Examples with LookaheadEventInfo org.antlr.v4.runtime.atn.LookaheadEventInfo used on opensource projects

Example 1 with LookaheadEventInfo

use of org.antlr.v4.runtime.atn.LookaheadEventInfo in project antlr4 by antlr.

the class TestLookaheadTrees method testLookaheadTrees.

public void testLookaheadTrees(LexerGrammar lg, Grammar g, String input, String startRuleName, int decision, String[] expectedTrees) {
    int startRuleIndex = g.getRule(startRuleName).index;
    InterpreterTreeTextProvider nodeTextProvider = new InterpreterTreeTextProvider(g.getRuleNames());
    LexerInterpreter lexEngine = lg.createLexerInterpreter(new ANTLRInputStream(input));
    CommonTokenStream tokens = new CommonTokenStream(lexEngine);
    GrammarParserInterpreter parser = g.createGrammarParserInterpreter(tokens);
    parser.setProfile(true);
    ParseTree t = parser.parse(startRuleIndex);
    DecisionInfo decisionInfo = parser.getParseInfo().getDecisionInfo()[decision];
    LookaheadEventInfo lookaheadEventInfo = decisionInfo.SLL_MaxLookEvent;
    List<ParserRuleContext> lookaheadParseTrees = GrammarParserInterpreter.getLookaheadParseTrees(g, parser, tokens, startRuleIndex, lookaheadEventInfo.decision, lookaheadEventInfo.startIndex, lookaheadEventInfo.stopIndex);
    assertEquals(expectedTrees.length, lookaheadParseTrees.size());
    for (int i = 0; i < lookaheadParseTrees.size(); i++) {
        ParserRuleContext lt = lookaheadParseTrees.get(i);
        assertEquals(expectedTrees[i], Trees.toStringTree(lt, nodeTextProvider));
    }
}