Bug fix: Show error highlighting only in Lua buffers

When luainspect.vim requests a tool tip text from luainspect4vim.lua but
a syntax error is found then no tool tips are available, however the
syntax error is reported so that it can be highlighted as such. This
feature and its sequence of events introduced the following bug:

 1. Open a Lua buffer.
 2. Create a syntax error in the Lua buffer.
 2. Create a split window showing a non-Lua buffer.
 3. With the focus on the non-Lua buffer, hover over the split window
    showing the Lua buffer and wait for the tool tip to appear.
 4. The tool tip will be correct but the syntax error highlighting is
    now applied in the non-Lua buffer: Clearly not the intention :-)

This commit fixes the problem. I've also added calls to my xolox#timer
functions so that, when you execute the following command:

    :verbose LuaInspect

You get a message with the time spent inside luainspect4vim.lua and the
overhead imposed by the communication between Vim and Lua.

README.md

@@ -10,7 +10,7 @@ The Vim plug-in `luainspect.vim` uses the [LuaInspect](http://lua-users.org/wiki
 
  * If the text cursor is on a variable while the highlighting is refreshed then all occurrences of the variable will be marked in the style of [Vim's cursorline option](http://vimdoc.sourceforge.net/htmldoc/options.html#%27cursorline%27).
 
- * When luainspect reports a wrong argument count for a function call the call will be highlighted with a green underline. When you hover over the highlighted text a tooltip shows the associated warning message.
+ * When luainspect reports a wrong argument count for a function call the text will be highlighted with a green underline. When you hover over the highlighted text a tooltip shows the associated warning message.
 
  * When a syntax error is found (during highlighting or using the rename functionality) the lines where the error is reported will be marked like a spelling error.
 

TODO.md

@@ -4,4 +4,3 @@
  * Document g:lua_inspect_path option.
  * Check whether "core/SciTE: jump to definition now supports functions in different files." is interesting.
  * Use the new 'init.get_variable_details' function to replace most of actions.tooltip()?
- * BUG: With a Lua script in one split window and a different file type in another split window, where the active window contains the non-Lua file, if you hover over the Lua window syntax error highlighting is applied to the non-Lua buffer! Hint: getbufline() / assert(v:beval_bufnr==bufnr('%'))

luainspect.vim

@@ -13,6 +13,8 @@ if &cp || exists('g:loaded_luainspect')
   finish
 endif
 
+let s:script = expand('<sfile>:p:~')
+
 " Configuration defaults. {{{1
 
 if !exists('g:lua_inspect_events')
@@ -56,109 +58,118 @@ let s:groups['WrongArgCount'] = 'SpellLocal'
 
 " (Automatic) command definitions. {{{1
 
-command! -bar -bang LuaInspect call s:run_lua_inspect('highlight', 1, <q-bang> != '!')
+command! -bar -bang LuaInspect call s:luainspect_command(<q-bang> == '!')
 
 augroup PluginLuaInspect
   " Clear existing automatic commands.
   autocmd!
-  " Disable easytags.vim because it doesn't play nice with luainspect.vim!
-  autocmd BufNewFile,BufReadPost,BufWritePost * call s:init_lua_buffer()
-  " Define the configured automatic commands.
+  " Automatically enable the plug-in on these events.
+  autocmd BufNewFile,BufReadPost,BufWritePost * call s:auto_enable_plugin()
+  " Define the configured automatic commands for highlighting.
   for s:event in split(g:lua_inspect_events, ',')
-    execute 'autocmd' s:event '* if s:check_plugin_enabled() | LuaInspect | endif'
+    execute 'autocmd' s:event '* if s:check_plugin_valid() | LuaInspect | endif'
   endfor
+  unlet s:event
 augroup END
 
 " Script local functions. {{{1
 
-function! s:check_plugin_enabled()
+function! s:check_plugin_valid() " {{{2
   return &ft == 'lua' && !&diff && !exists('b:luainspect_disabled')
 endfunction
 
