mru/plugin/mru.vim

" File: mru.vim
" Author: Yegappan Lakshmanan (yegappan AT yahoo DOT com)
" Version: 3.10.2
" Last Modified: August 14, 2021
" Copyright: Copyright (C) 2003-2021 Yegappan Lakshmanan
" License:   Permission is hereby granted to use and distribute this code,
"            with or without modifications, provided that this copyright
"            notice is copied with it. Like anything else that's free,
"            mru.vim is provided *as is* and comes with no warranty of any
"            kind, either expressed or implied. In no event will the copyright
"            holder be liable for any damages resulting from the use of this
"            software.
"
" ****************** Do not modify after this line ************************
if exists('loaded_mru')
  finish
endif
let loaded_mru=1

if v:version < 700
  finish
endif

" Line continuation used here
let s:cpo_save = &cpoptions
set cpoptions&vim

" MRU configuration variables {{{1
" Maximum number of entries allowed in the MRU list
if !exists('MRU_Max_Entries')
  let MRU_Max_Entries = 100
endif

" Files to exclude from the MRU list
if !exists('MRU_Exclude_Files')
  let MRU_Exclude_Files = ''
endif

" Files to include in the MRU list
if !exists('MRU_Include_Files')
  let MRU_Include_Files = ''
endif

" Height of the MRU window
" Default height is 8
if !exists('MRU_Window_Height')
  let MRU_Window_Height = 8
endif

if !exists('MRU_Use_Current_Window')
  let MRU_Use_Current_Window = 0
endif

if !exists('MRU_Auto_Close')
  let MRU_Auto_Close = 1
endif

if !exists('g:MRU_File')
  if has('unix') || has('macunix')
    let s:MRU_File = $HOME . '/.vim_mru_files'
  else
    let s:MRU_File = $VIM . '/_vim_mru_files'
    if has('win32')
      " MS-Windows
      if !empty($USERPROFILE)
	let s:MRU_File = $USERPROFILE . '\_vim_mru_files'
      endif
    endif
  endif
else
  let s:MRU_File = expand(g:MRU_File)
endif

" Option for enabling or disabling the MRU menu
if !exists('MRU_Add_Menu')
  let MRU_Add_Menu = 1
endif

" Maximum number of file names to show in the MRU menu. If too many files are
" listed in the menu, then Vim becomes slow when updating the menu. So set
" this to a low value.
if !exists('MRU_Max_Menu_Entries')
  let MRU_Max_Menu_Entries = 10
endif

" Maximum number of file names to show in a MRU sub-menu. If the MRU list
" contains more file names than this setting, then the MRU menu is split into
" one or more sub-menus.
if !exists('MRU_Max_Submenu_Entries')
  let MRU_Max_Submenu_Entries = 10
endif

" When only a single matching filename is found in the MRU list, the following
" option controls whether the file name is displayed in the MRU window or the
" file is directly opened. When this variable is set to 0 and a single
" matching file name is found, then the file is directly opened.
if !exists('MRU_Window_Open_Always')
  let MRU_Window_Open_Always = 0
endif

" When opening a file from the MRU list, the file is opened in the current
" tab. If the selected file has to be opened in a tab always, then set the
" following variable to 1. If the file is already opened in a tab, then the
" cursor will be moved to that tab.
if !exists('MRU_Open_File_Use_Tabs')
  let MRU_Open_File_Use_Tabs = 0
endif

" Controls whether fuzzy matching is used for matching a user supplied pattern
" against the file names in the MRU list.
if !exists('MRU_FuzzyMatch')
  if exists('*matchfuzzy')
    " Fuzzy matching is supported only when matchfuzzy() function is present
    let MRU_FuzzyMatch = 1
  else
    let MRU_FuzzyMatch = 0
  endif
endif

" Controls whether the alternate file (:help alternate-file) is set when the
" plugin is loaded to the first file in the MRU list. Default is to set the
" alternate file.
if !exists('MRU_Set_Alternate_File')
  let MRU_Set_Alternate_File = 0
endif

" Format of the file names displayed in the MRU window.
" The default is to display the filename followed by the complete path to the
" file in parenthesis. This variable controls the expressions used to format
" and parse the path. This can be changed to display the filenames in a
" different format. The 'formatter' specifies how to split/format the filename
" and 'parser' specifies how to read the filename back; 'syntax' matches the
" part to be highlighted.
if !exists('MRU_Filename_Format')
  let MRU_Filename_Format = {
	\ 'formatter': 'fnamemodify(v:val, ":t") . " (" . v:val . ")"',
	\ 'parser': '(\zs.*\ze)',
	\ 'syntax': '^.\{-}\ze('
	\}
endif

let s:MRU_buf_name = '-RecentFiles-'

