def METHOD_NAME(expr):
    """Parse expression."""
    input_stream = InputStream(expr)
    lexer = ECLsubsetLexer(input_stream)
    token_stream = CommonTokenStream(lexer)
    parser = ECLsubsetParser(token_stream)
    parser.removeErrorListeners()
    parser.addErrorListener(ErrorListener())
    tree = parser.expressionconstraint()
    visitor = Visitor()
    return visitor.visit(tree)