-function! s:init_lua_buffer()
-  if s:check_plugin_enabled()
+function! s:luainspect_command(disable) " {{{2
+  if a:disable
+    call s:clear_previous_matches()
+    unlet! b:luainspect_input b:luainspect_output
+    let b:luainspect_disabled = 1
+  else
+    unlet! b:luainspect_disabled
+    let starttime = xolox#timer#start()
+    call s:run_lua_inspect('highlight')
+    let bufname = expand('%:p:~')
+    let msg = "%s: Highlighted %s in %s."
+    call xolox#timer#stop(msg, s:script, bufname, starttime)
+  endif
+endfunction
+
+function! s:auto_enable_plugin() " {{{2
+  if s:check_plugin_valid()
+    " Disable easytags.vim because it doesn't play nice with luainspect.vim!
     let b:easytags_nohl = 1
-    inoremap <buffer> <silent> <F2> <C-o>:call <Sid>run_lua_inspect('rename', 0, 1)<CR>
-    nnoremap <buffer> <silent> <F2> :call <Sid>run_lua_inspect('rename', 0, 1)<CR>
-    nnoremap <buffer> <silent> gd :call <Sid>run_lua_inspect('goto', 0, 1)<CR>
+    inoremap <buffer> <silent> <F2> <C-o>:call <Sid>run_lua_inspect('rename')<CR>
+    nnoremap <buffer> <silent> <F2> :call <Sid>run_lua_inspect('rename')<CR>
+    nnoremap <buffer> <silent> gd :call <Sid>run_lua_inspect('goto')<CR>
     setlocal ballooneval balloonexpr=LuaInspectToolTip()
   endif
 endfunction
 
 function! LuaInspectToolTip() " {{{2
-  let text = s:run_lua_inspect('tooltip', 0, 1)
+  let text = s:run_lua_inspect('tooltip')
   if exists('b:luainspect_syntax_error')
     return b:luainspect_syntax_error
   else
     return type(text) == type('') ? text : ''
   endif
 endfunction
 
-function! s:run_lua_inspect(action, toggle, enabled) " {{{2
-  if !a:toggle || s:set_plugin_enabled(a:enabled)
+function! s:run_lua_inspect(action) " {{{2
+  if a:action == 'tooltip'
+    let lines = getbufline(v:beval_bufnr, 1, "$")
+    call insert(lines, v:beval_col)
+    call insert(lines, v:beval_lnum)
+  else
     let lines = getline(1, "$")
-    if a:action == 'tooltip'
-      call insert(lines, v:beval_col)
-      call insert(lines, v:beval_lnum)
-    else
-      call insert(lines, col('.'))
-      call insert(lines, line('.'))
+    call insert(lines, col('.'))
+    call insert(lines, line('.'))
+  endif
+  call insert(lines, a:action)
+  call s:parse_text(join(lines, "\n"), s:prepare_search_path())
+  if !empty(b:luainspect_output)
+    let response = b:luainspect_output[0]
+    if response == 'syntax_error' && len(b:luainspect_output) >= 4
+      " Never perform syntax error highlighting in non-Lua buffers!
+      let linenum = b:luainspect_output[1] + 0
+      let colnum = b:luainspect_output[2] + 0
+      let linenum2 = b:luainspect_output[3] + 0
+      let b:luainspect_syntax_error = b:luainspect_output[4]
+      if a:action != 'tooltip' || v:beval_bufnr == bufnr('%')
+        let error_cmd = 'syntax match luaInspectSyntaxError /\%%>%il\%%<%il.*/ containedin=ALLBUT,lua*Comment*'
+        execute printf(error_cmd, linenum - 1, (linenum2 ? linenum2 : line('$')) + 1)
+      endif
+      " But always let the user know that a syntax error exists.
+      let bufname = fnamemodify(bufname(a:action != 'tooltip' ? '%' : v:beval_bufnr), ':p:~')
+      call xolox#warning("Syntax error around line %i in %s: %s", linenum, bufname, b:luainspect_syntax_error)
+      return
     endif
-    call insert(lines, a:action)
-    call s:parse_text(join(lines, "\n"), s:prepare_search_path())
-    if !empty(b:luainspect_output)
-      let response = b:luainspect_output[0]
-      if response == 'syntax_error' && len(b:luainspect_output) >= 4
+    unlet! b:luainspect_syntax_error
+    if response == 'highlight'
+      call s:define_default_styles()
+      call s:clear_previous_matches()
+      call s:highlight_variables()
+    elseif response == 'goto'
+      if len(b:luainspect_output) < 3
+        call xolox#warning("No variable under cursor!")
+      else
         let linenum = b:luainspect_output[1] + 0
         let colnum = b:luainspect_output[2] + 0
-        let linenum2 = b:luainspect_output[3] + 0
-        let b:luainspect_syntax_error = b:luainspect_output[4]
-        let error_cmd = 'syntax match luaInspectSyntaxError /\%%>%il\%%<%il.*/ containedin=ALLBUT,lua*Comment*'
-        execute printf(error_cmd, linenum - 1, (linenum2 ? linenum2 : line('$')) + 1)
-        call xolox#warning("Syntax error around line %i: %s", linenum, b:luainspect_syntax_error)
-        return
+        call setpos('.', [0, linenum, colnum, 0])
+        call xolox#message("") " Clear any previous message to avoid confusion.
       endif
-      unlet! b:luainspect_syntax_error
-      if response == 'highlight'
-        call s:define_default_styles()
-        call s:clear_previous_matches()
-        call s:highlight_variables()
-      elseif response == 'goto'
-        if len(b:luainspect_output) < 3
-          call xolox#warning("No variable under cursor!")
-        else
-          let linenum = b:luainspect_output[1] + 0
-          let colnum = b:luainspect_output[2] + 0
-          call setpos('.', [0, linenum, colnum, 0])
-          call xolox#message("") " Clear any previous message to avoid confusion.
-        endif
-      elseif response == 'tooltip'
-        if len(b:luainspect_output) > 1
-          return join(b:luainspect_output[1:-1], "\n")
-        endif
-      elseif response == 'rename'
-        if len(b:luainspect_output) == 1
-          call xolox#warning("No variable under cursor!")
-        else
-          call s:rename_variable()
-        endif
+    elseif response == 'tooltip'
+      if len(b:luainspect_output) > 1
+        return join(b:luainspect_output[1:-1], "\n")
+      endif
+    elseif response == 'rename'
+      if len(b:luainspect_output) == 1
+        call xolox#warning("No variable under cursor!")
+      else
+        call s:rename_variable()
       endif
     endif
   endif
 endfunction
 
-function! s:set_plugin_enabled(enabled) " {{{2
-  if a:enabled
-    unlet! b:luainspect_disabled
-    return 1
-  else
-    call s:clear_previous_matches()
-    unlet! b:luainspect_input b:luainspect_output
-    let b:luainspect_disabled = 1
-    return 0
-  endif
-endfunction
-
 function! s:prepare_search_path() " {{{2
   let code = ''
   if !(has('lua') && g:lua_inspect_internal && exists('s:changed_path'))

luainspect4vim.lua

@@ -83,25 +83,34 @@ end
 
 function actions.tooltip(tokenlist, line, column) -- {{{1
   local did_details = false
+  local note
   for i, token in ipairs(tokenlist) do
     if token.ast.lineinfo then
       local l1, c1 = unpack(token.ast.lineinfo.first, 1, 2)
       local l2, c2 = unpack(token.ast.lineinfo.last, 1, 2)
       if l1 == line then
         local ast = token.ast
-        if ast and ast.id and column >= c1 and column <= c2 and not did_details then
-          printvartype(token)
-          printsignature(ast)
-          printvalue(ast)
-          did_details = true
-        end
-        if ast.note then
-          if ast.note:find '[Tt]oo%s+%w+%s+arguments' then
-            myprint("Warning: " .. ast.note)
-          else
-            myprint("Note: " .. ast.note)
+        if ast and column >= c1 and column <= c2 then
+          if ast.id and not did_details then
+            printvartype(token)
+            printsignature(ast)
+            printvalue(ast)
+            if note then
+              myprint(note)
+              break
+            end
+          end
+          if ast.note then
+            -- This is complicated by the fact that I don't really understand
+            -- the metalua/lua-inspect abstract syntax tree and apparently notes
+            -- are not always available on the identifier token printed above.
+            local iswarning = ast.note:find '[Tt]oo%s+%w+%s+arguments'
+            note = (iswarning and "Warning: " or "Note: ") .. ast.note
+            if did_details then
+              myprint(note)
+              break
+            end
           end
-          break
         end
       end
     end