Add executable status (#2723)

closes: #2722

autoload/airline/init.vim

@@ -136,6 +136,7 @@ function! airline#init#bootstrap()
           \ 'notexists': "\u0246",
           \ 'dirty': "\u26a1",
           \ 'crypt': nr2char(0x1F512),
+          \ 'executable': "\u2699",
           \ }, 'keep')
     "  Note: If "\u2046" (Ɇ) does not show up, try to use "\u2204" (∄)
     if exists("*setcellwidths")
@@ -160,6 +161,7 @@ function! airline#init#bootstrap()
           \ 'notexists': "\u0246",
           \ 'crypt': nr2char(0x1F512),
           \ 'dirty': '!',
+          \ 'executable': "\u2699",
           \ }, 'keep')
   else
     " Symbols for ASCII terminals
@@ -177,6 +179,7 @@ function! airline#init#bootstrap()
           \ 'notexists': '?',
           \ 'crypt': 'cr',
           \ 'dirty': '!',
+          \ 'executable': 'x',
           \ }, 'keep')
   endif
 
@@ -189,6 +192,7 @@ function! airline#init#bootstrap()
   call airline#parts#define_function('crypt', 'airline#parts#crypt')
   call airline#parts#define_function('spell', 'airline#parts#spell')
   call airline#parts#define_function('filetype', 'airline#parts#filetype')
+  call airline#parts#define_function('executable', 'airline#parts#executable')
   call airline#parts#define('readonly', {
         \ 'function': 'airline#parts#readonly',
         \ 'accent': 'red',
@@ -253,7 +257,7 @@ endfunction
 function! airline#init#sections()
   let spc = g:airline_symbols.space
   if !exists('g:airline_section_a')
-    let g:airline_section_a = airline#section#create_left(['mode', 'crypt', 'paste', 'keymap', 'spell', 'capslock', 'xkblayout', 'iminsert'])
+    let g:airline_section_a = airline#section#create_left(['mode', 'crypt', 'paste', 'keymap', 'spell', 'capslock', 'xkblayout', 'iminsert', 'executable'])
   endif
   if !exists('g:airline_section_b')
     if airline#util#winwidth() > 99

autoload/airline/parts.vim

@@ -206,3 +206,11 @@ function! airline#parts#ffenc()
     return &fenc.bomb.noeolf.ff
   endif
 endfunction
+
+function! airline#parts#executable()
+  if exists("*getfperm") && getfperm(bufname('%')) =~ 'x'
+    return g:airline_symbols.executable
+  else
+    return ''
+  endif
+endfunction

doc/airline.txt

@@ -374,6 +374,7 @@ its contents. >
   let g:airline_symbols.colnr = ' ㏇:'
   let g:airline_symbols.colnr = ' ℅:'
   let g:airline_symbols.crypt = '🔒'
+  let g:airline_symbols.executable = '⚙'
   let g:airline_symbols.linenr = '☰'
   let g:airline_symbols.linenr = ' ␊:'
   let g:airline_symbols.linenr = ' ␤:'
@@ -427,7 +428,7 @@ window.
 >
   variable names                default contents
   ---------------------------------------------------------------------------
-  let g:airline_section_a       (mode, crypt, paste, spell, iminsert)
+  let g:airline_section_a       (mode, crypt, paste, spell, iminsert, executable)
   let g:airline_section_b       (hunks, branch)[*]
   let g:airline_section_c       (bufferline or filename, readonly)
   let g:airline_section_gutter  (csv)
@@ -1918,6 +1919,7 @@ The following list of parts are predefined by vim-airline.
 * `iminsert`     displays the current insert method
 * `paste`        displays the paste indicator
 * `crypt`        displays the crypted indicator
+* `exectuable`   displays the executable indicator
 * `spell`        displays the spell indicator
 * `filetype`     displays the file type
 * `readonly`     displays the read only indicator