Merge branch 'feature/vim-fo-opt-toggle' into develop

* feature/vim-fo-opt-toggle:
  Restructure 'format' flag logic around vim-tiny
  Map <leader>j to toggle 'fo'-'j' flag in Vim
  Use :echoerr not :echomsg for 'fo'-'a' absence
  Use simpler error message for 'fo'-'a' absence
  Keep script var cache of 'a' 'fo' flag support
  Keep script var cache of 'j' 'fo' flag support

1 files changed, 45 insertions, 25 deletions

diff --git a/vim/config/format.vim b/vim/config/format.vim
index fe6da87c..61222164 100644
--- a/vim/config/format.vim
+++ b/vim/config/format.vim
@@ -1,26 +1,35 @@
-" If we can, add j to the format options to get rid of comment leaders when
-" joining lines
-if v:version > 703
-      \ || v:version ==# 703 && has('patch541')
-  set formatoptions+=j
-endif
+" All of this variable logic requires 'eval', and I can't just short-circuit
+" it due to a quirk in the way vim-tiny evaluates these expressions
+if has('eval')
+
+  " Figure out if we have the 'j' flag for 'formatoptions', to automatically
+  " delete comment leaders when joining lines; keep it in a script variable
+  let s:formatoptions_has_j = v:version > 703
+        \ || v:version ==# 703 && has('patch541')
+
+  " If we do have 'j', default to setting it
+  if s:formatoptions_has_j
+    set formatoptions+=j
+  endif
+
+  "
+  " Use toggle_option_flag.vim plugin to bind quick toggle actions for some
+  " 'formatoptions' flags; both of the above, plus:
+  "
+  " c - Automatically wrap comments at 'textwidth' (which I allow the filetypes
+  "     to set for me)
+  " t - Automatically wrap text at 'textwidth' (as above)
+  "
+  " We need user-defined commands to do this.
+  "
+  if !has('user_commands')
+    finish
+  endif
 
-"
-" Use toggle_option_flag.vim plugin to bind quick toggle actions for some
-" 'formatoptions' flags:
-"
-" c - Automatically wrap comments at 'textwidth' (which I allow the filetypes
-"     to set for me)
-" t - Automatically wrap text at 'textwidth' (as above)
-"
-" Only in Vim >= 7.0 (I think):
-"
-" a - Automatically format paragraphs, reapplying the wrap on every text
-"     insertion or deletion; sometimes I want this and sometimes I
-"     don't, it particularly varies when typing prose in Markdown that
-"     includes headings and code
-"
-if has('eval') && has('user_commands')
+  " Figure out if we have the 'a' flag for 'formatoptions', to reapply
+  " 'textwidth' wrapping to the current paragraph on every insertion or
+  " deletion; keep in a script variable
+  let s:formatoptions_has_a = v:version > 700
 
   " 'c' and 't' have both been around since at least 6.1
   nnoremap <silent>
@@ -30,15 +39,26 @@ if has('eval') && has('user_commands')
         \ <Leader>t
         \ :<C-U>ToggleOptionFlagLocal formatoptions t<CR>
 
-  " 'a' is newer
-  if v:version >= 700
+  " 'a' needs testing
+  if s:formatoptions_has_a
     nnoremap <silent>
           \ <Leader>a
           \ :<C-U>ToggleOptionFlagLocal formatoptions a<CR>
   else
     nnoremap <silent>
           \ <Leader>a
-          \ :<C-U>echomsg 'No "formatoptions" "a" flag in Vim < 7.0'<CR>
+          \ :<C-U>echoerr 'No formatoptions a-flag'<CR>
+  endif
+
+  " 'j' needs testing
+  if s:formatoptions_has_j
+    nnoremap <silent>
+          \ <Leader>j
+          \ :<C-U>ToggleOptionFlagLocal formatoptions j<CR>
+  else
+    nnoremap <silent>
+          \ <Leader>j
+          \ :<C-U>echoerr 'No formatoptions j-flag'<CR>
   endif
 
 endif