" Control to temporarily lock the MRU list. Used to prevent files from
" getting added to the MRU list when the ':vimgrep' command is executed.
let s:mru_list_locked = 0

" MRU_LoadList                          {{{1
" Loads the latest list of file names from the MRU file
func! s:MRU_LoadList() abort
  " If the MRU file is present, then load the list of filenames. Otherwise
  " start with an empty list.
  if filereadable(s:MRU_File)
    let s:MRU_files = readfile(s:MRU_File)
    if s:MRU_files[0] =~# '^\s*" Most recently edited files in Vim'
      " Generated by the previous version of the MRU plugin.
      " Discard the list.
      let s:MRU_files = []
    elseif s:MRU_files[0] =~# '^#'
      " Remove the comment line
      call remove(s:MRU_files, 0)
    else
      " Unsupported format
      let s:MRU_files = []
    endif
  else
    let s:MRU_files = []
  endif

  " Refresh the MRU menu with the latest list of filenames
  call s:MRU_Refresh_Menu()
endfunc

" MRU_SaveList                          {{{1
" Saves the MRU file names to the MRU file
func! s:MRU_SaveList() abort
  let l = []
  call add(l, '# Most recently edited files in Vim (version 3.0)')
  call extend(l, s:MRU_files)
  call writefile(l, s:MRU_File)
endfunc

" MRU_AddFile                           {{{1
" Adds a file to the MRU file list
"   acmd_bufnr - Buffer number of the file to add
func! s:MRU_AddFile(acmd_bufnr) abort
  if s:mru_list_locked
    " MRU list is currently locked
    return
  endif

  " Get the full path to the filename
  let fname = fnamemodify(bufname(a:acmd_bufnr + 0), ':p')
  if empty(fname)
    return
  endif

  " Skip temporary buffers with buftype set. The buftype is set for buffers
  " used by plugins.
  if !empty(&buftype)
    return
  endif

  if !empty(g:MRU_Include_Files)
    " If MRU_Include_Files is set, include only files matching the
    " specified pattern
    if fname !~# g:MRU_Include_Files
      return
    endif
  endif

  if !empty(g:MRU_Exclude_Files)
    " Do not add files matching the pattern specified in the
    " MRU_Exclude_Files to the MRU list
    if fname =~# g:MRU_Exclude_Files
      return
    endif
  endif

  " If the filename is not already present in the MRU list and is not
  " readable then ignore it
  let idx = index(s:MRU_files, fname)
  if idx == -1
    if !filereadable(fname)
      " File is not readable and is not in the MRU list
      return
    endif
  endif

  " Load the latest MRU file list
  call s:MRU_LoadList()

  " Remove the new file name from the existing MRU list (if already present)
  call filter(s:MRU_files, 'v:val !=# fname')

  " Add the new file list to the beginning of the updated old file list
  call insert(s:MRU_files, fname, 0)

  " Trim the list
  if len(s:MRU_files) > g:MRU_Max_Entries
    call remove(s:MRU_files, g:MRU_Max_Entries, -1)
  endif

  " Save the updated MRU list
  call s:MRU_SaveList()

  " Refresh the MRU menu
  call s:MRU_Refresh_Menu()

  " If the MRU window is open, update the displayed MRU list
  let bname = s:MRU_buf_name
  let winnum = bufwinnr(bname)
  if winnum != -1
    let cur_winnr = winnr()
    call s:MRU_Open_Window('', '', 0)
    if winnr() != cur_winnr
      exe cur_winnr . 'wincmd w'
    endif
  endif
endfunc

" MRU_escape_filename                   {{{1
" Escape special characters in a filename. Special characters in file names
" that should be escaped (for security reasons)
let s:esc_filename_chars = ' *?[{`$%#"|!<>();&' . "'\t\n"
func! s:MRU_escape_filename(fname) abort
  if exists('*fnameescape')
    return fnameescape(a:fname)
  else
    return escape(a:fname, s:esc_filename_chars)
  endif
endfunc

" MRU_Edit_File                         {{{1
" Edit the specified file
"   filename - Name of the file to edit
"   sanitized - Specifies whether the filename is already escaped for special
"   characters or not.
"   splitdir - command modifier for a split (topleft, belowright, etc.)
" Used by the :MRU command and the "Recent Files" menu item
func! s:MRU_Edit_File(filename, sanitized, splitdir) abort
  if !a:sanitized
    let esc_fname = s:MRU_escape_filename(a:filename)
  else
    let esc_fname = a:filename
  endif

  " If the user wants to always open the file in a tab, then open the file
  " in a tab. If it is already opened in a tab, then the cursor will be
  " moved to that tab.
  if g:MRU_Open_File_Use_Tabs
    call s:MRU_Open_File_In_Tab(a:filename, esc_fname)
    return
  endif

  " If the file is already open in one of the windows, jump to it
  let winnum = bufwinnr('^' . a:filename . '$')
  if winnum != -1
    if winnum != winnr()
      exe winnum . 'wincmd w'
    endif
  else
    if !empty(a:splitdir) || (!&hidden && (&modified || !empty(&buftype)
	  \ || &previewwindow))
      " If a split command modifier is specified, always open the file
      " in a new window.
      " Or if the current buffer has unsaved changes or is a special buffer or
      " is the preview window.  The 'hidden' option is also not set.  So open
      " the file in a new window.
      if bufexists(esc_fname)
	exe a:splitdir . ' sbuffer ' . esc_fname
      else
	exe a:splitdir . ' split ' . esc_fname
      endif
    else
      " The current file can be replaced with the selected file.
      if bufexists(esc_fname)
	exe 'buffer ' . esc_fname
      else
	exe 'edit ' . esc_fname
      endif
    endif
    " Make the buffer a listed buffer (in case it was deleted before)
    setlocal buflisted
  endif
endfunc

" MRU_Open_File_In_Tab
" Open a file in a tab. If the file is already opened in a tab, jump to the
" tab. Otherwise, create a new tab and open the file.
"   fname     : Name of the file to open
"   esc_fname : File name with special characters escaped
func! s:MRU_Open_File_In_Tab(fname, esc_fname) abort
  " If the selected file is already open in the current tab or in
  " another tab, jump to it. Otherwise open it in a new tab
  if bufwinnr('^' . a:fname . '$') == -1
    let tabnum = -1
    let i = 1
    let bnum = bufnr('^' . a:fname . '$')
    while i <= tabpagenr('$')
      if index(tabpagebuflist(i), bnum) != -1
	let tabnum = i
	break
      endif
      let i += 1
    endwhile

    if tabnum != -1
      " Goto the tab containing the file
      exe 'tabnext ' . i
    else
      if (winnr('$') == 1) && empty(@%) && !&modified
	" Reuse the current tab if it contains a single new unmodified
	" file.
	if bufexists(a:esc_fname)
	  exe 'buffer ' . a:esc_fname
	else
	  exe 'edit ' . a:esc_fname
	endif
      else
	" Open a new tab as the last tab page
	if v:version >= 800
	  if bufexists(a:esc_fname)
	    exe '$tab sbuffer ' . a:esc_fname
	  else
	    exe '$tabnew ' . a:esc_fname
	  endif
	else
	  if bufexists(a:esc_fname)
	    exe '99999tab sbuffer ' . a:esc_fname
	  else
	    exe '99999tabnew ' . a:esc_fname
	  endif
	endif
      endif
    endif
  endif

  " Jump to the window containing the file
  let winnum = bufwinnr('^' . a:fname . '$')
  if winnum != winnr()
    exe winnum . 'wincmd w'
  endif
endfunc

" MRU_Window_Edit_File                  {{{1
"   fname     : Name of the file to edit. May specify single or multiple
"               files.
"   edit_type : Specifies how to edit the file. Can be one of 'edit' or 'view'.
"               'view' - Open the file as a read-only file
"               'edit' - Edit the file as a regular file
"   multi     : Specifies  whether a single file or multiple files need to be
"               opened.
"   open_type : Specifies where to open the file.
"               useopen - If the file is already present in a window, then
"                         jump to that window.  Otherwise, open the file in
"                         the previous window.
"               newwin_horiz - Open the file in a new horizontal window.
"               newwin_vert - Open the file in a new vertical window.
"               newtab  - Open the file in a new tab. If the file is already
"                         opened in a tab, then jump to that tab.
"               preview - Open the file in the preview window
func! s:MRU_Window_Edit_File(fname, multi, edit_type, open_type) abort
  let esc_fname = s:MRU_escape_filename(a:fname)

