normaize fzf FIELD INDEX EXPRESSION, see below:

- refactor fzf field index experssion and line field number options
- enable native fzf previewers (bat/cat/head) for all file/buffer providers
- buffers|lines|blines|tabs now respect default previewer

README.md

@@ -586,7 +586,7 @@ require'fzf-lua'.setup {
     fzf_opts = {
       -- do not include bufnr in fuzzy matching
       -- tiebreak by line no.
-      ['--delimiter'] = vim.fn.shellescape('[]]'),
+      ['--delimiter'] = vim.fn.shellescape('[\\]:]'),
       ["--nth"]       = '2..',
       ["--tiebreak"]  = 'index',
     },

doc/fzf-lua.txt

@@ -628,7 +628,7 @@ Consult the list below for available settings:
         fzf_opts = {
           -- do not include bufnr in fuzzy matching
           -- tiebreak by line no.
-          ['--delimiter'] = vim.fn.shellescape('[]]'),
+          ['--delimiter'] = vim.fn.shellescape('[\\]:]'),
           ["--nth"]       = '2..',
           ["--tiebreak"]  = 'index',
         },

lua/fzf-lua/config.lua

@@ -169,6 +169,10 @@ M.globals = {
       cmd             = "man -c %s | col -bx",
       _ctor           = previewers.builtin.man_pages,
     },
+    man_native = {
+      cmd             = "man",
+      _ctor           = previewers.fzf.man_pages,
+    },
     builtin = {
       syntax          = true,
       syntax_delay    = 0,
@@ -309,7 +313,7 @@ M.globals.loclist = {
     _actions            = function() return M.globals.actions.files end,
   }
 M.globals.buffers = {
-    previewer             = "builtin",
+    previewer             = M._default_previewer_fn,
     prompt                = 'Buffers> ',
     file_icons            = true and M._has_devicons,
     color_icons           = true,
@@ -323,7 +327,7 @@ M.globals.buffers = {
     },
   }
 M.globals.tabs = {
-    previewer             = "builtin",
+    previewer             = M._default_previewer_fn,
     prompt                = 'Tabs> ',
     tab_title             = "Tab",
     tab_marker            = "<<",
@@ -336,21 +340,21 @@ M.globals.tabs = {
     },
   }
 M.globals.lines = {
-    previewer             = "builtin",
+    previewer             = M._default_previewer_fn,
     prompt                = 'Lines> ',
     file_icons            = true and M._has_devicons,
     color_icons           = true,
     show_unlisted         = false,
     no_term_buffers       = true,
     fzf_opts = {
-        ['--delimiter']   = vim.fn.shellescape('[]]'),
+        ['--delimiter']   = vim.fn.shellescape('[\\]:]'),
         ["--nth"]         = '2..',
         ["--tiebreak"]    = 'index',
     },
     _actions              = function() return M.globals.actions.buffers end,
   }
 M.globals.blines = {
-    previewer             = "builtin",
+    previewer             = M._default_previewer_fn,
     prompt                = 'BLines> ',
     file_icons            = true and M._has_devicons,
     color_icons           = true,
@@ -540,7 +544,7 @@ M.globals.dap = {
       previewer           = M._default_previewer_fn,
       _actions            = function() return M.globals.actions.files end,
       fzf_opts = {
-        ['--delimiter']   = vim.fn.shellescape('[]]'),
+        ['--delimiter']   = vim.fn.shellescape('[\\]:]'),
         ["--with-nth"]    = '2..',
       },
     },

lua/fzf-lua/core.lua

@@ -416,8 +416,22 @@ M.make_entry_lcol = function(opts, entry)
       (opts.trim_entry and vim.trim(entry.text)) or entry.text)
 end
 
