""" If you know what an abstract syntax tree (AST) is, you'll see that this module is pretty much that. The classes represent syntax elements like functions and imports. This is the "business logic" part of the parser. There's a lot of logic here that makes it easier for Jedi (and other libraries to deal with a Python syntax tree. By using `get_code` on a module, you can get back the 1-to-1 representation of the input given to the parser. This is important if you are using refactoring. The easiest way to play with this module is to use :class:`parsing.Parser`. :attr:`parsing.Parser.module` holds an instance of :class:`Module`: >>> from jedi._compatibility import u >>> from jedi.parser import Parser, load_grammar >>> parser = Parser(load_grammar(), u('import os'), 'example.py') >>> submodule = parser.module >>> submodule Any subclasses of :class:`Scope`, including :class:`Module` has an attribute :attr:`imports `: >>> submodule.imports [] See also :attr:`Scope.subscopes` and :attr:`Scope.statements`. """ import os import re from inspect import cleandoc from itertools import chain import textwrap from jedi._compatibility import (Python3Method, encoding, is_py3, utf8_repr, literal_eval, use_metaclass, unicode) from jedi import cache def is_node(node, *symbol_names): try: type = node.type except AttributeError: return False else: return type in symbol_names class PositionModifier(object): """A start_pos modifier for the fast parser.""" def __init__(self): self.line = 0 zero_position_modifier = PositionModifier() class DocstringMixin(object): __slots__ = () @property def raw_doc(self): """ Returns a cleaned version of the docstring token. """ if isinstance(self, Module): node = self.children[0] elif isinstance(self, ClassOrFunc): node = self.children[self.children.index(':') + 1] if is_node(node, 'suite'): # Normally a suite node = node.children[2] # -> NEWLINE INDENT stmt else: # ExprStmt simple_stmt = self.parent c = simple_stmt.parent.children index = c.index(simple_stmt) if not index: return '' node = c[index - 1] if is_node(node, 'simple_stmt'): node = node.children[0] if node.type == 'string': # TODO We have to check next leaves until there are no new # leaves anymore that might be part of the docstring. A # docstring can also look like this: ``'foo' 'bar' # Returns a literal cleaned version of the ``Token``. cleaned = cleandoc(literal_eval(node.value)) # Since we want the docstr output to be always unicode, just # force it. if is_py3 or isinstance(cleaned, unicode): return cleaned else: return unicode(cleaned, 'UTF-8', 'replace') return '' class Base(object): """ This is just here to have an isinstance check, which is also used on evaluate classes. But since they have sometimes a special type of delegation, it is important for those classes to override this method. I know that there is a chance to do such things with __instancecheck__, but since Python 2.5 doesn't support it, I decided to do it this way. """ __slots__ = () def isinstance(self, *cls): return isinstance(self, cls) @Python3Method def get_parent_until(self, classes=(), reverse=False, include_current=True): """ Searches the parent "chain" until the object is an instance of classes. If classes is empty return the last parent in the chain (is without a parent). """ if type(classes) not in (tuple, list): classes = (classes,) scope = self if include_current else self.parent while scope.parent is not None: # TODO why if classes? if classes and reverse != scope.isinstance(*classes): break scope = scope.parent return scope def get_parent_scope(self, include_flows=False): """ Returns the underlying scope. """ scope = self.parent while scope is not None: if include_flows and isinstance(scope, Flow): return scope if scope.is_scope(): break scope = scope.parent return scope def is_scope(self): # Default is not being a scope. Just inherit from Scope. return False class Leaf(Base): __slots__ = ('position_modifier', 'value', 'parent', '_start_pos', 'prefix') def __init__(self, position_modifier, value, start_pos, prefix=''): self.position_modifier = position_modifier self.value = value self._start_pos = start_pos self.prefix = prefix self.parent = None @property def start_pos(self): return self._start_pos[0] + self.position_modifier.line, self._start_pos[1] @start_pos.setter def start_pos(self, value): self._start_pos = value[0] - self.position_modifier.line, value[1] @property def end_pos(self): return (self._start_pos[0] + self.position_modifier.line, self._start_pos[1] + len(self.value)) def move(self, line_offset, column_offset): self._start_pos = (self._start_pos[0] + line_offset, self._start_pos[1] + column_offset) def get_previous(self): """ Returns the previous leaf in the parser tree. """ node = self while True: c = node.parent.children i = c.index(self) if i == 0: node = node.parent if node.parent is None: raise IndexError('Cannot access the previous element of the first one.') else: node = c[i - 1] break while True: try: node = node.children[-1] except AttributeError: # A Leaf doesn't have children. return node def get_code(self): return self.prefix + self.value def next_sibling(self): """ The node immediately following the invocant in their parent's children list. If the invocant does not have a next sibling, it is None """ # Can't use index(); we need to test by identity for i, child in enumerate(self.parent.children): if child is self: try: return self.parent.children[i + 1] except IndexError: return None def prev_sibling(self): """ The node/leaf immediately preceding the invocant in their parent's children list. If the invocant does not have a previous sibling, it is None. """ # Can't use index(); we need to test by identity for i, child in enumerate(self.parent.children): if child is self: if i == 0: return None return self.parent.children[i - 1] @utf8_repr def __repr__(self): return "<%s: %s>" % (type(self).__name__, self.value) class LeafWithNewLines(Leaf): __slots__ = () @property def end_pos(self): """ Literals and whitespace end_pos are more complicated than normal end_pos, because the containing newlines may change the indexes. """ end_pos_line, end_pos_col = self.start_pos lines = self.value.split('\n') end_pos_line += len(lines) - 1 # Check for multiline token if self.start_pos[0] == end_pos_line: end_pos_col += len(lines[-1]) else: end_pos_col = len(lines[-1]) return end_pos_line, end_pos_col class Whitespace(LeafWithNewLines): """Contains NEWLINE and ENDMARKER tokens.""" __slots__ = () type = 'whitespace' class Name(Leaf): """ A string. Sometimes it is important to know if the string belongs to a name or not. """ type = 'name' __slots__ = () def __str__(self): return self.value def __unicode__(self): return self.value def __repr__(self): return "<%s: %s@%s,%s>" % (type(self).__name__, self.value, self.start_pos[0], self.start_pos[1]) def get_definition(self): scope = self while scope.parent is not None: parent = scope.parent if scope.isinstance(Node, Name) and parent.type != 'simple_stmt': if scope.type == 'testlist_comp': try: if isinstance(scope.children[1], CompFor): return scope.children[1] except IndexError: pass scope = parent else: break return scope def is_definition(self): stmt = self.get_definition() if stmt.type in ('funcdef', 'classdef', 'file_input', 'param'): return self == stmt.name elif stmt.type == 'for_stmt': return self.start_pos < stmt.children[2].start_pos elif stmt.type == 'try_stmt': return self.prev_sibling() == 'as' else: return stmt.type in ('expr_stmt', 'import_name', 'import_from', 'comp_for', 'with_stmt') \ and self in stmt.get_defined_names() def assignment_indexes(self): """ Returns an array of ints of the indexes that are used in tuple assignments. For example if the name is ``y`` in the following code:: x, (y, z) = 2, '' would result in ``[1, 0]``. """ indexes = [] node = self.parent compare = self while node is not None: if is_node(node, 'testlist_comp', 'testlist_star_expr', 'exprlist'): for i, child in enumerate(node.children): if child == compare: indexes.insert(0, int(i / 2)) break else: raise LookupError("Couldn't find the assignment.") elif isinstance(node, (ExprStmt, CompFor)): break compare = node node = node.parent return indexes class Literal(LeafWithNewLines): __slots__ = () def eval(self): return literal_eval(self.value) class Number(Literal): type = 'number' __slots__ = () class String(Literal): type = 'string' __slots__ = () class Operator(Leaf): type = 'operator' __slots__ = () def __str__(self): return self.value def __eq__(self, other): """ Make comparisons with strings easy. Improves the readability of the parser. """ if isinstance(other, Operator): return self is other else: return self.value == other def __ne__(self, other): """Python 2 compatibility.""" return self.value != other def __hash__(self): return hash(self.value) class Keyword(Leaf): type = 'keyword' __slots__ = () def __eq__(self, other): """ Make comparisons with strings easy. Improves the readability of the parser. """ if isinstance(other, Keyword): return self is other return self.value == other def __ne__(self, other): """Python 2 compatibility.""" return not self.