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jedi-fork/jedi/evaluate/stdlib.py
2017-03-28 01:34:07 +02:00

302 lines
10 KiB
Python

"""
Implementations of standard library functions, because it's not possible to
understand them with Jedi.
To add a new implementation, create a function and add it to the
``_implemented`` dict at the bottom of this module.
Note that this module exists only to implement very specific functionality in
the standard library. The usual way to understand the standard library is the
compiled module that returns the types for C-builtins.
"""
import collections
import re
from jedi.common import unite
from jedi.evaluate import compiled
from jedi.evaluate import representation as er
from jedi.evaluate.instance import InstanceFunctionExecution, \
AbstractInstanceContext, CompiledInstance, BoundMethod
from jedi.evaluate import iterable
from jedi.parser.python import parse
from jedi import debug
from jedi.evaluate import precedence
from jedi.evaluate import param
from jedi.evaluate import analysis
from jedi.evaluate.context import LazyTreeContext, ContextualizedNode
class NotInStdLib(LookupError):
pass
def execute(evaluator, obj, arguments):
if isinstance(obj, BoundMethod):
raise NotInStdLib()
try:
obj_name = obj.name.string_name
except AttributeError:
pass
else:
if obj.parent_context == evaluator.BUILTINS:
module_name = 'builtins'
elif isinstance(obj.parent_context, er.ModuleContext):
module_name = obj.parent_context.name.string_name
else:
module_name = ''
# for now we just support builtin functions.
try:
func = _implemented[module_name][obj_name]
except KeyError:
pass
else:
return func(evaluator, obj, arguments)
raise NotInStdLib()
def _follow_param(evaluator, arguments, index):
try:
key, lazy_context = list(arguments.unpack())[index]
except IndexError:
return set()
else:
return lazy_context.infer()
def argument_clinic(string, want_obj=False, want_context=False, want_arguments=False):
"""
Works like Argument Clinic (PEP 436), to validate function params.
"""
clinic_args = []
allow_kwargs = False
optional = False
while string:
# Optional arguments have to begin with a bracket. And should always be
# at the end of the arguments. This is therefore not a proper argument
# clinic implementation. `range()` for exmple allows an optional start
# value at the beginning.
match = re.match('(?:(?:(\[),? ?|, ?|)(\w+)|, ?/)\]*', string)
string = string[len(match.group(0)):]
if not match.group(2): # A slash -> allow named arguments
allow_kwargs = True
continue
optional = optional or bool(match.group(1))
word = match.group(2)
clinic_args.append((word, optional, allow_kwargs))
def f(func):
def wrapper(evaluator, obj, arguments):
debug.dbg('builtin start %s' % obj, color='MAGENTA')
try:
lst = list(arguments.eval_argument_clinic(clinic_args))
except ValueError:
return set()
else:
kwargs = {}
if want_context:
kwargs['context'] = arguments.context
if want_obj:
kwargs['obj'] = obj
if want_arguments:
kwargs['arguments'] = arguments
return func(evaluator, *lst, **kwargs)
finally:
debug.dbg('builtin end', color='MAGENTA')
return wrapper
return f
@argument_clinic('iterator[, default], /')
def builtins_next(evaluator, iterators, defaults):
"""
TODO this function is currently not used. It's a stab at implementing next
in a different way than fake objects. This would be a bit more flexible.
"""
if evaluator.python_version[0] == 2:
name = 'next'
else:
name = '__next__'
types = set()
for iterator in iterators:
if isinstance(iterator, AbstractInstanceContext):
for filter in iterator.get_filters(include_self_names=True):
for n in filter.get(name):
for context in n.infer():
types |= context.execute_evaluated()
if types:
return types
return defaults
@argument_clinic('object, name[, default], /')
def builtins_getattr(evaluator, objects, names, defaults=None):
# follow the first param
for obj in objects:
for name in names:
if precedence.is_string(name):
return obj.py__getattribute__(name.obj)
else:
debug.warning('getattr called without str')
continue
return set()
@argument_clinic('object[, bases, dict], /')
def builtins_type(evaluator, objects, bases, dicts):
if bases or dicts:
# It's a type creation... maybe someday...
return set()
else:
return set([o.py__class__() for o in objects])
class SuperInstance(AbstractInstanceContext):
"""To be used like the object ``super`` returns."""
