Files
jedi/jedi/evaluate/iterable.py
2016-07-26 09:24:51 +02:00

847 lines
29 KiB
Python

"""
Contains all classes and functions to deal with lists, dicts, generators and
iterators in general.
Array modifications
*******************
If the content of an array (``set``/``list``) is requested somewhere, the
current module will be checked for appearances of ``arr.append``,
``arr.insert``, etc. If the ``arr`` name points to an actual array, the
content will be added
This can be really cpu intensive, as you can imagine. Because |jedi| has to
follow **every** ``append`` and check wheter it's the right array. However this
works pretty good, because in *slow* cases, the recursion detector and other
settings will stop this process.
It is important to note that:
1. Array modfications work only in the current module.
2. Jedi only checks Array additions; ``list.pop``, etc are ignored.
"""
from jedi.common import unite, safe_property
from jedi import debug
from jedi import settings
from jedi._compatibility import use_metaclass, unicode, zip_longest
from jedi.parser import tree
from jedi.evaluate import compiled
from jedi.evaluate import helpers
from jedi.evaluate.cache import CachedMetaClass, memoize_default
from jedi.evaluate import analysis
from jedi.evaluate import pep0484
class IterableWrapper(tree.Base):
def is_class(self):
return False
@memoize_default()
def _get_names_dict(self, names_dict):
builtin_methods = {}
for cls in reversed(type(self).mro()):
try:
builtin_methods.update(cls.builtin_methods)
except AttributeError:
pass
if not builtin_methods:
return names_dict
dct = {}
for names in names_dict.values():
for name in names:
name_str = name.value
try:
method = builtin_methods[name_str, self.type]
except KeyError:
dct[name_str] = [name]
else:
parent = BuiltinMethod(self, method, name.parent)
dct[name_str] = [helpers.FakeName(name_str, parent, is_definition=True)]
return dct
class BuiltinMethod(IterableWrapper):
"""``Generator.__next__`` ``dict.values`` methods and so on."""
def __init__(self, builtin, method, builtin_func):
self._builtin = builtin
self._method = method
self._builtin_func = builtin_func
def py__call__(self, params):
return self._method(self._builtin)
def __getattr__(self, name):
return getattr(self._builtin_func, name)
def has_builtin_methods(cls):
cls.builtin_methods = {}
for func in cls.__dict__.values():
try:
cls.builtin_methods.update(func.registered_builtin_methods)
except AttributeError:
pass
return cls
def register_builtin_method(method_name, type=None):
def wrapper(func):
dct = func.__dict__.setdefault('registered_builtin_methods', {})
dct[method_name, type] = func
return func
return wrapper
@has_builtin_methods
class GeneratorMixin(object):
type = None
@register_builtin_method('send')
@register_builtin_method('next')
@register_builtin_method('__next__')
def py__next__(self):
# TODO add TypeError if params are given.
return unite(self.py__iter__())
@memoize_default()
def names_dicts(self, search_global=False): # is always False
gen_obj = compiled.get_special_object(self._evaluator, 'GENERATOR_OBJECT')
yield self._get_names_dict(gen_obj.names_dict)
def py__bool__(self):
return True
def py__class__(self):
gen_obj = compiled.get_special_object(self._evaluator, 'GENERATOR_OBJECT')
return gen_obj.py__class__()
class Generator(use_metaclass(CachedMetaClass, IterableWrapper, GeneratorMixin)):
"""Handling of `yield` functions."""
def __init__(self, evaluator, func, var_args):
super(Generator, self).__init__()
self._evaluator = evaluator
self.func = func
self.var_args = var_args
def py__iter__(self):
from jedi.evaluate.representation import FunctionExecution
f = FunctionExecution(self._evaluator, self.func, self.var_args)
return f.get_yield_types()
def __getattr__(self, name):
if name not in ['start_pos', 'end_pos', 'parent', 'get_imports',
'doc', 'docstr', 'get_parent_until',
'get_code', 'subscopes']:
raise AttributeError("Accessing %s of %s is not allowed."
