1" Vim indent file
2" Language: PoV-Ray Scene Description Language
3" Maintainer: David Necas (Yeti) <yeti@physics.muni.cz>
4" Last Change: 2002-10-20
5" URI: http://trific.ath.cx/Ftp/vim/indent/pov.vim
6
7" Only load this indent file when no other was loaded.
8if exists("b:did_indent")
9  finish
10endif
11let b:did_indent = 1
12
13" Some preliminary settings.
14setlocal nolisp " Make sure lisp indenting doesn't supersede us.
15
16setlocal indentexpr=GetPoVRayIndent()
17setlocal indentkeys+==else,=end,0]
18
19" Only define the function once.
20if exists("*GetPoVRayIndent")
21  finish
22endif
23
24" Counts matches of a regexp <rexp> in line number <line>.
25" Doesn't count matches inside strings and comments (as defined by current
26" syntax).
27function! s:MatchCount(line, rexp)
28  let str = getline(a:line)
29  let i = 0
30  let n = 0
31  while i >= 0
32    let i = matchend(str, a:rexp, i)
33    if i >= 0 && synIDattr(synID(a:line, i, 0), "name") !~? "string\|comment"
34      let n = n + 1
35    endif
36  endwhile
37  return n
38endfunction
39
40" The main function.  Returns indent amount.
41function GetPoVRayIndent()
42  " If we are inside a comment (may be nested in obscure ways), give up
43  if synIDattr(synID(v:lnum, indent(v:lnum)+1, 0), "name") =~? "string\|comment"
44    return -1
45  endif
46
47  " Search backwards for the frist non-empty, non-comment line.
48  let plnum = prevnonblank(v:lnum - 1)
49  let plind = indent(plnum)
50  while plnum > 0 && synIDattr(synID(plnum, plind+1, 0), "name") =~? "comment"
51    let plnum = prevnonblank(plnum - 1)
52    let plind = indent(plnum)
53  endwhile
54
55  " Start indenting from zero
56  if plnum == 0
57    return 0
58  endif
59
60  " Analyse previous nonempty line.
61  let chg = 0
62  let chg = chg + s:MatchCount(plnum, '[[{(]')
63  let chg = chg + s:MatchCount(plnum, '#\s*\%(if\|ifdef\|ifndef\|switch\|while\|macro\|else\)\>')
64  let chg = chg - s:MatchCount(plnum, '#\s*end\>')
65  let chg = chg - s:MatchCount(plnum, '[]})]')
66  " Dirty hack for people writing #if and #else on the same line.
67  let chg = chg - s:MatchCount(plnum, '#\s*\%(if\|ifdef\|ifndef\|switch\)\>.*#\s*else\>')
68  " When chg > 0, then we opened groups and we should indent more, but when
69  " chg < 0, we closed groups and this already affected the previous line,
70  " so we should not dedent.  And when everything else fails, scream.
71  let chg = chg > 0 ? chg : 0
72
73  " Analyse current line
74  " FIXME: If we have to dedent, we should try to find the indentation of the
75  " opening line.
76  let cur = s:MatchCount(v:lnum, '^\s*\%(#\s*\%(end\|else\)\>\|[]})]\)')
77  if cur > 0
78    let final = plind + (chg - cur) * &sw
79  else
80    let final = plind + chg * &sw
81  endif
82
83  return final < 0 ? 0 : final
84endfunction
85