File icons: use colors from nvim-web-devicons if available

This improves the colors for file icons if nvim-web-devicons is
available. If it is, fzf-lua now uses those colors for the icons.

This should also improve the performance of make_entry_file by
optimizing string creation and when various regexes are matched.

lua/fzf-lua/config.lua

@@ -452,8 +452,24 @@ M.globals.nvim = {
       },
     },
   }
+
 M.globals.file_icon_padding = ''
-M.globals.file_icon_colors = {
+
+if M._has_devicons then
+  M.globals.file_icon_colors = {}
+
+  local function hex(hex)
+    local r,g,b = hex:match('.(..)(..)(..)')
+    r, g, b = tonumber(r, 16), tonumber(g, 16), tonumber(b, 16)
+    return r, g, b
+  end
+
+  for ext, info in pairs(M._devicons.get_icons()) do
+    local r, g, b = hex(info.color)
+    utils.add_ansi_code('DevIcon' .. info.name, string.format('[38;2;%s;%s;%sm', r, g, b))
+  end
+else
+  M.globals.file_icon_colors = {
     ["lua"]       = "blue",
     ["rockspec"]  = "magenta",
     ["vim"]       = "green",
@@ -502,7 +518,8 @@ M.globals.file_icon_colors = {
     ["svg"]       = "green",
     ["otf"]       = "green",
     ["ttf"]       = "green",
-}
+  }
+end
 
 function M.normalize_opts(opts, defaults)
   if not opts then opts = {} end

lua/fzf-lua/core.lua

@@ -38,13 +38,20 @@ M.fzf = function(opts, contents, previewer)
 end
 
 M.get_devicon = function(file, ext)
-  local icon = ''
-  if not file or #file == 0 then return icon end
+  local icon, hl
   if config._has_devicons and config._devicons then
-    local devicon = config._devicons.get_icon(file, ext)
-    if devicon then icon = devicon end
+    icon, hl  = config._devicons.get_icon(file, ext, {default = true})
+  else
+    icon, hl = '', 'dark_grey'
+  end
+
+  -- allow user override of the color
+  local override = config.globals.file_icon_colors[ext]
+  if override then
+      hl = override
   end
-  return icon..config.globals.file_icon_padding:gsub(" ", utils.nbsp)
+
+  return icon..config.globals.file_icon_padding:gsub(" ", utils.nbsp), hl
 end
 
 M.preview_window = function(opts)
@@ -124,8 +131,6 @@ local get_untracked_files = function(opts)
 end
 
 local get_git_indicator = function(file, diff_files, untracked_files)
-    -- remove colors from `rg` output
-    file = utils.strip_ansi_coloring(file)
     if diff_files and diff_files[file] then
         return diff_files[file]
     end
@@ -148,41 +153,44 @@ M.make_entry_lcol = function(_, entry)
 end
 
 M.make_entry_file = function(opts, x)
-  local icon
-  local prefix = ''
-  if opts.cwd_only and path.starts_with_separator(x) then
+  local icon, hl
+  local ret = {}
+  local file = utils.strip_ansi_coloring(string.match(x, '[^:]*'))
+  if opts.cwd_only and path.starts_with_separator(file) then
     local cwd = opts.cwd or vim.loop.cwd()
-    if not path.is_relative(x, cwd) then
+    if not path.is_relative(file, cwd) then
       return nil
     end
   end
   if opts.cwd and #opts.cwd > 0 then
+    -- TODO: does this work if there are ANSI escape codes in x?
     x = path.relative(x, opts.cwd)
   end
   if opts.file_icons then
-    local ext = path.extension(x)
-    icon = M.get_devicon(x, ext)
+    local filename = path.tail(file)
+    local ext = path.extension(filename)
+    icon, hl = M.get_devicon(filename, ext)
     if opts.color_icons then
-      icon = utils.ansi_codes[config.globals.file_icon_colors[ext] or "dark_grey"](icon)
+      icon = utils.ansi_codes[hl](icon)
     end
-    prefix = prefix .. icon
+    ret[#ret+1] = icon
+    ret[#ret+1] = utils.nbsp
   end
   if opts.git_icons then
-    local filepath = x:match("^[^:]+")
-    local indicator = get_git_indicator(filepath, opts.diff_files, opts.untracked_files)
+    local indicator = get_git_indicator(file, opts.diff_files, opts.untracked_files)
     icon = indicator
-    if config.globals.git.icons[indicator] then
-      icon = config.globals.git.icons[indicator].icon
+    local git_icon = config.globals.git.icons[indicator]
+    if git_icon then
+      icon = git_icon.icon
       if opts.color_icons then
-        icon = utils.ansi_codes[config.globals.git.icons[indicator].color or "dark_grey"](icon)
+        icon = utils.ansi_codes[git_icon.color or "dark_grey"](icon)
       end
     end
-    prefix = prefix .. utils._if(#prefix>0, utils.nbsp, '') .. icon
-  end
-  if #prefix > 0 then
-    x = prefix .. utils.nbsp .. x
+    ret[#ret+1] = icon
+    ret[#ret+1] = utils.nbsp
   end
-  return x
+  ret[#ret+1] = x
+  return table.concat(ret)
 end
 
