summaryrefslogtreecommitdiff
path: root/runtime/indent/fortran.vim
blob: b14273aa3212b7eb976ed11be8a59eb70caf7c58 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
" Vim indent file
" Language:	Fortran95 (and Fortran90, Fortran77, F and elf90)
" Version:	0.36
" URL:		http://www.unb.ca/chem/ajit/indent/fortran.vim
" Last Change:	2004 Apr. 05
" Maintainer:	Ajit J. Thakkar <ajit@unb.ca>; <http://www.unb.ca/chem/ajit/>
" Usage:	Do :help fortran-indent from Vim

" Only load this indent file when no other was loaded.
if exists("b:did_indent")
  finish
endif
let b:did_indent = 1

let s:cposet=&cpoptions
set cpoptions-=C

setlocal indentkeys+==~end,=~case,=~if,=~else,=~do,=~where,=~elsewhere,=~select
setlocal indentkeys+==~endif,=~enddo,=~endwhere,=~endselect

" Determine whether this is a fixed or free format source file
" if this hasn't been done yet
if !exists("b:fortran_fixed_source")
  if exists("fortran_free_source")
    " User guarantees free source form
    let b:fortran_fixed_source = 0
  elseif exists("fortran_fixed_source")
    " User guarantees fixed source form
    let b:fortran_fixed_source = 1
  else
    " f90 and f95 allow both fixed and free source form
    " assume fixed source form unless signs of free source form
    " are detected in the first five columns of the first 25 lines
    " Detection becomes more accurate and time-consuming if more lines
    " are checked. Increase the limit below if you keep lots of comments at
    " the very top of each file and you have a fast computer
    let s:lmax = 25
    if ( s:lmax > line("$") )
      let s:lmax = line("$")
    endif
    let b:fortran_fixed_source = 1
    let s:ln=1
    while s:ln <= s:lmax
      let s:test = strpart(getline(s:ln),0,5)
      if s:test[0] !~ '[Cc*!#]' && s:test !~ '^ \+[!#]' && s:test =~ '[^ 0-9\t]'
	let b:fortran_fixed_source = 0
	break
      endif
      let s:ln = s:ln + 1
    endwhile
  endif
endif

" Define the appropriate indent function but only once
if (b:fortran_fixed_source == 1)
  setlocal indentexpr=FortranGetFixedIndent()
  if exists("*FortranGetFixedIndent")
    finish
  endif
else
  setlocal indentexpr=FortranGetFreeIndent()
  if exists("*FortranGetFreeIndent")
    finish
  endif
endif

function FortranGetIndent(lnum)
  let ind = indent(a:lnum)
  let prevline=getline(a:lnum)
  " Strip tail comment
  let prevstat=substitute(prevline, '!.*$', '', '')

  "Indent do loops only if they are all guaranteed to be of do/end do type
  if exists("b:fortran_do_enddo") || exists("fortran_do_enddo")
    if prevstat =~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*do\>'
      let ind = ind + &sw
    endif
    if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*end\s*do\>'
      let ind = ind - &sw
    endif
  endif

  "Add a shiftwidth to statements following if, else, case,
  "where and elsewhere statements
  if prevstat =~? '^\s*\(\d\+\s\)\=\s*\(else\|case\|where\|elsewhere\)\>'
	\ || prevstat =~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*if\>'
     let ind = ind + &sw
    " Remove unwanted indent after logical and arithmetic ifs
    if prevstat =~? '\<if\>' && prevstat !~? '\<then\>'
      let ind = ind - &sw
    endif
  endif

  "Subtract a shiftwidth from else, elsewhere, case, end if,
  " end where and end select statements
  if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*'
	\. '\(else\|elsewhere\|case\|end\s*\(if\|where\|select\)\)\>'
    let ind = ind - &sw
    " Fix indent for case statement immediately after select
    if prevstat =~? '\<select\>'
      let ind = ind + &sw
    endif
  endif

  return ind
endfunction

function FortranGetFreeIndent()
  "Find the previous non-blank line
  let lnum = prevnonblank(v:lnum - 1)

  "Use zero indent at the top of the file
  if lnum == 0
    return 0
  endif

  let ind=FortranGetIndent(lnum)
  return ind
endfunction

function FortranGetFixedIndent()
  let currline=getline(v:lnum)
  "Don't indent comments, continuation lines and labelled lines
  if strpart(currline,0,6) =~ '[^ \t]'
    let ind = indent(v:lnum)
    return ind
  endif

  "Find the previous line which is not blank, not a comment,
  "not a continuation line, and does not have a label
  let lnum = v:lnum - 1
  while lnum > 0
    let prevline=getline(lnum)
    if (prevline =~ "^[C*!]") || (prevline =~ "^\s*$")
	\ || (strpart(prevline,5,1) !~ "[ 0]")
      " Skip comments, blank lines and continuation lines
      let lnum = lnum - 1
    else
      let test=strpart(prevline,0,5)
      if test =~ "[0-9]"
	" Skip lines with statement numbers
	let lnum = lnum - 1
      else
	break
      endif
    endif
  endwhile

  "First line must begin at column 7
  if lnum == 0
    return 6
  endif

  let ind=FortranGetIndent(lnum)
  return ind
endfunction

let &cpoptions=s:cposet
unlet s:cposet

" vim:sw=2 tw=130