% (self, name))
return getattr(self.func, name)
def __repr__(self):
return "<%s of %s>" % (type(self).__name__, self.func)
class Comprehension(IterableWrapper):
@staticmethod
def from_atom(evaluator, atom):
bracket = atom.children[0]
if bracket == '{':
if atom.children[1].children[1] == ':':
cls = DictComprehension
else:
cls = SetComprehension
elif bracket == '(':
cls = GeneratorComprehension
elif bracket == '[':
cls = ListComprehension
return cls(evaluator, atom)
def __init__(self, evaluator, atom):
self._evaluator = evaluator
self._atom = atom
def _get_comprehension(self):
# The atom contains a testlist_comp
return self._atom.children[1]
def _get_comp_for(self):
# The atom contains a testlist_comp
return self._get_comprehension().children[1]
@memoize_default()
def _eval_node(self, index=0):
"""
The first part `x + 1` of the list comprehension:
[x + 1 for x in foo]
"""
comp_for = self._get_comp_for()
# For nested comprehensions we need to search the last one.
last_comp = list(comp_for.get_comp_fors())[-1]
return helpers.deep_ast_copy(self._get_comprehension().children[index], parent=last_comp)
@memoize_default()
def _iterate(self):
def nested(comp_fors):
comp_for = comp_fors[0]
input_node = comp_for.children[3]
input_types = evaluator.eval_element(input_node)
iterated = py__iter__(evaluator, input_types, input_node)
exprlist = comp_for.children[1]
for types in iterated:
evaluator.predefined_if_name_dict_dict[comp_for] = \
unpack_tuple_to_dict(evaluator, types, exprlist)
try:
for result in nested(comp_fors[1:]):
yield result
except IndexError:
iterated = evaluator.eval_element(self._eval_node())
if self.type == 'dict':
yield iterated, evaluator.eval_element(self._eval_node(2))
else:
yield iterated
finally:
del evaluator.predefined_if_name_dict_dict[comp_for]
evaluator = self._evaluator
comp_fors = list(self._get_comp_for().get_comp_fors())
for result in nested(comp_fors):
yield result
def py__iter__(self):
return self._iterate()
def __repr__(self):
return "<%s of %s>" % (type(self).__name__, self._atom)
@has_builtin_methods
class ArrayMixin(object):
@memoize_default()
def names_dicts(self, search_global=False): # Always False.
# `array.type` is a string with the type, e.g. 'list'.
scope = compiled.builtin_from_name(self._evaluator, self.type)
# builtins only have one class -> [0]
scopes = self._evaluator.execute_evaluated(scope, self)
names_dicts = list(scopes)[0].names_dicts(search_global)
#yield names_dicts[0]
yield self._get_names_dict(names_dicts[1])
def py__bool__(self):
return None # We don't know the length, because of appends.
def py__class__(self):
return compiled.builtin_from_name(self._evaluator, self.type)
@safe_property
def parent(self):
return self._evaluator.BUILTINS
@property
def name(self):
return FakeSequence(self._evaluator, [], self.type).name
@memoize_default()
def dict_values(self):
return unite(self._evaluator.eval_element(v) for k, v in self._items())
@register_builtin_method('values', type='dict')
def _imitate_values(self):
items = self.dict_values()
return create_evaluated_sequence_set(self._evaluator, items, type='list')
#return set([FakeSequence(self._evaluator, [AlreadyEvaluated(items)], 'tuple')])
@register_builtin_method('items', type='dict')
def _imitate_items(self):
items = [set([FakeSequence(self._evaluator, (k, v), 'tuple')])
for k, v in self._items()]
return create_evaluated_sequence_set(self._evaluator, *items, type='list')
class ListComprehension(Comprehension, ArrayMixin):
type = 'list'
def py__getitem__(self, index):
all_types = list(self.py__iter__())
return all_types[index]
class SetComprehension(Comprehension, ArrayMixin):
type = 'set'
@has_builtin_methods
class DictComprehension(Comprehension, ArrayMixin):
type = 'dict'
def _get_comp_for(self):
return self._get_comprehension().children[3]
def py__iter__(self):
for keys, values in self._iterate():
yield keys
def py__getitem__(self, index):
for keys, values in self._iterate():
for k in keys:
if isinstance(k, compiled.CompiledObject):
if k.obj == index:
return values
return self.dict_values()
def dict_values(self):
return unite(values for keys, values in self._iterate())
@register_builtin_method('items', type='dict')
def _imitate_items(self):
items = set(FakeSequence(self._evaluator,
(AlreadyEvaluated(keys), AlreadyEvaluated(values)), 'tuple')
for keys, values in self._iterate())
return create_evaluated_sequence_set(self._evaluator, items, type='list')
class GeneratorComprehension(Comprehension, GeneratorMixin):
pass
class Array(IterableWrapper, ArrayMixin):
mapping = {'(': 'tuple',
'[': 'list',
'{': 'dict'}
def __init__(self, evaluator, atom):
self._evaluator = evaluator
self.atom = atom
self.type = Array.mapping[atom.children[0]]
"""The builtin name of the array (list, set, tuple or dict)."""
c = self.atom.children
array_node = c[1]
if self.type == 'dict' and array_node != '}' \
and (not hasattr(array_node, 'children')
or ':' not in array_node.children):
self.type = 'set'
@property
def name(self):
return helpers.FakeName(self.type, parent=self)
def py__getitem__(self, index):
"""Here the index is an int/str. Raises IndexError/KeyError."""
if self.type == 'dict':
for key, value in self._items():
for k in self._evaluator.eval_element(key):
if isinstance(k, compiled.CompiledObject) \
and index == k.obj:
return self._evaluator.eval_element(value)
raise KeyError('No key found in dictionary %s.' % self)
# Can raise an IndexError
if isinstance(index, slice):
return set([self])
else:
return self._evaluator.eval_element(self._items()[index])
def __getattr__(self, name):
if name not in ['start_pos', 'get_only_subelement', 'parent',
'get_parent_until', 'items']:
raise AttributeError('Strange access on %s: %s.' % (self, name))
return getattr(self.atom, name)
# @memoize_default()
def py__iter__(self):
"""
While values returns the possible values for any array field, this
function returns the value for a certain index.
"""
if self.type == 'dict':
# Get keys.
types = set()
for k, _ in self._items():
types |= self._evaluator.eval_element(k)
# We don't know which dict index comes first, therefore always
# yield all the types.
for _ in types:
yield types
else:
for value in self._items():
yield self._evaluator.eval_element(value)
additions = check_array_additions(self._evaluator, self)
if additions:
yield additions
def _values(self):
"""Returns a list of a list of node."""
if self.type == 'dict':
return unite(v for k, v in self._items())
else:
return self._items()
def _items(self):
c = self.atom.children
array_node = c[1]
if array_node in (']', '}', ')'):
return [] # Direct closing bracket, doesn't contain items.
if tree.is_node(array_node, 'testlist_comp'):
return array_node.children[::2]
elif tree.is_node(array_node, 'dictorsetmaker'):
kv = []
iterator = iter(array_node.children)
for key in iterator:
op = next(iterator, None)
if op is None or op == ',':
kv.append(key) # A set.
else:
assert op == ':' # A dict.
kv.append((key, next(iterator)))
next(iterator, None) # Possible comma.
return kv
else:
return [array_node]
def __repr__(self):
return "<%s of %s>" % (type(self).__name__, self.atom)
class _FakeArray(Array):
def __init__(self, evaluator, container, type):
self.type = type
self._evaluator = evaluator
self.atom = container
class ImplicitTuple(_FakeArray):
def __init__(self, evaluator, testlist):
super(ImplicitTuple, self).__init__(evaluator, testlist, 'tuple')
self._testlist = testlist
def _items(self):
return self._testlist.children[::2]
class FakeSequence(_FakeArray):
def __init__(self, evaluator, sequence_values, type):
"""
type should be one of "tuple", "list"
"""
super(FakeSequence, self).__init__(evaluator, sequence_values, type)
self._sequence_values = sequence_values
def _items(self):
return self._sequence_values
def create_evaluated_sequence_set(evaluator, *types_order, **kwargs):
"""
``sequence_type`` is a named argument, that doesn't work in Python2. For backwards
compatibility reasons, we're now using kwargs.