__eq__(other) def __hash__(self): return hash(self.value) class BaseNode(Base): """ The super class for Scope, Import, Name and Statement. Every object in the parser tree inherits from this class. """ __slots__ = ('children', 'parent') type = None def __init__(self, children): """ Initialize :class:`BaseNode`. :param children: The module in which this Python object locates. """ for c in children: c.parent = self self.children = children self.parent = None def move(self, line_offset, column_offset): """ Move the Node's start_pos. """ for c in self.children: c.move(line_offset, column_offset) @property def start_pos(self): return self.children[0].start_pos @property def end_pos(self): return self.children[-1].end_pos def get_code(self): return "".join(c.get_code() for c in self.children) @Python3Method def name_for_position(self, position): for c in self.children: if isinstance(c, Leaf): if isinstance(c, Name) and c.start_pos <= position <= c.end_pos: return c else: result = c.name_for_position(position) if result is not None: return result return None @Python3Method def get_statement_for_position(self, pos): for c in self.children: if c.start_pos <= pos <= c.end_pos: if c.type not in ('decorated', 'simple_stmt', 'suite') \ and not isinstance(c, (Flow, ClassOrFunc)): return c else: try: return c.get_statement_for_position(pos) except AttributeError: pass # Must be a non-scope return None def first_leaf(self): try: return self.children[0].first_leaf() except AttributeError: return self.children[0] @utf8_repr def __repr__(self): code = self.get_code().replace('\n', ' ') if not is_py3: code = code.encode(encoding, 'replace') return "<%s: %s@%s,%s>" % \ (type(self).__name__, code, self.start_pos[0], self.start_pos[1]) class Node(BaseNode): """Concrete implementation for interior nodes.""" __slots__ = ('type',) def __init__(self, type, children): """ Initializer. Takes a type constant (a symbol number >= 256), a sequence of child nodes, and an optional context keyword argument. As a side effect, the parent pointers of the children are updated. """ super(Node, self).__init__(children) self.type = type def __repr__(self): return "%s(%s, %r)" % (self.__class__.__name__, self.type, self.children) class IsScopeMeta(type): def __instancecheck__(self, other): return other.is_scope() class IsScope(use_metaclass(IsScopeMeta)): pass class Scope(BaseNode, DocstringMixin): """ Super class for the parser tree, which represents the state of a python text file. A Scope manages and owns its subscopes, which are classes and functions, as well as variables and imports. It is used to access the structure of python files. :param start_pos: The position (line and column) of the scope. :type start_pos: tuple(int, int) """ __slots__ = ('names_dict',) def __init__(self, children): super(Scope, self).__init__(children) @property def returns(self): # Needed here for fast_parser, because the fast_parser splits and # returns will be in "normal" modules. return self._search_in_scope(ReturnStmt) @property def subscopes(self): return self._search_in_scope(Scope) @property def flows(self): return self._search_in_scope(Flow) @property def imports(self): return self._search_in_scope(Import) @Python3Method def _search_in_scope(self, typ): def scan(children): elements = [] for element in children: if isinstance(element, typ): elements.append(element) if is_node(element, 'suite', 'simple_stmt', 'decorated') \ or isinstance(element, Flow): elements += scan(element.children) return elements return scan(self.children) @property def statements(self): return self._search_in_scope((ExprStmt, KeywordStatement)) def is_scope(self): return True def __repr__(self): try: name = self.path except AttributeError: try: name = self.name except AttributeError: name = self.command return "<%s: %s@%s-%s>" % (type(self).__name__, name, self.start_pos[0], self.end_pos[0]) def walk(self): yield self for s in self.subscopes: for scope in s.walk(): yield scope for r in self.statements: while isinstance(r, Flow): for scope in r.walk(): yield scope r = r.next class Module(Scope): """ The top scope, which is always a module. Depending on the underlying parser this may be a full module or just a part of a module. """ __slots__ = ('path', 'global_names', 'used_names', '_name', 'error_statement_stacks') type = 'file_input' def __init__(self, children): """ Initialize :class:`Module`. :type path: str :arg path: File path to this module. .. todo:: Document `top_module`. """ super(Module, self).__init__(children) self.path = None # Set later. @property @cache.underscore_memoization def name(self): """ This is used for the goto functions. """ if self.path is None: string = '' # no path -> empty name else: sep = (re.escape(os.path.sep),) * 2 r = re.search(r'([^%s]*?)