xref: /vim-8.2.3635/runtime/indent/python.vim (revision 577fadfc)
1" Vim indent file
2" Language:		Python
3" Maintainer:		Bram Moolenaar <[email protected]>
4" Original Author:	David Bustos <[email protected]>
5" Last Change:		2019 Feb 21
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
15setlocal autoindent	" indentexpr isn't much help otherwise
16
17setlocal indentexpr=GetPythonIndent(v:lnum)
18setlocal indentkeys+=<:>,=elif,=except
19
20" Only define the function once.
21if exists("*GetPythonIndent")
22  finish
23endif
24let s:keepcpo= &cpo
25set cpo&vim
26
27" Come here when loading the script the first time.
28
29let s:maxoff = 50	" maximum number of lines to look backwards for ()
30
31function GetPythonIndent(lnum)
32
33  " If this line is explicitly joined: If the previous line was also joined,
34  " line it up with that one, otherwise add two 'shiftwidth'
35  if getline(a:lnum - 1) =~ '\\$'
36    if a:lnum > 1 && getline(a:lnum - 2) =~ '\\$'
37      return indent(a:lnum - 1)
38    endif
39    return indent(a:lnum - 1) + (exists("g:pyindent_continue") ? eval(g:pyindent_continue) : (shiftwidth() * 2))
40  endif
41
42  " If the start of the line is in a string don't change the indent.
43  if has('syntax_items')
44	\ && synIDattr(synID(a:lnum, 1, 1), "name") =~ "String$"
45    return -1
46  endif
47
48  " Search backwards for the previous non-empty line.
49  let plnum = prevnonblank(v:lnum - 1)
50
51  if plnum == 0
52    " This is the first non-empty line, use zero indent.
53    return 0
54  endif
55
56  call cursor(plnum, 1)
57
58  " Identing inside parentheses can be very slow, regardless of the searchpair()
59  " timeout, so let the user disable this feature if he doesn't need it
60  let disable_parentheses_indenting = get(g:, "pyindent_disable_parentheses_indenting", 0)
61
62  if disable_parentheses_indenting == 1
63    let plindent = indent(plnum)
64    let plnumstart = plnum
65  else
66    " searchpair() can be slow sometimes, limit the time to 150 msec or what is
67    " put in g:pyindent_searchpair_timeout
68    let searchpair_stopline = 0
69    let searchpair_timeout = get(g:, 'pyindent_searchpair_timeout', 150)
70
71    " If the previous line is inside parenthesis, use the indent of the starting
72    " line.
73    " Trick: use the non-existing "dummy" variable to break out of the loop when
74    " going too far back.
75    let parlnum = searchpair('(\|{\|\[', '', ')\|}\|\]', 'nbW',
76            \ "line('.') < " . (plnum - s:maxoff) . " ? dummy :"
77            \ . " synIDattr(synID(line('.'), col('.'), 1), 'name')"
78            \ . " =~ '\\(Comment\\|Todo\\|String\\)$'",
79            \ searchpair_stopline, searchpair_timeout)
80    if parlnum > 0
81      let plindent = indent(parlnum)
82      let plnumstart = parlnum
83    else
84      let plindent = indent(plnum)
85      let plnumstart = plnum
86    endif
87
88    " When inside parenthesis: If at the first line below the parenthesis add
89    " two 'shiftwidth', otherwise same as previous line.
90    " i = (a
91    "       + b
92    "       + c)
93    call cursor(a:lnum, 1)
94    let p = searchpair('(\|{\|\[', '', ')\|}\|\]', 'bW',
95            \ "line('.') < " . (a:lnum - s:maxoff) . " ? dummy :"
96            \ . " synIDattr(synID(line('.'), col('.'), 1), 'name')"
97            \ . " =~ '\\(Comment\\|Todo\\|String\\)$'",
98            \ searchpair_stopline, searchpair_timeout)
99    if p > 0
100      if p == plnum
101        " When the start is inside parenthesis, only indent one 'shiftwidth'.
