Implement option to disable highlighting builtin functions as kwarg

Fixes vim-python#17

Author: nfnty

README.md

@@ -62,6 +62,7 @@ let g:python_highlight_all = 1
 | `g:python_highlight_builtins`                 | Highlight builtin functions and objects                        | `0`     |
 | `g:python_highlight_builtin_objs`             | Highlight builtin objects only                                 | `0`     |
 | `g:python_highlight_builtin_funcs`            | Highlight builtin functions only                               | `0`     |
+| `g:python_highlight_builtin_funcs_kwarg`      | Highlight builtin functions when used as kwarg                 | `1`     |
 | `g:python_highlight_exceptions`               | Highlight standard exceptions                                  | `0`     |
 | `g:python_highlight_string_formatting`        | Highlight `%` string formatting                                | `0`     |
 | `g:python_highlight_string_format`            | Highlight syntax of `str.format` syntax                        | `0`     |

doc/python-syntax.txt

@@ -65,6 +65,9 @@ following command to your `~/.config/nvim/init.vim` or `~/.vimrc`: >
 `g:python_highlight_builtin_funcs` (default `0`)
     Highlight builtin functions only
 
+`g:python_highlight_builtin_funcs_kwarg` (default `1`)
+    Highlight builtin functions when used as kwarg
+
 `g:python_highlight_exceptions` (default `0`)
     Highlight standard exceptions
 

syntax/python.vim

@@ -37,6 +37,7 @@ endfunction
 "
 
 call s:EnableByDefault('g:python_slow_sync')
+call s:EnableByDefault('g:python_highlight_builtin_funcs_kwarg')
 
 if s:Enabled('g:python_highlight_all')
   call s:EnableByDefault('g:python_highlight_builtins')
@@ -352,7 +353,13 @@ if s:Enabled('g:python_highlight_builtin_funcs')
       let s:funcs_re .= '|ascii|exec|print'
   endif
 
-  execute 'syn match pythonBuiltinFunc ''\v\.@<!\zs<%('  . s:funcs_re .  ')>'''
+  let s:funcs_re = 'syn match pythonBuiltinFunc ''\v\.@<!\zs<%(' . s:funcs_re . ')>'
+
+  if !s:Enabled('g:python_highlight_builtin_funcs_kwarg')
+      let s:funcs_re .= '\=@!'
+  endif
+
+  execute s:funcs_re . ''''
   unlet s:funcs_re
 endif