# Path: penman/types.py

# 
# Path: penman/tree.py
# class Tree:
#     """
#     A tree structure.
# 
#     A tree is essentially a node that contains other nodes, but this
#     Tree class is useful to contain any metadata and to provide
#     tree-based methods.
#     """
# 
#     __slots__ = 'node', 'metadata'
# 
#     def __init__(self,
#                  node: Node,
#                  metadata: Mapping[str, str] = None):
#         self.node = node
#         self.metadata = metadata or {}
# 
#     def __eq__(self, other) -> bool:
#         if isinstance(other, Tree):
#             other = other.node
#         return self.node == other
# 
#     def __repr__(self) -> str:
#         return f'Tree({self.node!r})'
# 
#     def __str__(self) -> str:
#         s = _format(self.node, 2)
#         return f'Tree(\n  {s})'
# 
#     def nodes(self) -> List[Node]:
#         """
#         Return the nodes in the tree as a flat list.
#         """
#         return _nodes(self.node)
# 
#     def walk(self) -> Iterator[_Step]:
#         """
#         Iterate over branches in the tree.
# 
#         This function yields pairs of (*path*, *branch*) where each
#         *path* is a tuple of 0-based indices of branches to get to
#         *branch*. For example, the path (2, 0) is the concept branch
#         `('/', 'bark-01')` in the tree for the following PENMAN
#         string, traversing first to the third (index 2) branch of the
#         top node, then to the first (index 0) branch of that node::
# 
#             (t / try-01
#                :ARG0 (d / dog)
#                :ARG1 (b / bark-01
#                         :ARG0 d))
# 
#         The (*path*, *branch*) pairs are yielded in depth-first order
#         of the tree traversal.
#         """
#         yield from _walk(self.node, ())
# 
#     def reset_variables(self, fmt='{prefix}{j}') -> None:
#         """
#         Recreate node variables formatted using *fmt*.
# 
#         The *fmt* string can be formatted with the following values:
# 
#         - ``prefix``: first alphabetic character in the node's concept
#         - ``i``: 0-based index of the current occurrence of the prefix
#         - ``j``: 1-based index starting from the second occurrence
#         """
#         varmap: Dict[Variable, Variable] = {}
#         used: Set[Variable] = set()
#         for var, branches in self.nodes():
#             if var not in varmap:
#                 concept = next((tgt for role, tgt in branches if role == '/'),
#                                None)
#                 pre = _default_variable_prefix(concept)
#                 i = 0
#                 newvar = None
#                 while newvar is None or newvar in used:
#                     newvar = fmt.format(
#                         prefix=pre,
#                         i=i,
#                         j='' if i == 0 else i + 1)
#                     i += 1
#                 used.add(newvar)
#                 varmap[var] = newvar
# 
#         self.node = _map_vars(self.node, varmap)
# 
# def is_atomic(x) -> bool:
#     """
#     Return ``True`` if *x* is a valid atomic value.
# 
#     Examples:
#         >>> from penman.tree import is_atomic
#         >>> is_atomic('a')
#         True
#         >>> is_atomic(None)
#         True
#         >>> is_atomic(3.14)
#         True
#         >>> is_atomic(('a', [('/', 'alpha')]))
#         False
#     """
#     return x is None or isinstance(x, (str, int, float))


from typing import Optional, Union, List, Iterable
from penman.types import BasicTriple
from penman.tree import (Tree, is_atomic)




def format(tree: Tree,
           indent: Union[int, None] = -1,
           compact: bool = False) -> str:
    """
    Format *tree* into a PENMAN string.

