Make the TerminalInteractiveShell class configurable.

Should allow custom frontend in separate packages.

IPython/terminal/ipapp.py

@@ -1,370 +1,377 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 The :class:`~IPython.core.application.Application` object for the command
 line :command:`ipython` program.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 import logging
 import os
 import sys
 import warnings
 
 from traitlets.config.loader import Config
 from traitlets.config.application import boolean_flag, catch_config_error, Application
 from IPython.core import release
 from IPython.core import usage
 from IPython.core.completer import IPCompleter
 from IPython.core.crashhandler import CrashHandler
 from IPython.core.formatters import PlainTextFormatter
 from IPython.core.history import HistoryManager
 from IPython.core.application import (
     ProfileDir, BaseIPythonApplication, base_flags, base_aliases
 )
 from IPython.core.magics import ScriptMagics
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.extensions.storemagic import StoreMagics
 from .interactiveshell import TerminalInteractiveShell
 from IPython.paths import get_ipython_dir
 from traitlets import (
-    Bool, List, Dict, default, observe,
+    Bool, List, Dict, default, observe, Type
 )
 
 #-----------------------------------------------------------------------------
 # Globals, utilities and helpers
 #-----------------------------------------------------------------------------
 
 _examples = """
 ipython --matplotlib       # enable matplotlib integration
 ipython --matplotlib=qt    # enable matplotlib integration with qt4 backend
 
 ipython --log-level=DEBUG  # set logging to DEBUG
 ipython --profile=foo      # start with profile foo
 
 ipython profile create foo # create profile foo w/ default config files
 ipython help profile       # show the help for the profile subcmd
 
 ipython locate             # print the path to the IPython directory
 ipython locate profile foo # print the path to the directory for profile `foo`
 """
 
 #-----------------------------------------------------------------------------
 # Crash handler for this application
 #-----------------------------------------------------------------------------
 
 class IPAppCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
 
     def __init__(self, app):
         contact_name = release.author
         contact_email = release.author_email
         bug_tracker = 'https://github.com/ipython/ipython/issues'
         super(IPAppCrashHandler,self).__init__(
             app, contact_name, contact_email, bug_tracker
         )
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
 
         sec_sep = self.section_sep
         # Start with parent report
         report = [super(IPAppCrashHandler, self).make_report(traceback)]
         # Add interactive-specific info we may have
         rpt_add = report.append
         try:
             rpt_add(sec_sep+"History of session input:")
             for line in self.app.shell.user_ns['_ih']:
                 rpt_add(line)
             rpt_add('\n*** Last line of input (may not be in above history):\n')
             rpt_add(self.app.shell._last_input_line+'\n')
         except:
             pass
 
         return ''.join(report)
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 flags = dict(base_flags)
 flags.update(shell_flags)
 frontend_flags = {}
 addflag = lambda *args: frontend_flags.update(boolean_flag(*args))
 addflag('autoedit-syntax', 'TerminalInteractiveShell.autoedit_syntax',
         'Turn on auto editing of files with syntax errors.',
         'Turn off auto editing of files with syntax errors.'
 )
 addflag('simple-prompt', 'TerminalInteractiveShell.simple_prompt',
         "Force simple minimal prompt using `raw_input`",
         "Use a rich interactive prompt with prompt_toolkit",
 )
 
 addflag('banner', 'TerminalIPythonApp.display_banner',
         "Display a banner upon starting IPython.",
         "Don't display a banner upon starting IPython."
 )
 addflag('confirm-exit', 'TerminalInteractiveShell.confirm_exit',
     """Set to confirm when you try to exit IPython with an EOF (Control-D
     in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
     you can force a direct exit without any confirmation.""",
     "Don't prompt the user when exiting."
 )
 addflag('term-title', 'TerminalInteractiveShell.term_title',
     "Enable auto setting the terminal title.",
     "Disable auto setting the terminal title."
 )
 classic_config = Config()
 classic_config.InteractiveShell.cache_size = 0
 classic_config.PlainTextFormatter.pprint = False
 classic_config.TerminalInteractiveShell.prompts_class='IPython.terminal.prompts.ClassicPrompts'
 classic_config.InteractiveShell.separate_in = ''
 classic_config.InteractiveShell.separate_out = ''
 classic_config.InteractiveShell.separate_out2 = ''
 classic_config.InteractiveShell.colors = 'NoColor'
 classic_config.InteractiveShell.xmode = 'Plain'
 