102        let pp = searchpair('(\|{\|\[', '', ')\|}\|\]', 'bW',
103            \ "line('.') < " . (a:lnum - s:maxoff) . " ? dummy :"
104            \ . " synIDattr(synID(line('.'), col('.'), 1), 'name')"
105            \ . " =~ '\\(Comment\\|Todo\\|String\\)$'",
106            \ searchpair_stopline, searchpair_timeout)
107        if pp > 0
108          return indent(plnum) + (exists("g:pyindent_nested_paren") ? eval(g:pyindent_nested_paren) : shiftwidth())
109        endif
110        return indent(plnum) + (exists("g:pyindent_open_paren") ? eval(g:pyindent_open_paren) : (shiftwidth() * 2))
111      endif
112      if plnumstart == p
113        return indent(plnum)
114      endif
115      return plindent
116    endif
117
118  endif
119
120
121  " Get the line and remove a trailing comment.
122  " Use syntax highlighting attributes when possible.
123  let pline = getline(plnum)
124  let pline_len = strlen(pline)
125  if has('syntax_items')
126    " If the last character in the line is a comment, do a binary search for
127    " the start of the comment.  synID() is slow, a linear search would take
128    " too long on a long line.
129    if synIDattr(synID(plnum, pline_len, 1), "name") =~ "\\(Comment\\|Todo\\)$"
130      let min = 1
131      let max = pline_len
132      while min < max
133	let col = (min + max) / 2
134	if synIDattr(synID(plnum, col, 1), "name") =~ "\\(Comment\\|Todo\\)$"
135	  let max = col
136	else
137	  let min = col + 1
138	endif
139      endwhile
140      let pline = strpart(pline, 0, min - 1)
141    endif
142  else
143    let col = 0
144    while col < pline_len
145      if pline[col] == '#'
146	let pline = strpart(pline, 0, col)
147	break
148      endif
149      let col = col + 1
150    endwhile
151  endif
152
153  " If the previous line ended with a colon, indent this line
154  if pline =~ ':\s*$'
155    return plindent + shiftwidth()
156  endif
157
158  " If the previous line was a stop-execution statement...
159  if getline(plnum) =~ '^\s*\(break\|continue\|raise\|return\|pass\)\>'
160    " See if the user has already dedented
161    if indent(a:lnum) > indent(plnum) - shiftwidth()
162      " If not, recommend one dedent
163      return indent(plnum) - shiftwidth()
164    endif
165    " Otherwise, trust the user
166    return -1
167  endif
168
169  " If the current line begins with a keyword that lines up with "try"
170  if getline(a:lnum) =~ '^\s*\(except\|finally\)\>'
171    let lnum = a:lnum - 1
172    while lnum >= 1
173      if getline(lnum) =~ '^\s*\(try\|except\)\>'
174	let ind = indent(lnum)
175	if ind >= indent(a:lnum)
176	  return -1	" indent is already less than this
177	endif
178	return ind	" line up with previous try or except
179      endif
180      let lnum = lnum - 1
181    endwhile
182    return -1		" no matching "try"!
183  endif
184
185  " If the current line begins with a header keyword, dedent
186  if getline(a:lnum) =~ '^\s*\(elif\|else\)\>'
187
188    " Unless the previous line was a one-liner
189    if getline(plnumstart) =~ '^\s*\(for\|if\|try\)\>'
190      return plindent
191    endif
192
193    " Or the user has already dedented
194    if indent(a:lnum) <= plindent - shiftwidth()
195      return -1
196    endif
197
198    return plindent - shiftwidth()
199  endif
200
201  " When after a () construct we probably want to go back to the start line.
202  " a = (b
203  "       + c)
204  " here
205  if parlnum > 0
206    return plindent
207  endif
208
209  return -1
210
211endfunction
212
213let &cpo = s:keepcpo
214unlet s:keepcpo
215
216" vim:sw=2
217