djavu-asus/elpy/rpc-venv/lib/python3.11/site-packages/jedi/inference/finder.py

   1 """
   2 Searching for names with given scope and name. This is very central in Jedi and
   3 Python. The name resolution is quite complicated with descripter,
   4 ``__getattribute__``, ``__getattr__``, ``global``, etc.
   5
   6 If you want to understand name resolution, please read the first few chapters
   7 in http://blog.ionelmc.ro/2015/02/09/understanding-python-metaclasses/.
   8
   9 Flow checks
  10 +++++++++++
  11
  12 Flow checks are not really mature. There's only a check for ``isinstance``.  It
  13 would check whether a flow has the form of ``if isinstance(a, type_or_tuple)``.
  14 Unfortunately every other thing is being ignored (e.g. a == '' would be easy to
  15 check for -> a is a string). There's big potential in these checks.
  16 """
  17
  18 from parso.tree import search_ancestor
  19 from parso.python.tree import Name
  20
  21 from jedi import settings
  22 from jedi.inference.arguments import TreeArguments
  23 from jedi.inference.value import iterable
  24 from jedi.inference.base_value import NO_VALUES
  25 from jedi.parser_utils import is_scope
  26
  27
  28 def filter_name(filters, name_or_str):
  29     """
  30     Searches names that are defined in a scope (the different
  31     ``filters``), until a name fits.
  32     """
  33     string_name = name_or_str.value if isinstance(name_or_str, Name) else name_or_str
  34     names = []
  35     for filter in filters:
  36         names = filter.get(string_name)
  37         if names:
  38             break
  39
  40     return list(_remove_del_stmt(names))
  41
  42
  43 def _remove_del_stmt(names):
  44     # Catch del statements and remove them from results.
  45     for name in names:
  46         if name.tree_name is not None:
  47             definition = name.tree_name.get_definition()
  48             if definition is not None and definition.type == 'del_stmt':
  49                 continue
  50         yield name
  51
  52
  53 def check_flow_information(value, flow, search_name, pos):
  54     """ Try to find out the type of a variable just with the information that
  55     is given by the flows: e.g. It is also responsible for assert checks.::
  56
  57         if isinstance(k, str):
  58             k.  # <- completion here
  59
  60     ensures that `k` is a string.
  61     """
  62     if not settings.dynamic_flow_information:
  63         return None
  64
  65     result = None
  66     if is_scope(flow):
  67         # Check for asserts.
  68         module_node = flow.get_root_node()
  69         try:
  70             names = module_node.get_used_names()[search_name.value]
  71         except KeyError:
  72             return None
  73         names = reversed([
  74             n for n in names
  75             if flow.start_pos <= n.start_pos < (pos or flow.end_pos)
  76         ])
  77
  78         for name in names:
  79             ass = search_ancestor(name, 'assert_stmt')
  80             if ass is not None:
  81                 result = _check_isinstance_type(value, ass.assertion, search_name)
  82                 if result is not None:
  83                     return result
  84
  85     if flow.type in ('if_stmt', 'while_stmt'):
  86         potential_ifs = [c for c in flow.children[1::4] if c != ':']
  87         for if_test in reversed(potential_ifs):
  88             if search_name.start_pos > if_test.end_pos:
  89                 return _check_isinstance_type(value, if_test, search_name)
  90     return result
  91
  92
  93 def _get_isinstance_trailer_arglist(node):
  94     if node.type in ('power', 'atom_expr') and len(node.children) == 2:
  95         # This might be removed if we analyze and, etc
  96         first, trailer = node.children
  97         if first.type == 'name' and first.value == 'isinstance' \
  98                 and trailer.type == 'trailer' and trailer.children[0] == '(':
  99             return trailer
 100     return None
 101
 102
 103 def _check_isinstance_type(value, node, search_name):
 104     lazy_cls = None
 105     trailer = _get_isinstance_trailer_arglist(node)
 106     if trailer is not None and len(trailer.children) == 3:
 107         arglist = trailer.children[1]
 108         args = TreeArguments(value.inference_state, value, arglist, trailer)
 109         param_list = list(args.unpack())
 110         # Disallow keyword arguments
 111         if len(param_list) == 2 and len(arglist.children) == 3:
 112             (key1, _), (key2, lazy_value_cls) = param_list
 113             if key1 is None and key2 is None:
 114                 call = _get_call_string(search_name)
 115                 is_instance_call = _get_call_string(arglist.children[0])
 116                 # Do a simple get_code comparison of the strings . They should
 117                 # just have the same code, and everything will be all right.
 118                 # There are ways that this is not correct, if some stuff is
 119                 # redefined in between. However here we don't care, because
 120                 # it's a heuristic that works pretty well.
 121                 if call == is_instance_call:
 122                     lazy_cls = lazy_value_cls
 123     if lazy_cls is None:
 124         return None
 125
 126     value_set = NO_VALUES
 127     for cls_or_tup in lazy_cls.infer():
 128         if isinstance(cls_or_tup, iterable.Sequence) and cls_or_tup.array_type == 'tuple':
 129             for lazy_value in cls_or_tup.py__iter__():
 130                 value_set |= lazy_value.infer().execute_with_values()
 131         else:
 132             value_set |= cls_or_tup.execute_with_values()
 133     return value_set
 134
 135
 136 def _get_call_string(node):
 137     if node.parent.type == 'atom_expr':
 138         return _get_call_string(node.parent)
 139
 140     code = ''
 141     leaf = node.get_first_leaf()
 142     end = node.get_last_leaf().end_pos
 143     while leaf.start_pos < end:
 144         code += leaf.value
 145         leaf = leaf.get_next_leaf()
 146     return code