-M.set_fzf_line_args = function(opts)
-  opts._line_placeholder = 2
+-- given the default delimiter ':' this is the
+-- fzf experssion field index for the line number
+-- when entry format is 'file:line:col: text'
+-- this is later used with native fzf previewers
+-- for setting the preview offset (and on some
+-- cases the highlighted line)
+M.set_fzf_field_index = function(opts, default_idx, default_expr)
+  opts.line_field_index = opts.line_field_index or default_idx or 2
+  -- when entry contains lines we set the fzf FIELD INDEX EXPRESSION
+  -- to the below so that only the filename is sent to the preview
+  -- action, otherwise we will have issues with entries with text
+  -- containing '--' as fzf won't know how to interpret the cmd
+  -- this works when the delimiter is only ':', when using multiple
+  -- or different delimiters (e.g. in 'lines') we need to use a different
+  -- field index experssion such as "{..-2}" (all fields but the last 2)
+  opts.field_index_expr = opts.field_index_expr or default_expr or "{1}"
   return opts
 end
 

lua/fzf-lua/path.lua

@@ -210,6 +210,8 @@ function M.entry_to_file(entry, cwd, force_uri)
   return {
     stripped = stripped,
     bufnr = tonumber(bufnr),
+    bufname = bufnr and vim.api.nvim_buf_is_valid(tonumber(bufnr))
+          and vim.api.nvim_buf_get_name(tonumber(bufnr)),
     terminal = terminal,
     path = file,
     line = tonumber(line) or 1,

lua/fzf-lua/previewer/fzf.lua

@@ -34,13 +34,13 @@ function Previewer.base:preview_offset()
     #
     '--preview-window '~3:+{2}+3/2''
   ]]
-  if self.opts._line_placeholder then
-    return ("+{%d}-/2"):format(self.opts._line_placeholder)
+  if self.opts.line_field_index then
+    return ("+{%d}-/2"):format(self.opts.line_field_index)
   end
 end
 
 function Previewer.base:fzf_delimiter()
-  if not self.opts._line_placeholder then return end
+  if not self.opts.line_field_index then return end
   -- set delimiter to ':'
   -- entry format is 'file:line:col: text'
   local delim = self.opts.fzf_opts and self.opts.fzf_opts["--delimiter"]
@@ -50,7 +50,9 @@ function Previewer.base:fzf_delimiter()
     if delim:match("%[.*%]")then
       delim = delim:match("(%[.*)%]") .. ':]'
     else
-      delim = '[' .. delim:match("[^[^']+") .. ':]'
+      delim = '[' ..
+        utils.rg_escape(delim:match("^'?(.*)'$?")):gsub("%]", "\\]")
+      .. ':]'
     end
   end
   return delim
@@ -73,15 +75,11 @@ end
 
 function Previewer.cmd:action(o)
   o = o or {}
-  local filespec = "{}"
-  if self.opts._line_placeholder then
-    filespec = "{1}"
-  end
   local act = shell.raw_action(function (items, _, _)
     -- only preview first item
-    local file = path.entry_to_file(items[1], not self.relative and self.opts.cwd)
-    return file.path
-  end, filespec)
+    local entry = path.entry_to_file(items[1], not self.relative and self.opts.cwd)
+    return entry.bufname or entry.path
+  end, self.opts.field_index_expr or "{}")
   return act
 end
 
@@ -98,8 +96,8 @@ function Previewer.bat:cmdline(o)
   o = o or {}
   o.action = o.action or self:action(o)
   local highlight_line = ""
-  if self.opts._line_placeholder then
-    highlight_line = string.format("--highlight-line={%d}", self.opts._line_placeholder)
+  if self.opts.line_field_index then
+    highlight_line = string.format("--highlight-line={%d}", self.opts.line_field_index)
   end
   return vim.fn.shellescape(string.format('sh -c "%s %s %s `%s`"',
     self.cmd, self.args, highlight_line, self:action(o)))
@@ -116,10 +114,11 @@ end
 function Previewer.head:cmdline(o)
   o = o or {}
   o.action = o.action or self:action(o)
-  local lines = ""
-  if self.opts._line_placeholder then
-    lines = string.format("--lines={%d}", self.opts._line_placeholder)
-  end
+  local lines = "--lines=-0"
+  -- print all lines instead
+  -- if self.opts.line_field_index then
+  --   lines = string.format("--lines={%d}", self.opts.line_field_index)
+  -- end
   return vim.fn.shellescape(string.format('sh -c "%s %s %s `%s`"',
     self.cmd, self.args, lines, self:action(o)))
 end
@@ -132,11 +131,24 @@ function Previewer.cmd_async:new(o, opts)
   return self
 end
 
