preventing trailing whitespace when using vim abbreviations

Question

I am a new user of vim (gvim in windows), and have found abbreviations a nice time saver - however they would be even better if i could stop the trailing whitespace at times.

I have some directories that i use a lot, and so i added some abbreviation/path pairs to my _vimrc:

:ab diR1 C:/dirA/dira/dir1/
:ab diR2 C:/dirA/dirb/dir2/ 

etc ...

Now when i type diR1 <space> i get C:/dirA/dira/dir1/[]| where the whitespace is represented by [] and the cursor is the | character. I would like to get rid of the [] == whitespace.

This is a minor complaint: however you seem to be able to customise everthing else in Vim so i figured i'd ask -- is it possible to avoid the trailing whitespace when one uses abbreviations in vim?

An alternate tool used within Vim is a good answer - my objective is to save re-typing frequently used directory structures, but to have the cursor handy as i would almost always add something to the end, such as myFile.txt.

The trailing white space (doubtless due to the fact that the space triggered the abbreviation) which i backspace over before adding myFile.txt to the end is less annoying than typing the whole thing over and over, but it would be ideal if i could avoid doing so ...

Answer 1

pb2q answer is exactly what you want in your current scenario, but does not fully answer the question presented in the title. This exact problem is addressed in the vim help file. See :helpgrep Eatchar. The example it gives is this:

You can even do more complicated things.  For example, to consume the space
typed after an abbreviation: >
   func Eatchar(pat)
      let c = nr2char(getchar(0))
      return (c =~ a:pat) ? '' : c
   endfunc
   iabbr <silent> if if ()<Left><C-R>=Eatchar('\s')<CR>

You would put the Eatchar function in your ~/.vimrc file and then use like so in your abbreviations:

iabbr <silent> diR1 C:/dirA/dira/dir1/<c-r>=Eatchar('\m\s\<bar>/')<cr>

This would "eat" any trailing white space character or a slash. Note that I used iabbr instead of just abbr, because it is rare to actually want abbreviations to expand in command line mode. You must be careful with abbreviations in command line mode as they will expand in unexpected places such as searches and input() commands.

For more information see:

:h abbreviations
:helpgrep Eatchar
:h :helpgrep