Added indentation file for bibliographies

doc/vimtex.txt

@@ -398,6 +398,10 @@ List of section constructs that should be folded. >
 Use |vimtex| indentation function.  Not as customizable as the official
 indentation function, but imho it is better. >
   let g:vimtex_indent_enabled = 1
+<
+                                                  *g:vimtex_indent_bib_enabled*
+Use |vimtex| indentation function for bibliography files. >
+  let g:vimtex_indent_bib_enabled = 1
 <
                                                    *g:vimtex_latexmk_build_dir*
 Set this variable in case a dedicated build dir is used with `latexmk`/`latex`
@@ -688,12 +692,15 @@ INDENTATION                                                     *vimtex-indent*
 
 The official indentation function is pretty good and allows for some
 customization.  However, I am not quite satisfied, so I wrote my own
-indentation function that is not customizable at all (at least for now), but
-that I think is better.  It is enabled by default, but may be disabled if
-desired |g:vimtex_indent_enabled|.
+indentation function that is not customizable, but that I think is better.  It
+is enabled by default, but may be disabled if desired.
+
+                                                            *vimtex-bib-indent*
+I've also written an indentation file for bibliography files (`.bib` files).
 
 Associated settings:
     |g:vimtex_indent_enabled|
+    |g:vimtex_indent_bib_enabled|
 
 ==============================================================================
 LATEXMK                                                        *vimtex-latexmk*

indent/bib.vim

@@ -0,0 +1,83 @@
+" vimtex - LaTeX plugin for Vim
+"
+" Maintainer: Karl Yngve Lervåg
+" Email:      karl.yngve@gmail.com
+"
+
+if exists('b:did_indent')
+  finish
+endif
+let b:did_indent = 1
+
+call vimtex#util#set_default('g:vimtex_indent_bib_enabled', 1)
+if !g:vimtex_indent_bib_enabled | finish | endif
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+setlocal autoindent
+setlocal indentexpr=VimtexIndentBib()
+
+function! VimtexIndentBib() " {{{1
+  " Find first non-blank line above the current line
+  let lnum = prevnonblank(v:lnum - 1)
+  if lnum == 0
+    return 0
+  endif
+
+  " Get some initial conditions
+  let ind   = indent(lnum)
+  let line  = getline(lnum)
+  let cline = getline(v:lnum)
+  let g:test = 1
+
+  " Zero indent for first line of each entry
+  if cline =~# '^\s*@'
+    return 0
+  endif
+
+  " Title line of entry
+  if line =~# '^@'
+    if cline =~# '^\s*}'
+      return 0
+    else
+      return &sw
+    endif
+  endif
+
+  if line =~# '='
+    " Indent continued bib info entries
+    if s:count('{', line) - s:count('}', line) > 0
+      let match = searchpos('.*=\s*{','bcne')
+      return match[1]
+    elseif cline =~# '^\s*}'
+      return 0
+    endif
+  elseif s:count('{', line) - s:count('}', line) < 0
+    if s:count('{', cline) - s:count('}', cline) < 0
+      return 0
+    else
+      return &sw
+    endif
+  endif
+
+  return ind
+endfunction
+
+function! s:count(pattern, line) " {{{1
+  let sum = 0
+  let indx = match(a:line, a:pattern)
+  while indx >= 0
+    let sum += 1
+    let indx += 1
+    let indx = match(a:line, a:pattern, indx)
+  endwhile
+  return sum
+endfunction
+
+" }}}1
+
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+" vim: fdm=marker sw=2