xref: /vim-8.2.3635/runtime/indent/fortran.vim (revision 94688b8a)
1" Vim indent file
2" Language:	Fortran 2008 (and older: Fortran 2003, 95, 90, and 77)
3" Version:	47
4" Last Change:	2016 Oct. 29
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, in chronological order, by:
9"  Albert Oliver Serra, Takuya Fujiwara and Philipp Edelmann.
10
11" Only load this indent file when no other was loaded.
12if exists("b:did_indent")
13  finish
14endif
15let b:did_indent = 1
16
17let s:cposet=&cpoptions
18set cpoptions&vim
19
20setlocal indentkeys+==~end,=~case,=~if,=~else,=~do,=~where,=~elsewhere,=~select
21setlocal indentkeys+==~endif,=~enddo,=~endwhere,=~endselect,=~elseif
22setlocal indentkeys+==~type,=~interface,=~forall,=~associate,=~block,=~enum
23setlocal indentkeys+==~endforall,=~endassociate,=~endblock,=~endenum
24if exists("b:fortran_indent_more") || exists("g:fortran_indent_more")
25  setlocal indentkeys+==~function,=~subroutine,=~module,=~contains,=~program
26  setlocal indentkeys+==~endfunction,=~endsubroutine,=~endmodule
27  setlocal indentkeys+==~endprogram
28endif
29
30" Determine whether this is a fixed or free format source file
31" if this hasn't been done yet using the priority:
32" buffer-local value
33" > global value
34" > file extension as in Intel ifort, gcc (gfortran), NAG, Pathscale, and Cray compilers
35if !exists("b:fortran_fixed_source")
36  if exists("fortran_free_source")
37    " User guarantees free source form
38    let b:fortran_fixed_source = 0
39  elseif exists("fortran_fixed_source")
40    " User guarantees fixed source form
41    let b:fortran_fixed_source = 1
42  elseif expand("%:e") ==? "f\<90\|95\|03\|08\>"
43    " Free-form file extension defaults as in Intel ifort, gcc(gfortran), NAG, Pathscale, and Cray compilers
44    let b:fortran_fixed_source = 0
45  elseif expand("%:e") ==? "f\|f77\|for"
46    " Fixed-form file extension defaults
47    let b:fortran_fixed_source = 1
48  else
49    " Modern fortran still allows both fixed and free source form
50    " Assume fixed source form unless signs of free source form
51    " are detected in the first five columns of the first s:lmax lines.
52    " Detection becomes more accurate and time-consuming if more lines
53    " are checked. Increase the limit below if you keep lots of comments at
54    " the very top of each file and you have a fast computer.
55    let s:lmax = 500
56    if ( s:lmax > line("$") )
57      let s:lmax = line("$")
58    endif
59    let b:fortran_fixed_source = 1
60    let s:ln=1
61    while s:ln <= s:lmax
62      let s:test = strpart(getline(s:ln),0,5)
63      if s:test !~ '^[Cc*]' && s:test !~ '^ *[!#]' && s:test =~ '[^ 0-9\t]' && s:test !~ '^[ 0-9]*\t'
64	let b:fortran_fixed_source = 0
65	break
66      endif
67      let s:ln = s:ln + 1
68    endwhile
69  endif
70endif
71
72" Define the appropriate indent function but only once
73if (b:fortran_fixed_source == 1)
74  setlocal indentexpr=FortranGetFixedIndent()
75  if exists("*FortranGetFixedIndent")
76    finish
77  endif
78else
79  setlocal indentexpr=FortranGetFreeIndent()
80  if exists("*FortranGetFreeIndent")
81    finish
82  endif
83endif
84
85function FortranGetIndent(lnum)
86  let ind = indent(a:lnum)
87  let prevline=getline(a:lnum)
88  " Strip tail comment
89  let prevstat=substitute(prevline, '!.*$', '', '')
90  let prev2line=getline(a:lnum-1)
91  let prev2stat=substitute(prev2line, '!.*$', '', '')
92
93  "Indent do loops only if they are all guaranteed to be of do/end do type
94  if exists("b:fortran_do_enddo") || exists("g:fortran_do_enddo")
95    if prevstat =~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*do\>'
96      let ind = ind + shiftwidth()
97    endif
98    if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*end\s*do\>'
99      let ind = ind - shiftwidth()
100    endif
101  endif
102
103  "Add a shiftwidth to statements following if, else, else if, case, class,
104  "where, else where, forall, type, interface and associate statements
105  if prevstat =~? '^\s*\(case\|class\|else\|else\s*if\|else\s*where\)\>'
106	\ ||prevstat=~? '^\s*\(type\|interface\|associate\|enum\)\>'
107	\ ||prevstat=~?'^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*\(forall\|where\|block\)\>'
108	\ ||prevstat=~? '^\s*\(\d\+\s\)\=\s*\(\a\w*\s*:\)\=\s*if\>'
109     let ind = ind + shiftwidth()
110    " Remove unwanted indent after logical and arithmetic ifs
111    if prevstat =~? '\<if\>' && prevstat !~? '\<then\>'
112      let ind = ind - shiftwidth()
113    endif
114    " Remove unwanted indent after type( statements
115    if prevstat =~? '^\s*type\s*('
116      let ind = ind - shiftwidth()
117    endif
118  endif
119
120  "Indent program units unless instructed otherwise
121  if !exists("b:fortran_indent_less") && !exists("g:fortran_indent_less")
122    let prefix='\(\(pure\|impure\|elemental\|recursive\)\s\+\)\{,2}'
123    let type='\(\(integer\|real\|double\s\+precision\|complex\|logical'
124          \.'\|character\|type\|class\)\s*\S*\s\+\)\='
125    if prevstat =~? '^\s*\(contains\|submodule\|program\)\>'
126            \ ||prevstat =~? '^\s*'.'module\>\(\s*\procedure\)\@!'
127            \ ||prevstat =~? '^\s*'.prefix.'subroutine\>'
128            \ ||prevstat =~? '^\s*'.prefix.type.'function\>'
129            \ ||prevstat =~? '^\s*'.type.prefix.'function\>'
130      let ind = ind + shiftwidth()
131    endif
132    if getline(v:lnum) =~? '^\s*contains\>'
133          \ ||getline(v:lnum)=~? '^\s*end\s*'
134          \ .'\(function\|subroutine\|module\|submodule\|program\)\>'
135      let ind = ind - shiftwidth()
136    endif
137  endif
138
139  "Subtract a shiftwidth from else, else if, elsewhere, case, class, end if,
140  " end where, end select, end forall, end interface, end associate,
141  " end enum, end type, end block and end type statements
142  if getline(v:lnum) =~? '^\s*\(\d\+\s\)\=\s*'
143        \. '\(else\|else\s*if\|else\s*where\|case\|class\|'
144        \. 'end\s*\(if\|where\|select\|interface\|'
145        \. 'type\|forall\|associate\|enum\|block\)\)\>'
146    let ind = ind - shiftwidth()
147    " Fix indent for case statement immediately after select
148    if prevstat =~? '\<select\s\+\(case\|type\)\>'
149      let ind = ind + shiftwidth()
150    endif
151  endif
152
153  "First continuation line
154  if prevstat =~ '&\s*$' && prev2stat !~ '&\s*$'
155    let ind = ind + shiftwidth()
156  endif
157  "Line after last continuation line
158  if prevstat !~ '&\s*$' && prev2stat =~ '&\s*$' && prevstat !~? '\<then\>'
159    let ind = ind - shiftwidth()
160  endif
161
162  return ind
163endfunction
164
165function FortranGetFreeIndent()
166  "Find the previous non-blank line
167  let lnum = prevnonblank(v:lnum - 1)
168
169  "Use zero indent at the top of the file
170  if lnum == 0
171    return 0
172  endif
173
174  let ind=FortranGetIndent(lnum)
175  return ind
176endfunction
177
178function FortranGetFixedIndent()
179  let currline=getline(v:lnum)
180  "Don't indent comments, continuation lines and labelled lines
181  if strpart(currline,0,6) =~ '[^ \t]'
182    let ind = indent(v:lnum)
183    return ind
184  endif
185
186  "Find the previous line which is not blank, not a comment,
187  "not a continuation line, and does not have a label
188  let lnum = v:lnum - 1
189  while lnum > 0
190    let prevline=getline(lnum)
191    if (prevline =~ "^[C*!]") || (prevline =~ "^\s*$")
192	\ || (strpart(prevline,5,1) !~ "[ 0]")
193      " Skip comments, blank lines and continuation lines
194      let lnum = lnum - 1
195    else
196      let test=strpart(prevline,0,5)
197      if test =~ "[0-9]"
198	" Skip lines with statement numbers
199	let lnum = lnum - 1
200      else
201	break
202      endif
203    endif
204  endwhile
205
206  "First line must begin at column 7
207  if lnum == 0
208    return 6
209  endif
210
211  let ind=FortranGetIndent(lnum)
212  return ind
213endfunction
214
215let &cpoptions=s:cposet
216unlet s:cposet
217
218" vim:sw=2 tw=130
219