xref: /vim-8.2.3635/runtime/indent/fortran.vim (revision 2bf24176)
1" Vim indent file
2" Language:	Fortran 2008 (and older: Fortran 2003, 95, 90, and 77)
3" Version:	0.42
4" Last Change:	2015 Nov. 30
5" Maintainer:	Ajit J. Thakkar <[email protected]>; <http://www2.unb.ca/~ajit/>
6" Usage:	For instructions, do :help fortran-indent from Vim
7" Credits:
8"  Useful suggestions were made by: Albert Oliver Serra.
9
10" Only load this indent file when no other was loaded.
11if exists("b:did_indent")
12  finish
13endif
14let b:did_indent = 1
15
16let s:cposet=&cpoptions
17set cpoptions&vim
18
19setlocal indentkeys+==~end,=~case,=~if,=~else,=~do,=~where,=~elsewhere,=~select
20setlocal indentkeys+==~endif,=~enddo,=~endwhere,=~endselect,=~elseif
21setlocal indentkeys+==~type,=~interface,=~forall,=~associate,=~block,=~enum
22setlocal indentkeys+==~endforall,=~endassociate,=~endblock,=~endenum
23if exists("b:fortran_indent_more") || exists("g:fortran_indent_more")
24  setlocal indentkeys+==~function,=~subroutine,=~module,=~contains,=~program
25  setlocal indentkeys+==~endfunction,=~endsubroutine,=~endmodule
26  setlocal indentkeys+==~endprogram
27endif
28
29" Determine whether this is a fixed or free format source file
30" if this hasn't been done yet using the priority:
31" buffer-local value
32" > global value
33" > file extension as in Intel ifort, gcc (gfortran), NAG, Pathscale, and Cray compilers
34if !exists("b:fortran_fixed_source")
35  if exists("fortran_free_source")
36    " User guarantees free source form
37    let b:fortran_fixed_source = 0
38  elseif exists("fortran_fixed_source")
39    " User guarantees fixed source form
40    let b:fortran_fixed_source = 1
41  elseif expand("%:e") ==? "f\<90\|95\|03\|08\>"
42    " Free-form file extension defaults as in Intel ifort, gcc(gfortran), NAG, Pathscale, and Cray compilers
43    let b:fortran_fixed_source = 0
44  elseif expand("%:e") ==? "f\|f77\|for"
45    " Fixed-form file extension defaults
46    let b:fortran_fixed_source = 1
47  else
48    " Modern fortran still allows both fixed and free source form
49    " Assume fixed source form unless signs of free source form
50    " are detected in the first five columns of the first s:lmax lines.
51    " Detection becomes more accurate and time-consuming if more lines
52    " are checked. Increase the limit below if you keep lots of comments at
53    " the very top of each file and you have a fast computer.
54    let s:lmax = 500
55    if ( s:lmax > line("$") )
56      let s:lmax = line("$")
57    endif
58    let b:fortran_fixed_source = 1
59    let s:ln=1
60    while s:ln <= s:lmax
61      let s:test = strpart(getline(s:ln),0,5)
62      if s:test !~ '^[Cc*]' && s:test !~ '^ *[!#]' && s:test =~ '[^ 0-9\t]' && s:test !~ '^[ 0-9]*\t'
63	let b:fortran_fixed_source = 0
64	break
65      endif
66      let s:ln = s:ln + 1
67    endwhile
68  endif
69endif
70
71" Define the appropriate indent function but only once
72if (b:fortran_fixed_source == 1)
73  setlocal indentexpr=FortranGetFixedIndent()
74  if exists("*FortranGetFixedIndent")
75    finish
76  endif
77else
78  setlocal indentexpr=FortranGetFreeIndent()
79  if exists("*FortranGetFreeIndent")
80    finish
81  endif
82endif
83
84function FortranGetIndent(lnum)
85  let ind = indent(a:lnum)
86  let prevline=getline(a:lnum)
87  " Strip tail comment
88  let prevstat=substitute(prevline, '!.*$', '', '')
89  let prev2line=getline(a:lnum-1)
90  let prev2stat=substitute(prev2line, '!.*$', '', '')
91
92  "Indent do loops only if they are all guaranteed to be of do/end do type
93  if exists("b:fortran_do_enddo") || exists("g:fortran_do_enddo")
94    if prevstat =~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*do\>'
95      let ind = ind + &sw
96    endif
97    if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*end\s*do\>'
98      let ind = ind - &sw
99    endif
100  endif
101
102  "Add a shiftwidth to statements following if, else, else if, case,
103  "where, else where, forall, type, interface and associate statements
104  if prevstat =~? '^\s*\(case\|else\|else\s*if\|else\s*where\)\>'
105	\ ||prevstat=~? '^\s*\(type\|interface\|associate\|enum\)\>'
106	\ ||prevstat=~?'^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*\(forall\|where\|block\)\>'
107	\ ||prevstat=~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*if\>'
108     let ind = ind + &sw
109    " Remove unwanted indent after logical and arithmetic ifs
110    if prevstat =~? '\<if\>' && prevstat !~? '\<then\>'
111      let ind = ind - &sw
112    endif
113    " Remove unwanted indent after type( statements
114    if prevstat =~? '^\s*type\s*('
115      let ind = ind - &sw
116    endif
117  endif
118
119  "Indent program units unless instructed otherwise
120  if !exists("b:fortran_indent_less") && !exists("g:fortran_indent_less")
121    let prefix='\(\(pure\|impure\|elemental\|recursive\)\s\+\)\{,2}'
122    let type='\(\(integer\|real\|double\s\+precision\|complex\|logical'
123          \.'\|character\|type\|class\)\s*\S*\s\+\)\='
124    if prevstat =~? '^\s*\(module\|contains\|program\)\>'
125            \ ||prevstat =~? '^\s*'.prefix.'subroutine\>'
126            \ ||prevstat =~? '^\s*'.prefix.type.'function\>'
127            \ ||prevstat =~? '^\s*'.type.prefix.'function\>'
128      let ind = ind + &sw
129    endif
130    if getline(v:lnum) =~? '^\s*contains\>'
131          \ ||getline(v:lnum)=~? '^\s*end\s*'
132          \ .'\(function\|subroutine\|module\|program\)\>'
133      let ind = ind - &sw
134    endif
135  endif
136
137  "Subtract a shiftwidth from else, else if, elsewhere, case, end if,
138  " end where, end select, end forall, end interface, end associate,
139  " end enum, and end type statements
140  if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*'
141        \. '\(else\|else\s*if\|else\s*where\|case\|'
142        \. 'end\s*\(if\|where\|select\|interface\|'
143        \. 'type\|forall\|associate\|enum\|block\)\)\>'
144    let ind = ind - &sw
145    " Fix indent for case statement immediately after select
146    if prevstat =~? '\<select\s\+\(case\|type\)\>'
147      let ind = ind + &sw
148    endif
149  endif
150
151  "First continuation line
152  if prevstat =~ '&\s*$' && prev2stat !~ '&\s*$'
153    let ind = ind + &sw
154  endif
155  if prevstat =~ '&\s*$' && prevstat =~ '\<else\s*if\>'
156    let ind = ind - &sw
157  endif
158  "Line after last continuation line
159  if prevstat !~ '&\s*$' && prev2stat =~ '&\s*$' && prevstat !~? '\<then\>'
160    let ind = ind - &sw
161  endif
162
163  return ind
164endfunction
165
166function FortranGetFreeIndent()
167  "Find the previous non-blank line
168  let lnum = prevnonblank(v:lnum - 1)
169
170  "Use zero indent at the top of the file
171  if lnum == 0
172    return 0
173  endif
174
175  let ind=FortranGetIndent(lnum)
176  return ind
177endfunction
178
179function FortranGetFixedIndent()
180  let currline=getline(v:lnum)
181  "Don't indent comments, continuation lines and labelled lines
182  if strpart(currline,0,6) =~ '[^ \t]'
183    let ind = indent(v:lnum)
184    return ind
185  endif
186
187  "Find the previous line which is not blank, not a comment,
188  "not a continuation line, and does not have a label
189  let lnum = v:lnum - 1
190  while lnum > 0
191    let prevline=getline(lnum)
192    if (prevline =~ "^[C*!]") || (prevline =~ "^\s*$")
193	\ || (strpart(prevline,5,1) !~ "[ 0]")
194      " Skip comments, blank lines and continuation lines
195      let lnum = lnum - 1
196    else
197      let test=strpart(prevline,0,5)
198      if test =~ "[0-9]"
199	" Skip lines with statement numbers
200	let lnum = lnum - 1
201      else
202	break
203      endif
204    endif
205  endwhile
206
207  "First line must begin at column 7
208  if lnum == 0
209    return 6
210  endif
211
212  let ind=FortranGetIndent(lnum)
213  return ind
214endfunction
215
216let &cpoptions=s:cposet
217unlet s:cposet
218
219" vim:sw=2 tw=130
220