=pod

=head1 NAME

vim_mode.pl

=head1 DESCRIPTION

An Irssi script to emulate some of the vi(m) features for the Irssi inputline.

=head1 INSTALLATION

Copy into your F<~/.irssi/scripts/> directory and load with
C</SCRIPT LOAD vim_mode.pl>. You may wish to have it autoload in one of the
L<usual ways|https://github.com/shabble/irssi-docs/wiki/Guide#Autorunning_Scripts>.

=head2 DEPENDENCIES

For proper :ex mode support, vim-mode requires the installation of F<uberprompt.pl>
Uberprompt can be downloaded from:

L<https://github.com/shabble/irssi-scripts/raw/master/prompt_info/uberprompt.pl>

and follow the instructions at the top of that file for installation.

If you don't need Ex-mode, you can run vim_mode.pl without the
uberprompt.pl script, but it is strongly recommended that you use it.

=head3 Irssi requirements

0.8.12 and above should work fine. However the following features are
disabled in irssi < 0.8.13:

=over 4

=item C<j> C<k> (only with count, they work fine without count in older versions)

=item C<gg>, C<G>

=back

It is intended to work with at Irssi  0.8.12 and later versions. However some
features are disabled in older versions (see below for details).

Perl >= 5.8.1 is recommended for UTF-8 support (which can be disabled if
necessary).  Please report bugs in older versions as well, we'll try to fix
them.  Later versions of Perl are also faster, which is probably beneficial
to a script of this size and complexity.

=head2 SETUP

Run the following command to add a statusbar item that shows which mode
you're in.

C</statusbar window add vim_mode>

And the following to let C<:b [str]> display a list of channels matching your
search string.

C</statusbar window add vim_windows>

B<Note:> Remember to C</save> after adding these statusbar items to make them
permanent.


=head3 FILE-BASED CONFIGURATION

Additionally to the irssi settings described in L<settings|/SETTINGS>, vim_mode
can be configured through an external configuration file named "vim_moderc"
located in F<~/.irssi/vim_moderc>. If available it's loaded on startup and every
supported ex-command is run. Its syntax is similar to "vimrc". To (re)load it
while vim_mode is running use C<:so[urce]>.

Currently Supported ex-commands:

=over 4

=item C<:map>

=back

=head1 USAGE

The following section is divided into the different modes as supported by Vim itself:

=head2 COMMAND MODE

It supports most commonly used command mode features:

=over 2

=item Insert/Command mode. C<Escape> and C<Ctrl-C> enter command mode.  C</set
vim_mode_cmd_seq j> allows to use C<jj> as Escape (any other character can be used as well).

=item Cursor motion: C<h l 0 ^ $ E<lt>SpaceE<gt> E<lt>BSE<gt> f t F T>

=item History motion: C<j k gg G> C<gg> moves to the oldest (first) history
line.  C<G> without a count moves to the current input line, with a count it goes to the I<count-th> history line (1 is the oldest).

=item Cursor word motion: C<w b ge e W gE B E>

=item Word objects (only the following work yet): C<aw aW>

=item Yank and paste: C<y p P>

=item Change and delete: C<c d>

=item Delete at cursor: C<x X>

=item Replace at cursor: C<r>

=item Insert mode: C<i a I A>

=item Switch case: C<~>

=item Repeat change: C<.>

=item Repeat C<ftFT: ; ,>

=item Registers: C<"a-"z "" "0 "* "+ "_> (black hole)

=item Line-wise shortcuts: C<dd cc yy>

=item Shortcuts: C<s S C D>

=item Scroll the scrollback buffer: C<Ctrl-E Ctrl-D Ctrl-Y Ctrl-U Ctrl-F Ctrl-B>

=item Switch to last active window: C<Ctrl-6/Ctrl-^>

=item Switch split windows: <Ctrl-W j Ctrl-W k>

=item Undo/Redo: C<u Ctrl-R>

=back

Counts and combinations work as well, e.g. C<d5fx> or C<3iabcE<lt>escE<gt>>. Counts also work with mapped ex-commands (see below), e.g. if you map C<gb> to do C<:bn>, then C<2gb> will switch to the second next buffer.  Repeat also supports counts.

=head3 REGISTERS

=over 4

=item Appending to register with C<"A-"Z>

=item C<""> is the default yank/delete register.

=item C<"0> contains the last yank (if no register was specified).

=item The special registers C<"* "+> both contain irssi's internal cut-buffer.

=back

=head2 INSERT MODE

The following insert mode mappings are supported:

=over 4

=item Insert register content: Ctrl-R x (where x is the register to insert)

=back

=head2 EX-MODE

Ex-mode (activated by C<:> in command mode) supports the following commands:

=over 4

=item Command History:

C<E<lt>uparrowE<gt>> - cycle backwards through history

C<E<lt>downarrowE<gt>> - cycle forwards through history

C<:eh> - show ex history

=item Switching buffers:

C<:[N]b [N]> - switch to channel number

C<:b#>       - switch to last channel

C<:b> E<lt>partial-channel-nameE<gt>

C<:b> <partial-server>/<partial-channel>

C<:buffer {args}> (same as C<:b>)

C<:[N]bn[ext] [N]> - switch to next window

C<:[N]bp[rev] [N]> - switch to previous window

=item Close window:

C<:[N]bd[elete] [N]>

=item Display windows:

C<:ls>, C<:buffers>

=item Display registers:

<:reg[isters] {args}>, C<:di[splay] {args}>

=item Display undolist:

C<:undol[ist]> (mostly used for debugging)

=item Source files:

C<:so[urce]> - only sources vim_moderc at the moment,
                         F<{file}> not supported