 M.set_fzf_line_args = function(opts)

lua/fzf-lua/path.lua

@@ -10,14 +10,16 @@ M.starts_with_separator = function(path)
   return path:find(M.separator()) == 1
 end
 
-M.tail = (function()
+function M.tail(path)
   local os_sep = M.separator()
   local match_string = '[^' .. os_sep .. ']*$'
 
-  return function(path)
-    return string.match(path, match_string)
-  end
-end)()
+  return string.match(path, match_string)
+end
+
+function M.extension(path)
+  return string.match(path, '[%w_+$]*$')
+end
 
 function M.to_matching_str(path)
   return path:gsub('(%-)', '(%%-)'):gsub('(%.)', '(%%.)'):gsub('(%_)', '(%%_)')
@@ -43,15 +45,6 @@ function M.basename(path)
   return path:sub(i + 1, #path)
 end
 
-function M.extension(path)
-  -- path = M.basename(path)
-  -- return path:match(".+%.(.*)")
-  -- 1. match anything before the first ':'
-  -- 2. greedy match anything after the last dot
-  -- 3. remove coloring escape sequence
-  return utils.strip_ansi_coloring(path:match("[^:]*"):match("[^.]*$"))
-end
-
 ---Get the path to the parent directory of the given path. Returns `nil` if the
 ---path has no parent.
 ---@param path string

lua/fzf-lua/providers/buffers.lua

@@ -110,16 +110,17 @@ M.buffers = function(opts)
       local bufnrstr = string.format("%s%s%s", leftbr,
         utils.ansi_codes.yellow(string.format(buf.bufnr)), rightbr)
       local buficon = ''
+      local hl = ''
       if opts.file_icons then
-        local extension = path.extension(buf.info.name)
         if utils.is_term_bufname(buf.info.name) then
           -- get shell-like icon for terminal buffers
-          buficon = core.get_devicon(buf.info.name, "sh")
+          buficon, hl = core.get_devicon(buf.info.name, "sh")
         else
-          buficon = core.get_devicon(buf.info.name, extension)
+          local extension = path.extension(buf.info.name)
+          buficon, hl = core.get_devicon(buf.info.name, extension)
         end
         if opts.color_icons then
-          buficon = utils.ansi_codes[config.globals.file_icon_colors[extension] or "dark_grey"](buficon)
+          buficon = utils.ansi_codes[hl](buficon)
         end
       end
       local item_str = string.format("%s%s%s%s%s%s%s",

lua/fzf-lua/utils.lua

@@ -173,13 +173,18 @@ M.ansi_colors = {
     white       = "",
 }
 
+M.add_ansi_code = function(name, escseq)
+  M.ansi_codes[name] = function(string)
+    if string == nil or #string == 0 then return '' end
+    return escseq .. string .. M.ansi_colors.clear
+  end
+end
+
 for color, escseq in pairs(M.ansi_colors) do
-    M.ansi_codes[color] = function(string)
-        if string == nil or #string == 0 then return '' end
-        return escseq .. string .. M.ansi_colors.clear
-    end
+  M.add_ansi_code(color, escseq)
 end
 
+
 function M.strip_ansi_coloring(str)
   if not str then return str end
   -- remove escape sequences of the following formats: