How to correctly map <tab> for <Plug>Functions() on Windows?

Question

I am using gVim on Windows, and have only recently run into a very problematic situation: my Tab key stops working in insert mode! Pressing the Tab key does not give any output.

In order to use the plugin snipmate which expands snippets by calling a function defined as <Plug>-function, I have to remap ctrl+q to achieve the functionality. However, when I map the same content to Tab, pressing the key is still not bringing me anything.

I checked the mappings defined for <tab> using two methods:

1. Using Listmaps plugin, by calling the command :Listmaps, and found that <tab> has been defined correctly;
2. The mapping on <tab> seems to be valid upon checking :map <tab>;

Nevertheless, Tab seems to have been disabled.

What I don't understand is that: how come the same syntax of mapping would bring about different results. Who should I specify the <Plug>Func() mappings? If this is really wired, would it be worth it to try a fresh installation?

Thank you!

The pair of mappings that I have specified:

imap <c-q> <Plug>snipMateNextOrTrigger
imap <tab> <Plug>snipMateNextOrTrigger

Answer 1

You might need to add <esc>a, especially if you are using YouCompleteMe plugin along with SnipMate.

imap <tab> <esc>a<Plug>snipMateNextOrTrigger

Also verify that tab key is working by pressing ctrl+i, as it is identical to <tab> in Vim.

Finally, check your .vimrc if there is set paste, and remove that line if it exists or replace it with set nopaste.