Xonsh

====================
**Added:**

* Question mark literals, ``?``, are now allowed as part of
subprocess argument names.
* IPython style visual pointer to show where syntax error was detected
* Pretty printing of output and syntax highlighting of input and output can now
be controlled via new environment variables ``$COLOR_INPUT``,
``$COLOR_RESULTS``, and ``$PRETTY_PRINT_RESULTS``.

* In interactive mode, if there are stopped or background jobs, Xonsh prompts
for confirmations rather than just killing all jobs and exiting.

**Changed:**

* ``which`` now gives a better verbose report of where the executables are
found.
* Tab completion now uses a different interface, which allows new completers
to be implemented in Python.
* Most functions in the ``Execer`` now take an extra argument
``transform``, indicating whether the syntax tree transformations should
be applied.
* ``prompt_toolkit`` is now loaded lazily, decreasing load times when using
the ``readline`` shell.
* RC files are now executed directly in the appropriate context.
* ``_`` is now updated by ``![]``, to contain the appropriate
``CompletedCommand`` object.



**Removed:**

* Fixed bug on Windows where ``which`` did not include current directory

**Fixed:**

* Fixed crashed bash-completer when bash is not available on Windows
* Fixed bug on Windows where tab-completion for executables would return all files.
* Fixed bug on Windows which caused the bash $PROMPT variable to be used when no
no $PROMPT variable was set in .xonshrc
* Improved start-up times by caching information about bash completion
functions
* The --shell-type CLI flag now takes precedence over $SHELL_TYPE specified in
.xonshrc
* Fixed an issue about ``os.killpg()`` on OS X which caused xonsh crash with
occasionally.

====================
**Fixed:**

* Fixed PermissionError when tab completions tries to lookup executables in
directories without read permissions.
* Fixed incorrect parsing of command line flags

====================
**Added:**

* When a subprocess exits with a signal (e.g. SIGSEGV), a message is printed,
similar to Bash.
* Added comma literals to subproc mode.
* ``$(cmd)`` has been added as a subprocess-mode operator, which replaces in
the subprocess command itself with the result of running ``cmd``.
* New ``showcmd`` alias for displaying how xonsh interprets subprocess mode
commands and arguments.
* Added ``$DYNAMIC_CWD_WIDTH`` to allow the adjusting of the current working
directory width in the prompt.
* Added ``$XONSH_DEBUG`` environment variable to help with debugging.
* The ``${...}`` shortcut for ``__xonsh_env__`` now returns appropriate
completion options

**Changed:**

* On Windows the default bash completions files ``$BASH_COMPLETIONS`` now points
to the default location of the completions files used by 'Git for Windows'
* On Cygwin, some tweaks are applied to foreign shell subprocess calls and the
readline import, in order to avoid hangs on launch.


**Removed:**

* Special cased code for handling version of prompt_toolkit < v1.0.0


**Fixed:**

* Show sorted bash completions suggestions.
* Fix bash completions (e.g git etc.) on windows when completions files have
spaces in their path names
* Fixed a bug preventing ``source-bash`` from working on Windows
* Numerous improvements to job control via a nearly-complete rewrite.
* Addressed issue with finding the next break in subproc mode in context
sensitive parsing.
* Fixed issue with loading readline init files (inputrc) that seems to be
triggered by libedit.
* ``$MULTILINE_PROMPT`` now allows colors, as originally intended.
* Rectified install issue with Jupyter hook when installing with pyenv,
Jupyter install hook now respects ``--prefix`` argument.
* Fixed issue with the xonsh.ply subpackage not being installed.
* Fixed a parsing bug whereby a trailing ``&`` on a line was being ignored
(processes were unable to be started in the background)

