Example of refactoring using rope library.

tools/telemetry/third_party/rope/rope/base/evaluate.py

Index: tools/telemetry/third_party/rope/rope/base/evaluate.py
diff --git a/tools/telemetry/third_party/rope/rope/base/evaluate.py b/tools/telemetry/third_party/rope/rope/base/evaluate.py
new file mode 100644
index 0000000000000000000000000000000000000000..faf094075f6ce34770695fb25e4359c342fe7ef7
--- /dev/null
+++ b/tools/telemetry/third_party/rope/rope/base/evaluate.py
@@ -0,0 +1,327 @@
+import rope.base.builtins
+import rope.base.pynames
+import rope.base.pyobjects
+from rope.base import ast, astutils, exceptions, pyobjects, arguments, worder
+
+
+BadIdentifierError = exceptions.BadIdentifierError
+
+
+def eval_location(pymodule, offset):
+    """Find the pyname at the offset"""
+    return eval_location2(pymodule, offset)[1]
+
+
+def eval_location2(pymodule, offset):
+    """Find the primary and pyname at offset"""
+    pyname_finder = ScopeNameFinder(pymodule)
+    return pyname_finder.get_primary_and_pyname_at(offset)
+
+
+def eval_node(scope, node):
+    """Evaluate a `ast.AST` node and return a PyName
+
+    Return `None` if the expression cannot be evaluated.
+    """
+    return eval_node2(scope, node)[1]
+
+
+def eval_node2(scope, node):
+    evaluator = StatementEvaluator(scope)
+    ast.walk(node, evaluator)
+    return evaluator.old_result, evaluator.result
+
+
+def eval_str(holding_scope, name):
+    return eval_str2(holding_scope, name)[1]
+
+
+def eval_str2(holding_scope, name):
+    try:
+        # parenthesizing for handling cases like 'a_var.\nattr'
+        node = ast.parse('(%s)' % name)
+    except SyntaxError:
+        raise BadIdentifierError(
+            'Not a resolvable python identifier selected.')
+    return eval_node2(holding_scope, node)
+
+
+class ScopeNameFinder(object):
+
+    def __init__(self, pymodule):
+        self.module_scope = pymodule.get_scope()
+        self.lines = pymodule.lines
+        self.worder = worder.Worder(pymodule.source_code, True)
+
+    def _is_defined_in_class_body(self, holding_scope, offset, lineno):
+        if lineno == holding_scope.get_start() and \
+           holding_scope.parent is not None and \
+           holding_scope.parent.get_kind() == 'Class' and \
+           self.worder.is_a_class_or_function_name_in_header(offset):
+            return True
+        if lineno != holding_scope.get_start() and \
+           holding_scope.get_kind() == 'Class' and \
+           self.worder.is_name_assigned_in_class_body(offset):
+            return True
+        return False
+
+    def _is_function_name_in_function_header(self, scope, offset, lineno):
+        if scope.get_start() <= lineno <= scope.get_body_start() and \
+           scope.get_kind() == 'Function' and \
+           self.worder.is_a_class_or_function_name_in_header(offset):
+            return True
+        return False
+
+    def get_pyname_at(self, offset):
+        return self.get_primary_and_pyname_at(offset)[1]
+
+    def get_primary_and_pyname_at(self, offset):
+        lineno = self.lines.get_line_number(offset)
+        holding_scope = self.module_scope.get_inner_scope_for_line(lineno)
+        # function keyword parameter
+        if self.worder.is_function_keyword_parameter(offset):
+            keyword_name = self.worder.get_word_at(offset)
+            pyobject = self.get_enclosing_function(offset)
+            if isinstance(pyobject, pyobjects.PyFunction):
+                return (None,
+                        pyobject.get_parameters().get(keyword_name, None))
+        # class body
+        if self._is_defined_in_class_body(holding_scope, offset, lineno):
+            class_scope = holding_scope
+            if lineno == holding_scope.get_start():
+                class_scope = holding_scope.parent
+            name = self.worder.get_primary_at(offset).strip()
+            try:
+                return (None, class_scope.pyobject[name])
+            except rope.base.exceptions.AttributeNotFoundError:
+                return (None, None)
+        # function header
+        if self._is_function_name_in_function_header(holding_scope,
+                                                     offset, lineno):
+            name = self.worder.get_primary_at(offset).strip()
+            return (None, holding_scope.parent[name])
+        # from statement module
+        if self.worder.is_from_statement_module(offset):
+            module = self.worder.get_primary_at(offset)
+            module_pyname = self._find_module(module)
+            return (None, module_pyname)
+        if self.worder.is_from_aliased(offset):
+            name = self.worder.get_from_aliased(offset)
+        else:
+            name = self.worder.get_primary_at(offset)
+        return eval_str2(holding_scope, name)
+
+    def get_enclosing_function(self, offset):
+        function_parens = self.worder.find_parens_start_from_inside(offset)
+        try:
+            function_pyname = self.get_pyname_at(function_parens - 1)
+        except BadIdentifierError:
+            function_pyname = None
+        if function_pyname is not None:
+            pyobject = function_pyname.get_object()
+            if isinstance(pyobject, pyobjects.AbstractFunction):
+                return pyobject
+            elif isinstance(pyobject, pyobjects.AbstractClass) and \
+                    '__init__' in pyobject:
+                return pyobject['__init__'].get_object()
+            elif '__call__' in pyobject:
+                return pyobject['__call__'].get_object()
+        return None
+
+    def _find_module(self, module_name):
+        dots = 0
+        while module_name[dots] == '.':
+            dots += 1
+        return rope.base.pynames.ImportedModule(
+            self.module_scope.pyobject, module_name[dots:], dots)
+
+
+class StatementEvaluator(object):
+
+    def __init__(self, scope):
+        self.scope = scope
+        self.result = None
+        self.old_result = None
+
+    def _Name(self, node):
+        self.result = self.scope.lookup(node.id)
+
+    def _Attribute(self, node):
+        pyname = eval_node(self.scope, node.value)
+        if pyname is None:
+            pyname = rope.base.pynames.UnboundName()
+        self.old_result = pyname
+        if pyname.get_object() != rope.base.pyobjects.get_unknown():
+            try:
+                self.result = pyname.get_object()[node.attr]
+            except exceptions.AttributeNotFoundError:
+                self.result = None
+
+    def _Call(self, node):
+        primary, pyobject = self._get_primary_and_object_for_node(node.func)
+        if pyobject is None:
+            return
+
+        def _get_returned(pyobject):
+            args = arguments.create_arguments(primary, pyobject,
+                                              node, self.scope)
+            return pyobject.get_returned_object(args)
+        if isinstance(pyobject, rope.base.pyobjects.AbstractClass):
+            result = None
+            if '__new__' in pyobject:
+                new_function = pyobject['__new__'].get_object()
+                result = _get_returned(new_function)
+            if result is None or \
+               result == rope.base.pyobjects.get_unknown():
+                result = rope.base.pyobjects.PyObject(pyobject)
+            self.result = rope.base.pynames.UnboundName(pyobject=result)
+            return
+
+        pyfunction = None
+        if isinstance(pyobject, rope.base.pyobjects.AbstractFunction):
+            pyfunction = pyobject
+        elif '__call__' in pyobject:
+            pyfunction = pyobject['__call__'].get_object()
+        if pyfunction is not None:
+            self.result = rope.base.pynames.UnboundName(
+                pyobject=_get_returned(pyfunction))
+
+    def _Str(self, node):
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_str())
+
+    def _Num(self, node):
+        type_name = type(node.n).__name__
+        self.result = self._get_builtin_name(type_name)
+
+    def _get_builtin_name(self, type_name):
+        pytype = rope.base.builtins.builtins[type_name].get_object()
+        return rope.base.pynames.UnboundName(
+            rope.base.pyobjects.PyObject(pytype))
+
+    def _BinOp(self, node):
+        self.result = rope.base.pynames.UnboundName(
+            self._get_object_for_node(node.left))
+
+    def _BoolOp(self, node):
+        pyobject = self._get_object_for_node(node.values[0])
+        if pyobject is None:
+            pyobject = self._get_object_for_node(node.values[1])
+        self.result = rope.base.pynames.UnboundName(pyobject)
+
+    def _Repr(self, node):
+        self.result = self._get_builtin_name('str')
+
+    def _UnaryOp(self, node):
+        self.result = rope.base.pynames.UnboundName(
+            self._get_object_for_node(node.operand))
+
+    def _Compare(self, node):
+        self.result = self._get_builtin_name('bool')
+
+    def _Dict(self, node):
+        keys = None
+        values = None
+        if node.keys:
+            keys = self._get_object_for_node(node.keys[0])
+            values = self._get_object_for_node(node.values[0])
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_dict(keys, values))
+
+    def _List(self, node):
+        holding = None
+        if node.elts:
+            holding = self._get_object_for_node(node.elts[0])
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_list(holding))
+
+    def _ListComp(self, node):
+        pyobject = self._what_does_comprehension_hold(node)
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_list(pyobject))
+
+    def _GeneratorExp(self, node):
+        pyobject = self._what_does_comprehension_hold(node)
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_iterator(pyobject))
+
+    def _what_does_comprehension_hold(self, node):
+        scope = self._make_comprehension_scope(node)
+        pyname = eval_node(scope, node.elt)
+        return pyname.get_object() if pyname is not None else None
+
+    def _make_comprehension_scope(self, node):
+        scope = self.scope
+        module = scope.pyobject.get_module()
+        names = {}
+        for comp in node.generators:
+            new_names = _get_evaluated_names(comp.target, comp.iter, module,
+                                             '.__iter__().next()', node.lineno)
+            names.update(new_names)
+        return rope.base.pyscopes.TemporaryScope(scope.pycore, scope, names)
+
+    def _Tuple(self, node):
+        objects = []
+        if len(node.elts) < 4:
+            for stmt in node.elts:
+                pyobject = self._get_object_for_node(stmt)
+                objects.append(pyobject)
+        else:
+            objects.append(self._get_object_for_node(node.elts[0]))
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.get_tuple(*objects))
+
+    def _get_object_for_node(self, stmt):
+        pyname = eval_node(self.scope, stmt)
+        pyobject = None
+        if pyname is not None:
+            pyobject = pyname.get_object()
+        return pyobject
+
+    def _get_primary_and_object_for_node(self, stmt):
+        primary, pyname = eval_node2(self.scope, stmt)
+        pyobject = None
+        if pyname is not None:
+            pyobject = pyname.get_object()
+        return primary, pyobject
+
+    def _Subscript(self, node):
+        if isinstance(node.slice, ast.Index):
+            self._call_function(node.value, '__getitem__',
+                                [node.slice.value])
+        elif isinstance(node.slice, ast.Slice):
+            self._call_function(node.value, '__getslice__')
+
+    def _call_function(self, node, function_name, other_args=None):
+        pyname = eval_node(self.scope, node)
+        if pyname is not None:
+            pyobject = pyname.get_object()
+        else:
+            return
+        if function_name in pyobject:
+            called = pyobject[function_name].get_object()
+            if not called or \
+                    not isinstance(called, pyobjects.AbstractFunction):
+                return
+            args = [node]
+            if other_args:
+                args += other_args
+            arguments_ = arguments.Arguments(args, self.scope)
+            self.result = rope.base.pynames.UnboundName(
+                pyobject=called.get_returned_object(arguments_))
+
+    def _Lambda(self, node):
+        self.result = rope.base.pynames.UnboundName(
+            pyobject=rope.base.builtins.Lambda(node, self.scope))
+
+
+def _get_evaluated_names(targets, assigned, module, evaluation, lineno):
+    result = {}
+    for name, levels in astutils.get_name_levels(targets):
+        assignment = rope.base.pynames.AssignmentValue(assigned, levels,
+                                                       evaluation)
+        # XXX: this module should not access `rope.base.pynamesdef`!
+        pyname = rope.base.pynamesdef.AssignedName(lineno, module)
+        pyname.assignments.append(assignment)
+        result[name] = pyname
+    return result