(%s__init__)?(\.py|\.so)?$' % sep, self.path) # Remove PEP 3149 names string = re.sub('\.[a-z]+-\d{2}[mud]{0,3}$', '', r.group(1)) # Positions are not real, but a module starts at (1, 0) p = (1, 0) name = Name(zero_position_modifier, string, p) name.parent = self return name @property def has_explicit_absolute_import(self): """ Checks if imports in this module are explicitly absolute, i.e. there is a ``__future__`` import. """ # TODO this is a strange scan and not fully correct. I think Python's # parser does it in a different way and scans for the first # statement/import with a tokenizer (to check for syntax changes like # the future print statement). for imp in self.imports: if imp.type == 'import_from' and imp.level == 0: for path in imp.paths(): if [str(name) for name in path] == ['__future__', 'absolute_import']: return True return False class Decorator(BaseNode): type = 'decorator' __slots__ = () class ClassOrFunc(Scope): __slots__ = () @property def name(self): return self.children[1] def get_decorators(self): decorated = self.parent if is_node(decorated, 'decorated'): if is_node(decorated.children[0], 'decorators'): return decorated.children[0].children else: return decorated.children[:1] else: return [] class Class(ClassOrFunc): """ Used to store the parsed contents of a python class. :param name: The Class name. :type name: str :param supers: The super classes of a Class. :type supers: list :param start_pos: The start position (line, column) of the class. :type start_pos: tuple(int, int) """ type = 'classdef' __slots__ = () def __init__(self, children): super(Class, self).__init__(children) def get_super_arglist(self): if self.children[2] != '(': # Has no parentheses return None else: if self.children[3] == ')': # Empty parentheses return None else: return self.children[3] @property def doc(self): """ Return a document string including call signature of __init__. """ docstr = self.raw_doc for sub in self.subscopes: if str(sub.name) == '__init__': return '%s\n\n%s' % ( sub.get_call_signature(func_name=self.name), docstr) return docstr def _create_params(parent, argslist_list): """ `argslist_list` is a list that can contain an argslist as a first item, but most not. It's basically the items between the parameter brackets (which is at most one item). This function modifies the parser structure. It generates `Param` objects from the normal ast. Those param objects do not exist in a normal ast, but make the evaluation of the ast tree so much easier. You could also say that this function replaces the argslist node with a list of Param objects. """ def check_python2_nested_param(node): """ Python 2 allows params to look like ``def x(a, (b, c))``, which is basically a way of unpacking tuples in params. Python 3 has ditched this behavior. Jedi currently just ignores those constructs. """ return node.type == 'tfpdef' and node.children[0] == '(' try: first = argslist_list[0] except IndexError: return [] if first.type in ('name', 'tfpdef'): if check_python2_nested_param(first): return [] else: return [Param([first], parent)] else: # argslist is a `typedargslist` or a `varargslist`. children = first.children params = [] start = 0 # Start with offset 1, because the end is higher. for end, child in enumerate(children + [None], 1): if child is None or child == ',': new_children = children[start:end] if new_children: # Could as well be comma and then end. if check_python2_nested_param(new_children[0]): continue params.append(Param(new_children, parent)) start = end return params class Function(ClassOrFunc): """ Used to store the parsed contents of a python function. """ __slots__ = ('listeners',) type = 'funcdef' def __init__(self, children): super(Function, self).__init__(children) self.listeners = set() # not used here, but in evaluation. parameters = self.children[2] # After `def foo` parameters.children[1:-1] = _create_params(parameters, parameters.children[1:-1]) @property def params(self): return self.children[2].children[1:-1] @property def name(self): return self.children[1] # First token after `def` @property def yields(self): # TODO This is incorrect, yields are also possible in a statement. return self._search_in_scope(YieldExpr) def is_generator(self): return bool(self.yields) def annotation(self): try: return self.children[6] # 6th element: def foo(...) -> bar except IndexError: return None def get_call_signature(self, width=72, func_name=None): """ Generate call signature of this function. :param width: Fold lines if a line is longer than this value. :type width: int :arg func_name: Override function name when given. :type func_name: str :rtype: str """ func_name = func_name or self.children[1] code = unicode(func_name) + self.children[2].get_code() return '\n'.join(textwrap.wrap(code, width)) @property def doc(self): """ Return a document string including call signature. """ docstr = self.raw_doc return '%s\n\n%s' % (self.get_call_signature(), docstr) class Lambda(Function): """ Lambdas are basically trimmed functions, so give it the same interface. """ type = 'lambda' __slots__ = () def __init__(self, children): # We don't want to call the Function constructor, call its parent. super(Function, self).__init__(children) self.listeners = set() # not used here, but in evaluation. lst = self.children[1:-2] # After `def foo` self.children[1:-2] = _create_params(self, lst) @property def params(self): return self.children[1:-2] def is_generator(self): return False def yields(self): return [] def __repr__(self): return "<%s@%s>" % (self.__class__.__name__, self.start_pos) class Flow(BaseNode): __slots__ = () class IfStmt(Flow): type = 'if_stmt' __slots__ = () def check_nodes(self): """ Returns all the `test` nodes that are defined as x, here: if x: pass elif x: pass """ for i, c in enumerate(self.children): if c in ('elif', 'if'): yield self.children[i + 1] def node_in_which_check_node(self, node): for check_node in reversed(list(self.check_nodes())): if check_node.start_pos < node.start_pos: return check_node def node_after_else(self, node): """ Checks if a node is defined after `else`. """ for c in self.children: if c == 'else': if node.start_pos > c.start_pos: return True else: return False class WhileStmt(Flow): type = 'while_stmt' __slots__ = () class ForStmt(Flow): type = 'for_stmt' __slots__ = () class TryStmt(Flow): type = 'try_stmt' __slots__ = () def except_clauses(self): """ Returns the ``test`` nodes found in ``except_clause`` nodes. Returns ``[None]`` for except clauses without an exception given. """ for node in self.children: if node.type == 'except_clause': yield node.children[1] elif node == 'except': yield None class WithStmt(Flow): type = 'with_stmt' __slots__ = () def get_defined_names(self): names = [] for with_item in self.children[1:-2:2]: # Check with items for 'as' names. if is_node(with_item, 'with_item'): names += _defined_names(with_item.children[2]) return names def node_from_name(self, name): node = name while True: node = node.parent if is_node(node, 'with_item'): return node.children[0] class Import(BaseNode): __slots__ = () def path_for_name(self, name): try: # The name may be an alias. If it is, just map it back to the name. name = self.aliases()[name] except KeyError: pass for path in self.paths(): if name in path: return path[:path.index(name) + 1] raise ValueError('Name should be defined in the import itself') def is_nested(self): return False # By default, sub classes may overwrite this behavior def is_star_import(self): return self.children[-1] == '*' class ImportFrom(Import): type = 'import_from' __slots__ = () def get_defined_names(self): return [alias or name for name, alias in self._as_name_tuples()] def aliases(self): """Mapping from alias to its corresponding name.""" return dict((alias, name) for name, alias in self._as_name_tuples() if alias is not None) def get_from_names(self): for n in self.children[1:]: if n not in ('.', '...'): break if is_node(n, 'dotted_name'): # from x.y import return n.children[::2] elif n == 'import': # from . import return [] else: # from x import return [n] @property def level(self): """The level parameter of ``__import__``.""" level = 0 for n in self.children[1:]: if n in ('.', '...'): level += len(n.value) else: break return level def _as_name_tuples(self): last = self.children[-1] if last == ')': last = self.children[-2] elif last == '*': return # No names defined directly. if is_node(last, 'import_as_names'): as_names = last.children[::2] else: as_names = [last] for as_name in as_names: if as_name.type == 'name': yield as_name, None else: yield as_name.children[::2] # yields x, y -> ``x as y`` def star_import_name(self): """ The last name defined in a star import. """ return self.paths()[-1][-1] def paths(self): """ The import paths defined in an import statement. Typically an array like this: ``[, ]``. """ dotted = self.get_from_names() if self.children[-1] == '*': return [dotted] return [dotted + [name] for name, alias in self._as_name_tuples()] class ImportName(Import): """For ``import_name`` nodes. Covers normal imports without ``from``.""" type = 'import_name' __slots__ = () def get_defined_names(self): return [alias or path[0] for path, alias in self._dotted_as_names()] @property def level(self): """The level parameter of ``__import__``.""" return 0 # Obviously 0 for imports without from. def paths(self): return [path for path, alias in self._dotted_as_names()] def _dotted_as_names(self): """Generator of (list(path), alias) where alias may be None.""" dotted_as_names = self.children[1] if is_node(dotted_as_names, 'dotted_as_names'): as_names = dotted_as_names.children[::2] else: as_names = [dotted_as_names] for as_name in as_names: if is_node(as_name, 'dotted_as_name'): alias = as_name.children[2] as_name = as_name.children[0] else: alias = None if as_name.type == 'name': yield [as_name], alias else: # dotted_names yield as_name.children[::2], alias def is_nested(self): """ This checks for the special case of nested imports, without aliases and from statement:: import foo.bar """ return [1 for path, alias in self._dotted_as_names() if alias is None and len(path) > 1] def aliases(self): return dict((alias, path[-1]) for path, alias in self._dotted_as_names() if alias is not None) class KeywordStatement(BaseNode): """ For the following statements: `assert`, `del`, `global`, `nonlocal`, `raise`, `return`, `yield`, `pass`, `continue`, `break`, `return`, `yield`. """ __slots__ = () @property def keyword(self): return self.children[0].value class AssertStmt(KeywordStatement): type = 'assert_stmt' __slots__ = () def assertion(self): return self.children[1] class GlobalStmt(KeywordStatement): type = 'global_stmt' __slots__ = () def get_defined_names(self): return [] def get_global_names(self): return self.children[1::2] class ReturnStmt(KeywordStatement): type = 'return_stmt' __slots__ = () class YieldExpr(BaseNode): type = 'yield_expr' __slots__ = () def _defined_names(current): """ A helper function to find the defined names in statements, for loops and list comprehensions. """ names = [] if is_node(current, 'testlist_star_expr', 'testlist_comp', 'exprlist'): for child in current.children[::2]: names += _defined_names(child) elif is_node(current, 'atom'): names += _defined_names(current.children[1]) elif is_node(current, 'power'): if current.children[-2] != '**': # Just if there's no operation trailer = current.children[-1] if trailer.children[0] == '.': names.append(trailer.children[1]) else: names.append(current) return names class ExprStmt(BaseNode, DocstringMixin): type = 'expr_stmt' __slots__ = () def get_defined_names(self): return list(chain.from_iterable(_defined_names(self.children[i]) for i in range(0, len(self.children) - 2, 2) if '=' in self.children[i + 1].value)) def get_rhs(self): """Returns the right-hand-side of the equals.""" return self.children[-1] def first_operation(self): """ Returns `+=`, `=`, etc or None if there is no operation. """ try: return self.children[1] except IndexError: return None class Param(BaseNode): """ It's a helper class that makes business logic with params much easier. The Python grammar defines no ``param`` node. It defines it in a different way that is not really suited to working with parameters. """ type = 'param' def __init__(self, children, parent): super(Param, self).__init__(children) self.parent = parent for child in children: child.parent = self @property def stars(self): first = self.children[0] if first in ('*', '**'): return len(first.value) return 0 @property def default(self): try: return self.children[int(self.children[0] in ('*', '**')) + 2] except IndexError: return None def annotation(self): # Generate from tfpdef. raise NotImplementedError def _tfpdef(self): """ tfpdef: see grammar.txt. """ offset = int(self.children[0] in ('*', '**')) return self.children[offset] @property def name(self): if is_node(self._tfpdef(), 'tfpdef'): return self._tfpdef().children[0] else: return self._tfpdef() @property def position_nr(self): return self.parent.children.index(self) - 1 @property def parent_function(self): return self.get_parent_until(IsScope) def __repr__(self): default = '' if self.default is None else '=%s' % self.default return '<%s: %s>' % (type(self).__name__, str(self._tfpdef()) + default) class CompFor(BaseNode): type = 'comp_for' __slots__ = () def is_scope(self): return True @property def names_dict(self): dct = {} for name in self.get_defined_names(): arr = dct.setdefault(name.value, []) arr.append(name) return dct def names_dicts(self, search_global): yield self.names_dict def get_defined_names(self): return _defined_names(self.children[1])