  if a:open_type ==# 'newwin_horiz'
    " Edit the file in a new horizontally split window below the previous
    " window
    wincmd p
    if bufexists(esc_fname)
      exe 'belowright sbuffer ' . esc_fname
    else
      exe 'belowright new ' . esc_fname
    endif
  elseif a:open_type ==# 'newwin_vert'
    " Edit the file in a new vertically split window right of the previous
    " window
    wincmd p
    if bufexists(esc_fname)
      exe 'vertical belowright sbuffer ' . esc_fname
    else
      exe 'belowright vnew ' . esc_fname
    endif
  elseif a:open_type ==# 'newtab' || g:MRU_Open_File_Use_Tabs
    call s:MRU_Open_File_In_Tab(a:fname, esc_fname)
  elseif a:open_type ==# 'preview'
    " Edit the file in the preview window
    exe 'topleft pedit ' . esc_fname
  else
    " If the selected file is already open in one of the windows,
    " jump to it
    let winnum = bufwinnr('^' . a:fname . '$')
    if winnum != -1
      exe winnum . 'wincmd w'
    else
      if g:MRU_Auto_Close == 1 && g:MRU_Use_Current_Window == 0
	" Jump to the window from which the MRU window was opened
	if exists('s:MRU_last_buffer')
	  let last_winnr = bufwinnr(s:MRU_last_buffer)
	  if last_winnr != -1 && last_winnr != winnr()
	    exe last_winnr . 'wincmd w'
	  endif
	endif
      else
	if g:MRU_Use_Current_Window == 0
	  " Goto the previous window
	  " If MRU_Use_Current_Window is set to one, then the
	  " current window is used to open the file
	  wincmd p
	endif
      endif

      let split_window = 0

      if (!&hidden && (&modified || &previewwindow)) || a:multi
	" Current buffer has unsaved changes or is the preview window
	" or the user is opening multiple files
	" So open the file in a new window
	let split_window = 1
      endif

      if !empty(&buftype)
	" Current buffer is a special buffer (maybe used by a plugin)
	if g:MRU_Use_Current_Window == 0 ||
	      \ bufnr('%') != bufnr(s:MRU_buf_name)
	  let split_window = 1
	endif
      endif

      " Edit the file
      if split_window
	" Current buffer has unsaved changes or is a special buffer or
	" is the preview window.  So open the file in a new window
	if a:edit_type ==# 'edit'
	  if bufexists(esc_fname)
	    exe 'sbuffer ' . esc_fname
	  else
	    exe 'split ' . esc_fname
	  endif
	else
	  exe 'sview ' . esc_fname
	endif
      else
	let mod = ''
	if g:MRU_Use_Current_Window
	  let mod = 'keepalt '
	endif
	if a:edit_type ==# 'edit'
	  if bufexists(esc_fname)
	    exe mod . 'buffer ' . esc_fname
	  else
	    exe mod . 'edit ' . esc_fname
	  endif
	else
	  exe mod . 'view ' . esc_fname
	endif
      endif
    endif
  endif

  " Make the buffer a listed buffer (in case it was deleted before)
  setlocal buflisted
endfunc

" MRU_Select_File_Cmd                   {{{1
" Open a file selected from the MRU window
"
"   'opt' has two values separated by comma. The first value specifies how to
"   edit the file  and can be either 'edit' or 'view'. The second value
"   specifies where to open the file. It can take one of the following values:
"     'useopen' to open file in the previous window
"     'newwin_horiz' to open the file in a new horizontal split window
"     'newwin_vert' to open the file in a new vertical split window.
"     'newtab' to open the file in a new tab.
" If multiple file names are selected using visual mode, then open multiple
" files (either in split windows or tabs)
func! s:MRU_Select_File_Cmd(opt) range abort
  let [edit_type, open_type] = split(a:opt, ',')

  let fnames = getline(a:firstline, a:lastline)

  if g:MRU_Auto_Close == 1 && g:MRU_Use_Current_Window == 0
    " Automatically close the window if the file window is
    " not used to display the MRU list.
    silent! close
  endif

  let multi = 0

  for f in fnames
    if empty(f)
      continue
    endif

    " The text in the MRU window contains the filename in parenthesis
    let file = matchstr(f, g:MRU_Filename_Format.parser)

    call s:MRU_Window_Edit_File(file, multi, edit_type, open_type)

    if a:firstline != a:lastline
      " Opening multiple files
      let multi = 1
    endif
  endfor
endfunc

" MRU_Warn_Msg                          {{{1
" Display a warning message
func! s:MRU_Warn_Msg(msg) abort
  echohl WarningMsg
  echo a:msg
  echohl None
endfunc

" MRU_Open_Window                       {{{1
" Display the Most Recently Used file list in a temporary window.
" If the 'pat' argument is not empty, then it specifies the pattern of files
" to selectively display in the MRU window.
" The 'splitdir' argument specifies the location (topleft, belowright, etc.)
" of the MRU window.
func! s:MRU_Open_Window(pat, splitdir, winsz) abort

  " Load the latest MRU file list
  call s:MRU_LoadList()

  " Check for empty MRU list
  if empty(s:MRU_files)
    call s:MRU_Warn_Msg('MRU file list is empty')
    return
  endif

