Strange behaviour of abbreviations triggered with shift+enter in gvim+vim-latex

Question

Playing with abbreviation in insert mode i noticed the following unexpected behaviour, when using gvim with vim-latex plugin:

Defining an abbreviation such as

:iab m <m>

or any similar "container" abbreviation such as

:iab m \(m\)
:iab m \m\
:iab m [m]

and so on, i get the expected behaviour when simply typing in insert mode

m<space>

However, if I type

m<shift><enter>

or

m<ctrl><enter>

the "container characters" are doubled, for example in the first two cases above I get

<<m>>
\(\(m\)\)

I don't find this kind of behaviour in the abbreviations section of the man page, nor in the relative vim.wikia page.

I'm using the vim version 7.4, and I can reproduce this both on Arch Linux and Windows 7.

Why does this happen? Can I prevent it? How?

Developers mailing list

I submitted the problem on the vim-latex mailing list. Here is the response I got:

Hi,

this seems to be a strange interaction with the IMAP-features of the latex-suite.

I tried

:iab a (m)
:iab m [a]

Now, a<space> => (m) a<s-space> => ([a])

Here, first a is expanded to (m) and the inner m is expanded to [a].

If one uses

 let Imap_FreezeImap=1

<space> triggers no expansions, but <s-space> works correctly.

I have no clue how to fix this.

Best regards, Gerd

Other unexpected behaviours

Using inoreab

Following a suggestion in the comments I tried with

:inoreab n <n>

When I do this something else happens: typing

n<space>

produces

* <n>

with a * character coming from nowhere. Typing instead n<shift><space> or n<enter> or n<ctrl><enter> I get the expected output <n>. Can you reproduce this?

Without set backspace=eol,indent,start

Even without using recursive abbreviations, there is a problem if

set keyboard=eol,start,indent

is not used.

Defining an abbreviation like

:iab alice bob

and using it typing

alice<space>

does not substitute alice with bob. Instead places bob at the right of alice, producing an output like

alice bob

Again, using <ctrl><space> or <enter> the substitution is made correctly.

Answer 1

Your updated findings give it away: The Latex plugin (incorrectly, that's why :inoremap causes the addition of a *) parses the output of the :iab command in s:LookupCharacter(char) from plugin/imaps.vim:

            " An extremeley wierd way to get around the fact that vim
            " doesn't have the equivalent of the :mapcheck() function for
            " abbreviations.
            let _a = @a
            exec "redir @a | silent! iab ".lastword." | redir END"

So, the problem is with the plugin's IMAP() function, which purportedly has the following

" Motivation:
" this script provides a way to generate insert mode mappings which do not
" suffer from some of the problem of mappings and abbreviations while allowing
" cursor placement after the expansion. It can alternatively be thought of as
" a template expander.

Therefore, it's a bug in the plugin; you either need to wait for / submit a patch, or avoid the problem by not defining such :iab yourself. (Maybe using the provided IMAP() function consistently will solve this?)