TITLE: Vim fold expression for BibTeX files

TITLE: Vim fold expression for BibTeX files
DATE: 2019-07-31
AUTHOR: John L. Godlee
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I wanted to be able to fold long BibTeX files to display a condensed
list of the references so I could quickly scan the contents of the
file. To do this, I created a function in my .vimrc which folds .bib
files on the @ symbol which prepends each reference entry in the
file. THis is the excerpt from my .vimrc:

" Set folding function for bibtex entries
function! BibTeXFold()
if getline(v:lnum) =~ '^@.*$'
return ">1"
endif
return "="
endfunction
au BufEnter *.bib setlocal foldexpr=BibTeXFold()
au BufEnter *.bib setlocal foldmethod=expr

The final two lines which start with au BufEnter set the method of
folding to expression and identifies the expression to use
(BibTeXFold()).