1
0
forked from VimPlug/jedi
Files
jedi-fork/jedi/inference/gradual/annotation.py
Peter Law e557129121 Remove check which doesn't seem to be needed
I'm not sure why I added this, though removing it doesn't seem to
casue any issues. I suspect there might be some oddness if the type
being passed in doesn't match the type expected, though them having
the same number of generic paramters isn't an expecially great way
to validate that.
2020-02-23 14:00:16 +00:00

540 lines
20 KiB
Python

"""
PEP 0484 ( https://www.python.org/dev/peps/pep-0484/ ) describes type hints
through function annotations. There is a strong suggestion in this document
that only the type of type hinting defined in PEP0484 should be allowed
as annotations in future python versions.
"""
import re
from parso import ParserSyntaxError, parse
from jedi._compatibility import force_unicode, Parameter
from jedi.inference.cache import inference_state_method_cache
from jedi.inference.base_value import ValueSet, NO_VALUES
from jedi.inference.gradual.base import DefineGenericBase, GenericClass
from jedi.inference.gradual.generics import TupleGenericManager
from jedi.inference.gradual.typing import TypingClassValueWithIndex
from jedi.inference.gradual.type_var import TypeVar
from jedi.inference.helpers import is_string
from jedi.inference.compiled import builtin_from_name
from jedi.inference.param import get_executed_param_names
from jedi import debug
from jedi import parser_utils
def infer_annotation(context, annotation):
"""
Inferes an annotation node. This means that it inferes the part of
`int` here:
foo: int = 3
Also checks for forward references (strings)
"""
value_set = context.infer_node(annotation)
if len(value_set) != 1:
debug.warning("Inferred typing index %s should lead to 1 object, "
" not %s" % (annotation, value_set))
return value_set
inferred_value = list(value_set)[0]
if is_string(inferred_value):
result = _get_forward_reference_node(context, inferred_value.get_safe_value())
if result is not None:
return context.infer_node(result)
return value_set
def _infer_annotation_string(context, string, index=None):
node = _get_forward_reference_node(context, string)
if node is None:
return NO_VALUES
value_set = context.infer_node(node)
if index is not None:
value_set = value_set.filter(
lambda value: value.array_type == u'tuple' # noqa
and len(list(value.py__iter__())) >= index
).py__simple_getitem__(index)
return value_set
def _get_forward_reference_node(context, string):
try:
new_node = context.inference_state.grammar.parse(
force_unicode(string),
start_symbol='eval_input',
error_recovery=False
)
except ParserSyntaxError:
debug.warning('Annotation not parsed: %s' % string)
return None
else:
module = context.tree_node.get_root_node()
parser_utils.move(new_node, module.end_pos[0])
new_node.parent = context.tree_node
return new_node
def _split_comment_param_declaration(decl_text):
"""
Split decl_text on commas, but group generic expressions
together.
For example, given "foo, Bar[baz, biz]" we return
['foo', 'Bar[baz, biz]'].
"""
try:
node = parse(decl_text, error_recovery=False).children[0]
except ParserSyntaxError:
debug.warning('Comment annotation is not valid Python: %s' % decl_text)
return []
if node.type in ['name', 'atom_expr', 'power']:
return [node.get_code().strip()]
params = []
try:
children = node.children
except AttributeError:
return []
else:
for child in children:
if child.type in ['name', 'atom_expr', 'power']:
params.append(child.get_code().strip())
return params
@inference_state_method_cache()
def infer_param(function_value, param, ignore_stars=False):
values = _infer_param(function_value, param)
if ignore_stars:
return values
inference_state = function_value.inference_state
if param.star_count == 1:
tuple_ = builtin_from_name(inference_state, 'tuple')
return ValueSet([GenericClass(
tuple_,
TupleGenericManager((values,)),
) for c in values])
elif param.star_count == 2:
dct = builtin_from_name(inference_state, 'dict')
generics = (
ValueSet([builtin_from_name(inference_state, 'str')]),
values
)
return ValueSet([GenericClass(
dct,
TupleGenericManager(generics),
) for c in values])
pass
return values
def _infer_param(function_value, param):
"""
Infers the type of a function parameter, using type annotations.
"""
annotation = param.annotation
if annotation is None:
# If no Python 3-style annotation, look for a Python 2-style comment
# annotation.
# Identify parameters to function in the same sequence as they would
# appear in a type comment.
all_params = [child for child in param.parent.children
if child.type == 'param']
node = param.parent.parent
comment = parser_utils.get_following_comment_same_line(node)
if comment is None:
return NO_VALUES
match = re.match(r"^#\s*type:\s*\(([^#]*)\)\s*->", comment)
if not match:
return NO_VALUES
params_comments = _split_comment_param_declaration(match.group(1))
# Find the specific param being investigated
index = all_params.index(param)
# If the number of parameters doesn't match length of type comment,
# ignore first parameter (assume it's self).
if len(params_comments) != len(all_params):
debug.warning(
"Comments length != Params length %s %s",
params_comments, all_params
)
if function_value.is_bound_method():
if index == 0:
# Assume it's self, which is already handled
return NO_VALUES
index -= 1
if index >= len(params_comments):
return NO_VALUES
param_comment = params_comments[index]
return _infer_annotation_string(
function_value.get_default_param_context(),
param_comment
)
# Annotations are like default params and resolve in the same way.
context = function_value.get_default_param_context()
return infer_annotation(context, annotation)
def py__annotations__(funcdef):
dct = {}
for function_param in funcdef.get_params():
param_annotation = function_param.annotation
if param_annotation is not None:
dct[function_param.name.value] = param_annotation
return_annotation = funcdef.annotation
if return_annotation:
dct['return'] = return_annotation
return dct
@inference_state_method_cache()
def infer_return_types(function, arguments):
"""
Infers the type of a function's return value,
according to type annotations.
"""
all_annotations = py__annotations__(function.tree_node)
annotation = all_annotations.get("return", None)
if annotation is None:
# If there is no Python 3-type annotation, look for a Python 2-type annotation
node = function.tree_node
comment = parser_utils.get_following_comment_same_line(node)
if comment is None:
return NO_VALUES
match = re.match(r"^#\s*type:\s*\([^#]*\)\s*->\s*([^#]*)", comment)
if not match:
return NO_VALUES
return _infer_annotation_string(
function.get_default_param_context(),
match.group(1).strip()
).execute_annotation()
if annotation is None:
return NO_VALUES
context = function.get_default_param_context()
unknown_type_vars = find_unknown_type_vars(context, annotation)
annotation_values = infer_annotation(context, annotation)
if not unknown_type_vars:
return annotation_values.execute_annotation()
type_var_dict = infer_type_vars_for_execution(function, arguments, all_annotations)
return ValueSet.from_sets(
ann.define_generics(type_var_dict)
if isinstance(ann, (DefineGenericBase, TypeVar)) else ValueSet({ann})
for ann in annotation_values
).execute_annotation()
def infer_type_vars_for_execution(function, arguments, annotation_dict):
"""
Some functions use type vars that are not defined by the class, but rather
only defined in the function. See for example `iter`. In those cases we
want to:
1. Search for undefined type vars.
2. Infer type vars with the execution state we have.
3. Return the union of all type vars that have been found.
"""
context = function.get_default_param_context()
annotation_variable_results = {}
executed_param_names = get_executed_param_names(function, arguments)
for executed_param_name in executed_param_names:
try:
annotation_node = annotation_dict[executed_param_name.string_name]
except KeyError:
continue
annotation_variables = find_unknown_type_vars(context, annotation_node)
if annotation_variables:
# Infer unknown type var
annotation_value_set = context.infer_node(annotation_node)
kind = executed_param_name.get_kind()
actual_value_set = executed_param_name.infer()
if kind is Parameter.VAR_POSITIONAL:
actual_value_set = actual_value_set.merge_types_of_iterate()
elif kind is Parameter.VAR_KEYWORD:
# TODO _dict_values is not public.
actual_value_set = actual_value_set.try_merge('_dict_values')
for ann in annotation_value_set:
_merge_type_var_dicts(
annotation_variable_results,
_infer_type_vars(ann, actual_value_set),
)
return annotation_variable_results
def infer_return_for_callable(arguments, param_values, result_values):
all_type_vars = {}
for pv in param_values:
if pv.array_type == 'list':
type_var_dict = infer_type_vars_for_callable(arguments, pv.py__iter__())
all_type_vars.update(type_var_dict)
return ValueSet.from_sets(
v.define_generics(all_type_vars)
if isinstance(v, (DefineGenericBase, TypeVar)) else ValueSet({v})
for v in result_values
).execute_annotation()
def infer_type_vars_for_callable(arguments, lazy_params):
"""
Infers type vars for the Calllable class:
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
annotation_variable_results = {}
for (_, lazy_value), lazy_callable_param in zip(arguments.unpack(), lazy_params):
callable_param_values = lazy_callable_param.infer()
# Infer unknown type var
actual_value_set = lazy_value.infer()
for v in callable_param_values:
_merge_type_var_dicts(
annotation_variable_results,
_infer_type_vars(v, actual_value_set),
)
return annotation_variable_results
def _merge_type_var_dicts(base_dict, new_dict):
for type_var_name, values in new_dict.items():
if values:
try:
base_dict[type_var_name] |= values
except KeyError:
base_dict[type_var_name] = values
def _infer_type_vars(annotation_value, value_set, is_class_value=False):
"""
This function tries to find information about undefined type vars and
returns a dict from type var name to value set.
This is for example important to understand what `iter([1])` returns.
According to typeshed, `iter` returns an `Iterator[_T]`:
def iter(iterable: Iterable[_T]) -> Iterator[_T]: ...
This functions would generate `int` for `_T` in this case, because it
unpacks the `Iterable`.