"""
sequence_type = kwargs.get('sequence_type')
sets = tuple(AlreadyEvaluated(types) for types in types_order)
return set([FakeSequence(evaluator, sets, sequence_type)])
class AlreadyEvaluated(frozenset):
"""A simple container to add already evaluated objects to an array."""
def get_code(self, normalized=False):
# For debugging purposes.
return str(self)
class MergedNodes(frozenset):
pass
class FakeDict(_FakeArray):
def __init__(self, evaluator, dct):
super(FakeDict, self).__init__(evaluator, dct, 'dict')
self._dct = dct
def py__iter__(self):
yield set(compiled.create(self._evaluator, key) for key in self._dct)
def py__getitem__(self, index):
return unite(self._evaluator.eval_element(v) for v in self._dct[index])
def _items(self):
for key, values in self._dct.items():
# TODO this is not proper. The values could be multiple values?!
yield key, values[0]
class MergedArray(_FakeArray):
def __init__(self, evaluator, arrays):
super(MergedArray, self).__init__(evaluator, arrays, arrays[-1].type)
self._arrays = arrays
def py__iter__(self):
for array in self._arrays:
for types in array.py__iter__():
yield types
def py__getitem__(self, index):
return unite(self.py__iter__())
def _items(self):
for array in self._arrays:
for a in array._items():
yield a
def __len__(self):
return sum(len(a) for a in self._arrays)
def unpack_tuple_to_dict(evaluator, types, exprlist):
"""
Unpacking tuple assignments in for statements and expr_stmts.
"""
if exprlist.type == 'name':
return {exprlist.value: types}
elif exprlist.type == 'atom' and exprlist.children[0] in '([':
return unpack_tuple_to_dict(evaluator, types, exprlist.children[1])
elif exprlist.type in ('testlist', 'testlist_comp', 'exprlist',
'testlist_star_expr'):
dct = {}
parts = iter(exprlist.children[::2])
n = 0
for iter_types in py__iter__(evaluator, types, exprlist):
n += 1
try:
part = next(parts)
except StopIteration:
analysis.add(evaluator, 'value-error-too-many-values', part,
message="ValueError: too many values to unpack (expected %s)" % n)
else:
dct.update(unpack_tuple_to_dict(evaluator, iter_types, part))
has_parts = next(parts, None)
if types and has_parts is not None:
analysis.add(evaluator, 'value-error-too-few-values', has_parts,
message="ValueError: need more than %s values to unpack" % n)
return dct
elif exprlist.type == 'power' or exprlist.type == 'atom_expr':
# Something like ``arr[x], var = ...``.
# This is something that is not yet supported, would also be difficult
# to write into a dict.
return {}
elif exprlist.type == 'star_expr': # `a, *b, c = x` type unpackings
# Currently we're not supporting them.
return {}
raise NotImplementedError
def py__iter__(evaluator, types, node=None):
debug.dbg('py__iter__')
type_iters = []
for typ in types:
try:
iter_method = typ.py__iter__
except AttributeError:
if node is not None:
analysis.add(evaluator, 'type-error-not-iterable', node,
message="TypeError: '%s' object is not iterable" % typ)
else:
type_iters.append(iter_method())
#for result in iter_method():
#yield result
for t in zip_longest(*type_iters, fillvalue=set()):
yield unite(t)
def py__iter__types(evaluator, types, node=None):
"""
Calls `py__iter__`, but ignores the ordering in the end and just returns
all types that it contains.