====================
**Added:**

* ``and``, ``or``, ``&&``, ``||`` have been added as subprocess logical operators,
by popular demand!
* Subprocesses may be negated with ``not`` and grouped together with parentheses.
* New framework for writing xonsh extensions, called ``xontribs``.
* Added a new shell type ``'none'``, used to avoid importing ``readline`` or
``prompt_toolkit`` when running scripts or running a single command.
* New: `sudo` functionality on Windows through an alias
* Automatically enhance colors for readability in the default terminal (cmd.exe)
on Windows. This functionality can be enabled/disabled with the
$INTENSIFY_COLORS_ON_WIN environment variable.
* Added ``Ellipsis`` lookup to ``__xonsh_env__`` to allow environment variable checks, e.g. ``'HOME' in ${...}``
* Added an option to update ``os.environ`` every time the xonsh environment changes.
This is disabled by default but can be enabled by setting ``$UPDATE_OS_ENVIRON`` to
True.
* Added Windows 'cmd.exe' as a foreign shell. This gives xonsh the ability to source
Windows Batch files (.bat and .cmd). Calling ``source-cmd script.bat`` or the
alias ``source-bat script.bat`` will call the bat file and changes to the
environment variables will be reflected in xonsh.
* Added an alias for the conda environment activate/deactivate batch scripts when
running the Anaconda python distribution on Windows.
* Added a menu entry to launch xonsh when installing xonsh from a conda package
* Added a new ``which`` alias that supports both regular ``which`` and also searches
through xonsh aliases. A pure python implementation of ``which`` is used. Thanks
to Trent Mick. https://github.com/trentm/which/
* Added support for prompt toolkit v1.0.0.
* Added ``$XONSH_CACHE_SCRIPTS`` and ``$XONSH_CACHE_EVERYTHING`` environment
variables to control caching of scripts and interactive commands. These can
also be controlled by command line options ``--no-script-cache`` and
``--cache-everything`` when starting xonsh.
* Added a workaround to allow ctrl-c to interrupt reverse incremental search in
the readline shell

**Changed:**

* Running scripts through xonsh (or running a single command with ``-c``) no
longer runs the user's rc file, unless the ``--login`` option is specified.
Also avoids loading aliases and environments from foreign shells, as well as
loading bash completions.
* rc files are now compiled and cached, to avoid re-parsing when they haven't
changed. Scripts are also compiled and cached, and there is the option to
cache interactive commands.
* Left and Right arrows in the ``prompt_toolkit`` shell now wrap in multiline
environments
* Regexpath matching with backticks, now returns an empty list in python mode.
* Pygments added as a dependency for the conda package
* Foreign shells now allow for setting exit-on-error commands before and after
all other commands via the ``seterrprevcmd`` and ``seterrpostcmd`` arguments.
Sensinble defaults are provided for existing shells.
* PLY is no longer a external dependency but is bundled in xonsh/ply. Xonsh can
therefore run without any external dependencies, although having prompt-toolkit
recommended.
* Provide better user feedback when running ``which`` in a platform that doesn't
provide it (e.g. Windows).
* The lexer now uses a custom tokenizer that handles regex globs in the proper
way.






**Fixed:**

* Fixed bug with loading prompt-toolkit shell < v0.57.
* Fixed bug with prompt-toolkit completion when the cursor is not at the end of
the line.
* Aliases will now evaluate environment variables and other expansions
at execution time rather than passing through a literal string.
* Fixed environment variables from os.environ not being loaded when a running
a script
* The readline shell will now load the inputrc files.
* Fixed bug that prevented `source-alias` from working.
* Now able to ``^C`` the xonfig wizard on start up.
* Fixed deadlock on Windows when running subprocess that generates enough output
to fill the OS pipe buffer.
* Sourcing foreign shells will now return a non-zero exit code if the
source operation failed for some reason.
* Fixed PermissionError when running commands in directories without read permissions
* Prevent Windows fixups from overriding environment vars in static config
* Fixed Optional Github project status to reflect added/removed files via git_dirty_working_directory()
* Fixed xonsh.exe launcher on Windows, when Python install directory has a space in it
* Fixed `$CDPATH` to support `~` and environments variables in its items

====================
**Added:**

* Added new valid ``$SHELL_TYPE`` called ``'best'``. This selects the best value
for the concrete shell type based on the availability on the user's machine.
* New environment variable ``$XONSH_COLOR_STYLE`` will set the color mapping
for all of xonsh.
* New ``XonshStyle`` pygments style will determine the appropriate color
mapping based on ``$XONSH_COLOR_STYLE``. The associated ``xonsh_style_proxy()``
is intended for wrapping ``XonshStyle`` when actually being used by
pygments.
* The functions ``print_color()`` and ``format_color()`` found in ``xonsh.tools``
dispatch to the approriate shell color handling and may be used from
anywhere.
* ``xonsh.tools.HAVE_PYGMENTS`` flag now denotes if pygments is installed and
available on the users system.
* The ``ansi_colors`` module is now available for handling ANSI color codes.
* ``?`` and ``??`` operator output now has colored titles, like in IPython.
* ``??`` will syntax highlight source code if pygments is available.
* Python mode output is now syntax highlighted if pygments is available.
* New ``$RIGHT_PROMPT`` environment variable for displaying right-aligned
text in prompt-toolkit shell.
* Added ``!(...)`` operator, which returns an object representing the result
of running a command. The truth value of this object is True if the
return code is equal to zero and False otherwise.
* Optional dependency on the win_unicode_console package to enable unicode
support in cmd.exe on Windows. This can be disabled/enabled with the
``$WIN_UNICODE_CONSOLE`` environment variable.

**Changed:**

* Updated ``$SHELL_TYPE`` default to ``'best'``.
* Shell classes are now responsible for implementing their own color
formatting and printing.
* Prompt coloring, history diffing, and tracing uses new color handling
capabilities.
* New ``Token.Color`` token for xonsh color names, e.g. we now use
``Token.Color.RED`` rather than ``Token.RED``.
* Untracked files in git are ignored when determining if a git workdir is
is dirty. This affects the coloring of the branch label.
* Regular expression globbing now uses ``re.fullmatch`` instead of
``re.match``, and the result of an empty regex glob does not cause the
argument to be deleted.


**Removed:**

* The ``xonsh.tools.TERM_COLORS`` mapping has been axed, along with all
references to it. This may cause a problem if you were using a raw color code
in your xonshrc file from ``$FORMATTER_DICT``. To fix, simply remove these
references.

**Fixed:**

* Multidimensional slicing, as in numpy, no longer throws SyntaxErrors.
* Some minor zsh fixes for more platforms and setups.
* The ``BaseShell.settitle`` method no longer has its commands captured by
``$(...)``

====================
**Added:**

* ``trace`` alias added that enables users to turn on and off the printing
of source code lines prior to their execution. This is useful for debugging scripts.
* New ability to force callable alias functions to be run in the foreground, i.e.
the main thread from which the function was called. This is useful for debuggers
and profilers which may require such access. Use the ``xonsh.proc.foreground``
decorator on an alias function to flag it. ``ForegroundProcProxy`` and
``SimpleForegroundProcProxy`` classes have been added to support this feature.
Normally, forcing a foreground alias is not needed.
* Added boolean ``$RAISE_SUBPROC_ERROR`` environment variable. If true
and a subprocess command exits with a non-zero return code, a
CalledProcessError will be raised. This is useful in scripts that should
fail at the first error.
* If the ``setproctitle`` package is installed, the process title will be
set to ``'xonsh'`` rather than the path to the Python interpreter.
* zsh foreign shell interface now supported natively in xonsh, like with Bash.
New ``source-zsh`` alias allows easy access to zsh scripts and functions.
* Vox virtual environment manager added.

**Changed:**

* The ``foreign_shell_data()`` keyword arguments ``envcmd`` and ``aliascmd``
now default to ``None``.
* Updated alias docs to pull in usage from the commands automatically.

**Fixed:**

* Hundreds of bugs related to line and column numbers have been addressed.
* Fixed path completion not working for absolute paths or for expanded paths on Windows.
* Fixed issue with hg dirty branches and $PATH.
* Fixed issues related to foreign shell data in files with whitespace in the names.
* Worked around bug in ConEmu/cmder which prevented ``get_git_branch()``
from working in these terminal emulators on Windows.