  " Save the current buffer number. This is used later to open a file when a
  " entry is selected from the MRU window. The window number is not saved,
  " as the window number will change when new windows are opened.
  let s:MRU_last_buffer = bufnr('%')

  let bname = s:MRU_buf_name

  " If the window is already open, jump to it
  let winnum = bufwinnr(bname)
  if winnum != -1
    if winnr() != winnum
      " If not already in the window, jump to it
      exe winnum . 'wincmd w'
    endif

    setlocal modifiable

    " Delete the contents of the buffer to the black-hole register
    silent! %delete _
  else
    if g:MRU_Use_Current_Window
      " Reuse the current window

      " If the current buffer has unsaved changes or is a special buffer
      " or is the preview window and 'hidden' is not set, then open a
      " new window. Otherwise, open in the current window.
      if !&hidden && (&modified || !empty(&buftype) || &previewwindow)
	let split_window = 1
      else
	let split_window = 0
      endif

      " If the __MRU_Files__ buffer exists, then reuse it. Otherwise open
      " a new buffer
      let bufnum = bufnr(bname)
      if bufnum == -1
	if split_window
	  let cmd = 'botright split ' . bname
	else
	  let cmd = 'edit ' . bname
	endif
      else
	if split_window
	  let cmd = 'botright sbuffer ' . bufnum
	else
	  let cmd = 'buffer ' . bufnum
	endif
      endif

      exe cmd

      if bufnr('%') != bufnr(bname)
	" Failed to edit the MRU buffer
	return
      endif
    else
      " Open a new window at the bottom
      let cmd = 'silent! '
      if empty(a:splitdir)
	let cmd .= 'botright '
      else
	let cmd .= a:splitdir . ' '
      endif
      let sz = a:winsz
      if sz == 0
	let sz = g:MRU_Window_Height
      endif
      let cmd .= sz . 'split '

      " If the __MRU_Files__ buffer exists, then reuse it. Otherwise open
      " a new buffer
      let bufnum = bufnr(bname)
      if bufnum == -1
	let cmd .= bname
      else
	let cmd .= '+buffer' . bufnum
      endif

      exe cmd
    endif
  endif

  setlocal modifiable

  " Mark the buffer as scratch
  setlocal buftype=nofile
  if g:MRU_Use_Current_Window
    " avoid using mru buffer as alternate file
    setlocal bufhidden=wipe
  else
    setlocal bufhidden=delete
  endif
  setlocal noswapfile
  setlocal nobuflisted
  setlocal nowrap
  setlocal nonumber
  if exists('&relativenumber')
    setlocal norelativenumber
  endif
  if exists('&signcolumn')
    setlocal signcolumn=no
  endif
  setlocal foldcolumn=0
  " Set the 'filetype' to 'mru'. This allows the user to apply custom
  " syntax highlighting or other changes to the MRU bufer.
  setlocal filetype=mru
  " Use fixed height and width for the MRU window
  setlocal winfixheight winfixwidth

  " Setup the cpoptions properly for the maps to work
  let old_cpoptions = &cpoptions
  set cpoptions&vim

  " Create mappings to select and edit a file from the MRU list
  nnoremap <buffer> <silent> <CR>
	\ :call <SID>MRU_Select_File_Cmd('edit,useopen')<CR>
  vnoremap <buffer> <silent> <CR>
	\ :call <SID>MRU_Select_File_Cmd('edit,useopen')<CR>
  nnoremap <buffer> <silent> o
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_horiz')<CR>
  vnoremap <buffer> <silent> o
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_horiz')<CR>
  nnoremap <buffer> <silent> <S-CR>
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_horiz')<CR>
  vnoremap <buffer> <silent> <S-CR>
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_horiz')<CR>
  nnoremap <buffer> <silent> O
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_vert')<CR>
  vnoremap <buffer> <silent> O
	\ :call <SID>MRU_Select_File_Cmd('edit,newwin_vert')<CR>
  nnoremap <buffer> <silent> t
	\ :call <SID>MRU_Select_File_Cmd('edit,newtab')<CR>
  vnoremap <buffer> <silent> t
	\ :call <SID>MRU_Select_File_Cmd('edit,newtab')<CR>
  nnoremap <buffer> <silent> v
	\ :call <SID>MRU_Select_File_Cmd('view,useopen')<CR>
  nnoremap <buffer> <silent> p
	\ :call <SID>MRU_Select_File_Cmd('view,preview')<CR>
  vnoremap <buffer> <silent> p
	\ :<C-u>if line("'<") == line("'>")<Bar>
	\     call <SID>MRU_Select_File_Cmd('open,preview')<Bar>
	\ else<Bar>
	\     echoerr "Only a single file can be previewed"<Bar>
	\ endif<CR>
  nnoremap <buffer> <silent> u :MRU<CR>
  nnoremap <buffer> <silent> <2-LeftMouse>
	\ :call <SID>MRU_Select_File_Cmd('edit,useopen')<CR>
  nnoremap <buffer> <silent> d
	\ :<C-U>call <SID>MRU_Delete_From_List()<CR>
  nnoremap <buffer> <silent> q :close<CR>

  " Restore the previous cpoptions settings
  let &cpoptions = old_cpoptions

  " Display the MRU list
  if empty(a:pat)
    " No search pattern specified. Display the complete list
    let m = copy(s:MRU_files)
  else
    " Display only the entries matching the specified pattern. First try
    " fuzzy matching or as a literal pattern.
    if g:MRU_FuzzyMatch
      let m = matchfuzzy(s:MRU_files, a:pat)
    else
      let m = filter(copy(s:MRU_files), 'stridx(v:val, a:pat) != -1')
    endif
    if len(m) == 0
      " No match. Try using it as a regular expression
      let m = filter(copy(s:MRU_files), 'v:val =~# a:pat')
    endif
  endif

  " Get the tail part of the file name (without the directory) and display
  " it along with the full path in parenthesis.
  let  output = map(m, g:MRU_Filename_Format.formatter)
  silent! 0put =output

  " Delete the empty line at the end of the buffer
  silent! $delete _

  " Move the cursor to the beginning of the file
  normal! gg

  " Add syntax highlighting for the file names
  if has_key(g:MRU_Filename_Format, 'syntax')
    exe "syntax match MRUFileName '" . g:MRU_Filename_Format.syntax . "'"
    highlight default link MRUFileName Identifier
  endif

  setlocal nomodifiable
endfunc

" MRU_Complete                          {{{1
" Command-line completion function used by :MRU command
func! s:MRU_Complete(ArgLead, CmdLine, CursorPos) abort
  if empty(a:ArgLead)
    " Return the complete list of MRU files
    return s:MRU_files
  else
    if g:MRU_FuzzyMatch
      " Return only the files fuzzy matching the specified pattern
      return matchfuzzy(s:MRU_files, a:ArgLead)
    else
      " Return only the files matching the specified pattern
      return filter(copy(s:MRU_files), 'v:val =~? a:ArgLead')
    endif
  endif
endfunc

" MRU_Cmd                               {{{1
" Function to handle the MRU command
"   pat - File name pattern passed to the MRU command
func! s:MRU_Cmd(pat, splitdir, winsz) abort
  if empty(a:pat)
    " No arguments specified. Open the MRU window
    call s:MRU_Open_Window('', a:splitdir, a:winsz)
    return
  endif

  " Load the latest MRU file
  call s:MRU_LoadList()

  " Empty MRU list
  if empty(s:MRU_files)
    call s:MRU_Warn_Msg('MRU file list is empty')
    return
  endif

  " If Vim supports fuzzy matching, then try fuzzy matching the pattern
  " against the file names. Otherwise, use the specified string as a literal
  " string and search for filenames containing the string. If only one
  " filename is found, then edit it (unless the user wants to open the MRU
  " window always)
  if g:MRU_FuzzyMatch
    let m = matchfuzzy(s:MRU_files, a:pat)
  else
    let m = filter(copy(s:MRU_files), 'stridx(v:val, a:pat) != -1')
  endif
  if len(m) > 0
    if len(m) == 1 && !g:MRU_Window_Open_Always
      call s:MRU_Edit_File(m[0], 0, a:splitdir)
      return
    endif

    " More than one file matches. Try to find an accurate match
    let new_m = filter(m, 'v:val ==# a:pat')
    if len(new_m) == 1 && !g:MRU_Window_Open_Always
      call s:MRU_Edit_File(new_m[0], 0, a:splitdir)
      return
    endif

    " Couldn't find an exact match, open the MRU window with all the
    " files matching the pattern.
    call s:MRU_Open_Window(a:pat, a:splitdir, a:winsz)
    return
  endif

  " Use the specified string as a regular expression pattern and search
  " for filenames matching the pattern
  let m = filter(copy(s:MRU_files), 'v:val =~? a:pat')

  if len(m) == 0
    " If an existing file (not present in the MRU list) is specified,
    " then open the file.
    if filereadable(a:pat)
      call s:MRU_Edit_File(a:pat, 0, a:splitdir)
      return
    endif

    " No filenames matching the specified pattern are found
    call s:MRU_Warn_Msg("MRU file list doesn't contain " .
	  \ 'files matching ' . a:pat)
    return
  endif

  if len(m) == 1 && !g:MRU_Window_Open_Always
    call s:MRU_Edit_File(m[0], 0, a:splitdir)
    return
  endif

  call s:MRU_Open_Window(a:pat, a:splitdir, a:winsz)
endfunc

" MRU_Toggle                          {{{1
" Toggle MRU
"   pat - File name pattern passed to the MRU command
func! s:MRU_Toggle(pat, splitdir) abort
    " If the MRU window is open, close it
    let winnum = bufwinnr(s:MRU_buf_name)
    if winnum != -1
        exe winnum . 'wincmd w'
        if g:MRU_Use_Current_Window && !empty(expand('#'))
          silent! b #
        else
          silent! close
        endif
    else
        call s:MRU_Cmd(a:pat, a:splitdir, '')
    endif
endfunction

