Improve handling of ignored syntax groups (issue #57)

Author: xolox

README.md

@@ -205,10 +205,6 @@ If this is set and not false, it will suppress the warning on startup if ctags i
 
     :let g:easytags_suppress_ctags_warning = 1
 
-### The `g:easytags_ignored_syntax_groups` option
-
-This variable is a string of comma separated names of syntax groups in which dynamic highlighting is not applied. It defaults to `.*String.*,.*Comment.*,cIncluded`.
-
 ## Customizing the easytags plug-in
 
 Advanced users may wish to customize how the easytags plug-in works beyond the point of changing configuration defaults. This section contains some hints about this. If you have suggestions, please feel free to submit them.

autoload/xolox/easytags.vim

@@ -1,9 +1,9 @@
 " Vim script
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: June 19, 2013
+" Last Change: June 20, 2013
 " URL: http://peterodding.com/code/vim/easytags/
 
-let g:xolox#easytags#version = '3.3.8'
+let g:xolox#easytags#version = '3.3.9'
 
 " Public interface through (automatic) commands. {{{1
 
@@ -383,7 +383,7 @@ function! xolox#easytags#highlight() " {{{2
             let matches = xolox#misc#list#unique(map(matches, 'xolox#misc#escape#pattern(get(v:val, "name"))'))
             let pattern = tagkind.pattern_prefix . '\%(' . join(matches, '\|') . '\)' . tagkind.pattern_suffix
             let template = 'syntax match %s /%s/ containedin=ALLBUT,%s'
-            let command = printf(template, hlgroup_tagged, escape(pattern, '/'), xolox#misc#option#get('easytags_ignored_syntax_groups'))
+            let command = printf(template, hlgroup_tagged, escape(pattern, '/'), xolox#easytags#syntax_groups_to_ignore())
             call xolox#misc#msg#debug("easytags.vim %s: Executing command '%s'.", g:xolox#easytags#version, command)
             try
               execute command
@@ -670,6 +670,32 @@ function! xolox#easytags#get_tagsfile() " {{{2
   return tagsfile
 endfunction
 
+function! xolox#easytags#syntax_groups_to_ignore() " {{{2
+  " Get a string matching the syntax groups where dynamic highlighting should
+  " *not* apply. This is complicated by the fact that Vim has a tendency to do
+  " this:
+  "
+  "     Vim(syntax):E409: Unknown group name: doxygen.*
+  "
+  " This happens when a group wildcard doesn't match *anything*. Why does Vim
+  " always have to make everything so complicated? :-(
+  let groups = ['.*String.*', '.*Comment.*']
+  for group_name in ['cIncluded', 'cCppOut2', 'cCppInElse2', 'cCppOutIf2']
+    if hlexists(group_name)
+      call add(groups, group_name)
+    endif
+  endfor
+  " Doxygen is an "add-on syntax script", it's usually used in combination:
+  "   :set syntax=c.doxygen
+  " It gets special treatment because it defines a dozen or so groups :-)
+  if hlexists('doxygenComment')
+    call add(groups, 'doxygen.*')
+  endif
+  return join(groups, ',')
+filetype
+
+endfunction
+
 " Public API for definition of file type specific dynamic syntax highlighting. {{{1
 
 function! xolox#easytags#define_tagkind(object) " {{{2
@@ -780,7 +806,7 @@ function! s:highlight_with_python(syntax_group, tagkind) " {{{2
     let context['prefix'] = get(a:tagkind, 'pattern_prefix', '')
     let context['suffix'] = get(a:tagkind, 'pattern_suffix', '')
     let context['filters'] = get(a:tagkind, 'python_filter', {})
-    let context['ignoresyntax'] = xolox#misc#option#get('easytags_ignored_syntax_groups')
+    let context['ignoresyntax'] = xolox#easytags#syntax_groups_to_ignore()
     " Call the Python function and intercept the output.
     try
       redir => commands

doc/easytags.txt

@@ -26,7 +26,6 @@ Contents ~
   14. The |g:easytags_include_members| option
   15. The |g:easytags_resolve_links| option
   16. The |g:easytags_suppress_ctags_warning| option
-  17. The |g:easytags_ignored_syntax_groups| option
  5. Customizing the easytags plug-in             |customizing-easytags-plug-in|
   1. Passing custom command line arguments to Exuberant Ctags |easytags-passing-custom-command-line-arguments-to-exuberant-ctags|
   2. Update & highlight tags immediately after save |easytags-update-highlight-tags-immediately-after-save|
@@ -443,13 +442,6 @@ is not found or not recent enough.
 >
   :let g:easytags_suppress_ctags_warning = 1
 <
--------------------------------------------------------------------------------
-The *g:easytags_ignored_syntax_groups* option
-
-This variable is a string of comma separated names of syntax groups in which
-dynamic highlighting is not applied. It defaults to
-'.*String.*,.*Comment.*,cIncluded'.
-
 ===============================================================================
                                                  *customizing-easytags-plug-in*
 Customizing the easytags plug-in ~

plugin/easytags.vim

@@ -1,6 +1,6 @@
 " Vim plug-in
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: June 19, 2013
+" Last Change: June 20, 2013
 " URL: http://peterodding.com/code/vim/easytags/
 " Requires: Exuberant Ctags (http://ctags.sf.net)
 
@@ -40,8 +40,8 @@ if !exists('g:easytags_ignored_filetypes')
   let g:easytags_ignored_filetypes = '^tex$'
 endif
 
-if !exists('g:easytags_ignored_syntax_groups')
-  let g:easytags_ignored_syntax_groups = '.*String.*,.*Comment.*,cIncluded,cCppInElse2,cCppOutIf2,cCppOut2,doxygen.*'
+if exists('g:easytags_ignored_syntax_groups')
+  call xolox#misc#msg#warn("easytags.vim %s: The 'g:easytags_ignored_syntax_groups' option is no longer supported. It has been moved back into the code base for more flexible handling at runtime.", g:xolox#easytags#version)
 endif
 
 if !exists('g:easytags_python_script')