YangStatementStreamSource.java 文件源码

private static StatementContext parseYangSource(final SourceIdentifier source, final InputStream stream)
        throws IOException, YangSyntaxErrorException {
    final YangStatementLexer lexer = new YangStatementLexer(CharStreams.fromStream(stream));
    final CommonTokenStream tokens = new CommonTokenStream(lexer);
    final YangStatementParser parser = new YangStatementParser(tokens);
    //disconnect from console error output
    parser.removeErrorListeners();

    final YangErrorListener errorListener = new YangErrorListener(source);
    parser.addErrorListener(errorListener);

    final StatementContext result = parser.statement();
    errorListener.validate();

    // Walk the resulting tree and replace each children with an immutable list, lowering memory requirements
    // and making sure the resulting tree will not get accidentally modified. An alternative would be to use
    // org.antlr.v4.runtime.Parser.TrimToSizeListener, but that does not make the tree immutable.
    ParseTreeWalker.DEFAULT.walk(MAKE_IMMUTABLE_LISTENER, result);

    return result;
}