Creating imaps in vim that don't cause to much of a delay

Question

I'm working on a little vim plugin for a new language. I'm currently working on some cool effects to change some characters and words into badass unicode character such as \ turns into λ.

I now want to make not turn into ¬ but this causes some complications since I cant just match on not since that would cause a word like nottingham to turn into ¬tingham so I created the imap:

inoremap <space>not<space> ¬

But this causes an annoying delay every time space is pressed. Is there anyway to fix this?

NOTE: I'm not using conceal since it causes the characters to flip back and fourth and it messes with the highlighting.

Answer 1

Use an abbreviation for this:

:abbrev not ¬

For the "space before 'not' part":
from :help abbreviations ('not' is a full-id abbreviation, see the help for all abbreviation types):

The characters before the cursor must match the abbreviation.  Each type has
an additional rule:

full-id   In front of the match is a non-keyword character, or this is where
          the line or insertion starts.  Exception: When the abbreviation is
          only one character, it is not recognized if there is a non-keyword
          character in front of it, other than a space or a tab.

For the "space after 'not' part":

An abbreviation is only recognized when you type a non-keyword character.
This can also be the <Esc> that ends insert mode or the <CR> that ends a
command.