertEquals(1, ambiguities.size());
    AmbiguityInfo ambiguityInfo = ambiguities.get(0);
    List<ParserRuleContext> ambiguousParseTrees = GrammarParserInterpreter.getAllPossibleParseTrees(g, parser, tokens, decision, ambiguityInfo.ambigAlts, ambiguityInfo.startIndex, ambiguityInfo.stopIndex, ruleIndex);
    assertEquals(expectedAmbigAlts, ambiguityInfo.ambigAlts.toString());
    assertEquals(ambiguityInfo.ambigAlts.cardinality(), ambiguousParseTrees.size());
    for (int i = 0; i < ambiguousParseTrees.size(); i++) {
        ParserRuleContext t = ambiguousParseTrees.get(i);
        assertEquals(expectedParseTrees[i], Trees.toStringTree(t, nodeTextProvider));
    }
}