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# Source code for xonsh.lib.pretty

    """
    Python advanced pretty printer.  This pretty printer is intended to
    replace the old `pprint` python module which does not allow developers
    to provide their own pretty print callbacks.

    This module is based on ruby's `prettyprint.rb` library by `Tanaka Akira`.

    The following implementations were forked from the IPython project:
    * Copyright (c) 2008-2014, IPython Development Team
    * Copyright (C) 2001-2007 Fernando Perez <fperez@colorado.edu>
    * Copyright (c) 2001, Janko Hauser <jhauser@zscout.de>
    * Copyright (c) 2001, Nathaniel Gray <n8gray@caltech.edu>

    Example Usage
    -------------

    To directly print the representation of an object use `pprint`::

        from pretty import pretty_print
        pretty_pprint(complex_object)

    To get a string of the output use `pretty`::

        from pretty import pretty
        string = pretty(complex_object)

    Extending
    ---------

    The pretty library allows developers to add pretty printing rules for their
    own objects.  This process is straightforward.  All you have to do is to
    add a `_repr_pretty_` method to your object and call the methods on the
    pretty printer passed::

        class MyObject(object):

            def _repr_pretty_(self, p, cycle):
                ...

    Here is an example implementation of a `_repr_pretty_` method for a list
    subclass::

        class MyList(list):

            def _repr_pretty_(self, p, cycle):
                if cycle:
                    p.text('MyList(...)')
                else:
                    with p.group(8, 'MyList([', '])'):
                        for idx, item in enumerate(self):
                            if idx:
                                p.text(',')
                                p.breakable()
                            p.pretty(item)

    The `cycle` parameter is `True` if pretty detected a cycle.  You *have* to
    react to that or the result is an infinite loop.  `p.text()` just adds
    non breaking text to the output, `p.breakable()` either adds a whitespace
    or breaks here.  If you pass it an argument it's used instead of the
    default space.  `p.pretty` prettyprints another object using the pretty print
    method.

    The first parameter to the `group` function specifies the extra indentation
    of the next line.  In this example the next item will either be on the same
    line (if the items are short enough) or aligned with the right edge of the
    opening bracket of `MyList`.

    If you just want to indent something you can use the group function
    without open / close parameters.  You can also use this code::

        with p.indent(2):
            ...

    :copyright: 2007 by Armin Ronacher.
                Portions (c) 2009 by Robert Kern.
    :license: BSD License.
    """

    import collections
    import contextlib
    import datetime
    import io
    import re
    import sys
    import types

    from xonsh.lib.lazyasd import LazyObject, lazyobject

    __all__ = [
        "pretty",
        "pretty_print",
        "PrettyPrinter",
        "RepresentationPrinter",
        "for_type",
        "for_type_by_name",
    ]

    MAX_SEQ_LENGTH = 1000

    def _safe_getattr(obj, attr, default=None):
        """Safe version of getattr.

        Same as getattr, but will return ``default`` on any Exception,
        rather than raising.
        """
        try:
            return getattr(obj, attr, default)
        except Exception:
            return default

    def pretty(
        obj, verbose=False, max_width=79, newline="\n", max_seq_length=MAX_SEQ_LENGTH
    ):
        """
        Pretty print the object's representation.
        """
        if _safe_getattr(obj, "xonsh_display"):
            return obj.xonsh_display()

        stream = io.StringIO()
        printer = RepresentationPrinter(
            stream, verbose, max_width, newline, max_seq_length=max_seq_length
        )
        printer.pretty(obj)
        printer.flush()
        return stream.getvalue()

    def pretty_print(
        obj, verbose=False, max_width=79, newline="\n", max_seq_length=MAX_SEQ_LENGTH
    ):
        """
        Like pretty() but print to stdout.
        """
        printer = RepresentationPrinter(
            sys.stdout, verbose, max_width, newline, max_seq_length=max_seq_length
        )
        printer.pretty(obj)
        printer.flush()
        sys.stdout.write(newline)
        sys.stdout.flush()

    class _PrettyPrinterBase:
        @contextlib.contextmanager
        def indent(self, indent):
            """with statement support for indenting/dedenting."""
            self.indentation += indent
            try:
                yield
            finally:
                self.indentation -= indent

