forked from VimPlug/jedi
185 lines
6.7 KiB
Python
185 lines
6.7 KiB
Python
"""
|
|
To understand Python on a deeper level, |jedi| needs to understand some of the
|
|
dynamic features of Python, however this probably the most complicated part:
|
|
|
|
- Array modifications (e.g. ``list.append``)
|
|
- Parameter completion in functions
|
|
- Flow checks (e.g. ``if isinstance(a, str)`` -> a is a str)
|
|
|
|
Array modifications
|
|
*******************
|
|
|
|
If the content of an array (``set``/``list``) is wanted 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``. 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. Only Array additions are being checked, ``list.pop``, etc. is being ignored.
|
|
|
|
Parameter completion
|
|
********************
|
|
|
|
One of the really important features of |jedi| is to have an option to
|
|
understand code like this::
|
|
|
|
def foo(bar):
|
|
bar. # completion here
|
|
foo(1)
|
|
|
|
There's no doubt wheter bar is an ``int`` or not, but if there's also a call
|
|
like ``foo('str')``, what would happen? Well, we'll just show both. Because
|
|
that's what a human would expect.
|
|
|
|
It works as follows:
|
|
|
|
- A param is being encountered
|
|
- search for function calls named ``foo``
|
|
- execute these calls and check the injected params. This work with a
|
|
``ParamListener``.
|
|
|
|
Flow checks
|
|
***********
|
|
|
|
Flow checks are not really mature. There's only a check for ``isinstance``. It
|
|
would check whether a flow has the form of ``if isinstance(a, type_or_tuple)``.
|
|
Unfortunately every other thing is being ignored (e.g. a == '' would be easy to
|
|
check for -> a is a string). There's big potential in these checks.
|
|
"""
|
|
from jedi.parser import representation as pr
|
|
from jedi import settings
|
|
from jedi.evaluate import helpers
|
|
from jedi.evaluate.cache import memoize_default
|
|
|
|
# This is something like the sys.path, but only for searching params. It means
|
|
# that this is the order in which Jedi searches params.
|
|
search_param_modules = ['.']
|
|
|
|
|
|
class ParamListener(object):
|
|
"""
|
|
This listener is used to get the params for a function.
|
|
"""
|
|
def __init__(self):
|
|
self.param_possibilities = []
|
|
|
|
def execute(self, params):
|
|
self.param_possibilities.append(params)
|
|
|
|
|
|
@memoize_default([], evaluator_is_first_arg=True)
|
|
def search_params(evaluator, param):
|
|
"""
|
|
This is a dynamic search for params. If you try to complete a type:
|
|
|
|
>>> def func(foo):
|
|
... foo
|
|
>>> func(1)
|
|
>>> func("")
|
|
|
|
It is not known what the type is, because it cannot be guessed with
|
|
recursive madness. Therefore one has to analyse the statements that are
|
|
calling the function, as well as analyzing the incoming params.
|
|
"""
|
|
if not settings.dynamic_params:
|
|
return []
|
|
|
|
def get_params_for_module(module):
|
|
"""
|
|
Returns the values of a param, or an empty array.
|
|
"""
|
|
@memoize_default([], evaluator_is_first_arg=True)
|
|
def get_posibilities(evaluator, module, func_name):
|
|
try:
|
|
possible_stmts = module.used_names[func_name]
|
|
except KeyError:
|
|
return []
|
|
|
|
for stmt in possible_stmts:
|
|
if isinstance(stmt, pr.Import):
|
|
continue
|
|
calls = helpers.scan_statement(stmt, func_name)
|
|
for c in calls:
|
|
# no execution means that params cannot be set
|
|
call_path = list(c.generate_call_path())
|
|
pos = c.start_pos
|
|
scope = stmt.parent
|
|
|
|
# this whole stuff is just to not execute certain parts
|
|
# (speed improvement), basically we could just call
|
|
# ``eval_call_path`` on the call_path and it would
|
|
# also work.
|
|
def listRightIndex(lst, value):
|
|
return len(lst) - lst[-1::-1].index(value) - 1
|
|
|
|
# Need to take right index, because there could be a
|
|
# func usage before.
|
|
i = listRightIndex(call_path, func_name)
|
|
first, last = call_path[:i], call_path[i + 1:]
|
|
if not last and not call_path.index(func_name) != i:
|
|
continue
|
|
scopes = [scope]
|
|
if first:
|
|
scopes = evaluator.eval_call_path(iter(first), scope, pos)
|
|
pos = None
|
|
from jedi.evaluate import representation as er
|
|
for scope in scopes:
|
|
s = evaluator.find_types(scope, func_name, position=pos,
|
|
search_global=not first,
|
|
resolve_decorator=False)
|
|
|
|
c = [getattr(escope, 'base_func', None) or escope.base
|
|
for escope in s
|
|
if escope.isinstance(er.Function, er.Class)]
|
|
if compare in c:
|
|
# only if we have the correct function we execute
|
|
# it, otherwise just ignore it.
|
|
evaluator.follow_path(iter(last), s, scope)
|
|
|
|
return listener.param_possibilities
|
|
|
|
result = []
|
|
for params in get_posibilities(evaluator, module, func_name):
|
|
for p in params:
|
|
if str(p) == param_name:
|
|
result += evaluator.eval_statement(p.parent)
|
|
return result
|
|
|
|
func = param.get_parent_until(pr.Function)
|
|
current_module = param.get_parent_until()
|
|
func_name = str(func.name)
|
|
compare = func
|
|
if func_name == '__init__' and isinstance(func.parent, pr.Class):
|
|
func_name = str(func.parent.name)
|
|
compare = func.parent
|
|
|
|
# get the param name
|
|
if param.assignment_details:
|
|
# first assignment details, others would be a syntax error
|
|
expression_list, op = param.assignment_details[0]
|
|
else:
|
|
expression_list = param.expression_list()
|
|
offset = 1 if expression_list[0] in ['*', '**'] else 0
|
|
param_name = str(expression_list[offset].name)
|
|
|
|
# add the listener
|
|
listener = ParamListener()
|
|
func.listeners.add(listener)
|
|
|
|
result = []
|
|
# This is like backtracking: Get the first possible result.
|
|
for mod in helpers.get_modules_containing_name([current_module], func_name):
|
|
result = get_params_for_module(mod)
|
|
if result:
|
|
break
|
|
|
|
# cleanup: remove the listener; important: should not stick.
|
|
func.listeners.remove(listener)
|
|
|
|
return result
|