    Args:
        tree: a Tree object
        indent: how to indent formatted strings
        compact: if ``True``, put initial attributes on the first line
    Returns:
        the PENMAN-serialized string of the Tree *t*
    Example:
        >>> import penman
        >>> print(penman.format(
        ...     ('b', [('/', 'bark-01'),
        ...            (':ARG0', ('d', [('/', 'dog')]))])))
        (b / bark-01
           :ARG0 (d / dog))
    """
    if not isinstance(tree, Tree):

# Path: penman/types.py

# 
# Path: penman/tree.py
# class Tree:
#     """
#     A tree structure.
# 
#     A tree is essentially a node that contains other nodes, but this
#     Tree class is useful to contain any metadata and to provide
#     tree-based methods.
#     """
# 
#     __slots__ = 'node', 'metadata'
# 
#     def __init__(self,
#                  node: Node,
#                  metadata: Mapping[str, str] = None):
#         self.node = node
#         self.metadata = metadata or {}
# 
#     def __eq__(self, other) -> bool:
#         if isinstance(other, Tree):
#             other = other.node
#         return self.node == other
# 
#     def __repr__(self) -> str:
#         return f'Tree({self.node!r})'
# 
#     def __str__(self) -> str:
#         s = _format(self.node, 2)
#         return f'Tree(\n  {s})'
# 
#     def nodes(self) -> List[Node]:
#         """
#         Return the nodes in the tree as a flat list.
#         """
#         return _nodes(self.node)
# 
#     def walk(self) -> Iterator[_Step]:
#         """
#         Iterate over branches in the tree.
# 
#         This function yields pairs of (*path*, *branch*) where each
#         *path* is a tuple of 0-based indices of branches to get to
#         *branch*. For example, the path (2, 0) is the concept branch
#         `('/', 'bark-01')` in the tree for the following PENMAN
#         string, traversing first to the third (index 2) branch of the
#         top node, then to the first (index 0) branch of that node::
# 
#             (t / try-01
#                :ARG0 (d / dog)
#                :ARG1 (b / bark-01
#                         :ARG0 d))
# 
#         The (*path*, *branch*) pairs are yielded in depth-first order
#         of the tree traversal.
#         """
#         yield from _walk(self.node, ())
# 
#     def reset_variables(self, fmt='{prefix}{j}') -> None:
#         """
#         Recreate node variables formatted using *fmt*.
# 
#         The *fmt* string can be formatted with the following values:
# 
#         - ``prefix``: first alphabetic character in the node's concept
#         - ``i``: 0-based index of the current occurrence of the prefix
#         - ``j``: 1-based index starting from the second occurrence
#         """
#         varmap: Dict[Variable, Variable] = {}
#         used: Set[Variable] = set()
#         for var, branches in self.nodes():
#             if var not in varmap:
#                 concept = next((tgt for role, tgt in branches if role == '/'),
#                                None)
#                 pre = _default_variable_prefix(concept)
#                 i = 0
#                 newvar = None
#                 while newvar is None or newvar in used:
#                     newvar = fmt.format(
#                         prefix=pre,
#                         i=i,
#                         j='' if i == 0 else i + 1)
#                     i += 1
#                 used.add(newvar)
#                 varmap[var] = newvar
# 
#         self.node = _map_vars(self.node, varmap)
# 
# def is_atomic(x) -> bool:
#     """
#     Return ``True`` if *x* is a valid atomic value.
# 
#     Examples:
#         >>> from penman.tree import is_atomic
#         >>> is_atomic('a')
#         True
#         >>> is_atomic(None)
#         True
#         >>> is_atomic(3.14)
#         True
#         >>> is_atomic(('a', [('/', 'alpha')]))
#         False
#     """
#     return x is None or isinstance(x, (str, int, float))


# Path: penman/_format.py
from typing import Optional, Union, List, Iterable
from penman.types import BasicTriple
from penman.tree import (Tree, is_atomic)





def format(tree: Tree,
           indent: Union[int, None] = -1,
           compact: bool = False) -> str:
    """
    Format *tree* into a PENMAN string.

    Args:
        tree: a Tree object
        indent: how to indent formatted strings
        compact: if ``True``, put initial attributes on the first line
    Returns:
        the PENMAN-serialized string of the Tree *t*
    Example:
        >>> import penman
        >>> print(penman.format(
        ...     ('b', [('/', 'bark-01'),
        ...            (':ARG0', ('d', [('/', 'dog')]))])))
        (b / bark-01
           :ARG0 (d / dog))
    """
    if not isinstance(tree, Tree):

        tree = Tree(tree)