"""
return unite(py__iter__(evaluator, types, node))
def py__getitem__(evaluator, types, trailer):
from jedi.evaluate.representation import Class
result = set()
trailer_op, node, trailer_cl = trailer.children
assert trailer_op == "["
assert trailer_cl == "]"
# special case: PEP0484 typing module, see
# https://github.com/davidhalter/jedi/issues/663
for typ in list(types):
if isinstance(typ, Class):
typing_module_types = \
pep0484.get_types_for_typing_module(evaluator, typ, node)
if typing_module_types is not None:
types.remove(typ)
result |= typing_module_types
if not types:
# all consumed by special cases
return result
for index in create_index_types(evaluator, node):
if isinstance(index, (compiled.CompiledObject, Slice)):
index = index.obj
if type(index) not in (float, int, str, unicode, slice):
# If the index is not clearly defined, we have to get all the
# possiblities.
for typ in list(types):
if isinstance(typ, Array) and typ.type == 'dict':
types.remove(typ)
result |= typ.dict_values()
return result | py__iter__types(evaluator, types)
for typ in types:
# The actual getitem call.
try:
getitem = typ.py__getitem__
except AttributeError:
analysis.add(evaluator, 'type-error-not-subscriptable', trailer_op,
message="TypeError: '%s' object is not subscriptable" % typ)
else:
try:
result |= getitem(index)
except IndexError:
result |= py__iter__types(evaluator, set([typ]))
except KeyError:
# Must be a dict. Lists don't raise KeyErrors.
result |= typ.dict_values()
return result
def check_array_additions(evaluator, array):
""" Just a mapper function for the internal _check_array_additions """
if array.type not in ('list', 'set'):
# TODO also check for dict updates
return set()
is_list = array.type == 'list'
try:
current_module = array.atom.get_parent_until()
except AttributeError:
# If there's no get_parent_until, it's a FakeSequence or another Fake
# type. Those fake types are used inside Jedi's engine. No values may
# be added to those after their creation.
return set()
return _check_array_additions(evaluator, array, current_module, is_list)
@memoize_default(default=set(), evaluator_is_first_arg=True)
@debug.increase_indent
def _check_array_additions(evaluator, compare_array, module, is_list):
"""
Checks if a `Array` has "add" (append, insert, extend) statements:
>>> a = [""]
>>> a.append(1)
"""
debug.dbg('Dynamic array search for %s' % compare_array, color='MAGENTA')
if not settings.dynamic_array_additions or isinstance(module, compiled.CompiledObject):
debug.dbg('Dynamic array search aborted.', color='MAGENTA')
return set()
def check_additions(arglist, add_name):
params = list(param.Arguments(evaluator, arglist).unpack())
result = set()
if add_name in ['insert']:
params = params[1:]
if add_name in ['append', 'add', 'insert']:
for key, nodes in params:
result |= unite(evaluator.eval_element(node) for node in nodes)
elif add_name in ['extend', 'update']:
for key, nodes in params:
for node in nodes:
types = evaluator.eval_element(node)
result |= py__iter__types(evaluator, types, node)
return result
from jedi.evaluate import representation as er, param
def get_execution_parent(element):
""" Used to get an Instance/FunctionExecution parent """
if isinstance(element, Array):
node = element.atom
else:
# Is an Instance with an
# Arguments([AlreadyEvaluated([_ArrayInstance])]) inside
# Yeah... I know... It's complicated ;-)
node = list(element.var_args.argument_node[0])[0].var_args.trailer
if isinstance(node, er.InstanceElement) or node is None:
return node
return node.get_parent_until(er.FunctionExecution)
temp_param_add, settings.dynamic_params_for_other_modules = \
settings.dynamic_params_for_other_modules, False
search_names = ['append', 'extend', 'insert'] if is_list else ['add', 'update']
comp_arr_parent = get_execution_parent(compare_array)
added_types = set()
for add_name in search_names:
try:
possible_names = module.used_names[add_name]
except KeyError:
continue
else:
for name in possible_names:
# Check if the original scope is an execution. If it is, one
# can search for the same statement, that is in the module
# dict. Executions are somewhat special in jedi, since they
# literally copy the contents of a function.
if isinstance(comp_arr_parent, er.FunctionExecution):
if comp_arr_parent.start_pos < name.start_pos < comp_arr_parent.end_pos:
name = comp_arr_parent.name_for_position(name.start_pos)
else:
# Don't check definitions that are not defined in the
# same function. This is not "proper" anyway. It also
# improves Jedi's speed for array lookups, since we
# don't have to check the whole source tree anymore.
continue
trailer = name.parent
power = trailer.parent
trailer_pos = power.children.index(trailer)
try:
execution_trailer = power.children[trailer_pos + 1]
except IndexError:
continue
else:
if execution_trailer.type != 'trailer' \
or execution_trailer.children[0] != '(' \
or execution_trailer.children[1] == ')':
continue
power = helpers.call_of_leaf(name, cut_own_trailer=True)
# InstanceElements are special, because they don't get copied,
# but have this wrapper around them.
if isinstance(comp_arr_parent, er.InstanceElement):
power = er.get_instance_el(evaluator, comp_arr_parent.instance, power)
if evaluator.recursion_detector.push_stmt(power):
# Check for recursion. Possible by using 'extend' in
# combination with function calls.
continue
if compare_array in evaluator.eval_element(power):
# The arrays match. Now add the results
added_types |= check_additions(execution_trailer.children[1], add_name)
evaluator.recursion_detector.pop_stmt()
# reset settings
settings.dynamic_params_for_other_modules = temp_param_add
debug.dbg('Dynamic array result %s' % added_types, color='MAGENTA')
return added_types
def check_array_instances(evaluator, instance):
"""Used for set() and list() instances."""
if not settings.dynamic_array_additions:
return instance.var_args
ai = _ArrayInstance(evaluator, instance)
from jedi.evaluate import param
return param.Arguments(evaluator, [AlreadyEvaluated([ai])])
class _ArrayInstance(IterableWrapper):
"""
Used for the usage of set() and list().
This is definitely a hack, but a good one :-)
It makes it possible to use set/list conversions.
In contrast to Array, ListComprehension and all other iterable types, this
is something that is only used inside `evaluate/compiled/fake/builtins.py`
and therefore doesn't need `names_dicts`, `py__bool__` and so on, because
we don't use these operations in `builtins.py`.
"""
def __init__(self, evaluator, instance):
self._evaluator = evaluator
self.instance = instance
self.var_args = instance.var_args
def py__iter__(self):
try:
_, first_nodes = next(self.var_args.unpack())
except StopIteration:
types = set()
else:
types = unite(self._evaluator.eval_element(node) for node in first_nodes)
for types in py__iter__(self._evaluator, types, first_nodes[0]):
yield types
module = self.var_args.get_parent_until()
if module is None:
return
is_list = str(self.instance.name) == 'list'
additions = _check_array_additions(self._evaluator, self.instance, module, is_list)
if additions:
yield additions
class Slice(object):
def __init__(self, evaluator, start, stop, step):
self._evaluator = evaluator
# all of them are either a Precedence or None.
self._start = start
self._stop = stop
self._step = step
@property
def obj(self):
"""
Imitate CompiledObject.obj behavior and return a ``builtin.slice()``
object.
"""
def get(element):
if element is None:
return None
result = self._evaluator.eval_element(element)
if len(result) != 1:
# For simplicity, we want slices to be clear defined with just
# one type. Otherwise we will return an empty slice object.
raise IndexError
try:
return list(result)[0].obj
except AttributeError:
return None
try:
return slice(get(self._start), get(self._stop), get(self._step))
except IndexError:
return slice(None, None, None)
def create_index_types(evaluator, index):
"""
Handles slices in subscript nodes.
"""
if index == ':':
# Like array[:]
return set([Slice(evaluator, None, None, None)])
elif tree.is_node(index, 'subscript'): # subscript is a slice operation.
# Like array[:3]
result = []
for el in index.children:
if el == ':':
if not result:
result.append(None)
elif tree.is_node(el, 'sliceop'):
if len(el.children) == 2:
result.append(el.children[1])
else:
result.append(el)
result += [None] * (3 - len(result))
return set([Slice(evaluator, *result)])
# No slices
return evaluator.eval_element(index)