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jedi-fork/jedi/evaluate/pep0484.py

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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.
The (initial / probably incomplete) implementation todo list for pep-0484:
v Function parameter annotations with builtin/custom type classes
v Function returntype annotations with builtin/custom type classes
v Function parameter annotations with strings (forward reference)
v Function return type annotations with strings (forward reference)
x Local variable type hints
v Assigned types: `Url = str\ndef get(url:Url) -> str:`
x Type hints in `with` statements
x Stub files support
x support `@no_type_check` and `@no_type_check_decorator`
x support for type hint comments `# type: (int, str) -> int`. See comment from
Guido https://github.com/davidhalter/jedi/issues/662
"""
from itertools import chain
import os
from jedi.parser import \
Parser, load_grammar, ParseError, ParserWithRecovery, tree
from jedi.evaluate.cache import memoize_default
from jedi.evaluate import compiled
from jedi import debug
def _evaluate_for_annotation(evaluator, annotation):
if annotation is not None:
dereferenced_annotation = _fix_forward_reference(evaluator, annotation)
definitions = evaluator.eval_element(dereferenced_annotation)
return list(chain.from_iterable(
evaluator.execute(d) for d in definitions))
else:
return []
def _fix_forward_reference(evaluator, item):
"""
Gets something from the parse tree, and replaces any string literal
in there with the result of evaluating that string at the bottom of the
module
"""
if isinstance(item, tree.String):
compiledobjects = evaluator.eval_element(item)
assert len(compiledobjects) == 1
compiledobject = list(compiledobjects)[0]
try:
p = Parser(load_grammar(), compiledobject.obj, start='eval_input')
element = p.get_parsed_node()
except ParseError:
debug.warning('Annotation not parsed: %s' % compiledobject.obj)
return item
else:
module = item.get_parent_until()
p.position_modifier.line = module.end_pos[0]
element.parent = module
dereferenced = _fix_forward_reference(evaluator, element)
return dereferenced
if isinstance(item, tree.Node):
newnode = tree.Node(item.type, [])
for child in item.children:
newchild = _fix_forward_reference(evaluator, child)
newchild.parent = newnode
newnode.children.append(newchild)
newnode.parent = item.parent
return newnode
return item
@memoize_default(None, evaluator_is_first_arg=True)
def follow_param(evaluator, param):
annotation = param.annotation()
return _evaluate_for_annotation(evaluator, annotation)
@memoize_default(None, evaluator_is_first_arg=True)
def find_return_types(evaluator, func):
annotation = func.py__annotations__().get("return", None)
return _evaluate_for_annotation(evaluator, annotation)
# TODO: Memoize
def _get_typing_replacement_module():
"""
The idea is to return our jedi replacement for the PEP-0484 typing module
as discussed at https://github.com/davidhalter/jedi/issues/663
"""
typing_path = os.path.abspath(os.path.join(__file__, "../jedi_typing.py"))
with open(typing_path) as f:
code = f.read()
p = ParserWithRecovery(load_grammar(), code)
return p.module
def get_types_for_typing_module(evaluator, typ, trailer):
if not typ.base.get_parent_until().name.value == "typing":
return None
# we assume that any class using [] in a module called
# "typing" with a name for which we have a replacement
# should be replaced by that class. This is not 100%
# airtight but I don't have a better idea to check that it's
# actually the PEP-0484 typing module and not some other
indextypes = evaluator.eval_element(trailer.children[1])
if not isinstance(indextypes, set):
indextypes = set([indextypes])
typing = _get_typing_replacement_module()
factories = evaluator.find_types(typing, "factory")
assert len(factories) == 1
factory = list(factories)[0]
assert factory
function_body_nodes = factory.children[4].children
valid_classnames = set(child.name.value
for child in function_body_nodes
if isinstance(child, tree.Class))
if typ.name.value not in valid_classnames:
return None
compiled_classname = compiled.create(evaluator, typ.name.value)
result = set()
for indextyp in indextypes:
result |= \
evaluator.execute_evaluated(factory, compiled_classname, indextyp)
for singleresult in result:
singleresult.name.value += "[%s]" % indextyp.name
return result