*mark.txt*              Highlight several words in different colors simultaneously. 

			    MARK    by Ingo Karkat
		       (original version by Yuheng Xie)
								    *mark.vim*
description			|mark-description|
usage				|mark-usage|
installation			|mark-installation|
configuration			|mark-configuration|
limitations			|mark-limitations|
known problems			|mark-known-problems|
todo				|mark-todo|
history				|mark-history|

==============================================================================
DESCRIPTION						    *mark-description*

This plugin adds mappings and a :Mark command to highlight several words in
different colors simultaneously, similar to the built-in 'hlsearch'
highlighting of search results and the * |star| command. For example, when you
are browsing a big program file, you could highlight multiple identifiers in
parallel. This will make it easier to trace the source code.

This is a continuation of vimscript #1238 by Yuheng Xie, who apparently
doesn't maintain his original version anymore and cannot be reached via the
email address in his profile. This plugin offers the following advantages over
the original:
- Much faster, all colored words can now be highlighted, no more clashes with
  syntax highlighting (due to use of matchadd()). 
- Many bug fixes. 
- Jumps behave like the built-in search, including wrap and error messages. 
- Like the built-in commands, jumps take an optional [count] to quickly skip
  over some marks. 

RELATED WORKS								     *

- MultipleSearch (vimscript #479) can highlight in a single window and in all
  buffers, but still relies on the :syntax highlighting method, which is
  slower and less reliable. 
- http://vim.wikia.com/wiki/Highlight_multiple_words offers control over the
  color used by mapping the 1-9 keys on the numeric keypad, persistence, and
  highlights only a single window. 
- highlight.vim (vimscript #1599) highlights lines or patterns of interest in
  different colors, using mappings that start with CTRL-H and work on cword. 
- quickhl.vim (vimscript #3692) can also list the matches with colors and in
  addition offers on-the-fly highlighting of the current word (like many IDEs
  do). 

==============================================================================
USAGE								  *mark-usage*

HIGHLIGHTING						   *mark-highlighting*
						     *<Leader>m* *v_<Leader>m*
<Leader>m		Mark the word under the cursor, similar to the |star|
			command. The next free highlight group is used. 
			If already on a mark: Clear the mark, like
			|<Leader>n|. 
{Visual}<Leader>m	Mark or unmark the visual selection. 
						     *<Leader>r* *v_<Leader>r*
<Leader>r		Manually input a regular expression to mark. 
{Visual}<Leader>r	Ditto, based on the visual selection. 

			In accordance with the built-in |star| command,
			all these mappings use 'ignorecase', but not
			'smartcase'. 
								   *<Leader>n*
<Leader>n		Clear the mark under the cursor.
			If not on a mark: Disable all marks, similar to
			|:nohlsearch|. 

			Note: Marks that span multiple lines are not detected,
			so the use of <Leader>n on such a mark will
			unintentionally remove all marks! Use
			{Visual}<Leader>r or :Mark {pattern} to clear
			multi-line marks. 
								       *:Mark*
:Mark {pattern}		Mark or unmark {pattern}. 
			For implementation reasons, {pattern} cannot use the
			'smartcase' setting, only 'ignorecase'. 
:Mark			Disable all marks, similar to |:nohlsearch|. Marks
			will automatically re-enable when a mark is added or
			removed, or a search for marks is performed. 
								  *:MarkClear*
:MarkClear		Clear all marks. In contrast to disabling marks, the
			actual mark information is cleared, the next mark will
			use the first highlight group. This cannot be undone. 


SEARCHING						      *mark-searching*
			    *<Leader>star* *<Leader>#* *<Leader>/* *<Leader>?*
[count]*         [count]#
[count]<Leader>* [count]<Leader>#
[count]<Leader>/ [count]<Leader>?
			Use these six keys to jump to the [count]'th next /
			previous occurrence of a mark. 
			You could also use Vim's / and ? to search, since the
			mark patterns are (optionally, see configuration)
			added to the search history, too. 

            Cursor over mark                    Cursor not over mark
 ---------------------------------------------------------------------------
  <Leader>* Jump to the next occurrence of      Jump to the next occurrence of
            current mark, and remember it       "last mark". 
            as "last mark". 

  <Leader>/ Jump to the next occurrence of      Same as left. 
            ANY mark. 

   *        If <Leader>* is the most recently   Do Vim's original * command. 
            used, do a <Leader>*; otherwise
            (<Leader>/ is the most recently
            used), do a <Leader>/. 

			Note: When the cursor is on a mark, the backwards
			search does not jump to the beginning of the current
			mark (like the built-in search), but to the previous
			mark. The entire mark text is treated as one entity. 

			You can use Vim's |jumplist| to go back to previous
			mark matches and the position before a mark search. 

MARK PERSISTENCE					    *mark-persistence*

The marks can be kept and restored across Vim sessions, using the |viminfo|
file. For this to work, the "!" flag must be part of the 'viminfo' setting: >
    set viminfo+=!  " Save and restore global variables. 
<								   *:MarkLoad*
:MarkLoad		Restore the marks from the previous Vim session. All
			current marks are discarded. 
								   *:MarkSave*
:MarkSave		Save the currently defined marks (or clear the
			persisted marks if no marks are currently defined) for
			use in a future Vim session. 

By default, automatic persistence is enabled (so you don't need to explicitly
|:MarkSave|), but you have to explicitly load the persisted marks in a new Vim
session via |:MarkLoad|, to avoid that you accidentally drag along outdated
highlightings from Vim session to session, and be surprised by the arbitrary
highlight groups and occasional appearance of forgotten marks. If you want
just that though and automatically restore any marks, set |g:mwAutoLoadMarks|. 

You can also initialize the marks to static values, e.g. by including this in
|vimrc|: >
    runtime plugin/mark.vim
    silent MarkClear
    Mark foo
    Mark bar
Or you can define custom commands that preset certain marks: >
    command -bar MyMarks silent MarkClear | execute 'Mark foo' | execute 'Mark bar'
Or a command that adds to the existing marks and then toggles them: >
    command -bar ToggleFooBarMarks execute 'Mark foo' | execute 'Mark bar'

==============================================================================
INSTALLATION						   *mark-installation*

This script is packaged as a|vimball|. If you have the "gunzip" decompressor
in your PATH, simply edit the *.vba.gz package in Vim; otherwise, decompress
the archive first, e.g. using WinZip. Inside Vim, install by sourcing the
vimball or via the |:UseVimball| command. >
    vim mark.vba.gz
    :so %
To uninstall, use the |:RmVimball| command. 

DEPENDENCIES						   *mark-dependencies*

- Requires Vim 7.1 with "matchadd()", or Vim 7.2 or higher. 

==============================================================================
CONFIGURATION						  *mark-configuration*

For a permanent configuration, put the following commands into your |vimrc|. 

						       *mark-highlight-colors*
You may define your own colors or more than the default 6 highlightings in
your vimrc file (or anywhere before this plugin is sourced), in the following
form (where N = 1..): >
    highlight MarkWordN ctermbg=Cyan ctermfg=Black guibg=#8CCBEA guifg=Black
Higher numbers always take precedence and are displayed above lower ones. 

The search type highlighting (in the search message) can be changed via: >
    highlight link SearchSpecialSearchType MoreMsg
<
								 *g:mwHistAdd*
By default, any marked words are also added to the search (/) and input (@)
history; if you don't want that, remove the corresponding symbols from: >
    let g:mwHistAdd = '/@'
<
							   *g:mwAutoLoadMarks*
To enable the automatic restore of marks from a previous Vim session: >
    let g:mwAutoLoadMarks = 1
<							   *g:mwAutoSaveMarks*
To turn off the automatic persistence of marks across Vim sessions: >
    let g:mwAutoSaveMarks = 0
You can still explicitly save marks via |:MarkSave|. 

							       *mark-mappings*
You can use different mappings by mapping to the <Plug>Mark... mappings (use
":map <Plug>Mark" to list them all) before this plugin is sourced. 

There are no default mappings for toggling all marks and for the |:MarkClear|
command, but you can define some yourself: >
    nmap <Leader>M <Plug>MarkToggle
    nmap <Leader>N <Plug>MarkAllClear
<
To remove the default overriding of * and #, use: >
    nmap <Plug>IgnoreMarkSearchNext <Plug>MarkSearchNext
    nmap <Plug>IgnoreMarkSearchPrev <Plug>MarkSearchPrev
<
						 *mark-whitespace-indifferent*
Some people like to create a mark based on the visual selection, like
|v_<Leader>m|, but have whitespace in the selection match any whitespace when
searching (searching for "hello world" will also find "hello<Tab>world" as
well as "hello" at the end of a line, with "world" at the start of the next
line). The Vim Tips Wiki describes such a setup for the built-in search at 
    http://vim.wikia.com/wiki/Search_for_visually_selected_text
You can achieve the same with the Mark plugin through the following scriptlet: >
    function! s:GetVisualSelectionAsLiteralWhitespaceIndifferentPattern()
    	return substitute(escape(mark#GetVisualSelection(), '\' . '^$.*[~'), '\_s\+', '\\_s\\+', 'g')
    endfunction
    vnoremap <silent> <Plug>MarkWhitespaceIndifferent <C-\><C-n>:call mark#DoMark(<SID>GetVisualSelectionAsLiteralWhitespaceIndifferentPattern())<CR>
Using this, you can assign a new visual mode mapping <Leader>* >
    vmap <Leader>* <Plug>MarkWhitespaceIndifferent
or override the default |v_<Leader>m| mapping, in case you always want this
behavior: >
    vmap <Plug>IgnoreMarkSet <Plug>MarkSet
    vmap <Leader>m <Plug>MarkWhitespaceIndifferent
<
==============================================================================
LIMITATIONS						    *mark-limitations*