=item Mappings:

C<:map> - display custom mappings

=item Save mappings:

C<:mkv[imrc][!]> - like in Vim, but [file] not supported

=item Substitute: 

C<:s///> - I<i> and I<g> are supported as flags, only /// can be used as
                             separator, uses Perl regex instead of Vim regex

=item Settings: 

C<:se[t]> - display all options

C<:se[t] {option}>         - display all matching options

C<:se[t] {option} {value}> - change option to value

=back

=head3 MAPPINGS

=head4 Commands

=over 4

=item C<:map {lhs}>       - display mappings starting with {lhs}

=item C<:map {lhs} {rhs}> - add mapping

=item C<:unm[ap] {lhs}>   - remove custom mapping

=back

=head4 Parameters

I<{lhs}> is the key combination to be mapped, I<{rhs}> the target. The
C<E<lt>E<gt>> notation is used

(e.g. C<E<lt>C-FE<gt>> is I<Ctrl-F>), case is ignored.
 Supported C<E<lt>E<gt>> keys are:

=over 4

=item C<E<lt>C-AE<gt>> - C<E<lt>C-ZE<gt>>,

=item C<E<lt>C-^E<gt>>, C<E<lt>C-6E<gt>>

=item C<E<lt>SpaceE<gt>>

=item C<E<lt>CRE<gt>> - Enter

=item C<E<lt>BSE<gt>> - Backspace

=item C<E<lt>NopE<gt>> - No-op (Do Nothing).

=back

Mapping ex-mode and irssi commands is supported. When mapping ex-mode commands
the trailing C<E<lt>CrE<gt>> is not necessary. Only default mappings can be used
in I<{rhs}>.

Examples:

=over 4

=item C<:map w  W>      - to remap w to work like W

=item C<:map gb :bnext> - to map gb to call :bnext

=item C<:map gB :bprev>

=item C<:map g1 :b 1>   - to map g1 to switch to buffer 1

=item C<:map gb :b>     - to map gb to :b, 1gb switches to buffer 1, 5gb to 5

=item C<:map E<lt>C-LE<gt> /clear> - map Ctrl-L to irssi command /clear

=item C<:map E<lt>C-GE<gt> /window goto 1>

=item C<:map E<lt>C-EE<gt> <Nop>> - disable <C-E>, it does nothing now

=item C<:unmap E<lt>C-EE<gt>> - restore default behavior of C<E<lt>C-EE<gt>>
after disabling it

=back

Note that you must use C</> for irssi commands (like C</clear>), the current value
of Irssi's cmdchars does B<not> work! This is necessary do differentiate between
ex-commands and irssi commands.

=head2 SETTINGS

The settings are stored as irssi settings and can be set using C</set> as usual
(prepend C<vim_mode_> to setting name) or using the C<:set> ex-command. The
following settings are available:

=over 4

=item utf8:                 support UTF-8 characters, boolean, default on

=item debug:                enable debug output, boolean, default off

=item cmd_seq:              char that when double-pressed simulates C<E<lt>EscE<gt>>, string, default '' (disabled)

=item start_cmd:            start every line in command mode, boolean, default off

=item max_undo_lines:       size of the undo buffer. Integer, default 50 items.

=item ex_history_size:      number of items stored in the ex-mode history. Integer, default 100.

=item prompt_leading_space: determines whether ex mode prepends a space to the displayed input. Boolean, default on

=back

In contrast to irssi's settings, C<:set> accepts 0 and 1 as values for boolean
settings, but only vim_mode's settings can be set/displayed.

Examples:

   :set cmd_seq=j   # set cmd_seq to j
   :set cmd_seq=    # disable cmd_seq
   :set debug=on    # enable debug
   :set debug=off   # disable debug

=head1 SUPPORT

Any behavior different from Vim (unless explicitly documented) should be
considered a bug and reported.

B<NOTE:> This script is still under heavy development, and there may be bugs.
Please submit reproducible sequences to the bug-tracker at:
L<http://github.com/shabble/irssi-scripts/issues/new>

or contact rudi_s or shabble on irc.freenode.net (#irssi and #irssi_vim)

=head1 AUTHORS

Copyright E<copy> 2010-2011 Tom Feist C<E<lt>shabble+irssi@metavore.orgE<gt>> and
Copyright E<copy> 2010-2011 Simon Ruderich C<E<lt>simon@ruderich.orgE<gt>>

=head1 THANKS

Particular thanks go to

=over 4

=item estragib: a lot of testing and many bug reports and feature requests

=item iaj: testing

=item tmr: explaining how various bits of vim work

=back

as well as the rest of C<#irssi> and C<#irssi_vim> on Freenode IRC.

=head1 LICENCE

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

=head1 BUGS

=over 4

=item  count before register doesn't work: e.g. 3"ap doesn't work, but "a3p does

=item mapping an incomplete ex-command doesn't open the ex-mode with the partial
  command (e.g. C<:map gb :b> causes an error instead of opening the ex-mode and
  displaying C<:bE<lt>cursorE<gt>>)

=item undo/redo cursor positions are mostly wrong

=back

=head1 TODO

=over 4

=item History:

=over 4

=item C< * /,?,n,N> to search through history (like rl_history_search.pl)

=back

=item Window switching (C<:b>)

=over 4

=item Tab completion of window(-item) names

=item non-sequential matches(?)

=back

=back

See also the TODO file at
L<github|https://github.com/shabble/irssi-scripts/blob/master/vim-mode/TODO> for
many many more things.

=head2 WONTFIX

Things we're not ever likely to do:

=over 4

=item Macros

=back