def __init__(self, evaluator, cls):
su = cls.py_mro()[1]
super().__init__(evaluator, su and su[0] or self)
@argument_clinic('[type[, obj]], /', want_context=True)
def builtins_super(evaluator, types, objects, context):
# TODO make this able to detect multiple inheritance super
if isinstance(context, InstanceFunctionExecution):
su = context.instance.py__class__().py__bases__()
return unite(context.execute_evaluated() for context in su[0].infer())
return set()
@argument_clinic('sequence, /', want_obj=True, want_arguments=True)
def builtins_reversed(evaluator, sequences, obj, arguments):
# While we could do without this variable (just by using sequences), we
# want static analysis to work well. Therefore we need to generated the
# values again.
key, lazy_context = next(arguments.unpack())
cn = None
if isinstance(lazy_context, LazyTreeContext):
# TODO access private
cn = ContextualizedNode(lazy_context._context, lazy_context.data)
ordered = list(iterable.py__iter__(evaluator, sequences, cn))
rev = list(reversed(ordered))
# Repack iterator values and then run it the normal way. This is
# necessary, because `reversed` is a function and autocompletion
# would fail in certain cases like `reversed(x).__iter__` if we
# just returned the result directly.
seq = iterable.FakeSequence(evaluator, 'list', rev)
arguments = param.ValuesArguments([[seq]])
return set([CompiledInstance(evaluator, evaluator.BUILTINS, obj, arguments)])
@argument_clinic('obj, type, /', want_arguments=True)
def builtins_isinstance(evaluator, objects, types, arguments):
bool_results = set([])
for o in objects:
try:
mro_func = o.py__class__().py__mro__
except AttributeError:
# This is temporary. Everything should have a class attribute in
# Python?! Maybe we'll leave it here, because some numpy objects or
# whatever might not.
return set([compiled.create(True), compiled.create(False)])
mro = mro_func()
for cls_or_tup in types:
if cls_or_tup.is_class():
bool_results.add(cls_or_tup in mro)
elif cls_or_tup.name.string_name == 'tuple' \
and cls_or_tup.get_root_context() == evaluator.BUILTINS:
# Check for tuples.
classes = unite(
lazy_context.infer()
for lazy_context in cls_or_tup.py__iter__()
)
bool_results.add(any(cls in mro for cls in classes))
else:
_, lazy_context = list(arguments.unpack())[1]
if isinstance(lazy_context, LazyTreeContext):
node = lazy_context.data
message = 'TypeError: isinstance() arg 2 must be a ' \
'class, type, or tuple of classes and types, ' \
'not %s.' % cls_or_tup
analysis.add(lazy_context._context, 'type-error-isinstance', node, message)
return set(compiled.create(evaluator, x) for x in bool_results)
def collections_namedtuple(evaluator, obj, arguments):
"""
Implementation of the namedtuple function.
This has to be done by processing the namedtuple class template and
evaluating the result.
.. note:: |jedi| only supports namedtuples on Python >2.6.
"""
# Namedtuples are not supported on Python 2.6
if not hasattr(collections, '_class_template'):
return set()
# Process arguments
# TODO here we only use one of the types, we should use all.
name = list(_follow_param(evaluator, arguments, 0))[0].obj
_fields = list(_follow_param(evaluator, arguments, 1))[0]
if isinstance(_fields, compiled.CompiledObject):
fields = _fields.obj.replace(',', ' ').split()
elif isinstance(_fields, iterable.AbstractSequence):
fields = [
v.obj
for lazy_context in _fields.py__iter__()
for v in lazy_context.infer() if hasattr(v, 'obj')
]
else:
return set()
# Build source
source = collections._class_template.format(
typename=name,
field_names=fields,
num_fields=len(fields),
arg_list=', '.join(fields),
repr_fmt=', '.join(collections._repr_template.format(name=name) for name in fields),
field_defs='\n'.join(collections._field_template.format(index=index, name=name)
for index, name in enumerate(fields))
)
# Parse source
generated_class = parse(source, grammar=evaluator.grammar).subscopes[0]
return set([er.ClassContext(evaluator, generated_class, evaluator.BUILTINS)])
@argument_clinic('first, /')
def _return_first_param(evaluator, firsts):
return firsts
_implemented = {
'builtins': {
'getattr': builtins_getattr,
'type': builtins_type,
'super': builtins_super,
'reversed': builtins_reversed,
'isinstance': builtins_isinstance,
},
'copy': {
'copy': _return_first_param,
'deepcopy': _return_first_param,
},
'json': {
'load': lambda *args: set(),
'loads': lambda *args: set(),
},
'collections': {
'namedtuple': collections_namedtuple,
},
}