        @contextlib.contextmanager
        def group(self, indent=0, open="", close=""):
            """like begin_group / end_group but for the with statement."""
            self.begin_group(indent, open)
            try:
                yield
            finally:
                self.end_group(indent, close)

    class PrettyPrinter(_PrettyPrinterBase):
        """
        Baseclass for the `RepresentationPrinter` prettyprinter that is used to
        generate pretty reprs of objects.  Contrary to the `RepresentationPrinter`
        this printer knows nothing about the default pprinters or the `_repr_pretty_`
        callback method.
        """

        def __init__(
            self, output, max_width=79, newline="\n", max_seq_length=MAX_SEQ_LENGTH
        ):
            self.output = output
            self.max_width = max_width
            self.newline = newline
            self.max_seq_length = max_seq_length
            self.output_width = 0
            self.buffer_width = 0
            self.buffer = collections.deque()

            root_group = Group(0)
            self.group_stack = [root_group]
            self.group_queue = GroupQueue(root_group)
            self.indentation = 0

        def _break_outer_groups(self):
            while self.max_width < self.output_width + self.buffer_width:
                group = self.group_queue.deq()
                if not group:
                    return
                while group.breakables:
                    x = self.buffer.popleft()
                    self.output_width = x.output(self.output, self.output_width)
                    self.buffer_width -= x.width
                while self.buffer and isinstance(self.buffer[0], Text):
                    x = self.buffer.popleft()
                    self.output_width = x.output(self.output, self.output_width)
                    self.buffer_width -= x.width

        def text(self, obj):
            """Add literal text to the output."""
            width = len(obj)
            if self.buffer:
                text = self.buffer[-1]
                if not isinstance(text, Text):
                    text = Text()
                    self.buffer.append(text)
                text.add(obj, width)
                self.buffer_width += width
                self._break_outer_groups()
            else:
                self.output.write(obj)
                self.output_width += width

        def breakable(self, sep=" "):
            """
            Add a breakable separator to the output.  This does not mean that it
            will automatically break here.  If no breaking on this position takes
            place the `sep` is inserted which default to one space.
            """
            width = len(sep)
            group = self.group_stack[-1]
            if group.want_break:
                self.flush()
                self.output.write(self.newline)
                self.output.write(" " * self.indentation)
                self.output_width = self.indentation
                self.buffer_width = 0
            else:
                self.buffer.append(Breakable(sep, width, self))
                self.buffer_width += width
                self._break_outer_groups()

        def break_(self):
            """
            Explicitly insert a newline into the output, maintaining correct indentation.
            """
            self.flush()
            self.output.write(self.newline)
            self.output.write(" " * self.indentation)
            self.output_width = self.indentation
            self.buffer_width = 0

        def begin_group(self, indent=0, open=""):
            """
            Begin a group.  If you want support for python < 2.5 which doesn't has
            the with statement this is the preferred way:

                p.begin_group(1, '{')
                ...
                p.end_group(1, '}')

            The python 2.5 expression would be this:

                with p.group(1, '{', '}'):
                    ...

            The first parameter specifies the indentation for the next line (usually
            the width of the opening text), the second the opening text.  All
            parameters are optional.
            """
            if open:
                self.text(open)
            group = Group(self.group_stack[-1].depth + 1)
            self.group_stack.append(group)
            self.group_queue.enq(group)
            self.indentation += indent

        def _enumerate(self, seq):
            """like enumerate, but with an upper limit on the number of items"""
            for idx, x in enumerate(seq):
                if self.max_seq_length and idx >= self.max_seq_length:
                    self.text(",")
                    self.breakable()
                    self.text("...")
                    return
                yield idx, x

        def end_group(self, dedent=0, close=""):
            """End a group. See `begin_group` for more details."""
            self.indentation -= dedent
            group = self.group_stack.pop()
            if not group.breakables:
                self.group_queue.remove(group)
            if close:
                self.text(close)

