I cannot append a matching pair to b:match_words

Question

I use matchit.vim and it works. Indeed I write a Fortran code and I can jump from IF to END IF pressing %. I'm trying to add the couple <+, > to b:match_words, adding

let b:match_words = b:match_words . '<+:>'

to my ~/.vimrc file, but I get errors E121 and E15 bout undefined variable b:match_words and invalid expression b:match_words . '<+:>', respectively.

If i change to

let b:match_words = '<+:>'

The error disappear, but obviously I cannot match anything else that this only pair.

Answer 1

You want to extend matchit's default b:match_words, so you'll have to to wait for it to be initialised first. The docs make reference to setting it from ftplugins, so the solution is to add

let b:match_words .= ',<+:>'

to a file after/ftplugin/fortran.vim. That's about all there is to it.

On a side note: beware that <+ and > above are actually regexps. This is important if you want to add more pairs to b:match_words.