+function Previewer.cmd_async:parse_entry_and_verify(entrystr)
+  local entry = path.entry_to_file(entrystr, not self.relative and self.opts.cwd)
+  local filepath = entry.bufname or entry.path or ''
+  local errcmd = nil
+  -- verify the file exists on disk and is accessible
+  if #filepath==0 or not vim.loop.fs_stat(filepath) then
+    errcmd = ('echo "%s: NO SUCH FILE OR ACCESS DENIED"'):format(
+      filepath and #filepath>0 and vim.fn.shellescape(filepath) or "<null>")
+  end
+  return filepath, entry, errcmd
+end
+
 function Previewer.cmd_async:cmdline(o)
   o = o or {}
   local act = shell.preview_action_cmd(function(items)
-    local file = path.entry_to_file(items[1], not self.relative and self.opts.cwd)
-    local cmd = string.format('%s %s %s', self.cmd, self.args, vim.fn.shellescape(file.path))
+    local filepath, _, errcmd = self:parse_entry_and_verify(items[1])
+    local cmd = errcmd or ('%s %s %s'):format(
+      self.cmd, self.args, vim.fn.shellescape(filepath))
     -- uncomment to see the command in the preview window
     -- cmd = vim.fn.shellescape(cmd)
     return cmd
@@ -154,17 +166,13 @@ end
 
 function Previewer.bat_async:cmdline(o)
   o = o or {}
-  local highlight_line = ""
-  if self.opts._line_placeholder then
-    highlight_line = string.format("--highlight-line=", self.opts._line_placeholder)
-  end
   local act = shell.preview_action_cmd(function(items)
-    local file = path.entry_to_file(items[1], not self.relative and self.opts.cwd)
-    local cmd = string.format('%s %s %s%s "%s"',
+    local filepath, entry, errcmd = self:parse_entry_and_verify(items[1])
+    local cmd = errcmd or ('%s %s %s %s'):format(
       self.cmd, self.args,
-      highlight_line,
-      utils._if(#highlight_line>0, tostring(file.line), ""),
-      file.path)
+      self.opts.line_field_index and
+        ("--highlight-line=%d"):format(entry.line) or '',
+      vim.fn.shellescape(filepath))
     -- uncomment to see the command in the preview window
     -- cmd = vim.fn.shellescape(cmd)
     return cmd
@@ -172,7 +180,7 @@ function Previewer.bat_async:cmdline(o)
   return act
 end
 
-Previewer.git_diff = Previewer.cmd_async:extend()
+Previewer.git_diff = Previewer.base:extend()
 
 function Previewer.git_diff:new(o, opts)
   Previewer.git_diff.super.new(self, o, opts)
@@ -236,7 +244,7 @@ function Previewer.git_diff:cmdline(o)
   return act
 end
 
-Previewer.man_pages = Previewer.cmd_async:extend()
+Previewer.man_pages = Previewer.base:extend()
 
 function Previewer.man_pages:new(o, opts)
   Previewer.man_pages.super.new(self, o, opts)

lua/fzf-lua/providers/buffers.lua

@@ -186,6 +186,8 @@ M.buffers = function(opts)
   opts.fzf_opts['--header-lines'] =
     (not opts.ignore_current_buffer and opts.sort_lastused) and '1'
 
+  opts = core.set_fzf_field_index(opts)
+
   core.fzf_wrap(opts, contents, function(selected)
 
     if not selected then return end
@@ -260,7 +262,7 @@ M.buffer_lines = function(opts)
     opts.fzf_opts['--query'] = vim.fn.shellescape(opts.search)
   end
 
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts, 3, "{..-2}")
 
   core.fzf_wrap(opts, items, function(selected)
     if not selected then return end
@@ -343,8 +345,10 @@ M.tabs = function(opts)
 
   -- opts.fzf_opts["--no-multi"] = ''
   opts.fzf_opts["--preview-window"] = 'hidden:right:0'
-  opts.fzf_opts["--delimiter"] = vim.fn.shellescape('[\\)]')
-  opts.fzf_opts["--with-nth"] = '2'
+  opts.fzf_opts["--delimiter"] = vim.fn.shellescape('[\\):]')
+  opts.fzf_opts["--with-nth"] = '2..'
+
+  opts = core.set_fzf_field_index(opts, 3)
 
   core.fzf_wrap(opts, contents, function(selected)
 

lua/fzf-lua/providers/dap.lua

@@ -162,7 +162,7 @@ M.breakpoints = function(opts)
       :format(utils.ansi_codes.yellow("<Ctrl-x>")))
   end
 
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts, 3, "{..-2}")
 
   core.fzf_wrap(opts, contents, function(selected)
 

lua/fzf-lua/providers/grep.lua

@@ -104,7 +104,7 @@ M.grep = function(opts)
     contents = contents .. " 2>&1"
   end
 
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   core.fzf_files(opts, contents)
   opts.search = nil
 end
@@ -157,7 +157,7 @@ M.live_grep_st = function(opts)
   -- conflicts with 'change:reload' event
   opts.global_resume_query = false
   opts.__FNCREF__ = opts.__FNCREF__ or utils.__FNCREF__()
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   opts = core.set_fzf_interactive_cmd(opts)
   core.fzf_files(opts)
 end
@@ -280,7 +280,7 @@ M.live_grep_mt = function(opts)
   -- conflicts with 'change:reload' event
   opts.global_resume_query = false
   opts.__FNCREF__ = opts.__FNCREF__ or utils.__FNCREF__()
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   core.fzf_files(opts)
   opts.search = nil
 end

lua/fzf-lua/providers/lsp.lua

@@ -294,7 +294,7 @@ end
 local function fzf_lsp_locations(opts)
   opts = normalize_lsp_opts(opts, config.globals.lsp)
   if not opts then return end
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   if opts.force_uri == nil then opts.force_uri = true end
   opts = set_lsp_fzf_fn(opts)
   if not opts.fzf_fn then return end
@@ -335,7 +335,7 @@ M.workspace_symbols = function(opts)
   opts = normalize_lsp_opts(opts, config.globals.lsp)
   if not opts then return end
   opts.lsp_params = {query = opts.query or ''}
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   if opts.force_uri == nil then opts.force_uri = true end
   opts = set_lsp_fzf_fn(opts)
   if not opts.fzf_fn then return end
@@ -633,7 +633,7 @@ M.diagnostics = function(opts)
     end)()
   end
 
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   if opts.force_uri == nil then opts.force_uri = true end
   return core.fzf_files(opts)
 end
@@ -694,7 +694,7 @@ M.live_workspace_symbols = function(opts)
   opts.global_resume_query = false
   opts.__FNCREF__ = M.live_workspace_symbols
   opts = core.set_fzf_interactive_cb(opts)
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   if opts.force_uri == nil then opts.force_uri = true end
   core.fzf_files(opts)
   opts.search = nil

lua/fzf-lua/providers/quickfix.lua

@@ -31,7 +31,7 @@ local quickfix_run = function(opts, cfg, locations)
     utils.delayed_cb(cb)
   end
 
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   return core.fzf_files(opts, contents)
 end
 

lua/fzf-lua/providers/tags.lua

@@ -144,7 +144,7 @@ local fzf_tags = function(opts)
   -- signal actions this is a ctag
   opts._ctag = true
   opts = core.set_header(opts, 2)
-  opts = core.set_fzf_line_args(opts)
+  opts = core.set_fzf_field_index(opts)
   return core.fzf_files(opts, contents)
 end