"""
type_var_dict = {}
annotation_name = annotation_value.py__name__()
if isinstance(annotation_value, TypeVar):
if not is_class_value:
return {annotation_name: value_set.py__class__()}
return {annotation_name: value_set}
elif isinstance(annotation_value, TypingClassValueWithIndex):
if annotation_name == 'Type':
given = annotation_value.get_generics()
if given:
if is_class_value:
for element in value_set:
element_name = element.py__name__()
if annotation_name == element_name:
annotation_generics = annotation_value.get_generics()
actual_generics = element.get_generics()
for annotation_generics_set, actual_generic_set in zip(annotation_generics, actual_generics):
for nested_annotation_value in annotation_generics_set:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
actual_generic_set,
# This is a note to ourselves that we
# have already converted the instance
# representation to its class.
is_class_value=True,
),
)
else:
for nested_annotation_value in given[0]:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
value_set,
is_class_value=True,
)
)
elif annotation_name == 'Callable':
given = annotation_value.get_generics()
if len(given) == 2:
for nested_annotation_value in given[1]:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
value_set.execute_annotation(),
)
)
elif annotation_name == 'Tuple':
# TODO: check that this works both for fixed and variadic tuples
# (and maybe for combiantions of those).
# TODO: this logic is pretty similar to the general logic below, can
# we combine them?
for element in value_set:
py_class = element.py__class__()
if not isinstance(py_class, GenericClass):
py_class = element
if not isinstance(py_class, DefineGenericBase):
continue
annotation_generics = annotation_value.get_generics()
actual_generics = py_class.get_generics()
for annotation_generics_set, actual_generic_set in zip(annotation_generics, actual_generics):
for nested_annotation_value in annotation_generics_set:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
actual_generic_set,
# This is a note to ourselves that we
# have already converted the instance
# representation to its class.
is_class_value=True,
),
)
elif isinstance(annotation_value, GenericClass):
if annotation_name == 'Iterable' and not is_class_value:
given = annotation_value.get_generics()
if given:
for nested_annotation_value in given[0]:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
value_set.merge_types_of_iterate(),
)
)
else:
# Note: we need to handle the MRO _in order_, so we need to extract
# the elements from the set first, then handle them, even if we put
# them back in a set afterwards.
for element in value_set:
if not hasattr(element, 'is_instance'):
continue
if element.is_instance():
py_class = element.py__class__()
else:
py_class = element
for klass in py_class.py__mro__():
class_name = klass.py__name__()
if annotation_name == class_name:
if not isinstance(klass, DefineGenericBase):
continue
annotation_generics = annotation_value.get_generics()
actual_generics = klass.get_generics()
for annotation_generics_set, actual_generic_set in zip(annotation_generics, actual_generics):
for nested_annotation_value in annotation_generics_set:
_merge_type_var_dicts(
type_var_dict,
_infer_type_vars(
nested_annotation_value,
actual_generic_set,
# This is a note to ourselves that we
# have already converted the instance
# representation to its class.
is_class_value=True,
),
)
break
return type_var_dict
def find_type_from_comment_hint_for(context, node, name):
return _find_type_from_comment_hint(context, node, node.children[1], name)
def find_type_from_comment_hint_with(context, node, name):
assert len(node.children[1].children) == 3, \
"Can only be here when children[1] is 'foo() as f'"
varlist = node.children[1].children[2]
return _find_type_from_comment_hint(context, node, varlist, name)
def find_type_from_comment_hint_assign(context, node, name):
return _find_type_from_comment_hint(context, node, node.children[0], name)
def _find_type_from_comment_hint(context, node, varlist, name):
index = None
if varlist.type in ("testlist_star_expr", "exprlist", "testlist"):
# something like "a, b = 1, 2"
index = 0
for child in varlist.children:
if child == name:
break
if child.type == "operator":
continue
index += 1
else:
return []
comment = parser_utils.get_following_comment_same_line(node)
if comment is None:
return []
match = re.match(r"^#\s*type:\s*([^#]*)", comment)
if match is None:
return []
return _infer_annotation_string(
context, match.group(1).strip(), index
).execute_annotation()
def find_unknown_type_vars(context, node):
def check_node(node):
if node.type in ('atom_expr', 'power'):
trailer = node.children[-1]
if trailer.type == 'trailer' and trailer.children[0] == '[':
for subscript_node in _unpack_subscriptlist(trailer.children[1]):
check_node(subscript_node)
else:
found[:] = _filter_type_vars(context.infer_node(node), found)
found = [] # We're not using a set, because the order matters.
check_node(node)
return found
def _filter_type_vars(value_set, found=()):
new_found = list(found)
for type_var in value_set:
if isinstance(type_var, TypeVar) and type_var not in found:
new_found.append(type_var)
return new_found
def _unpack_subscriptlist(subscriptlist):
if subscriptlist.type == 'subscriptlist':
for subscript in subscriptlist.children[::2]:
if subscript.type != 'subscript':
yield subscript
else:
if subscriptlist.type != 'subscript':
yield subscriptlist