path: root/doc/evil.texi

\input texinfo @c -*-texinfo-*-
@setfilename evil.info
@documentencoding ISO-8859-1
@include version.texi
@settitle Evil-mode manual
@include macros.texi

@copying
This manual is for Evil (version @value{VERSION} of @value{UPDATED}),
an extensible vi layer for Emacs.

Copyright @copyright{} 2011 @authors{}.

@quotation
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled
``GNU Free Documentation License''.
@end quotation

The Evil team thanks everyone at gmane.emacs.vim-emulation for
their feedback and contributions.
@end copying

@dircategory Emacs
@direntry
* Evil: (evil). Extensible vi layer for Emacs.
@end direntry

@titlepage
@title Evil
@subtitle Extensible vi layer for Emacs
@author @authors{}
@page
@insertcopying
@end titlepage

@contents

@ifnottex
@node Top, Overview, (dir), (dir)
@top Evil

This is the manual for Evil, an extensible vi layer for Emacs.
@end ifnottex

@menu
* Overview::
* Settings::
* Keymaps::
* Hooks::
* Macros::
* Other internals::
* GNU Free Documentation License::
@end menu

@node Overview
@chapter Overview

Evil is an extensible vi layer for Emacs.  It emulates the main features
of Vim,@footnote{Vim is the most popular version of @dfn{vi}, a modal
text editor with many implementations.  Vim also adds some functions of
its own, like Visual selection and text objects.  For more information,
see: @uref{http://www.vim.org/}} turning Emacs into a modal editor.
Like Emacs in general, Evil is extensible in Emacs Lisp.

@menu
* Installation::
* Modes and states::
@end menu

@node Installation
@section Installation

Evil lives in a Git repository.  To download Evil, do:

@example
git clone git://gitorious.org/evil/evil.git
@end example

@noindent Move Evil to @code{~/.emacs.d/evil}.  Then add the following
lines to @code{~/.emacs}:

@lisp
(add-to-list 'load-path "~/.emacs.d/evil")
(require 'evil)
(evil-mode 1)
@end lisp

@noindent Evil requires @code{undo-tree.el} to provide linear undo
and undo branches.  It is available from
EmacsWiki.@footnote{@uref{http://www.emacswiki.org/emacs/UndoTree}}
(A copy of @code{undo-tree.el} is also included in the Git repository.)

@node Modes and states
@section Modes and states

The next time Emacs is started, it will come up in @dfn{Normal state},
denoted by @code{<N>} on the mode line.  This is where the main vi
bindings are defined.  Note that you can always disable Normal state
with @kbd{C-z}, which switches to an ``Emacs state'' (denoted by
@code{<E>}) in which vi keys are completely disabled.  Press @kbd{C-z}
again to switch back to Normal state.

Evil uses the term @dfn{state} for what is called a ``mode'' in vi,
since ``mode'' already has its own meaning in Emacs.  Evil defines a
number of states, such as Normal state (@code{<N>}), Insert state
(@code{<I>}), Visual state (@code{<V>}), Replace state (@code{<R>}),
Operator-Pending state (@code{<O>}), Motion state (@code{<M>}) and Emacs
state (@code{<E>}).  Each state has its own keymaps and customization
variables.

Meanwhile, a @dfn{mode} in Emacs is a set of key bindings for editing a
certain sort of text, like @code{emacs-lisp-mode} for Emacs Lisp.  Modes
may include custom bindings for Evil states.

@node Settings
@chapter Settings

Evil's behavior can be adjusted by setting various variables.
The current values may be inspected by doing
@kbd{M-x customize-group RET evil RET}.

To change the value of a variable, add a @samp{setq} form to
@code{~/.emacs}, preferably before Evil is loaded:@footnote{Strictly
speaking, the order only matters if the variable affects the way Evil is
loaded.  This is the case with some of the @samp{evil-want-} variables.}

@lisp
(setq evil-shift-width 8)
;; @r{Load Evil}
(require 'evil) @r{@dots{}}
@end lisp

@noindent Note that if a variable is buffer-local, you must use
@samp{setq-default} instead of @samp{setq} to change its global value.

@defvar evil-auto-indent
Whether the current line is indented when entering Insert state.
If @code{t} (the default), then the line is indented.  If @code{nil},
then the line is not indented.  Buffer-local.
@end defvar

@defvar evil-shift-width
The number of columns a line is shifted by the commands
@kbd{>} and @kbd{<}.
@end defvar

@defvar evil-repeat-move-cursor
If @code{t} (the default), then repeating a command with @kbd{.} may
change the position of the cursor.  If @code{nil}, then the original
position is preserved.
@end defvar

@defvar evil-find-skip-newlines
If @code{t}, then @kbd{f}, @kbd{F}, @kbd{t} and @kbd{T} may skip over
newlines to find a character.  If @code{nil} (the default), then they
are restricted to the current line.
@end defvar

@defvar evil-move-cursor-back
If @code{t} (the default), then the cursor moves backwards when exiting
Insert state.  If @code{nil}, then the cursor does not move.
@end defvar

@defvar evil-want-fine-undo
If @code{t}, then a change-based action like @kbd{cw} may be undone
in several steps.  If @code{nil} (the default), then it is undone in
one step.
@end defvar

@defvar evil-regexp-search
If @code{t} (the default), then @kbd{/} and @kbd{?} use regular
expressions for searching.  If @code{nil}, they use plain text.
@end defvar

@defvar evil-search-wrap
If @code{t} (the default), then @kbd{/} and @kbd{?} wrap the search
around the buffer.  If @code{nil}, then they stop at buffer boundaries.
@end defvar

@defvar evil-flash-delay
The number of seconds to flash search matches when pressing @kbd{n}
and @kbd{N}.
@end defvar

@defvar evil-want-C-i-jump
If @code{t} (the default), then @kbd{C-i} jumps forwards in the jump
list.  If @code{nil}, then @kbd{C-i} inserts a tab.
@end defvar

@defvar evil-want-C-u-scroll
If @code{t}, then @kbd{C-u} scrolls the buffer.  If @code{nil} (the
default), then @kbd{C-u} begins a numeric prefix argument.
@end defvar

@menu
* The cursor::
* The initial state::
@end menu

@node The cursor
@section The cursor

A state may change the cursor's appearance.  The cursor settings are
stored in the variables below, which may contain a cursor type as per
the @samp{cursor-type} variable, a color string as passed to the
@samp{set-cursor-color} function, a zero-argument function for changing
the cursor, or a list of the above.  For example, the following changes
the cursor in Replace state to a red box:

@lisp
(setq evil-replace-state-cursor '("red" box))
@end lisp

@noindent If the state does not specify a cursor,
@samp{evil-default-cursor} is used.

@defvar evil-default-cursor
The default cursor.
@end defvar

@defvar evil-normal-state-cursor
The cursor for Normal state.
@end defvar

@defvar evil-insert-state-cursor
The cursor for Insert state.
@end defvar

@defvar evil-visual-state-cursor
The cursor for Visual state.
@end defvar

@defvar evil-replace-state-cursor
The cursor for Replace state.
@end defvar

@defvar evil-operator-state-cursor
The cursor for Operator-Pending state.
@end defvar

@defvar evil-motion-state-cursor
The cursor for Motion state.
@end defvar

@defvar evil-emacs-state-cursor
The cursor for Emacs state.
@end defvar

@node The initial state
@section The initial state

By default, a new buffer comes up in Normal state.  This can be changed
with the function @samp{evil-set-initial-state}.

@defun evil-set-initial-state mode state
Set the initial state for a buffer in which @var{mode} is active to
@var{state}.  @var{mode} should be a major mode such as
@code{text-mode}, although minor modes work as well.
@end defun

@node Keymaps
@chapter Keymaps

Evil's key bindings are stored in a number of keymaps.  Each state has a
@dfn{global keymap}, where the default key bindings for the state are
stored.  For example, the global keymap for Normal state is
@samp{evil-normal-state-map}, and the key bindings in this map are seen
in all buffers that are currently in Normal state.

Keymaps are modified with the Emacs function @samp{define-key}:

@lisp
(define-key evil-normal-state-map "w" 'foo)
@end lisp

@noindent This binds the key @kbd{w} to the command @samp{foo}
in Normal state.  The file @code{evil-maps.el} contains all the
key bindings.

@defvar evil-normal-state-map
The global keymap for Normal state.
@end defvar

@defvar evil-insert-state-map
The global keymap for Insert state.
@end defvar

@defvar evil-visual-state-map
The global keymap for Visual state.
@end defvar

@defvar evil-replace-state-map
The global keymap for Replace state.
@end defvar

@defvar evil-operator-state-map
The global keymap for Operator-Pending state.
@end defvar

@defvar evil-motion-state-map
The global keymap for Motion state.
@end defvar

@noindent Each state also has a @dfn{buffer-local keymap},
which is specific to the current buffer and has precedence over
the global keymap.  These maps may be changed from a mode hook.

@defvar evil-normal-state-local-map
Buffer-local keymap for Normal state.
@end defvar

@defvar evil-insert-state-local-map
Buffer-local keymap for Insert state.
@end defvar

@defvar evil-visual-state-local-map
Buffer-local keymap for Visual state.
@end defvar

@defvar evil-replace-state-local-map
Buffer-local keymap for Replace state.
@end defvar

@defvar evil-operator-state-local-map
Buffer-local keymap for Operator-Pending state.
@end defvar

@defvar evil-motion-state-local-map
Buffer-local keymap for Motion state.
@end defvar

@menu
* @samp{evil-define-key}::
@end menu

@node @samp{evil-define-key}
@section @samp{evil-define-key}

Finally, Evil provides the function @samp{evil-define-key} for adding
state bindings to a regular keymap.

@defun evil-define-key state keymap key def
In @var{keymap}, create a binding from @var{key} to @var{def} in
@var{state}.  @var{state} is one of @samp{normal}, @samp{insert},
@samp{visual}, @samp{replace}, @samp{operator} and @samp{motion}.
The other parameters are like those of @samp{define-key}.
@end defun

@noindent @samp{evil-define-key} can be used to augment existing
modes with state bindings, as well as create packages for custom
bindings.  For example, the following will create a minor mode
@code{foo-mode} with Normal state bindings for the keys @kbd{w}
and @kbd{e}:

@lisp
(define-minor-mode foo-mode
  "Foo mode."
  :keymap (make-sparse-keymap))

(evil-define-key 'normal foo-mode-map "w" 'bar)
(evil-define-key 'normal foo-mode-map "e" 'baz)
@end lisp

@noindent This minor mode can then be enabled in any buffers where
the custom bindings are desired:

@lisp
(add-hook 'text-mode-hook 'foo-mode) ; @r{enable alongside @code{text-mode}}
@end lisp

@noindent If the minor mode is put into its own file @code{foo.el}
with a @code{(provide 'foo)} statement, it becomes an Emacs package.

@node Hooks
@chapter Hooks

A @dfn{hook} is a list of functions to execute.  Hooks are modified with
the Emacs function @samp{add-hook}.  Evil provides entry and exit hooks
for all of its states.

@defvar evil-normal-state-entry-hook
Run when entering Normal state.
@end defvar

@defvar evil-normal-state-exit-hook
Run when exiting Normal state.
@end defvar

@defvar evil-insert-state-entry-hook
Run when entering Insert state.
@end defvar

@defvar evil-insert-state-exit-hook
Run when exiting Insert state.
@end defvar

@defvar evil-visual-state-entry-hook
Run when entering Visual state.
@end defvar

@defvar evil-visual-state-exit-hook
Run when exiting Visual state.
@end defvar

@defvar evil-replace-state-entry-hook
Run when entering Replace state.
@end defvar

@defvar evil-replace-state-exit-hook
Run when exiting Replace state.
@end defvar

@defvar evil-operator-state-entry-hook
Run when entering Operator-Pending state.
@end defvar

@defvar evil-operator-state-exit-hook
Run when exiting Operator-Pending state.
@end defvar

@defvar evil-motion-state-entry-hook
Run when entering Motion state.
@end defvar

@defvar evil-motion-state-exit-hook
Run when exiting Motion state.
@end defvar

@noindent When these hooks are run, the variables @samp{evil-next-state}
and @samp{evil-previous-state} hold information about the states being
switched to and from.

@defvar evil-next-state
The state being switched to.
@end defvar

@defvar evil-previous-state
The state being switched from.
@end defvar

@node Macros
@chapter Macros

Evil is implemented in terms of reusable macros.  Package writers can
use these to define new commands.

@menu
* Motions::
* Operators::
* Text objects::
* Types::
* States::
@end menu

@node Motions
@section Motions

A @dfn{motion} is a command which moves the cursor, such as @kbd{w} and
@kbd{e}.  Motions are defined with the macro @samp{evil-define-motion}.
Motions not defined in this way should be declared with
@samp{evil-declare-motion}.

@defun evil-declare-motion command
Declare @var{command} to be a motion.  This ensures that it works
properly in Visual state.
@end defun

@defmac evil-define-motion motion (count args@dots{}) doc keyword-args@dots{} body@dots{}
Define a movement command @var{motion}.  A motion can have any number of
arguments, but the first argument, if any, has a predefined meaning as
the @var{count}. It is a positive or negative number, or @code{nil}.
The argument list is followed by the documentation string @var{doc},
which is followed by optional keyword arguments:

@table @code
@item :type @var{type}
The @var{type} determines how the motion works after an operator.  If
@var{type} is @samp{inclusive}, then the ending position is included in
the motion range.  If @var{type} is @samp{line}, then the range is
expanded to linewise positions.  If @var{type} is @samp{block}, then the
range is blockwise.  The default is @samp{exclusive}, which means that
the range is used as-is.

@item :jump @var{jump}
If @var{jump} is @code{t}, then the previous position is stored in the
jump list so it can be restored with @kbd{C-o}.  The default is
@code{nil}.
@end table

The keyword arguments are followed by the @var{body}, which is where
the motion's behavior is defined.  For instance:

@lisp
(evil-define-motion foo-forward (count)
  "Move to the right by COUNT characters."
  :type inclusive
  (forward-char (or count 1)))
@end lisp

For more examples, you can view the source code for any command with
@kbd{C-h k}.  For instance, @samp{evil-goto-line} may be viewed by
typing @kbd{C-h k G} and following the file link.
@end defmac

@node Operators
@section Operators

An @dfn{operator} is a command which acts on the text moved over by a
motion, such as @kbd{c}, @kbd{d} and @kbd{y}.  Operators are defined
with the macro @samp{evil-define-operator}.

@defmac evil-define-operator operator (beg end type args@dots{}) doc keyword-args@dots{} body@dots{}
Define an operator command @var{operator}.  An operator must have at
least two or three arguments, which have predefined meanings.
@var{beg} is the beginning position, @var{end} is the ending position,
and @var{type}, if given, is the type of the motion range.  The argument
list is followed by the documentation string @var{doc}, which is
followed by optional keyword arguments:

@table @code
@item :type @var{type}
Make the input range be a certain @var{type}.  For example, an operator
which only works with whole lines may set @var{type} to @samp{line}.

@item :motion @var{motion}
Use the motion @var{motion} instead of reading one from the keyboard.
This does not affect the behavior in Visual state, where the selection
boundaries are used instead.

@item :repeat @var{repeat}
If @var{repeat} is @code{t} (the default), then @kbd{.} will repeat the
operator.  If @var{repeat} is @code{nil}, then the operator will not be
repeated.

@item :move-point @var{move-point}
If @var{move-point} is @code{t} (the default), then the cursor is
positioned at the beginning of the range.  If @var{move-point} is
@code{nil}, then the original position is preserved.

@item :keep-visual @var{keep-visual}
If @var{keep-visual} is @code{t}, then the selection is not disabled
when the operator is run in Visual state; it is up to the operator to do
this.  The default is @code{nil}, which means that Visual state is
exited automatically.
@end table

The keyword arguments are followed by the @var{body}, which is where the
operator's actions on @var{beg} and @var{end} are defined.  For example,
@samp{evil-rot13}, which is bound to @kbd{g?} and performs ROT13
encryption on the text, may be defined as:

@lisp
(evil-define-operator evil-rot13 (beg end)
  "ROT13 encrypt text."
  (rot13-region beg end))
@end lisp

Pressing @kbd{g?w} will encrypt a word by calling @samp{rot13-region}
on the text moved over by the @kbd{w} motion.
@end defmac

@node Text objects
@section Text objects

A @dfn{text object} is a special kind of motion which sets a beginning
position as well as an ending position, such as @kbd{iw} and @kbd{a(}.
In Visual state, text objects alter both ends of the selection.  Text
objects are defined with the macro @samp{evil-define-text-object}.

@defmac evil-define-text-object object (count args@dots{}) doc keyword-args@dots{} body@dots{}
Define a text object @var{object}.  The first argument has a predefined
meaning as the @var{count}: it is a positive or negative number.  The
argument list is followed by the documentation string @var{doc}, which
is followed by optional keyword arguments:

@table @code
@item :type @var{type}
Use the type @var{type} after an operator.  In Visual state, this is the
type of the selection.

@item :extend-selection @var{extend-selection}
If @var{extend-selection} is @code{t} (the default), then the text
object always enlarges the current selection.  If @code{nil}, then the
object replaces the selection.
@end table

The keyword arguments are followed by the @var{body}, which should
evaluate to a list @code{(@var{beg} @var{end})} of two positions in the
buffer.  For example, a text object which selects three characters
following the current position could be defined as:

@lisp
(evil-define-text-object foo (count)
  "Select three characters."
  (list (point) (+ (point) 3)))
@end lisp
@end defmac

@noindent Evil provides several functions which return a list of
positions, for use in the definition of a text object.  These functions
follow the rule that a positive @var{count} selects text after the
current position, while a negative @var{count} selects text before it.

@defun evil-inner-object-range count forward backward
Return a text range @code{(@var{beg} @var{end})} of @var{count}
``inner'' text objects (e.g., @kbd{iw}, @kbd{is}).  @var{forward} is a
function which moves to the end of an object, and @var{backward} is a
function which moves to the beginning.
@end defun

@defun evil-an-object-range count forward backward
Return a text range @code{(@var{beg} @var{end})} of @var{count} text
objects with whitespace (e.g., @kbd{aw}, @kbd{as}).  @var{forward} is a
function which moves to the end of an object, and @var{backward} is a
function which moves to the beginning.
@end defun

@defun evil-paren-range count open close &optional exclusive
Return a text range @code{(@var{beg} @var{end})} of @var{count}
delimited blocks (e.g., @kbd{i(}, @kbd{a(}). @var{open} and @var{close}
are characters.  If @var{exclusive} is non-nil, then the delimiters are
excluded from the range.  This function uses Emacs' syntax table and is
only applicable for single-character delimiters; use
@samp{evil-regexp-range} to match multiple characters.
@end defun

@defun evil-regexp-range count open close &optional exclusive
Return a text range @code{(@var{beg} @var{end})} of @var{count}
delimited blocks (e.g., @kbd{it}, @kbd{at}). @var{open} and @var{close}
are regular expressions.  If @var{exclusive} is non-nil, then the
delimiters are excluded from the range.
@end defun

@node Types
@section Types

A @dfn{type} is a transformation on a pair of buffer positions.  Evil
defines the types @samp{exclusive}, @samp{inclusive}, @samp{line} and
@samp{block}, which are used for motion ranges and Visual selection.
Types are defined with the macro @samp{evil-define-type}.

@defmac evil-define-type type doc keyword-args@dots{}
Define a type @var{type}, described by the documentation string
@var{doc}.  Then follows keyword arguments:

@table @code
@item :expand @var{expand}
A function which takes two buffer positions and returns a list
@code{(@var{beg} @var{end})} of expanded positions.

@item :contract @var{contract}
A function which takes two expanded buffer positions and returns a list
@code{(@var{beg} @var{end})} of unexpanded positions.  Optional.

@item :normalize @var{normalize}
A function which takes two unexpanded buffer positions and returns a
list @code{(@var{beg} @var{end})} of adjusted positions.  Optional.

@item :injective @var{injective}
If @code{t} (the default), then expansion is one-to-one -- i.e.,
@var{expand} followed by @var{contract} always returns the original
positions.  If @code{nil}, then several positions may expand to the same
(for example, the @samp{line} type is one-to-many as it expands to the
containing lines).
@end table

Further keywords and functions may be specified.  These are understood
to be transformations on buffer positions, like @var{expand} and
@var{contract}.
@end defmac

@node States
@section States

States are defined with the macro @samp{evil-define-state}.  The macro
defines the necessary hooks, keymaps and variables for a state, as well
as a toggle function @samp{evil-@var{state}-state} for entering the
state, and a predicate function @samp{evil-@var{state}-state-p} which
returns @code{t} when the state is active, and @code{nil} otherwise.

@defmac evil-define-state state doc keyword-args@dots{} body@dots{}
Define an Evil state @var{state}, described by the documentation string
@var{doc}.  Then follows optional keyword arguments:

@table @code
@item :tag @var{tag}
Mode line indicitor, e.g., @code{"<T>"}.
@item :message @var{message}
String shown in the echo area.
@item :cursor @var{cursor}
Cursor specification.
@item :enable @var{enable}
List of other modes and states to enable.  A state may enable another
state's keymaps in addition to its own.
@end table

This is followed the @var{body}, which is executed whenever the state is
enabled or disabled.  The state's predicate function may be used to
distinguish between the two.
@end defmac

@node Other internals
@chapter Other internals

@menu
* Command properties::
@end menu

@node Command properties
@section Command properties

Evil defines @dfn{command properties} to store information about
commands, such as whether they should be repeated.  A command property
is a @code{@var{:keyword}} with an associated value, e.g., @code{:repeat
nil}.

@defun evil-add-command-properties command &rest properties
Add @var{properties} to @var{command}.  The properties should be
specified as a list of keywords and values:

@lisp
(evil-add-command-properties 'my-command :repeat t)
@end lisp
@end defun

@defun evil-set-command-properties command &rest properties
Like @samp{evil-add-command-properties}, but resets all
previous properties.
@end defun

@defun evil-get-command-property command property
Return the value of a command property.
@end defun

@defmac evil-define-command command (args@dots{}) doc keyword-args@dots{} body@dots{}
Define a command with command properties @var{keyword-args}.
@end defmac

@noindent For setting repeat properties, Evil provides the
following functions:

@defun evil-declare-repeat command
Declare @var{command} to be repeatable.
@end defun

@defun evil-declare-not-repeat command
Declare @var{command} to be nonrepeatable.
@end defun

@defun evil-declare-change-repeat command
Declare @var{command} to be repeatable by buffer changes rather than
keystrokes.
@end defun

@node GNU Free Documentation License
@appendix GNU Free Documentation License
@include fdl-1.3.texi

@bye

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