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jedi-fork/jedi/evaluate/finder.py
2014-01-10 15:14:55 +01:00

363 lines
14 KiB
Python

import copy
from jedi._compatibility import hasattr, unicode, u
from jedi.parser import representation as pr
from jedi import debug
from jedi import common
from jedi import settings
from jedi.evaluate import representation as er
from jedi.evaluate import dynamic
from jedi.evaluate import compiled
from jedi.evaluate import docstrings
from jedi.evaluate import iterable
class NameFinder(object):
def __init__(self, evaluator, scope, name_str, position=None):
self._evaluator = evaluator
self.scope = scope
self.name_str = name_str
self.position = position
def find(self, scopes, resolve_decorator=True):
names = self.filter_name(scopes)
types = self._names_to_types(names, resolve_decorator)
debug.dbg('_names_to_types: %s, old: %s' % (names, types))
return self._resolve_descriptors(types)
def scopes(self, search_global=False):
if search_global:
return self._evaluator.get_names_of_scope(self.scope, self.position)
else:
if isinstance(self.scope, er.Instance):
return self.scope.scope_generator()
else:
if isinstance(self.scope, (er.Class, pr.Module)):
# classes are only available directly via chaining?
# strange stuff...
names = self.scope.get_defined_names()
else:
names = _get_defined_names_for_position(self.scope, self.position)
return iter([(self.scope, names)])
def filter_name(self, scope_generator):
"""
Filters all variables of a scope (which are defined in the
`scope_generator`), until the name fits.
"""
result = []
for nscope, name_list in scope_generator:
break_scopes = []
# here is the position stuff happening (sorting of variables)
for name in sorted(name_list, key=lambda n: n.start_pos, reverse=True):
p = name.parent.parent if name.parent else None
if isinstance(p, er.InstanceElement) \
and isinstance(p.var, pr.Class):
p = p.var
if self.name_str == name.get_code() and p not in break_scopes:
if not self._name_is_array_assignment(name):
result.append(name) # `arr[1] =` is not the definition
# for comparison we need the raw class
s = nscope.base if isinstance(nscope, er.Class) else nscope
# this means that a definition was found and is not e.g.
# in if/else.
if result and not self._name_is_no_break_scope(name):
if not name.parent or p == s:
break
break_scopes.append(p)
if result:
break
if not result and isinstance(self.scope, er.Instance):
# __getattr__ / __getattribute__
for r in self._check_getattr(self.scope):
if not isinstance(r, compiled.PyObject):
new_name = copy.copy(r.name)
new_name.parent = r
result.append(new_name)
debug.dbg('sfn filter "%s" in (%s-%s): %s@%s'
% (self.name_str, self.scope, nscope, u(result), self.position))
return result
def _check_getattr(self, inst):
"""Checks for both __getattr__ and __getattribute__ methods"""
result = []
# str is important to lose the NamePart!
name = compiled.create(str(self.name_str))
with common.ignored(KeyError):
result = inst.execute_subscope_by_name('__getattr__', [name])
if not result:
# this is a little bit special. `__getattribute__` is executed
# before anything else. But: I know no use case, where this
# could be practical and the jedi would return wrong types. If
# you ever have something, let me know!
with common.ignored(KeyError):
result = inst.execute_subscope_by_name('__getattribute__', [name])
return result
def _name_is_no_break_scope(self, name):
"""
Returns the parent of a name, which means the element which stands
behind a name.
"""
par = name.parent
if par.isinstance(pr.Statement):
details = par.assignment_details
if details and details[0][1] != '=':
return True
if isinstance(name, er.InstanceElement) \
and not name.is_class_var:
return True
elif isinstance(par, pr.Import) and len(par.namespace) > 1:
# TODO multi-level import non-breakable
return True
return False
def _name_is_array_assignment(self, name):
if name.parent.isinstance(pr.Statement):
def is_execution(calls):
for c in calls:
if isinstance(c, (unicode, str)):
continue
if c.isinstance(pr.Array):
if is_execution(c):
return True
elif c.isinstance(pr.Call):
# Compare start_pos, because names may be different
# because of executions.
if c.name.start_pos == name.start_pos \
and c.execution:
return True
return False
is_exe = False
for assignee, op in name.parent.assignment_details:
is_exe |= is_execution(assignee)
if is_exe:
# filter array[3] = ...
# TODO check executions for dict contents
return True
return False
def _names_to_types(self, names, resolve_decorator):
types = []
# Add isinstance and other if/assert knowledge.
flow_scope = self.scope
while flow_scope:
# TODO check if result is in scope -> no evaluation necessary
n = check_flow_information(self._evaluator, flow_scope,
self.name_str, self.position)
if n:
return n
flow_scope = flow_scope.parent
for name in names:
typ = name.parent
if typ.isinstance(pr.ForFlow):
types += self._handle_for_loops(typ)
elif isinstance(typ, pr.Param):
types += self._eval_param(typ)
elif typ.isinstance(pr.Statement):
types += self._remove_statements(typ)
else:
if isinstance(typ, pr.Class):
typ = er.Class(self._evaluator, typ)
elif isinstance(typ, pr.Function):
typ = er.Function(self._evaluator, typ)
if typ.isinstance(er.Function) and resolve_decorator:
typ = typ.get_decorated_func()
types.append(typ)
return types
def _remove_statements(self, stmt):
"""
This is the part where statements are being stripped.
Due to lazy evaluation, statements like a = func; b = a; b() have to be
evaluated.
"""
evaluator = self._evaluator
types = []
if stmt.is_global():
# global keyword handling.
for token_name in stmt.token_list[1:]:
if isinstance(token_name, pr.Name):
return evaluator.find_types(stmt.parent, str(token_name))
else:
# Remove the statement docstr stuff for now, that has to be
# implemented with the evaluator class.
#if stmt.docstr:
#res_new.append(stmt)
check_instance = None
if isinstance(stmt, er.InstanceElement) and stmt.is_class_var:
check_instance = stmt.instance
stmt = stmt.var
types += evaluator.eval_statement(stmt, seek_name=self.name_str)
if check_instance is not None:
# class renames
types = [er.InstanceElement(evaluator, check_instance, a, True)
if isinstance(a, (er.Function, pr.Function))
else a for a in types]
return types
def _eval_param(self, r):
evaluator = self._evaluator
res_new = []
func = r.parent
cls = func.parent.get_parent_until((pr.Class, pr.Function))
if isinstance(cls, pr.Class) and r.position_nr == 0:
# This is where we add self - if it has never been
# instantiated.
if isinstance(self.scope, er.InstanceElement):
res_new.append(self.scope.instance)
else:
for inst in evaluator.execute(er.Class(evaluator, cls)):
inst.is_generated = True
res_new.append(inst)
return res_new
# Instances are typically faked, if the instance is not called from
# outside. Here we check it for __init__ functions and return.
if isinstance(func, er.InstanceElement) \
and func.instance.is_generated and str(func.name) == '__init__':
r = func.var.params[r.position_nr]
# Add docstring knowledge.
doc_params = docstrings.follow_param(evaluator, r)
if doc_params:
return doc_params
if not r.is_generated:
# Param owns no information itself.
res_new += dynamic.search_params(evaluator, r)
if not res_new:
c = r.expression_list()[0]
if c in ('*', '**'):
t = 'tuple' if c == '*' else 'dict'
typ = evaluator.find_types(compiled.builtin, t)[0]
res_new = evaluator.execute(typ)
if not r.assignment_details:
# this means that there are no default params,
# so just ignore it.
return res_new
return set(res_new) | evaluator.eval_statement(r, seek_name=self.name_str)
def _handle_for_loops(self, loop):
# Take the first statement (for has always only
# one, remember `in`). And follow it.
if not loop.inputs:
return []
result = iterable.get_iterator_types(self._evaluator.eval_statement(loop.inputs[0]))
if len(loop.set_vars) > 1:
expression_list = loop.set_stmt.expression_list()
# loops with loop.set_vars > 0 only have one command
from jedi import evaluate
result = evaluate._assign_tuples(expression_list[0], result, self.name_str)
return result
def _resolve_descriptors(self, types):
"""Processes descriptors"""
result = []
for r in types:
if isinstance(self.scope, (er.Instance, er.Class)) \
and hasattr(r, 'get_descriptor_return'):
# handle descriptors
with common.ignored(KeyError):
result += r.get_descriptor_return(self.scope)
continue
result.append(r)
return result
def check_flow_information(evaluator, flow, search_name, pos):
""" Try to find out the type of a variable just with the information that
is given by the flows: e.g. It is also responsible for assert checks.::
if isinstance(k, str):
k. # <- completion here
ensures that `k` is a string.
"""
if not settings.dynamic_flow_information:
return None
result = []
if isinstance(flow, pr.IsScope) and not result:
for ass in reversed(flow.asserts):
if pos is None or ass.start_pos > pos:
continue
result = _check_isinstance_type(evaluator, ass, search_name)
if result:
break
if isinstance(flow, pr.Flow) and not result:
if flow.command in ['if', 'while'] and len(flow.inputs) == 1:
result = _check_isinstance_type(evaluator, flow.inputs[0], search_name)
return result
def _check_isinstance_type(evaluator, stmt, search_name):
try:
expression_list = stmt.expression_list()
# this might be removed if we analyze and, etc
assert len(expression_list) == 1
call = expression_list[0]
assert isinstance(call, pr.Call) and str(call.name) == 'isinstance'
assert bool(call.execution)
# isinstance check
isinst = call.execution.values
assert len(isinst) == 2 # has two params
obj, classes = [statement.expression_list() for statement in isinst]
assert len(obj) == 1
assert len(classes) == 1
assert isinstance(obj[0], pr.Call)
# names fit?
assert str(obj[0].name) == search_name
assert isinstance(classes[0], pr.StatementElement) # can be type or tuple
except AssertionError:
return []
result = []
for c in evaluator.eval_call(classes[0]):
for typ in (c.get_index_types() if isinstance(c, iterable.Array) else [c]):
result += evaluator.execute(typ)
return result
def _get_defined_names_for_position(scope, position=None, start_scope=None):
"""
Return filtered version of ``scope.get_defined_names()``.
This function basically does what :meth:`scope.get_defined_names
<parsing_representation.Scope.get_defined_names>` does.
- If `position` is given, delete all names defined after `position`.
- For special objects like instances, `position` is ignored and all
names are returned.
:type scope: :class:`parsing_representation.IsScope`
:param scope: Scope in which names are searched.
:param position: The position as a line/column tuple, default is infinity.
"""
names = scope.get_defined_names()
# Instances have special rules, always return all the possible completions,
# because class variables are always valid and the `self.` variables, too.
if (not position or isinstance(scope, (iterable.Array, er.Instance))
or start_scope != scope
and isinstance(start_scope, (pr.Function, er.FunctionExecution))):
return names
names_new = []
for n in names:
if n.start_pos[0] is not None and n.start_pos < position:
names_new.append(n)
return names_new