        def flush(self):
            """Flush data that is left in the buffer."""
            for data in self.buffer:
                self.output_width += data.output(self.output, self.output_width)
            self.buffer.clear()
            self.buffer_width = 0

    def _get_mro(obj_class):
        """Get a reasonable method resolution order of a class and its superclasses
        for both old-style and new-style classes.
        """
        if not hasattr(obj_class, "__mro__"):
            # Old-style class. Mix in object to make a fake new-style class.
            try:
                obj_class = type(obj_class.__name__, (obj_class, object), {})
            except TypeError:
                # Old-style extension type that does not descend from object.
                # FIXME: try to construct a more thorough MRO.
                mro = [obj_class]
            else:
                mro = obj_class.__mro__[1:-1]
        else:
            mro = obj_class.__mro__
        return mro

    class RepresentationPrinter(PrettyPrinter):
        """
        Special pretty printer that has a `pretty` method that calls the pretty
        printer for a python object.

        This class stores processing data on `self` so you must *never* use
        this class in a threaded environment.  Always lock it or reinstantiate
        it.

        Instances also have a verbose flag callbacks can access to control their
        output.  For example the default instance repr prints all attributes and
        methods that are not prefixed by an underscore if the printer is in
        verbose mode.
        """

        def __init__(
            self,
            output,
            verbose=False,
            max_width=79,
            newline="\n",
            singleton_pprinters=None,
            type_pprinters=None,
            deferred_pprinters=None,
            max_seq_length=MAX_SEQ_LENGTH,
        ):
            PrettyPrinter.__init__(
                self, output, max_width, newline, max_seq_length=max_seq_length
            )
            self.verbose = verbose
            self.stack = []
            if singleton_pprinters is None:
                singleton_pprinters = _singleton_pprinters.copy()
            self.singleton_pprinters = singleton_pprinters
            if type_pprinters is None:
                type_pprinters = _type_pprinters.copy()
            self.type_pprinters = type_pprinters
            if deferred_pprinters is None:
                deferred_pprinters = _deferred_type_pprinters.copy()
            self.deferred_pprinters = deferred_pprinters

        def pretty(self, obj):
            """Pretty print the given object."""
            obj_id = id(obj)
            cycle = obj_id in self.stack
            self.stack.append(obj_id)
            self.begin_group()
            try:
                obj_class = _safe_getattr(obj, "__class__", None) or type(obj)
                # First try to find registered singleton printers for the type.
                try:
                    printer = self.singleton_pprinters[obj_id]
                except (TypeError, KeyError):
                    pass
                else:
                    return printer(obj, self, cycle)
                # Next walk the mro and check for either:
                #   1) a registered printer
                #   2) a _repr_pretty_ method
                for cls in _get_mro(obj_class):
                    if cls in self.type_pprinters:
                        # printer registered in self.type_pprinters
                        return self.type_pprinters[cls](obj, self, cycle)
                    else:
                        # deferred printer
                        printer = self._in_deferred_types(cls)
                        if printer is not None:
                            return printer(obj, self, cycle)
                        else:
                            # Finally look for special method names.
                            # Some objects automatically create any requested
                            # attribute. Try to ignore most of them by checking for
                            # callability.
                            if "_repr_pretty_" in cls.__dict__:
                                meth = cls._repr_pretty_
                                if callable(meth):
                                    return meth(obj, self, cycle)
                return _default_pprint(obj, self, cycle)
            finally:
                self.end_group()
                self.stack.pop()

        def _in_deferred_types(self, cls):
            """
            Check if the given class is specified in the deferred type registry.

            Returns the printer from the registry if it exists, and None if the
            class is not in the registry. Successful matches will be moved to the
            regular type registry for future use.
            """
            mod = _safe_getattr(cls, "__module__", None)
            name = _safe_getattr(cls, "__name__", None)
            key = (mod, name)
            printer = None
            if key in self.deferred_pprinters:
                # Move the printer over to the regular registry.
                printer = self.deferred_pprinters.pop(key)
                self.type_pprinters[cls] = printer
            return printer

    class Printable:
        def output(self, stream, output_width):
            return output_width

    class Text(Printable):
        def __init__(self):
            self.objs = []
            self.width = 0

