How to use the mako.util function in Mako

def repr_arg(x):
    if isinstance(x, dict):
        return util.sorted_dict_repr(x)
    else:
        return repr(x)

del sys.modules[self.module_id]
            if module._magic_number != codegen.MAGIC_NUMBER:
                data = util.read_file(filename)
                _compile_module_file(
                    self,
                    data,
                    filename,
                    path,
                    self.module_writer)
                module = compat.load_module(self.module_id, path)
                del sys.modules[self.module_id]
            ModuleInfo(module, path, self, filename, None, None)
        else:
            # template filename and no module directory, compile code
            # in memory
            data = util.read_file(filename)
            code, module = _compile_text(
                self,
                data,
                filename)
            self._source = None
            self._code = code
            ModuleInfo(module, None, self, filename, code, None)
        return module

def code(self):
        if self.module_source is not None:
            return self.module_source
        else:
            return util.read_python_file(self.module_filename)

    @util.memoized_property
    def reserved_names(self):
        if self.enable_loop:
            return codegen.RESERVED_NAMES
        else:
            return codegen.RESERVED_NAMES.difference(['loop'])

def code(self):
        if self.module_source is not None:
            return self.module_source
        else:
            return util.read_python_file(self.module_filename)

    @util.memoized_instancemethod
    def __len__(self):
        return len(self._iterable)

self._source = text
            ModuleInfo(module, None, self, filename, code, text)
        elif filename is not None:
            # if template filename and a module directory, load
            # a filesystem-based module file, generating if needed
            if module_filename is not None:
                path = module_filename
            elif module_directory is not None:
                u = self.uri
                if u[0] == '/':
                    u = u[1:]
                path = os.path.normpath(os.path.join(module_directory.replace('/', os.path.sep), u + ".py"))
            else:
                path = None
            if path is not None:
                util.verify_directory(os.path.dirname(path))
                filemtime = os.stat(filename)[stat.ST_MTIME]
                if not os.access(path, os.F_OK) or os.stat(path)[stat.ST_MTIME] < filemtime:
                    _compile_module_file(self, file(filename).read(), filename, path)
                module = imp.load_source(self.module_id, path, file(path))
                del sys.modules[self.module_id]
                if module._magic_number != codegen.MAGIC_NUMBER:
                    _compile_module_file(self, file(filename).read(), filename, path)
                    module = imp.load_source(self.module_id, path, file(path))
                    del sys.modules[self.module_id]
                ModuleInfo(module, path, self, filename, None, None)
            else:
                # template filename and no module directory, compile code
                # in memory
                (code, module) = _compile_text(self, file(filename).read(), filename)
                self._source = None
                self._code = code

def __init__(self, code, lineno, pos, filename):
        self.code = code

        # represents all identifiers which are assigned to at some point in the code
        self.declared_identifiers = util.Set()

        # represents all identifiers which are referenced before their assignment, if any
        self.undeclared_identifiers = util.Set()

        # note that an identifier can be in both the undeclared and declared lists.

        # using AST to parse instead of using code.co_varnames, code.co_names has several advantages:
        # - we can locate an identifier as "undeclared" even if its declared later in the same block of code
        # - AST is less likely to break with version changes (for example, the behavior of co_names changed a little bit
        # in python version 2.5)
        if isinstance(code, basestring):
            expr = parse(code.lstrip(), "exec", lineno, pos, filename)
        else:
            expr = code

        class FindIdentifiers(object):
            def __init__(self):
                self.in_function = False
                self.local_ident_stack = {}