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- from abc import abstractmethod, abstractproperty
- from parso._compatibility import utf8_repr, encoding, py_version
-
-
- def search_ancestor(node, *node_types):
- """
- Recursively looks at the parents of a node and returns the first found node
- that matches node_types. Returns ``None`` if no matching node is found.
-
- :param node: The ancestors of this node will be checked.
- :param node_types: type names that are searched for.
- :type node_types: tuple of str
- """
- while True:
- node = node.parent
- if node is None or node.type in node_types:
- return node
-
-
- class NodeOrLeaf(object):
- """
- The base class for nodes and leaves.
- """
- __slots__ = ()
- type = None
- '''
- The type is a string that typically matches the types of the grammar file.
- '''
-
- def get_root_node(self):
- """
- Returns the root node of a parser tree. The returned node doesn't have
- a parent node like all the other nodes/leaves.
- """
- scope = self
- while scope.parent is not None:
- scope = scope.parent
- return scope
-
- def get_next_sibling(self):
- """
- Returns the node immediately following this node in this parent's
- children list. If this node 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 get_previous_sibling(self):
- """
- Returns the node immediately preceding this node in this parent's
- children list. If this node 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]
-
- def get_previous_leaf(self):
- """
- Returns the previous leaf in the parser tree.
- Returns `None` if this is the first element in the parser tree.
- """
- node = self
- while True:
- c = node.parent.children
- i = c.index(node)
- if i == 0:
- node = node.parent
- if node.parent is None:
- return None
- 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_next_leaf(self):
- """
- Returns the next leaf in the parser tree.
- Returns None if this is the last element in the parser tree.
- """
- node = self
- while True:
- c = node.parent.children
- i = c.index(node)
- if i == len(c) - 1:
- node = node.parent
- if node.parent is None:
- return None
- else:
- node = c[i + 1]
- break
-
- while True:
- try:
- node = node.children[0]
- except AttributeError: # A Leaf doesn't have children.
- return node
-
- @abstractproperty
- def start_pos(self):
- """
- Returns the starting position of the prefix as a tuple, e.g. `(3, 4)`.
-
- :return tuple of int: (line, column)
- """
-
- @abstractproperty
- def end_pos(self):
- """
- Returns the end position of the prefix as a tuple, e.g. `(3, 4)`.
-
- :return tuple of int: (line, column)
- """
-
- @abstractmethod
- def get_start_pos_of_prefix(self):
- """
- Returns the start_pos of the prefix. This means basically it returns
- the end_pos of the last prefix. The `get_start_pos_of_prefix()` of the
- prefix `+` in `2 + 1` would be `(1, 1)`, while the start_pos is
- `(1, 2)`.
-
- :return tuple of int: (line, column)
- """
-
- @abstractmethod
- def get_first_leaf(self):
- """
- Returns the first leaf of a node or itself if this is a leaf.
- """
-
- @abstractmethod
- def get_last_leaf(self):
- """
- Returns the last leaf of a node or itself if this is a leaf.
- """
-
- @abstractmethod
- def get_code(self, include_prefix=True):
- """
- Returns the code that was input the input for the parser for this node.
-
- :param include_prefix: Removes the prefix (whitespace and comments) of
- e.g. a statement.
- """
-
-
- class Leaf(NodeOrLeaf):
- '''
- Leafs are basically tokens with a better API. Leafs exactly know where they
- were defined and what text preceeds them.
- '''
- __slots__ = ('value', 'parent', 'line', 'column', 'prefix')
-
- def __init__(self, value, start_pos, prefix=''):
- self.value = value
- '''
- :py:func:`str` The value of the current token.
- '''
- self.start_pos = start_pos
- self.prefix = prefix
- '''
- :py:func:`str` Typically a mixture of whitespace and comments. Stuff
- that is syntactically irrelevant for the syntax tree.
- '''
- self.parent = None
- '''
- The parent :class:`BaseNode` of this leaf.
- '''
-
- @property
- def start_pos(self):
- return self.line, self.column
-
- @start_pos.setter
- def start_pos(self, value):
- self.line = value[0]
- self.column = value[1]
-
- def get_start_pos_of_prefix(self):
- previous_leaf = self.get_previous_leaf()
- if previous_leaf is None:
- return self.line - self.prefix.count('\n'), 0 # It's the first leaf.
- return previous_leaf.end_pos
-
- def get_first_leaf(self):
- return self
-
- def get_last_leaf(self):
- return self
-
- def get_code(self, include_prefix=True):
- if include_prefix:
- return self.prefix + self.value
- else:
- return self.value
-
- @property
- def end_pos(self):
- lines = self.value.split('\n')
- end_pos_line = self.line + len(lines) - 1
- # Check for multiline token
- if self.line == end_pos_line:
- end_pos_column = self.column + len(lines[-1])
- else:
- end_pos_column = len(lines[-1])
- return end_pos_line, end_pos_column
-
- @utf8_repr
- def __repr__(self):
- value = self.value
- if not value:
- value = self.type
- return "<%s: %s>" % (type(self).__name__, value)
-
-
- class TypedLeaf(Leaf):
- __slots__ = ('type',)
-
- def __init__(self, type, value, start_pos, prefix=''):
- super(TypedLeaf, self).__init__(value, start_pos, prefix)
- self.type = type
-
-
- class BaseNode(NodeOrLeaf):
- """
- The super class for all nodes.
- A node has children, a type and possibly a parent node.
- """
- __slots__ = ('children', 'parent')
- type = None
-
- def __init__(self, children):
- for c in children:
- c.parent = self
- self.children = children
- """
- A list of :class:`NodeOrLeaf` child nodes.
- """
- self.parent = None
- '''
- The parent :class:`BaseNode` of this leaf.
- None if this is the root node.
- '''
-
- @property
- def start_pos(self):
- return self.children[0].start_pos
-
- def get_start_pos_of_prefix(self):
- return self.children[0].get_start_pos_of_prefix()
-
- @property
- def end_pos(self):
- return self.children[-1].end_pos
-
- def _get_code_for_children(self, children, include_prefix):
- if include_prefix:
- return "".join(c.get_code() for c in children)
- else:
- first = children[0].get_code(include_prefix=False)
- return first + "".join(c.get_code() for c in children[1:])
-
- def get_code(self, include_prefix=True):
- return self._get_code_for_children(self.children, include_prefix)
-
- def get_leaf_for_position(self, position, include_prefixes=False):
- """
- Get the :py:class:`parso.tree.Leaf` at ``position``
-
- :param tuple position: A position tuple, row, column. Rows start from 1
- :param bool include_prefixes: If ``False``, ``None`` will be returned if ``position`` falls
- on whitespace or comments before a leaf
- :return: :py:class:`parso.tree.Leaf` at ``position``, or ``None``
- """
- def binary_search(lower, upper):
- if lower == upper:
- element = self.children[lower]
- if not include_prefixes and position < element.start_pos:
- # We're on a prefix.
- return None
- # In case we have prefixes, a leaf always matches
- try:
- return element.get_leaf_for_position(position, include_prefixes)
- except AttributeError:
- return element
-
-
- index = int((lower + upper) / 2)
- element = self.children[index]
- if position <= element.end_pos:
- return binary_search(lower, index)
- else:
- return binary_search(index + 1, upper)
-
- if not ((1, 0) <= position <= self.children[-1].end_pos):
- raise ValueError('Please provide a position that exists within this node.')
- return binary_search(0, len(self.children) - 1)
-
- def get_first_leaf(self):
- return self.children[0].get_first_leaf()
-
- def get_last_leaf(self):
- return self.children[-1].get_last_leaf()
-
- @utf8_repr
- def __repr__(self):
- code = self.get_code().replace('\n', ' ').strip()
- if not py_version >= 30:
- 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):
- super(Node, self).__init__(children)
- self.type = type
-
- def __repr__(self):
- return "%s(%s, %r)" % (self.__class__.__name__, self.type, self.children)
-
-
- class ErrorNode(BaseNode):
- """
- A node that contains valid nodes/leaves that we're follow by a token that
- was invalid. This basically means that the leaf after this node is where
- Python would mark a syntax error.
- """
- __slots__ = ()
- type = 'error_node'
-
-
- class ErrorLeaf(Leaf):
- """
- A leaf that is either completely invalid in a language (like `$` in Python)
- or is invalid at that position. Like the star in `1 +* 1`.
- """
- __slots__ = ('token_type',)
- type = 'error_leaf'
-
- def __init__(self, token_type, value, start_pos, prefix=''):
- super(ErrorLeaf, self).__init__(value, start_pos, prefix)
- self.token_type = token_type
-
- def __repr__(self):
- return "<%s: %s:%s, %s>" % \
- (type(self).__name__, self.token_type, repr(self.value), self.start_pos)
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