        def output(self, stream, output_width):
            for obj in self.objs:
                stream.write(obj)
            return output_width + self.width

        def add(self, obj, width):
            self.objs.append(obj)
            self.width += width

    class Breakable(Printable):
        def __init__(self, seq, width, pretty):
            self.obj = seq
            self.width = width
            self.pretty = pretty
            self.indentation = pretty.indentation
            self.group = pretty.group_stack[-1]
            self.group.breakables.append(self)

        def output(self, stream, output_width):
            self.group.breakables.popleft()
            if self.group.want_break:
                stream.write(self.pretty.newline)
                stream.write(" " * self.indentation)
                return self.indentation
            if not self.group.breakables:
                self.pretty.group_queue.remove(self.group)
            stream.write(self.obj)
            return output_width + self.width

    class Group(Printable):
        def __init__(self, depth):
            self.depth = depth
            self.breakables = collections.deque()
            self.want_break = False

    class GroupQueue:
        def __init__(self, *groups):
            self.queue = []
            for group in groups:
                self.enq(group)

        def enq(self, group):
            depth = group.depth
            while depth > len(self.queue) - 1:
                self.queue.append([])
            self.queue[depth].append(group)

        def deq(self):
            for stack in self.queue:
                for idx, group in enumerate(reversed(stack)):
                    if group.breakables:
                        del stack[idx]
                        group.want_break = True
                        return group
                for group in stack:
                    group.want_break = True
                del stack[:]

        def remove(self, group):
            try:
                self.queue[group.depth].remove(group)
            except ValueError:
                pass

    @lazyobject
    def _baseclass_reprs():
        try:
            br = (object.__repr__, types.InstanceType.__repr__)
        except AttributeError:  # Python 3
            br = (object.__repr__,)
        return br

    def _default_pprint(obj, p, cycle):
        """
        The default print function.  Used if an object does not provide one and
        it's none of the builtin objects.
        """
        klass = _safe_getattr(obj, "__class__", None) or type(obj)
        if _safe_getattr(klass, "__repr__", None) not in _baseclass_reprs:
            # A user-provided repr. Find newlines and replace them with p.break_()
            _repr_pprint(obj, p, cycle)
            return
        p.begin_group(1, "<")
        p.pretty(klass)
        p.text(f" at 0x{id(obj):x}")
        if cycle:
            p.text(" ...")
        elif p.verbose:
            first = True
            for key in dir(obj):
                if not key.startswith("_"):
                    try:
                        value = getattr(obj, key)
                    except AttributeError:
                        continue
                    if isinstance(value, types.MethodType):
                        continue
                    if not first:
                        p.text(",")
                    p.breakable()
                    p.text(key)
                    p.text("=")
                    step = len(key) + 1
                    p.indentation += step
                    p.pretty(value)
                    p.indentation -= step
                    first = False
        p.end_group(1, ">")

    def _seq_pprinter_factory(start, end, basetype):
        """
        Factory that returns a pprint function useful for sequences.  Used by
        the default pprint for tuples, dicts, and lists.
        """

        def inner(obj, p, cycle):
            typ = type(obj)
            if (
                basetype is not None
                and typ is not basetype
                and typ.__repr__ != basetype.__repr__
            ):
                # If the subclass provides its own repr, use it instead.
                return p.text(typ.__repr__(obj))

            if cycle:
                return p.text(start + "..." + end)
            step = len(start)
            p.begin_group(step, start)
            for idx, x in p._enumerate(obj):
                if idx:
                    p.text(",")
                    p.breakable()
                p.pretty(x)
            if len(obj) == 1 and type(obj) is tuple:
                # Special case for 1-item tuples.
                p.text(",")
            p.end_group(step, end)

        return inner

    def _set_pprinter_factory(start, end, basetype):
        """
        Factory that returns a pprint function useful for sets and frozensets.
        """

        def inner(obj, p, cycle):
            typ = type(obj)
            if (
                basetype is not None
                and typ is not basetype
                and typ.__repr__ != basetype.__repr__
            ):
                # If the subclass provides its own repr, use it instead.
                return p.text(typ.__repr__(obj))

            if cycle:
                return p.text(start + "..." + end)
            if len(obj) == 0:
                # Special case.
                p.text(basetype.__name__ + "()")
            else:
                step = len(start)
                p.begin_group(step, start)
                # Like dictionary keys, we will try to sort the items if there aren't too many
                items = obj
                if not (p.max_seq_length and len(obj) >= p.max_seq_length):
                    try:
                        items = sorted(obj)
                    except Exception:
                        # Sometimes the items don't sort.
                        pass
                for idx, x in p._enumerate(items):
                    if idx:
                        p.text(",")
                        p.breakable()
                    p.pretty(x)
                p.end_group(step, end)

        return inner

    def _dict_pprinter_factory(start, end, basetype=None):
        """
        Factory that returns a pprint function used by the default pprint of
        dicts and dict proxies.
        """

        def inner(obj, p, cycle):
            typ = type(obj)
            if (
                basetype is not None
                and typ is not basetype
                and typ.__repr__ != basetype.__repr__
            ):
                # If the subclass provides its own repr, use it instead.
                return p.text(typ.__repr__(obj))

            if cycle:
                return p.text("{...}")
            p.begin_group(1, start)
            keys = obj.keys()
            for idx, key in p._enumerate(keys):
                if idx:
                    p.text(",")
                    p.breakable()
                p.pretty(key)
                p.text(": ")
                p.pretty(obj[key])
            p.end_group(1, end)

        return inner

    def _super_pprint(obj, p, cycle):
        """The pprint for the super type."""
        p.begin_group(8, "<super: ")
        p.pretty(obj.__thisclass__)
        p.text(",")
        p.breakable()
        p.pretty(obj.__self__)
        p.end_group(8, ">")

    def _re_pattern_pprint(obj, p, cycle):
        """The pprint function for regular expression patterns."""
        p.text("re.compile(")
        pattern = repr(obj.pattern)
        if pattern[:1] in "uU":
            pattern = pattern[1:]
            prefix = "ur"
        else:
            prefix = "r"
        pattern = prefix + pattern.replace("\\\\", "\\")
        p.text(pattern)
        if obj.flags:
            p.text(",")
            p.breakable()
            done_one = False
            for flag in (
                "IGNORECASE",
                "LOCALE",
                "MULTILINE",
                "DOTALL",
                "UNICODE",
                "VERBOSE",
                "DEBUG",
            ):
                if obj.flags & getattr(re, flag):
                    if done_one:
                        p.text("|")
                    p.text("re." + flag)
                    done_one = True
        p.text(")")

    def _type_pprint(obj, p, cycle):
        """The pprint for classes and types."""
        # Heap allocated types might not have the module attribute,
        # and others may set it to None.

        # Checks for a __repr__ override in the metaclass
        if type(obj).__repr__ is not type.__repr__:
            _repr_pprint(obj, p, cycle)
            return

        mod = _safe_getattr(obj, "__module__", None)
        try:
            name = obj.__qualname__
            if not isinstance(name, str):
                # This can happen if the type implements __qualname__ as a property
                # or other descriptor in Python 2.
                raise Exception("Try __name__")
        except Exception:
            name = obj.__name__
            if not isinstance(name, str):
                name = "<unknown type>"

        if mod in (None, "__builtin__", "builtins", "exceptions"):
            p.text(name)
        else:
            p.text(mod + "." + name)

    def _repr_pprint(obj, p, cycle):
        """A pprint that just redirects to the normal repr function."""
        # Find newlines and replace them with p.break_()
        output = repr(obj)
        for idx, output_line in enumerate(output.splitlines()):
            if idx:
                p.break_()
            p.text(output_line)

    def _function_pprint(obj, p, cycle):
        """Base pprint for all functions and builtin functions."""
        name = _safe_getattr(obj, "__qualname__", obj.__name__)
        mod = obj.__module__
        if mod and mod not in ("__builtin__", "builtins", "exceptions"):
            name = mod + "." + name
        p.text(f"<function {name}>")

    def _exception_pprint(obj, p, cycle):
        """Base pprint for all exceptions."""
        name = getattr(obj.__class__, "__qualname__", obj.__class__.__name__)
        if obj.__class__.__module__ not in ("exceptions", "builtins"):
            name = f"{obj.__class__.__module__}.{name}"
        step = len(name) + 1
        p.begin_group(step, name + "(")
        for idx, arg in enumerate(getattr(obj, "args", ())):
            if idx:
                p.text(",")
                p.breakable()
            p.pretty(arg)
        p.end_group(step, ")")

    @lazyobject
    def _type_pprinters():
        #: printers for builtin types
        tp = {
            int: _repr_pprint,
            float: _repr_pprint,
            str: _repr_pprint,
            tuple: _seq_pprinter_factory("(", ")", tuple),
            list: _seq_pprinter_factory("[", "]", list),
            dict: _dict_pprinter_factory("{", "}", dict),
            set: _set_pprinter_factory("{", "}", set),
            frozenset: _set_pprinter_factory("frozenset({", "})", frozenset),
            super: _super_pprint,
            re.Pattern: _re_pattern_pprint,
            type: _type_pprint,
            types.FunctionType: _function_pprint,
            types.BuiltinFunctionType: _function_pprint,
            types.MethodType: _repr_pprint,
            datetime.datetime: _repr_pprint,
            datetime.timedelta: _repr_pprint,
            slice: _repr_pprint,
            range: _repr_pprint,
            bytes: _repr_pprint,
        }
        #: the exception base
        try:
            _exception_base = BaseException
        except NameError:
            _exception_base = Exception
        tp[_exception_base] = _exception_pprint
        return tp

    #: printers for types specified by name
    @lazyobject
    def _deferred_type_pprinters():
        dtp = {}
        for_type_by_name("collections", "defaultdict", _defaultdict_pprint, dtp=dtp)
        for_type_by_name("collections", "OrderedDict", _ordereddict_pprint, dtp=dtp)
        for_type_by_name("collections", "deque", _deque_pprint, dtp=dtp)
        for_type_by_name("collections", "Counter", _counter_pprint, dtp=dtp)
        return dtp

    def for_type(typ, func):
        """
        Add a pretty printer for a given type.
        """
        oldfunc = _type_pprinters.get(typ, None)
        if func is not None:
            # To support easy restoration of old pprinters, we need to ignore Nones.
            _type_pprinters[typ] = func
        return oldfunc

    def for_type_by_name(type_module, type_name, func, dtp=None):
        """
        Add a pretty printer for a type specified by the module and name of a type
        rather than the type object itself.
        """
        if dtp is None:
            dtp = _deferred_type_pprinters
        key = (type_module, type_name)
        oldfunc = dtp.get(key, None)
        if func is not None:
            # To support easy restoration of old pprinters, we need to ignore Nones.
            dtp[key] = func
        return oldfunc

    #: printers for the default singletons
    _singleton_pprinters = LazyObject(
        lambda: dict.fromkeys(
            map(id, [None, True, False, Ellipsis, NotImplemented]), _repr_pprint
        ),
        globals(),
        "_singleton_pprinters",
    )

    def _defaultdict_pprint(obj, p, cycle):
        name = obj.__class__.__name__
        with p.group(len(name) + 1, name + "(", ")"):
            if cycle:
                p.text("...")
            else:
                p.pretty(obj.default_factory)
                p.text(",")
                p.breakable()
                p.pretty(dict(obj))

    def _ordereddict_pprint(obj, p, cycle):
        name = obj.__class__.__name__
        with p.group(len(name) + 1, name + "(", ")"):
            if cycle:
                p.text("...")
            elif len(obj):
                p.pretty(list(obj.items()))

    def _deque_pprint(obj, p, cycle):
        name = obj.__class__.__name__
        with p.group(len(name) + 1, name + "(", ")"):
            if cycle:
                p.text("...")
            else:
                p.pretty(list(obj))

    def _counter_pprint(obj, p, cycle):
        name = obj.__class__.__name__
        with p.group(len(name) + 1, name + "(", ")"):
            if cycle:
                p.text("...")
            elif len(obj):
                p.pretty(dict(obj))