Vim: set langmap=e;h breaks supertab plugin

Question

I am new to Vim and trying to set up some plugins. So far I have installed pathogen, pyflakes and supertab. The latter does not seem to work; pressing tab while in insert mode simply writes the string <Plug>SuperTabForward.

The problem only occurs with the following line in my vimrc (for better navigation using colemak layout):

set langmap=hjklneiHJKLNEI;kniejhlKNIEJHL

Without the above line it works just fine. After further experiments I've narrowed it down to set langmap=e;h. This single line breaks supertab.

I am entirely too inexperienced with Vim to have the faintest idea of what is going on or how to fix it. Even a workaround would be of interest.

Lipp

I have exactly the same problem. – Granulose

I think your problem is similar to this one. – Archdeacon

@romainl: Actually, that link made me try a workaround (which I posted as an answer below). It brings up more questions than it answers though, and I'd gladly award the bounty to anyone that can explain. – Granulose

Answer 1

I figured out a workaround: Editing supertab.vim, replacing instances of <Plug>SuperTab with <P>P, which causes strings like <Plug>SuperTabForward to become <P>PForward.

I reckon it works because those strings no longer include any of the letters involved in set langmap=hjklneiHJKLNEI;kniejhlKNIEJHL. Several issues are unresolved still. Is langmap bugged? To me it seems the option exists explicitly to allow mapping that effects only commands:

When you are typing text in Insert mode the characters are
inserted directly.  When in command mode the 'langmap' option takes
care of translating these special characters to the original meaning
of the key.  This means you don't have to change the keyboard mode to
be able to execute Normal mode commands.

It makes no sense to me what so ever, then, that the presence of a langmap mapped character in an imap string, that is an insert mode mapping, makes any difference. If it does, it will randomly break any plugin such as SuperTab that uses long imap strings. Just to illustrate how strange this is, if I do imap no yes, writing jo is necessary to make it trigger. I have no idea how the logic behind that works.

Granulose

If you have set showmode, do you see even a brief -- SELECT -- in the command line while you hit <Tab>? – Archdeacon

Not as far as I can tell. It says -- INSERT -- and a very brief =<SNR>17_SuperTab('n') that I only noticed by holding down the <TAB> key. That's all. – Granulose

Answer 2

I had the same problem, but this workaround didn't fit my case, so I posted my own question and someone made a patch that fixes it:

Vim langmap breaks plugin (bépo)

https://groups.google.com/forum/#!msg/vim_dev/QnNwLWhJ744/1qNcD7d9OvgJ (see the last message)

This patch introduces a new setting: langnoremap which, when set, prevents langmap from affecting such mappings.

It may need some more testing and may not be included in vim very soon, but it seems to work quite well!

Tso