--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.7/site-packages/docutils/io.py	Sat May 02 07:14:21 2020 -0400
@@ -0,0 +1,481 @@
+# $Id: io.py 8394 2019-09-18 10:13:17Z milde $
+# Author: David Goodger <goodger@python.org>
+# Copyright: This module has been placed in the public domain.
+
+"""
+I/O classes provide a uniform API for low-level input and output.  Subclasses
+exist for a variety of input/output mechanisms.
+"""
+from __future__ import print_function
+
+__docformat__ = 'reStructuredText'
+
+import sys
+import os
+import re
+import codecs
+from docutils import TransformSpec
+from docutils.utils.error_reporting import locale_encoding, ErrorString, ErrorOutput
+
+if sys.version_info >= (3, 0):
+    unicode = str  # noqa
+
+
+class InputError(IOError): pass
+class OutputError(IOError): pass
+
+def check_encoding(stream, encoding):
+    """Test, whether the encoding of `stream` matches `encoding`.
+
+    Returns
+
+    :None:  if `encoding` or `stream.encoding` are not a valid encoding
+            argument (e.g. ``None``) or `stream.encoding is missing.
+    :True:  if the encoding argument resolves to the same value as `encoding`,
+    :False: if the encodings differ.
+    """
+    try:
+        return codecs.lookup(stream.encoding) == codecs.lookup(encoding)
+    except (LookupError, AttributeError, TypeError):
+        return None
+
+
+class Input(TransformSpec):
+
+    """
+    Abstract base class for input wrappers.
+    """
+
+    component_type = 'input'
+
+    default_source_path = None
+
+    def __init__(self, source=None, source_path=None, encoding=None,
+                 error_handler='strict'):
+        self.encoding = encoding
+        """Text encoding for the input source."""
+
+        self.error_handler = error_handler
+        """Text decoding error handler."""
+
+        self.source = source
+        """The source of input data."""
+
+        self.source_path = source_path
+        """A text reference to the source."""
+
+        if not source_path:
+            self.source_path = self.default_source_path
+
+        self.successful_encoding = None
+        """The encoding that successfully decoded the source data."""
+
+    def __repr__(self):
+        return '%s: source=%r, source_path=%r' % (self.__class__, self.source,
+                                                  self.source_path)
+
+    def read(self):
+        raise NotImplementedError
+
+    def decode(self, data):
+        """
+        Decode a string, `data`, heuristically.
+        Raise UnicodeError if unsuccessful.
+
+        The client application should call ``locale.setlocale`` at the
+        beginning of processing::
+
+            locale.setlocale(locale.LC_ALL, '')
+        """
+        if self.encoding and self.encoding.lower() == 'unicode':
+            assert isinstance(data, unicode), (
+                'input encoding is "unicode" '
+                'but input is not a unicode object')
+        if isinstance(data, unicode):
+            # Accept unicode even if self.encoding != 'unicode'.
+            return data
+        if self.encoding:
+            # We believe the user/application when the encoding is
+            # explicitly given.
+            encodings = [self.encoding]
+        else:
+            data_encoding = self.determine_encoding_from_data(data)
+            if data_encoding:
+                # If the data declares its encoding (explicitly or via a BOM),
+                # we believe it.
+                encodings = [data_encoding]
+            else:
+                # Apply heuristics only if no encoding is explicitly given and
+                # no BOM found.  Start with UTF-8, because that only matches
+                # data that *IS* UTF-8:
+                encodings = ['utf-8', 'latin-1']
+                if locale_encoding:
+                    encodings.insert(1, locale_encoding)
+        for enc in encodings:
+            try:
+                decoded = unicode(data, enc, self.error_handler)
+                self.successful_encoding = enc
+                # Return decoded, removing BOMs.
+                return decoded.replace(u'\ufeff', u'')
+            except (UnicodeError, LookupError) as err:
+                error = err # in Python 3, the <exception instance> is
+                            # local to the except clause
+        raise UnicodeError(
+            'Unable to decode input data.  Tried the following encodings: '
+            '%s.\n(%s)' % (', '.join([repr(enc) for enc in encodings]),
+                         ErrorString(error)))
+
+    coding_slug = re.compile(br"coding[:=]\s*([-\w.]+)")
+    """Encoding declaration pattern."""
+
+    byte_order_marks = ((codecs.BOM_UTF8, 'utf-8'),
+                        (codecs.BOM_UTF16_BE, 'utf-16-be'),
+                        (codecs.BOM_UTF16_LE, 'utf-16-le'),)
+    """Sequence of (start_bytes, encoding) tuples for encoding detection.
+    The first bytes of input data are checked against the start_bytes strings.
+    A match indicates the given encoding."""
+
+    def determine_encoding_from_data(self, data):
+        """
+        Try to determine the encoding of `data` by looking *in* `data`.
+        Check for a byte order mark (BOM) or an encoding declaration.
+        """
+        # check for a byte order mark:
+        for start_bytes, encoding in self.byte_order_marks:
+            if data.startswith(start_bytes):
+                return encoding
+        # check for an encoding declaration pattern in first 2 lines of file:
+        for line in data.splitlines()[:2]:
+            match = self.coding_slug.search(line)
+            if match:
+                return match.group(1).decode('ascii')
+        return None
+
+
+class Output(TransformSpec):
+
+    """
+    Abstract base class for output wrappers.
+    """
+
+    component_type = 'output'
+
+    default_destination_path = None
+
+    def __init__(self, destination=None, destination_path=None,
+                 encoding=None, error_handler='strict'):
+        self.encoding = encoding
+        """Text encoding for the output destination."""
+
+        self.error_handler = error_handler or 'strict'
+        """Text encoding error handler."""
+
+        self.destination = destination
+        """The destination for output data."""
+
+        self.destination_path = destination_path
+        """A text reference to the destination."""
+
+        if not destination_path:
+            self.destination_path = self.default_destination_path
+
+    def __repr__(self):
+        return ('%s: destination=%r, destination_path=%r'
+                % (self.__class__, self.destination, self.destination_path))
+
+    def write(self, data):
+        """`data` is a Unicode string, to be encoded by `self.encode`."""
+        raise NotImplementedError
+
+    def encode(self, data):
+        if self.encoding and self.encoding.lower() == 'unicode':
+            assert isinstance(data, unicode), (
+                'the encoding given is "unicode" but the output is not '
+                'a Unicode string')
+            return data
+        if not isinstance(data, unicode):
+            # Non-unicode (e.g. bytes) output.
+            return data
+        else:
+            return data.encode(self.encoding, self.error_handler)
+
+
+class FileInput(Input):
+
+    """
+    Input for single, simple file-like objects.
+    """
+    def __init__(self, source=None, source_path=None,
+                 encoding=None, error_handler='strict',
+                 autoclose=True,
+                 mode='r' if sys.version_info >= (3, 0) else 'rU'):
+        """
+        :Parameters:
+            - `source`: either a file-like object (which is read directly), or
+              `None` (which implies `sys.stdin` if no `source_path` given).
+            - `source_path`: a path to a file, which is opened and then read.
+            - `encoding`: the expected text encoding of the input file.
+            - `error_handler`: the encoding error handler to use.
+            - `autoclose`: close automatically after read (except when
+              `sys.stdin` is the source).
+            - `mode`: how the file is to be opened (see standard function
+              `open`). The default 'rU' provides universal newline support
+              for text files with Python 2.x.
+        """
+        Input.__init__(self, source, source_path, encoding, error_handler)
+        self.autoclose = autoclose
+        self._stderr = ErrorOutput()
+
+        if source is None:
+            if source_path:
+                # Specify encoding in Python 3
+                if sys.version_info >= (3, 0):
+                    kwargs = {'encoding': self.encoding,
+                              'errors': self.error_handler}
+                else:
+                    kwargs = {}
+                try:
+                    self.source = open(source_path, mode, **kwargs)
+                except IOError as error:
+                    raise InputError(error.errno, error.strerror, source_path)
+            else:
+                self.source = sys.stdin
+        elif (sys.version_info >= (3, 0) and
+              check_encoding(self.source, self.encoding) is False):
+            # TODO: re-open, warn or raise error?
+            raise UnicodeError('Encoding clash: encoding given is "%s" '
+                               'but source is opened with encoding "%s".' %
+                               (self.encoding, self.source.encoding))
+        if not source_path:
+            try:
+                self.source_path = self.source.name
+            except AttributeError:
+                pass
+
+    def read(self):
+        """
+        Read and decode a single file and return the data (Unicode string).
+        """
+        try:
+            if self.source is sys.stdin and sys.version_info >= (3, 0):
+                # read as binary data to circumvent auto-decoding
+                data = self.source.buffer.read()
+                # normalize newlines
+                data = b'\n'.join(data.splitlines()) + b'\n'
+            else:
+                data = self.source.read()
+        except (UnicodeError, LookupError) as err: # (in Py3k read() decodes)
+            if not self.encoding and self.source_path:
+                # re-read in binary mode and decode with heuristics
+                b_source = open(self.source_path, 'rb')
+                data = b_source.read()
+                b_source.close()
+                # normalize newlines
+                data = b'\n'.join(data.splitlines()) + b'\n'
+            else:
+                raise
+        finally:
+            if self.autoclose:
+                self.close()
+        return self.decode(data)
+
+    def readlines(self):
+        """
+        Return lines of a single file as list of Unicode strings.
+        """
+        return self.read().splitlines(True)
+
+    def close(self):
+        if self.source is not sys.stdin:
+            self.source.close()
+
+
+class FileOutput(Output):
+
+    """
+    Output for single, simple file-like objects.
+    """
+
+    mode = 'w'
+    """The mode argument for `open()`."""
+    # 'wb' for binary (e.g. OpenOffice) files (see also `BinaryFileOutput`).
+    # (Do not use binary mode ('wb') for text files, as this prevents the
+    # conversion of newlines to the system specific default.)
+
+    def __init__(self, destination=None, destination_path=None,
+                 encoding=None, error_handler='strict', autoclose=True,
+                 handle_io_errors=None, mode=None):
+        """
+        :Parameters:
+            - `destination`: either a file-like object (which is written
+              directly) or `None` (which implies `sys.stdout` if no
+              `destination_path` given).
+            - `destination_path`: a path to a file, which is opened and then
+              written.
+            - `encoding`: the text encoding of the output file.
+            - `error_handler`: the encoding error handler to use.
+            - `autoclose`: close automatically after write (except when
+              `sys.stdout` or `sys.stderr` is the destination).
+            - `handle_io_errors`: ignored, deprecated, will be removed.
+            - `mode`: how the file is to be opened (see standard function
+              `open`). The default is 'w', providing universal newline
+              support for text files.
+        """
+        Output.__init__(self, destination, destination_path,
+                        encoding, error_handler)
+        self.opened = True
+        self.autoclose = autoclose
+        if mode is not None:
+            self.mode = mode
+        self._stderr = ErrorOutput()
+        if destination is None:
+            if destination_path:
+                self.opened = False
+            else:
+                self.destination = sys.stdout
+        elif (# destination is file-type object -> check mode:
+              mode and hasattr(self.destination, 'mode')
+              and mode != self.destination.mode):
+                print('Warning: Destination mode "%s" differs from specified '
+                      'mode "%s"' % (self.destination.mode, mode),
+                      file=self._stderr)
+        if not destination_path:
+            try:
+                self.destination_path = self.destination.name
+            except AttributeError:
+                pass
+
+    def open(self):
+        # Specify encoding in Python 3.
+        if sys.version_info >= (3, 0) and 'b' not in self.mode:
+            kwargs = {'encoding': self.encoding,
+                      'errors': self.error_handler}
+        else:
+            kwargs = {}
+        try:
+            self.destination = open(self.destination_path, self.mode, **kwargs)
+        except IOError as error:
+            raise OutputError(error.errno, error.strerror,
+                              self.destination_path)
+        self.opened = True
+
+    def write(self, data):
+        """Encode `data`, write it to a single file, and return it.
+
+        With Python 3 or binary output mode, `data` is returned unchanged,
+        except when specified encoding and output encoding differ.
+        """
+        if not self.opened:
+            self.open()
+        if ('b' not in self.mode and sys.version_info < (3, 0)
+            or check_encoding(self.destination, self.encoding) is False
+           ):
+            data = self.encode(data)
+            if sys.version_info >= (3, 0) and os.linesep != '\n':
+                data = data.replace(b'\n', bytes(os.linesep, 'ascii')) # fix endings
+
+        try:
+            self.destination.write(data)
+        except TypeError as e:
+            if sys.version_info >= (3, 0) and isinstance(data, bytes):
+                try:
+                    self.destination.buffer.write(data)
+                except AttributeError:
+                    if check_encoding(self.destination,
+                                      self.encoding) is False:
+                        raise ValueError('Encoding of %s (%s) differs \n'
+                            '  from specified encoding (%s)' %
+                            (self.destination_path or 'destination',
+                            self.destination.encoding, self.encoding))
+                    else:
+                        raise e
+        except (UnicodeError, LookupError) as err:
+            raise UnicodeError(
+                'Unable to encode output data. output-encoding is: '
+                '%s.\n(%s)' % (self.encoding, ErrorString(err)))
+        finally:
+            if self.autoclose:
+                self.close()
+        return data
+
+    def close(self):
+        if self.destination not in (sys.stdout, sys.stderr):
+            self.destination.close()
+            self.opened = False
+
+
+class BinaryFileOutput(FileOutput):
+    """
+    A version of docutils.io.FileOutput which writes to a binary file.
+    """
+    # Used by core.publish_cmdline_to_binary() which in turn is used by
+    # rst2odt (OpenOffice writer)
+    mode = 'wb'
+
+
+class StringInput(Input):
+
+    """
+    Direct string input.
+    """
+
+    default_source_path = '<string>'
+
+    def read(self):
+        """Decode and return the source string."""
+        return self.decode(self.source)
+
+
+class StringOutput(Output):
+
+    """
+    Direct string output.
+    """
+
+    default_destination_path = '<string>'
+
+    def write(self, data):
+        """Encode `data`, store it in `self.destination`, and return it."""
+        self.destination = self.encode(data)
+        return self.destination
+
+
+class NullInput(Input):
+
+    """
+    Degenerate input: read nothing.
+    """
+
+    default_source_path = 'null input'
+
+    def read(self):
+        """Return a null string."""
+        return u''
+
+
+class NullOutput(Output):
+
+    """
+    Degenerate output: write nothing.
+    """
+
+    default_destination_path = 'null output'
+
+    def write(self, data):
+        """Do nothing ([don't even] send data to the bit bucket)."""
+        pass
+
+
+class DocTreeInput(Input):
+
+    """
+    Adapter for document tree input.
+
+    The document tree must be passed in the ``source`` parameter.
+    """
+
+    default_source_path = 'doctree input'
+
+    def read(self):
+        """Return the document tree."""
+        return self.source