 frontend_flags['classic']=(
     classic_config,
     "Gives IPython a similar feel to the classic Python prompt."
 )
 # # log doesn't make so much sense this way anymore
 # paa('--log','-l',
 #     action='store_true', dest='InteractiveShell.logstart',
 #     help="Start logging to the default log file (./ipython_log.py).")
 #
 # # quick is harder to implement
 frontend_flags['quick']=(
     {'TerminalIPythonApp' : {'quick' : True}},
     "Enable quick startup with no config files."
 )
 
 frontend_flags['i'] = (
     {'TerminalIPythonApp' : {'force_interact' : True}},
     """If running code from the command line, become interactive afterwards.
     It is often useful to follow this with `--` to treat remaining flags as
     script arguments.
     """
 )
 flags.update(frontend_flags)
 
 aliases = dict(base_aliases)
 aliases.update(shell_aliases)
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 
 class LocateIPythonApp(BaseIPythonApplication):
     description = """print the path to the IPython dir"""
     subcommands = Dict(dict(
         profile=('IPython.core.profileapp.ProfileLocate',
             "print the path to an IPython profile directory",
         ),
     ))
     def start(self):
         if self.subapp is not None:
             return self.subapp.start()
         else:
             print(self.ipython_dir)
 
 
 class TerminalIPythonApp(BaseIPythonApplication, InteractiveShellApp):
     name = u'ipython'
     description = usage.cl_usage
     crash_handler_class = IPAppCrashHandler
     examples = _examples
 
     flags = Dict(flags)
     aliases = Dict(aliases)
     classes = List()
+
+    interactive_shell_class = Type(
+        klass=object,   # use default_value otherwise which only allow subclasses.
+        default_value=TerminalInteractiveShell,
+        help="Class to use to instantiate the TerminalInteractiveShell object. Useful for custom Frontends"
+    ).tag(config=True)
+
     @default('classes')
     def _classes_default(self):
         """This has to be in a method, for TerminalIPythonApp to be available."""
         return [
             InteractiveShellApp, # ShellApp comes before TerminalApp, because
             self.__class__,      # it will also affect subclasses (e.g. QtConsole)
             TerminalInteractiveShell,
             HistoryManager,
             ProfileDir,
             PlainTextFormatter,
             IPCompleter,
             ScriptMagics,
             StoreMagics,
         ]
 
     deprecated_subcommands = dict(
         qtconsole=('qtconsole.qtconsoleapp.JupyterQtConsoleApp',
             """DEPRECATED, Will be removed in IPython 6.0 : Launch the Jupyter Qt Console."""
         ),
         notebook=('notebook.notebookapp.NotebookApp',
             """DEPRECATED, Will be removed in IPython 6.0 : Launch the Jupyter HTML Notebook Server."""
         ),
         console=('jupyter_console.app.ZMQTerminalIPythonApp',
             """DEPRECATED, Will be removed in IPython 6.0 : Launch the Jupyter terminal-based Console."""
         ),
         nbconvert=('nbconvert.nbconvertapp.NbConvertApp',
             "DEPRECATED, Will be removed in IPython 6.0 : Convert notebooks to/from other formats."
         ),
         trust=('nbformat.sign.TrustNotebookApp',
             "DEPRECATED, Will be removed in IPython 6.0 : Sign notebooks to trust their potentially unsafe contents at load."
         ),
         kernelspec=('jupyter_client.kernelspecapp.KernelSpecApp',
             "DEPRECATED, Will be removed in IPython 6.0 : Manage Jupyter kernel specifications."
         ),
     )
     subcommands = dict(
         profile = ("IPython.core.profileapp.ProfileApp",
             "Create and manage IPython profiles."
         ),
         kernel = ("ipykernel.kernelapp.IPKernelApp",
             "Start a kernel without an attached frontend."
         ),
         locate=('IPython.terminal.ipapp.LocateIPythonApp',
             LocateIPythonApp.description
         ),
         history=('IPython.core.historyapp.HistoryApp',
             "Manage the IPython history database."
         ),
     )
     deprecated_subcommands['install-nbextension'] = (
         "notebook.nbextensions.InstallNBExtensionApp",
         "DEPRECATED, Will be removed in IPython 6.0 : Install Jupyter notebook extension files"
     )
     subcommands.update(deprecated_subcommands)
 
     # *do* autocreate requested profile, but don't create the config file.
     auto_create=Bool(True)
     # configurables
     quick = Bool(False,
         help="""Start IPython quickly by skipping the loading of config files."""
     ).tag(config=True)
     @observe('quick')
     def _quick_changed(self, change):
         if change['new']:
             self.load_config_file = lambda *a, **kw: None
 
     display_banner = Bool(True,
         help="Whether to display a banner upon starting IPython."
     ).tag(config=True)
 
     # if there is code of files to run from the cmd line, don't interact
     # unless the --i flag (App.force_interact) is true.
     force_interact = Bool(False,
         help="""If a command or file is given via the command-line,
         e.g. 'ipython foo.py', start an interactive shell after executing the
         file or command."""
     ).tag(config=True)
     @observe('force_interact')
     def _force_interact_changed(self, change):
         if change['new']:
             self.interact = True
 
     @observe('file_to_run', 'code_to_run', 'module_to_run')
     def _file_to_run_changed(self, change):
         new = change['new']
         if new:
             self.something_to_run = True
         if new and not self.force_interact:
                 self.interact = False
 
     # internal, not-configurable
     something_to_run=Bool(False)
 
     def parse_command_line(self, argv=None):
         """override to allow old '-pylab' flag with deprecation warning"""
 
         argv = sys.argv[1:] if argv is None else argv
 
         if '-pylab' in argv:
             # deprecated `-pylab` given,
             # warn and transform into current syntax
             argv = argv[:] # copy, don't clobber
             idx = argv.index('-pylab')
             warnings.warn("`-pylab` flag has been deprecated.\n"
             "    Use `--matplotlib <backend>` and import pylab manually.")
             argv[idx] = '--pylab'
 
         return super(TerminalIPythonApp, self).parse_command_line(argv)
     
     @catch_config_error
     def initialize(self, argv=None):
         """Do actions after construct, but before starting the app."""
         super(TerminalIPythonApp, self).initialize(argv)
         if self.subapp is not None:
             # don't bother initializing further, starting subapp
             return
         # print self.extra_args
         if self.extra_args and not self.something_to_run:
             self.file_to_run = self.extra_args[0]
         self.init_path()
         # create the shell
         self.init_shell()
         # and draw the banner
         self.init_banner()
         # Now a variety of things that happen after the banner is printed.
         self.init_gui_pylab()
         self.init_extensions()
         self.init_code()
 
     def init_shell(self):
         """initialize the InteractiveShell instance"""
         # Create an InteractiveShell instance.
         # shell.display_banner should always be False for the terminal
         # based app, because we call shell.show_banner() by hand below
         # so the banner shows *before* all extension loading stuff.
-        self.shell = TerminalInteractiveShell.instance(parent=self,
+        self.shell = self.interactive_shell_class.instance(parent=self,
                         profile_dir=self.profile_dir,
                         ipython_dir=self.ipython_dir, user_ns=self.user_ns)
         self.shell.configurables.append(self)
 
     def init_banner(self):
         """optionally display the banner"""
         if self.display_banner and self.interact:
             self.shell.show_banner()
         # Make sure there is a space below the banner.
         if self.log_level <= logging.INFO: print()
 
     def _pylab_changed(self, name, old, new):
         """Replace --pylab='inline' with --pylab='auto'"""
         if new == 'inline':
             warnings.warn("'inline' not available as pylab backend, "
                       "using 'auto' instead.")
             self.pylab = 'auto'
 
     def start(self):
         if self.subapp is not None:
             return self.subapp.start()
         # perform any prexec steps:
         if self.interact:
             self.log.debug("Starting IPython's mainloop...")
             self.shell.mainloop()
         else:
             self.log.debug("IPython not interactive...")
 
 def load_default_config(ipython_dir=None):
     """Load the default config file from the default ipython_dir.
 