- If the 'ignorecase' setting is changed, there will be discrepancies between
  the highlighted marks and subsequent jumps to marks. 
- If {pattern} in a :Mark command contains atoms that change the semantics of
  the entire (|/\c|, |/\C|) or following (|/\v|,|/\V|, |/\M|) regular
  expression, there may be discrepancies between the highlighted marks and
  subsequent jumps to marks.  

KNOWN PROBLEMS						 *mark-known-problems*

TODO								   *mark-todo*

IDEAS								  *mark-ideas*

Taken from an alternative implementation at
http://vim.wikia.com/wiki/Highlight_multiple_words: 
- Allow to specify the highlight group number via :[N]Mark {regexp}
- Use keys 1-9 on the numeric keypad to toggle a highlight group number. 

==============================================================================
HISTORY								*mark-history*

2.5.2	09-Nov-2011
Fixed various problems with wrap-around warnings: 
- BUG: With a single match and 'wrapscan' set, a search error was issued. 
- FIX: Backwards search with single match leads to wrong error message
  instead. 
- FIX: Wrong logic for determining l:isWrapped lets wrap-around go undetected. 

2.5.1	17-May-2011
- FIX: == comparison in s:DoMark() leads to wrong regexp (\A vs. \a) being
  cleared when 'ignorecase' is set. Use case-sensitive comparison ==# instead. 
- Refine :MarkLoad messages 
- Add whitespace-indifferent visual mark configuration example. Thanks to Greg
  Klein for the suggestion. 

2.5.0	07-May-2011
- ENH: Add explicit mark persistence via :MarkLoad and :MarkSave commands and
  automatic persistence via the g:mwAutoLoadMarks and g:mwAutoSaveMarks
  configuration flags. (Request from Mun Johl, 16-Apr-2010) 
- Expose toggling of mark display (keeping the mark patterns) via new
  <Plug>MarkToggle mapping. Offer :MarkClear command as a replacement for the
  old argumentless :Mark command, which now just disables, but not clears all
  marks. 

2.4.4	18-Apr-2011
- BUG: Include trailing newline character in check for current mark, so that a
  mark that matches the entire line (e.g. created by V<Leader>m) can be
  cleared via <Leader>n. Thanks to ping for reporting this. 
- FIX: On overlapping marks, mark#CurrentMark() returned the lowest, not the
  highest visible mark. So on overlapping marks, the one that was not visible
  at the cursor position was removed; very confusing! Use reverse iteration
  order.  
- FIX: To avoid an arbitrary ordering of highlightings when the highlighting
  group names roll over, and to avoid order inconsistencies across different
  windows and tabs, we assign a different priority based on the highlighting
  group. 

2.4.3	16-Apr-2011
- Avoid losing the mark highlightings on :syn on or :colorscheme commands.
  Thanks to Zhou YiChao for alerting me to this issue and suggesting a fix. 
- Made the script more robust when somehow no highlightings have been defined
  or when the window-local reckoning of match IDs got lost. I had very
  occasionally encountered such script errors in the past. 
- Made global housekeeping variables script-local, only g:mwHistAdd is used
  for configuration. 

2.4.2	14-Jan-2011 (unreleased)
- FIX: Capturing the visual selection could still clobber the blockwise yank
  mode of the unnamed register. 

2.4.1	13-Jan-2011
- FIX: Using a named register for capturing the visual selection on
  {Visual}<Leader>m and {Visual}<Leader>r clobbered the unnamed register. Now
  using the unnamed register. 

2.4.0	13-Jul-2010
- ENH: The MarkSearch mappings (<Leader>[*#/?]) add the original cursor
  position to the jump list, like the built-in [/?*#nN] commands. This allows
  to use the regular jump commands for mark matches, like with regular search
  matches. 

2.3.3	19-Feb-2010
- BUG: Clearing of an accidental zero-width match (e.g. via :Mark \zs) results
  in endless loop. Thanks to Andy Wokula for the patch. 

2.3.2	17-Nov-2009
- BUG: Creation of literal pattern via '\V' in {Visual}<Leader>m mapping
  collided with individual escaping done in <Leader>m mapping so that an
  escaped '\*' would be interpreted as a multi item when both modes are used
  for marking. Thanks to Andy Wokula for the patch. 

2.3.1	06-Jul-2009
- Now working correctly when 'smartcase' is set. All mappings and the :Mark
  command use 'ignorecase', but not 'smartcase'. 

2.3.0	04-Jul-2009
- All jump commands now take an optional [count], so you can quickly skip over
  some marks, as with the built-in */# and n/N commands. For this, the entire
  core search algorithm has been rewritten. The script's logic has been
  simplified through the use of Vim 7 features like Lists. 
- Now also printing a Vim-alike search error message when 'nowrapscan' is set. 

2.2.0	02-Jul-2009
- Split off functions into autoload script. 
- Initialization of global variables and autocommands is now done lazily on
  the first use, not during loading of the plugin. This reduces Vim startup
  time and footprint as long as the functionality isn't yet used. 
- Split off documentation into separate help file. Now packaging as VimBall.


2.1.0	06-Jun-2009
- Replaced highlighting via :syntax with matchadd() / matchdelete(). This
  requires Vim 7.2 / 7.1 with patches. This method is faster, there are no
  more clashes with syntax highlighting (:match always has preference), and
  the background highlighting does not disappear under 'cursorline'. 
- Using winrestcmd() to fix effects of :windo: By entering a window, its
  height is potentially increased from 0 to 1. 
- Handling multiple tabs by calling s:UpdateScope() on the TabEnter event. 

2.0.0	01-Jun-2009
- Now using Vim List for g:mwWord and thus requiring Vim 7. g:mwCycle is now
  zero-based, but the syntax groups "MarkWordx" are still one-based. 
- Factored :syntax operations out of s:DoMark() and s:UpdateMark() so that
  they can all be done in a single :windo. 
- Normal mode <Plug>MarkSet now has the same semantics as its visual mode
  cousin: If the cursor is on an existing mark, the mark is removed.
  Beforehand, one could only remove a visually selected mark via again
  selecting it. Now, one simply can invoke the mapping when on such a mark. 

1.6.1	31-May-2009
Publication of improved version by Ingo Karkat. 
- Now prepending search type ("any-mark", "same-mark", "new-mark") for better
  identification. 
- Retired the algorithm in s:PrevWord in favor of simply using <cword>, which
  makes mark.vim work like the * command. At the end of a line, non-keyword
  characters may now be marked; the previous algorithm preferred any preceding
  word. 
- BF: If 'iskeyword' contains characters that have a special meaning in a
  regexp (e.g. [.*]), these are now escaped properly. 
- Highlighting can now actually be overridden in the vimrc (anywhere _before_
  sourcing this script) by using ':hi def'. 
- Added missing setter for re-inclusion guard. 

1.5.0	01-Sep-2008
Bug fixes and enhancements by Ingo Karkat. 
- Added <Plug>MarkAllClear (without a default mapping), which clears all
  marks, even when the cursor is on a mark.
- Added <Plug>... mappings for hard-coded \*, \#, \/, \?, * and #, to allow
  re-mapping and disabling. Beforehand, there were some <Plug>... mappings
  and hard-coded ones; now, everything can be customized.
- BF: Using :autocmd without <bang> to avoid removing _all_ autocmds for the
  BufWinEnter event. (Using a custom :augroup would be even better.)
- BF: Explicitly defining s:current_mark_position; some execution paths left
  it undefined, causing errors.
- ENH: Make the match according to the 'ignorecase' setting, like the star
  command.
- ENH: The jumps to the next/prev occurrence now print 'search hit BOTTOM,
  continuing at TOP" and "Pattern not found:..." messages, like the * and n/N
  Vim search commands.
- ENH: Jumps now open folds if the occurrence is inside a closed fold, just
  like n/N do. 

1.1.8-g	25-Apr-2008
Last version published by Yuheng Xie on vim.org. 

1.1.2	22-Mar-2005
Initial version published by Yuheng Xie on vim.org. 

==============================================================================
Copyright: (C) 2005-2008 by Yuheng Xie
           (C) 2008-2011 by Ingo Karkat
The VIM LICENSE applies to this script; see|copyright|. 

Maintainer:	Ingo Karkat <ingo@karkat.de>
==============================================================================
 vim:tw=78:ts=8:ft=help:norl:
