One of the best new features in Vim 7 is built-in spell-check (although plugins for spellcheck have been available earlier). With spell-check, I can now use Vim exclusively for editing text formatted files – latex, blog entries and the like – in addition to code. Here’s a quick look at the various spell checking features.
Turning on spellcheck
Spellcheck can be turned on/off with the following commands
:setlocal spell spelllang=en_gb
en_gb can of course be replaced by your language of choice (en_us for example). Vim 7 supports spell-check for more than 50 languages, and the dictionaries are stored in
$VIMRUNTIME/spell. I’ve mapped this to the F6 and F7 keys by adding the following lines to the
map <F6> <Esc>:setlocal spell spelllang=en_gb<CR>
map <F7> <Esc>:setlocal nospell<CR>
Once spell-check is turned on, words with spelling errors will be highlighted. You can move to the next and previous misspelled words by typing
[s respectively, in normal mode. If the cursor is on a misspelled word,
z= shows suggestions and
zg adds the word to the dictionary.
zug performs an undo to the dictionary addition.
Highlighting spelling errors
You can customize the way misspelled words are highlighted by editing your colorscheme file. Vim recognizes four categories of misspelled words - SpellBad (for words not recognized), SpellCap (words which should be spelled with a capital), SpellRare (for rare words, I've no idea what the logic is here) and SpellLocal (for words that belong to the same language in a localization different from the current one). The last category is especially useful - for example in UK English, the word "analyze" is not shown as a SpellBad error (as it is in MS Word), but as a SpellLocal error, since it exists in the US English dictionary. Looking inside Vim's dictionary directory, I note that there is an overall "english.ascii.spl" file and and "en" directory lists files such as "en_GB.diff" and "en_US.diff" which allows this feature, as well as saves space by not having the large common set of English words duplicated for five localizations. Neat!
But I digress. You can customize the highlight for any category by adding in the appropriate categories and their keywords to your colorscheme file (usually located in $VIMRUNTIME/colors). My colorscheme file has the following lines:
hi SpellBad term=reverse ctermfg=white ctermbg=darkred guifg=#ffffff guibg=#7f0000 gui=underline
hi SpellCap guifg=#ffffff guibg=#7f007f
hi SpellRare guifg=#ffffff guibg=#00007f gui=underline
hi SpellLocal term=reverse ctermfg=black ctermbg=darkgreen guifg=#ffffff guibg=#7f0000 gui=underline
Linux.com reported problems while using spell-check with syntax highlighting, but I experienced no such issues. Below are screenshots of Vim7 with my homepage source with spell-check disabled and enabled (click for large versions).
[Update: It seems vi has intelligent spell-checking depending on syntax. In a C++ file, for example, enabling spell checking ONLY applies spell-checking to strings and comments! How cool is that!]
(HTML syntax highlighting with no spell-check)
(HTML syntax highlighting with spell-check enabled, the names "Anshul", "Nigham" for example are highlighted with red background)