     This is useful for embedded shells.
     """
     if ipython_dir is None:
         ipython_dir = get_ipython_dir()
 
     profile_dir = os.path.join(ipython_dir, 'profile_default')
 
     config = Config()
     for cf in Application._load_config_files("ipython_config", path=profile_dir):
         config.update(cf)
 
     return config
 
 launch_new_instance = TerminalIPythonApp.launch_instance
 
 
 if __name__ == '__main__':
     launch_new_instance()

docs/source/whatsnew/development.rst

@@ -1,176 +1,185 b''
 =====================
  Development version
 =====================
 
 This document describes in-flight development work.
 
 .. warning::
 
     Please do not edit this file by hand (doing so will likely cause merge
     conflicts for other Pull Requests). Instead, create a new file in the
     `docs/source/whatsnew/pr` folder
 
 IPython 6.0
 ===========
 
 Released .... ...., 2017
 
 IPython 6 feature a major improvement in the completion machinery which is now
 capable of completing non-executed code. It is also the first version of IPython
 to stop compatibility with Python 2, which is still supported on the bugfix only
 5.x branch. Read below to have a non-exhaustive list of new features.
 
 Make sure you have pip > 9.0 before upgrading. 
 You should be able to update by using:
 
 .. code::
 
     pip install ipython --upgrade
 
 New completion API and Interface
 --------------------------------
 
 The completer Completion API has seen an overhaul, and the new completer have
 plenty of improvement both from the end users of terminal IPython or for
 consumers of the API.
 
 This new API is capable of pulling completions from :any:`jedi`, thus allowing
 type inference on non-executed code. If :any:`jedi` is installed completion like
 the following are now becoming possible without code evaluation:
 
     >>> data = ['Number of users', 123_456]
     ... data[0].<tab>
 
 That is to say, IPython is now capable of inferring that `data[0]` is a string,
 and will suggest completions like `.capitalize`. The completion power of IPython
 will increase with new Jedi releases, and a number of bugs and more completions
 are already available on development version of :any:`jedi` if you are curious.
 
 With the help of prompt toolkit, types of completions can be shown in the
 completer interface:
 
 .. image:: ../_images/jedi_type_inference_60.png
     :alt: Jedi showing ability to do type inference
     :align: center
     :width: 400px
     :target: ../_images/jedi_type_inference_60.png
 
 The appearance of the completer is controlled by the
 ``c.TerminalInteractiveShell.display_completions`` option that will show the
 type differently depending on the value among ``'column'``, ``'multicolumn'``
 and ``'readlinelike'``
 
 The use of Jedi also full fill a number of request and fix a number of bugs
 like case insensitive completion, completion after division operator: See
 :ghpull:`10182`.
 
 Extra patches and updates will be needed to the :mod:`ipykernel` package for
 this feature to be available to other clients like jupyter Notebook, Lab,
 Nteract, Hydrogen...
 
 The use of Jedi can is barely noticeable on recent enough machines, but can be
 feel on older ones,  in cases were Jedi behavior need to be adjusted, the amount
 of time given to Jedi to compute type inference can be adjusted with
 ``c.IPCompleter.jedi_compute_type_timeout``, with object whose type were not
 inferred will be shown as ``<unknown>``. Jedi can also be completely deactivated
 by using the ``c.Completer.use_jedi=False`` option.
 
 
 The old ``Completer.complete()`` API is waiting deprecation and should be
 replaced replaced by ``Completer.completions()`` in a near future. Feedback on
 the current state of the API and suggestions welcome.
 
 Python 3 only codebase
 ----------------------
 
 One of the large challenges in IPython 6.0 has been the adoption of a pure
 Python 3 code base, which lead us to great length to upstream patches in pip,
 pypi and warehouse to make sure Python 2 system still upgrade to the latest
 compatible Python version compatible.
 
 We remind our Python 2 users that IPython 5 is still compatible with Python 2.7,
 still maintained and get regular releases. Using pip 9+, upgrading IPython will
 automatically upgrade to the latest version compatible with your system.
 
 .. warning::
 
   If you are on a system using an older verison of pip on Python 2, pip may
   still install IPython 6.0 on your system, and IPython will refuse to start. 
   You can fix this by ugrading pip, and reinstalling ipython, or forcing pip to
   install an earlier version: ``pip install 'ipython<6'``
 
 The ability to use only Python 3 on the code base of IPython has bring a number
 of advantage. Most of the newly written code make use of `optional function type
 anotation <https://www.python.org/dev/peps/pep-0484/>`_ leading to clearer code
 and better documentation.
 
 The total size of the repository has also for a first time between releases
 (excluding the big split for 4.0) decreased by about 1500 lines, potentially
 quite a bit more codewide as some documents like this one are append only and
 are about 300 lines long.
 
 The removal as of Python2/Python3 shim layer has made the code quite clearer and
 more idiomatic in a number of location, and much friendlier to work with and
 understand. We hope to further embrace Python 3 capability in the next release
 cycle and introduce more of the Python 3 only idioms (yield from, kwarg only,
 general unpacking) in the code base of IPython, and see if we can take advantage
 of these as well to improve user experience with better error messages and
 hints.
 
 
+Configurable TerminalInteractiveShell
+-------------------------------------
+
+IPython gained a new ``c.TerminalIPythonApp.interactive_shell_class`` option
+that allow to customize the class used to start the terminal frontend. This
+should allow user to use custom interfaces, like reviving the former readline
+interface which is now a separate package not maintained by the core team.
+
+
 Miscs improvements
 ------------------
 
 
 - The :cellmagic:`capture` magic can now capture the result of a cell (from an
   expression on the last line), as well as printed and displayed output.
   :ghpull:`9851`.
 
 - Pressing Ctrl-Z in the terminal debugger now suspends IPython, as it already
   does in the main terminal prompt.
 
 - autoreload can now reload ``Enum``. See :ghissue:`10232` and :ghpull:`10316`
 
 - IPython.display has gained a :any:`GeoJSON <IPython.display.GeoJSON>` object.
   :ghpull:`10288` and :ghpull:`10253`
 
 .. DO NOT EDIT THIS LINE BEFORE RELEASE. FEATURE INSERTION POINT.
 
 
 Functions Deprecated in 6.x Development cycle
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 - Loading extensions from ``ipython_extension_dir`` print a warning that this
   location is pending deprecation. This should only affect users still having
   extensions installed with ``%install_ext`` which has been deprecated since
   IPython 4.0, and removed in 5.0. Extensions still present in
   ``ipython_extension_dir`` may shadow more recently installed versions using
   pip. It is thus recommended to clean ``ipython_extension_dir`` of any
   extension now available as a package.
 
 
 - ``IPython.utils.warn`` was deprecated in IPython 4.0, and has now been removed.
   instead of ``IPython.utils.warn`` inbuilt :any:`warnings` module is used.
 
 
 - The function `IPython.core.oinspect.py:call_tip` is unused, was marked as
   Deprecated (raising a Deprecation Warning) and marked for later removal
   :ghpull:`10104`
 
 Backwards incompatible changes
 ------------------------------
 
 Functions Removed in 6.x Development cycle
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The following functions have been removed in the
 development cycle marked for Milestone 6.0.
 
 - ``IPython/utils/process.py`` - ``is_cmd_found``
 - ``IPython/utils/process.py`` - ``pycmd2argv``
 
 - The `--deep-reload` flag and the corresponding options to inject `dreload` or
   `reload` into the interactive namespace have been removed. You have to
   explicitly import `reload` from `IPython.lib.deepreload` to use it.
 
 .. DO NOT EDIT THIS LINE BEFORE RELEASE. INCOMPAT INSERTION POINT.