" MRU_add_files_to_menu                 {{{1
" Adds a list of files to the "Recent Files" sub menu under the "File" menu.
"   prefix - Prefix to use for each of the menu entries
"   file_list - List of file names to add to the menu
func! s:MRU_add_files_to_menu(prefix, file_list) abort
  for fname in a:file_list
    " Escape special characters in the filename
    let esc_fname = escape(fnamemodify(fname, ':t'), ".\\" .
	  \ s:esc_filename_chars)
    let esc_fname = substitute(esc_fname, '&', '&&', 'g')

    " Truncate the directory name if it is long
    let dir_name = fnamemodify(fname, ':h')
    if v:version >= 800 || has('patch-7.4.1730')
      let len = strchars(dir_name)
      " Shorten long file names by adding only few characters from
      " the beginning and end.
      if len > 30
	let dir_name = strcharpart(dir_name, 0, 10) .
	      \ '...' .
	      \ strcharpart(dir_name, len - 20)
      endif
    else
      let len = strlen(dir_name)
      " Shorten long file names by adding only few characters from
      " the beginning and end.
      if len > 30
	let dir_name = strpart(dir_name, 0, 10) .
	      \ '...' .
	      \ strpart(dir_name, len - 20)
      endif
    endif
    let esc_dir_name = escape(dir_name, ".\\" . s:esc_filename_chars)
    let esc_dir_name = substitute(esc_dir_name, '&', '&&', 'g')

    let menu_path = '&File.&Recent\ Files.' . a:prefix . esc_fname .
	  \ '\ (' . esc_dir_name . ')'
    let esc_mfname = s:MRU_escape_filename(fname)
    exe 'anoremenu <silent> ' . menu_path .
	  \ " :call <SID>MRU_Edit_File('" . esc_mfname . "', 1, '')<CR>"
    exe 'tmenu ' . menu_path . ' Edit file ' . esc_mfname
  endfor
endfunc

" MRU_Refresh_Menu                      {{{1
" Refresh the MRU menu
func! s:MRU_Refresh_Menu() abort
  if !has('menu') || !g:MRU_Add_Menu
    " No support for menus
    return
  endif

  " Setup the cpoptions properly for the maps to work
  let old_cpoptions = &cpoptions
  set cpoptions&vim

  " Remove the MRU menu
  " To retain the teared-off MRU menu, we need to add a dummy entry
  silent! unmenu &File.&Recent\ Files
  " The menu priority of the File menu is 10. If the MRU plugin runs
  " first before menu.vim, the File menu order may not be correct.
  " So specify the priority of the File menu here.
  10noremenu &File.&Recent\ Files.Dummy <Nop>
  silent! unmenu! &File.&Recent\ Files

  anoremenu <silent> &File.&Recent\ Files.Refresh\ list
	\ :call <SID>MRU_LoadList()<CR>
  exe 'tmenu File.&Recent\ Files.Refresh\ list Reload the MRU file list from '
	\ . s:MRU_escape_filename(s:MRU_File)
  anoremenu File.&Recent\ Files.-SEP1-           :

  " Add the filenames in the MRU list to the menu
  let entry_cnt = len(s:MRU_files)
  if entry_cnt > g:MRU_Max_Menu_Entries
    " Show only MRU_Max_Menu_Entries file names in the menu
    let mru_list = s:MRU_files[0 : g:MRU_Max_Menu_Entries - 1]
    let entry_cnt = g:MRU_Max_Menu_Entries
  else
    let mru_list = s:MRU_files
  endif
  if entry_cnt > g:MRU_Max_Submenu_Entries
    " Split the MRU menu into sub-menus
    for start_idx in range(0, entry_cnt, g:MRU_Max_Submenu_Entries)
      let last_idx = start_idx + g:MRU_Max_Submenu_Entries - 1
      if last_idx >= entry_cnt
	let last_idx = entry_cnt - 1
      endif
      let prefix = 'Files\ (' . (start_idx + 1) . '\.\.\.' .
	    \ (last_idx + 1) . ').'
      call s:MRU_add_files_to_menu(prefix,
	    \ mru_list[start_idx : last_idx])
    endfor
  else
    call s:MRU_add_files_to_menu('', mru_list)
  endif

