Merge pull request #397 from lambdalisue/fix-syntax

Use `syntax/fern.vim` instead to define syntax/highlight

autoload/fern/internal/viewer.vim

@@ -57,8 +57,6 @@ function! s:init() abort
     autocmd! * <buffer>
     autocmd BufEnter <buffer> setlocal nobuflisted
     autocmd BufReadCmd <buffer> nested call s:BufReadCmd()
-    autocmd Syntax <buffer> call s:Syntax()
-    autocmd ColorScheme <buffer> call s:ColorScheme()
     autocmd CursorMoved,CursorMovedI,BufLeave <buffer> let b:fern_cursor = getcurpos()[1:2]
   augroup END
   call fern#internal#viewer#auto_duplication#init()
@@ -94,9 +92,6 @@ function! s:init() abort
   if !g:fern#disable_viewer_spinner
     call fern#internal#spinner#start()
   endif
-  call helper.fern.renderer.highlight()
-  call fern#hook#emit('viewer:highlight', helper)
-  doautocmd <nomodeline> User FernHighlight
 
   " now the buffer is ready so set filetype to emit FileType
   setlocal filetype=fern
@@ -139,20 +134,6 @@ function! s:BufReadCmd() abort
         \.catch({ e -> fern#logger#error(e) })
 endfunction
 
-function! s:Syntax() abort
-  let helper = fern#helper#new()
-  call helper.fern.renderer.syntax()
-  call fern#hook#emit('viewer:syntax', helper)
-  doautocmd <nomodeline> User FernSyntax
-endfunction
-
-function! s:ColorScheme() abort
-  let helper = fern#helper#new()
-  call helper.fern.renderer.highlight()
-  call fern#hook#emit('viewer:highlight', helper)
-  doautocmd <nomodeline> User FernHighlight
-endfunction
-
 augroup fern_internal_viewer
   autocmd!
   autocmd User FernSyntax :

syntax/fern.vim

@@ -0,0 +1,28 @@
+if exists('b:current_syntax')
+  finish
+endif
+let b:current_syntax = 'fern'
+
+syntax clear
+
+function! s:ColorScheme() abort
+  let helper = fern#helper#new()
+  call helper.fern.renderer.highlight()
+  call fern#hook#emit('viewer:highlight', helper)
+  doautocmd <nomodeline> User FernHighlight
+endfunction
+
+function! s:Syntax() abort
+  let helper = fern#helper#new()
+  call helper.fern.renderer.syntax()
+  call fern#hook#emit('viewer:syntax', helper)
+  doautocmd <nomodeline> User FernSyntax
+endfunction
+
+augroup fern_syntax_internal
+  autocmd! * <buffer>
+  autocmd ColorScheme <buffer> call s:ColorScheme()
+augroup END
+
+call s:ColorScheme()
+call s:Syntax()