Completed
Pull Request — master (#179)
by Björn
21:14
created

neovim.api.Nvim   B

Complexity

Total Complexity 48

Size/Duplication

Total Lines 279
Duplicated Lines 0 %

Test Coverage

Coverage 72.97%
Metric Value
dl 0
loc 279
ccs 81
cts 111
cp 0.7297
rs 8.4864
wmc 48

35 Methods

Rating   Name   Duplication   Size   Complexity  
A from_session() 0 22 3
A foreach_rtp() 0 14 4
A err_write() 0 3 1
A new_highlight_source() 0 3 1
A feedkeys() 0 10 1
A run_loop() 0 11 3
A async_call() 0 22 3
A list_runtime_paths() 0 3 1
A handler() 0 9 2
A eval() 0 3 1
A next_message() 0 5 2
A filter_notification_cb() 0 2 1
A _from_nvim() 0 7 3
A ui_detach() 0 3 1
A out_write() 0 3 1
A session() 0 4 1
A ui_attach() 0 7 1
A quit() 0 13 2
A from_nvim() 0 5 1
A unsubscribe() 0 3 1
A _to_nvim() 0 4 2
A replace_termcodes() 0 16 1
A subscribe() 0 3 1
A __init__() 0 17 1
A command_output() 0 3 1
A with_decodehook() 0 4 1
A call() 0 7 3
A input() 0 9 1
A strwidth() 0 6 1
A chdir() 0 4 1
A ui_try_resize() 0 6 1
A command() 0 3 1
A request() 0 5 1
A stop_loop() 0 3 1
A filter_request_cb() 0 4 1

How to fix   Complexity   

Complex Class

Complex classes like neovim.api.Nvim often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

1
"""Main Nvim interface."""
2 6
import functools
3 6
import os
4
5 6
from traceback import format_exc, format_stack
6
7 6
from msgpack import ExtType
0 ignored issues
show
Configuration introduced by
The import msgpack could not be resolved.

This can be caused by one of the following:

1. Missing Dependencies

This error could indicate a configuration issue of Pylint. Make sure that your libraries are available by adding the necessary commands.

# .scrutinizer.yml
before_commands:
    - sudo pip install abc # Python2
    - sudo pip3 install abc # Python3
Tip: We are currently not using virtualenv to run pylint, when installing your modules make sure to use the command for the correct version.

2. Missing __init__.py files

This error could also result from missing __init__.py files in your module folders. Make sure that you place one file in each sub-folder.

Loading history...
8
9 6
from .buffer import Buffer
10 6
from .common import (DecodeHook, Remote, RemoteApi,
11
                     RemoteMap, RemoteSequence, walk)
12 6
from .tabpage import Tabpage
13 6
from .window import Window
14 6
from ..compat import IS_PYTHON3
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__all__ = ('Nvim')
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19
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os_chdir = os.chdir
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class Nvim(object):
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    """Class that represents a remote Nvim instance.
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    This class is main entry point to Nvim remote API, it is a thin wrapper
28
    around Session instances.
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    The constructor of this class must not be called directly. Instead, the
31
    `from_session` class method should be used to create the first instance
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    from a raw `Session` instance.
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    Subsequent instances for the same session can be created by calling the
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    `with_hook` instance method and passing a SessionHook instance. This can
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    be useful to have multiple `Nvim` objects that behave differently without
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    one affecting the other.
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    """
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    @classmethod
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    def from_session(cls, session):
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        """Create a new Nvim instance for a Session instance.
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        This method must be called to create the first Nvim instance, since it
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        queries Nvim metadata for type information and sets a SessionHook for
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        creating specialized objects from Nvim remote handles.
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        """
48 6
        session.error_wrapper = lambda e: NvimError(e[1])
49 6
        channel_id, metadata = session.request(b'vim_get_api_info')
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51 6
        if IS_PYTHON3:
52 6
            # decode all metadata strings for python3
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            metadata = DecodeHook().walk(metadata)
54 6
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        types = {
56 6
            metadata['types']['Buffer']['id']: Buffer,
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            metadata['types']['Window']['id']: Window,
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            metadata['types']['Tabpage']['id']: Tabpage,
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        }
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        return cls(session, channel_id, metadata, types)
62 6
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    @classmethod
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    def from_nvim(cls, nvim):
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        """Create a new Nvim instance from an extisting instance."""
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        return cls(nvim.session, nvim.channel_id, nvim.metadata,
67 6
                   nvim.types, nvim._decodehook)
0 ignored issues
show
Coding Style Best Practice introduced by
It seems like _decodehook was declared protected and should not be accessed from this context.

Prefixing a member variable _ is usually regarded as the equivalent of declaring it with protected visibility that exists in other languages. Consequentially, such a member should only be accessed from the same class or a child class:

class MyParent:
    def __init__(self):
        self._x = 1;
        self.y = 2;

class MyChild(MyParent):
    def some_method(self):
        return self._x    # Ok, since accessed from a child class

class AnotherClass:
    def some_method(self, instance_of_my_child):
        return instance_of_my_child._x   # Would be flagged as AnotherClass is not
                                         # a child class of MyParent
Loading history...
68 6
69 6
    def __init__(self, session, channel_id, metadata, types, decodehook=None):
70 6
        """Initialize a new Nvim instance. This method is module-private."""
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        self._session = session
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        self.channel_id = channel_id
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        self.metadata = metadata
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        self.types = types
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        self.api = RemoteApi(self, 'vim_')
76 6
        self.vars = RemoteMap(self, 'vim_get_var', 'vim_set_var')
77 6
        self.vvars = RemoteMap(self, 'vim_get_vvar', None)
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        self.options = RemoteMap(self, 'vim_get_option', 'vim_set_option')
79 6
        self.buffers = RemoteSequence(self, 'vim_get_buffers')
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        self.windows = RemoteSequence(self, 'vim_get_windows')
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        self.tabpages = RemoteSequence(self, 'vim_get_tabpages')
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        self.current = Current(self)
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        self.funcs = Funcs(self)
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        self.error = NvimError
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        self._decodehook = decodehook
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    def _from_nvim(self, obj):
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        if type(obj) is ExtType:
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            cls = self.types[obj.code]
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            return cls(self, (obj.code, obj.data))
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        if self._decodehook is not None:
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            obj = self._decodehook.decode_if_bytes(obj)
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        return obj
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    def _to_nvim(self, obj):
0 ignored issues
show
Coding Style introduced by
This method could be written as a function/class method.

If a method does not access any attributes of the class, it could also be implemented as a function or static method. This can help improve readability. For example

class Foo:
    def some_method(self, x, y):
        return x + y;

could be written as

class Foo:
    @classmethod
    def some_method(cls, x, y):
        return x + y;
Loading history...
96
        if isinstance(obj, Remote):
97 6
            return ExtType(*obj.code_data)
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        return obj
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    def request(self, name, *args, **kwargs):
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        """Wrapper for Session.request."""
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        args = walk(self._to_nvim, args)
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        res = self._session.request(name, *args, **kwargs)
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        return walk(self._from_nvim, res)
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    def next_message(self):
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        """Wrapper for Session.next_message."""
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        msg = self._session.next_message()
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        if msg:
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            return walk(self._from_nvim, msg)
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    def run_loop(self, request_cb, notification_cb, setup_cb=None):
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        """Wrapper for Session.run."""
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        def filter_request_cb(name, args):
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            args = walk(self._from_nvim, args)
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            result = request_cb(self._from_nvim(name), args)
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            return walk(self._to_nvim, result)
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        def filter_notification_cb(name, args):
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            notification_cb(self._from_nvim(name), walk(self._from_nvim, args))
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        self._session.run(filter_request_cb, filter_notification_cb, setup_cb)
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124 6
    def stop_loop(self):
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        """Wrapper for Session.stop."""
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        self._session.stop()
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    def with_decodehook(self, hook):
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        """Initialize a new Nvim instance."""
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        return Nvim(self.session, self.channel_id,
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                    self.metadata, self.types, hook)
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    @property
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    def session(self):
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        """Return the Session or SessionFilter for a Nvim instance."""
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        return self._session
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    def ui_attach(self, width, height, rgb):
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        """Register as a remote UI.
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        After this method is called, the client will receive redraw
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        notifications.
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        """
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        return self.request('ui_attach', width, height, rgb)
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    def ui_detach(self):
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        """Unregister as a remote UI."""
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        return self.request('ui_detach')
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    def ui_try_resize(self, width, height):
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        """Notify nvim that the client window has resized.
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        If possible, nvim will send a redraw request to resize.
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        """
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        return self.request('ui_try_resize', width, height)
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    def subscribe(self, event):
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        """Subscribe to a Nvim event."""
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        return self.request('vim_subscribe', event)
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    def unsubscribe(self, event):
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        """Unsubscribe to a Nvim event."""
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        return self.request('vim_unsubscribe', event)
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    def command(self, string, async=False):
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        """Execute a single ex command."""
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        return self.request('vim_command', string, async=async)
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    def command_output(self, string):
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        """Execute a single ex command and return the output."""
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        return self.request('vim_command_output', string)
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    def eval(self, string, async=False):
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        """Evaluate a vimscript expression."""
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        return self.request('vim_eval', string, async=async)
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    def call(self, name, *args, **kwargs):
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        """Call a vimscript function."""
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        for k in kwargs:
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            if k != "async":
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                raise TypeError(
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                    "call() got an unexpected keyword argument '{}'".format(k))
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        return self.request('vim_call_function', name, args, **kwargs)
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    def strwidth(self, string):
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        """Return the number of display cells `string` occupies.
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        Tab is counted as one cell.
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        """
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        return self.request('vim_strwidth', string)
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    def list_runtime_paths(self):
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        """Return a list of paths contained in the 'runtimepath' option."""
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        return self.request('vim_list_runtime_paths')
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    def foreach_rtp(self, cb):
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        """Invoke `cb` for each path in 'runtimepath'.
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        Call the given callable for each path in 'runtimepath' until either
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        callable returns something but None, the exception is raised or there
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        are no longer paths. If stopped in case callable returned non-None,
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        vim.foreach_rtp function returns the value returned by callable.
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        """
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        for path in self.request('vim_list_runtime_paths'):
205 6
            try:
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                if cb(path) is not None:
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                    break
208
            except Exception:
0 ignored issues
show
Best Practice introduced by
Catching very general exceptions such as Exception is usually not recommended.

Generally, you would want to handle very specific errors in the exception handler. This ensure that you do not hide other types of errors which should be fixed.

So, unless you specifically plan to handle any error, consider adding a more specific exception.

Loading history...
209 6
                break
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    def chdir(self, dir_path):
212
        """Run os.chdir, then all appropriate vim stuff."""
213 6
        os_chdir(dir_path)
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        return self.request('vim_change_directory', dir_path)
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    def feedkeys(self, keys, options='', escape_csi=True):
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        """Push `keys` to Nvim user input buffer.
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        Options can be a string with the following character flags:
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        - 'm': Remap keys. This is default.
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        - 'n': Do not remap keys.
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        - 't': Handle keys as if typed; otherwise they are handled as if coming
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               from a mapping. This matters for undo, opening folds, etc.
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        """
225
        return self.request('vim_feedkeys', keys, options, escape_csi)
226
227 6
    def input(self, bytes):
0 ignored issues
show
Bug Best Practice introduced by
This seems to re-define the built-in bytes.

It is generally discouraged to redefine built-ins as this makes code very hard to read.

Loading history...
228
        """Push `bytes` to Nvim low level input buffer.
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        Unlike `feedkeys()`, this uses the lowest level input buffer and the
231 6
        call is not deferred. It returns the number of bytes actually
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        written(which can be less than what was requested if the buffer is
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        full).
234
        """
235
        return self.request('vim_input', bytes)
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    def replace_termcodes(self, string, from_part=False, do_lt=True,
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                          special=True):
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        r"""Replace any terminal code strings by byte sequences.
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        The returned sequences are Nvim's internal representation of keys,
242
        for example:
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        <esc> -> '\x1b'
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        <cr>  -> '\r'
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        <c-l> -> '\x0c'
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        <up>  -> '\x80ku'
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        The returned sequences can be used as input to `feedkeys`.
250
        """
251
        return self.request('vim_replace_termcodes', string,
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                            from_part, do_lt, special)
253
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    def out_write(self, msg):
255 6
        """Print `msg` as a normal message."""
256
        return self.request('vim_out_write', msg)
257
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    def err_write(self, msg, async=False):
259 6
        """Print `msg` as an error message."""
260 6
        return self.request('vim_err_write', msg, async=async)
261 6
262
    def quit(self, quit_command='qa!'):
263 6
        """Send a quit command to Nvim.
264
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        By default, the quit command is 'qa!' which will make Nvim quit without
266
        saving anything.
267 6
        """
268
        try:
269 6
            self.command(quit_command)
270
        except IOError:
0 ignored issues
show
Unused Code introduced by
This except handler seems to be unused and could be removed.

Except handlers which only contain pass and do not have an else clause can usually simply be removed:

try:
    raises_exception()
except:  # Could be removed
    pass
Loading history...
271 6
            # sending a quit command will raise an IOError because the
272
            # connection is closed before a response is received. Safe to
273 6
            # ignore it.
274
            pass
275 6
276
    def new_highlight_source(self):
277 6
        """Return new src_id for use with Buffer.add_highlight."""
278
        return self.current.buffer.add_highlight("", 0, src_id=0)
279 6
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    def async_call(self, fn, *args, **kwargs):
281 6
        """Schedule `fn` to be called by the event loop soon.
282
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        This function is thread-safe, and is the only way code not
284
        on the main thread could interact with nvim api objects.
285 6
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        This function can also be called in a synchronous
287 6
        event handler, just before it returns, to defer execution
288
        that shouldn't block neovim.
289 6
        """
290
        call_point = ''.join(format_stack(None, 5)[:-1])
291 6
292
        def handler():
293 6
            try:
294
                fn(*args, **kwargs)
295
            except Exception as err:
296 6
                msg = ("error caught while executing async callback:\n"
297
                       "{!r}\n{}\n \nthe call was requested at\n{}"
298
                       .format(err, format_exc(5), call_point))
299
                self.err_write(msg, async=True)
300 6
                raise
301 6
        self._session.threadsafe_call(handler)
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304 6
class Current(object):
305
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    """Helper class for emulating vim.current from python-vim."""
307 6
308 6
    def __init__(self, session):
309 6
        self._session = session
310 6
        self.range = None
311
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    @property
313 6
    def line(self):
314 6
        return self._session.request('vim_get_current_line')
315 6
316 6
    @line.setter
317 6
    def line(self, line):
318
        return self._session.request('vim_set_current_line', line)
319 6
320 6
    @property
321 6
    def buffer(self):
322 6
        return self._session.request('vim_get_current_buffer')
323
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    @buffer.setter
325 6
    def buffer(self, buffer):
326 6
        return self._session.request('vim_set_current_buffer', buffer)
327
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    @property
329
    def window(self):
330
        return self._session.request('vim_get_current_window')
331
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    @window.setter
333
    def window(self, window):
334
        return self._session.request('vim_set_current_window', window)
335
336
    @property
337
    def tabpage(self):
338
        return self._session.request('vim_get_current_tabpage')
339
340
    @tabpage.setter
341
    def tabpage(self, tabpage):
342
        return self._session.request('vim_set_current_tabpage', tabpage)
343
344
345
class Funcs(object):
346
347
    """Helper class for functional vimscript interface."""
348
349
    def __init__(self, nvim):
350
        self._nvim = nvim
351
352
    def __getattr__(self, name):
353
        return functools.partial(self._nvim.call, name)
354
355
356
class NvimError(Exception):
357
    pass
358