  " Remove the dummy menu entry
  unmenu &File.&Recent\ Files.Dummy

  " Restore the previous cpoptions settings
  let &cpoptions = old_cpoptions
endfunc

" MRU_Refresh    {{{1
" Remove non-existing files from the MRU list
func s:MRU_Refresh()
  call filter(s:MRU_files, 'filereadable(v:val)')
  call s:MRU_SaveList()
  call s:MRU_Refresh_Menu()
endfunc

" MRU_Delete_From_List    {{{1
" remove the entry under cursor in the MRU window from the MRU list
func s:MRU_Delete_From_List()
  call filter(s:MRU_files,
	\ 'v:val != matchstr(getline("."), g:MRU_Filename_Format.parser)')
  setlocal modifiable
  del _
  setlocal nomodifiable
  call s:MRU_SaveList()
  call s:MRU_Refresh_Menu()
endfunc

" Return the list of file names in the MRU list {{{1
func MruGetFiles(...)
  " Load the latest MRU list
  call s:MRU_LoadList()
  if a:0 == 1
    if g:MRU_FuzzyMatch
      " Return only the files fuzzy matching the specified pattern
      return matchfuzzy(s:MRU_files, a:1)
    endif
    " Return only the files matching the specified pattern
    return filter(copy(s:MRU_files), 'v:val =~? a:1')
  endif
  return copy(s:MRU_files)
endfunc

" Load the MRU list on plugin startup
call s:MRU_LoadList()

" Set the first entry in the MRU list as the alternate file
" Credit to Martin Roa Villescas (https://github.com/mroavi) for the patch.
" bufadd() is available starting from Vim 8.1.1610
if g:MRU_Set_Alternate_File == 1 && (v:version >= 802 || has('patch-8.1.1610'))
  if !empty(s:MRU_files)
    let first_mru_file = s:MRU_files[0]
    if filereadable(first_mru_file)
      call bufadd(first_mru_file)
      let @# = first_mru_file
    endif
  endif
endif

" MRU autocommands {{{1
" Autocommands to update the most recently used files
augroup MRUAutoCmds
  au!
  autocmd BufRead * call s:MRU_AddFile(expand('<abuf>'))
  autocmd BufWritePost * call s:MRU_AddFile(expand('<abuf>'))
  autocmd BufEnter * call s:MRU_AddFile(expand('<abuf>'))

  " The ':vimgrep' command adds all the files searched to the buffer list.
  " This also modifies the MRU list, even though the user didn't edit the
  " files. Use the following autocmds to prevent this.
  autocmd QuickFixCmdPre *vimgrep* let s:mru_list_locked = 1
  autocmd QuickFixCmdPost *vimgrep* let s:mru_list_locked = 0
augroup END

" MRU custom commands {{{1
if v:version >= 800
  command! -nargs=? -complete=customlist,s:MRU_Complete -count=0 MRU
	\ call s:MRU_Cmd(<q-args>, <q-mods>, <count>)
  command! -nargs=? -complete=customlist,s:MRU_Complete -count=0 Mru
	\ call s:MRU_Cmd(<q-args>, <q-mods>, <count>)
  command! -nargs=? -complete=customlist,s:MRU_Complete MRUToggle
              \ call s:MRU_Toggle(<q-args>, <q-mods>)
else
  command! -nargs=? -complete=customlist,s:MRU_Complete -count=0 MRU
	\ call s:MRU_Cmd(<q-args>, '', <count>)
  command! -nargs=? -complete=customlist,s:MRU_Complete -count=0 Mru
	\ call s:MRU_Cmd(<q-args>, '', <count>)
  command! -nargs=? -complete=customlist,s:MRU_Complete MRUToggle
              \ call s:MRU_Toggle(<q-args>, '')
endif
command! -nargs=0 MruRefresh call s:MRU_Refresh()

" FZF (fuzzy finder) integration    {{{1
func s:MRU_FZF_EditFile(fname) abort
  call s:MRU_Window_Edit_File(a:fname, 0, 'edit', 'useopen')
endfunc

func s:MRU_FZF_Run() abort
  if !exists('*fzf#run')
    call s:MRU_Warn_Msg('FZF plugin is not present')
    return
  endif
  call fzf#run(fzf#wrap({'source' : s:MRU_files,
    \ 'options' : '--no-sort',
    \ 'sink' : function('s:MRU_FZF_EditFile'),
    \ 'down' : g:MRU_Window_Height}, 0))
endfunc
command! -nargs=0 FZFMru call s:MRU_FZF_Run()

" }}}

" restore 'cpoptions'
let &cpoptions = s:cpo_save
unlet s:cpo_save

" vim:set sw=2 sts=2 foldenable foldmethod=marker: