I previously asked how I could set up a toggle for syntax highlighting
of non-ASCII characters. I was having problems clearing a
highlighting group and then never being able to reactivate it.
Ben Fritz suggested using the matchadd()/matchdelete() functions
for the job. That looks like a good idea and would probably be cleaner
than what I did, but I solved the problem another way before seeing his
comments.
Tony Mechelynck suggested using some functions (see above).
I tried these and they exhibit the same problem I was finding: they
work exactly once and then not again. There is some strange
interaction happening with the highlight group that I have not yet been
able to identify.
I did manage to resolve the problem and integrate it into other syntax
highlighting with some work. Here is my solution.
First, I assigned a command to the L9 key that would toggle basic
syntax highlighting on/off:
" L9 Key [Toggle syntax hilight
on/off]
nnoremap <Esc>[55~ :if exists("g:syntax_on") <Bar>
\ syntax off <Bar>
\ endif <Bar>
\ else <Bar>
\ syntax enable <Bar>
\ endif<CR><CR>
Next, I assigned the shifted L9 key a command to toggle non-ASCII
highlighting on/off. The trick here was to clear the syntax but NOT
the highlighting group.
" L9 (Shifted) [Toggle nonascii highlighting]
nnoremap <Esc>[55;2~ :source /u/jeff/lib/vi/vimrc.nonascii<CR>
Where the vimrc.nonascii file contains:
if (nonascii == "on")
syntax clear NONASCII
let nonascii = "off"
else
syntax match NONASCII "[^\x00-\x7F]"
highlight NONASCII ctermbg=13
let nonascii = "on"
endif
Now you ask, why is this in an external file rather than directly
mapped as in the previous case. Well, I tried that and found that
while it sort of worked, not only did all non-ASCII characters get
highlighted, but so did all white space (space and tabs) between
them! This does not happen when the command is read from the
external file. [I'd be happy to hear any ideas as to why that is
happening and what to do about it!]
OK so far. However, if non-ASCII highlighting was active and syntax
highlighting was toggled, it forced the non-ASCII highlight off too and
left the "nonascii" variable in the wrong state.
I wanted these to operate independently, so I modified the previous
L9 Key mapping as follows, to force non-ASCII highlight back on if
it was currently on.
" L9 Key [Toggle syntax hilight
on/off]
nnoremap <Esc>[55~ :if exists("g:syntax_on") <Bar>
\ syntax off <Bar>
\ if (nonascii == "on") <Bar>
\ let nonascii = "off" <Bar>
\ :source /u/jeff/lib/vi/vimrc.nonascii <Bar>
\ endif <Bar>
\ else <Bar>
\ syntax enable <Bar>
\ if (nonascii == "on") <Bar>
\ let nonascii = "off" <Bar>
\ :source /u/jeff/lib/vi/vimrc.nonascii <Bar>
\ endif <Bar>
\ endif<CR><CR>
Why two <CR> are required here is another minor mystery. It's
probably because of the :source command which gobbles one
<CR> leaving the second for the overall command. However,
adding a <CR> to the end of the :source lines and removing one
from the end does not work!
I hope someone finds this instructive. Continue the discussion if
there are more insights as to what is going on with these perceived
glitches I was experiencing.
Much thanks to Ben and Tony for their very helpful feedback. I
learned a few things and got pushed in the right direction.
--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php
---
You received this message because you are subscribed to the Google Groups
"vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
