summaryrefslogtreecommitdiffstats
path: root/runtime/indent/hare.vim
blob: bc4fea4e61f012ad888242f04d0f9f9541ede308 (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
" Vim indent file
" Language: Hare
" Maintainer: Amelia Clarke <me@rsaihe.dev>
" Last Change: 2022 Sep 22

if exists("b:did_indent")
  finish
endif
let b:did_indent = 1

if !has("cindent") || !has("eval")
  finish
endif

setlocal cindent

" L0 -> don't deindent labels
" (s -> use one indent after a trailing (
" m1 -> if ) starts a line, indent it the same as its matching (
" ks -> add an extra indent to extra lines in an if expression or for expression
" j1 -> indent code inside {} one level when in parentheses
" J1 -> see j1
" *0 -> don't search for unclosed block comments
" #1 -> don't deindent lines that begin with #
setlocal cinoptions=L0,(s,m1,ks,j1,J1,*0,#1

" Controls which keys reindent the current line.
" 0{     -> { at beginning of line
" 0}     -> } at beginning of line
" 0)     -> ) at beginning of line
" 0]     -> ] at beginning of line
" !^F    -> <C-f> (not inserted)
" o      -> <CR> or `o` command
" O      -> `O` command
" e      -> else
" 0=case -> case
setlocal indentkeys=0{,0},0),0],!^F,o,O,e,0=case

setlocal cinwords=if,else,for,switch,match

setlocal indentexpr=GetHareIndent()

function! FloorCindent(lnum)
  return cindent(a:lnum) / shiftwidth() * shiftwidth()
endfunction

function! GetHareIndent()
  let line = getline(v:lnum)
  let prevlnum = prevnonblank(v:lnum - 1)
  let prevline = getline(prevlnum)
  let prevprevline = getline(prevnonblank(prevlnum - 1))

  " This is all very hacky and imperfect, but it's tough to do much better when
  " working with regex-based indenting rules.

  " If the previous line ended with =, indent by one shiftwidth.
  if prevline =~# '\v\=\s*(//.*)?$'
    return indent(prevlnum) + shiftwidth()
  endif

  " If the previous line ended in a semicolon and the line before that ended
  " with =, deindent by one shiftwidth.
  if prevline =~# '\v;\s*(//.*)?$' && prevprevline =~# '\v\=\s*(//.*)?$'
    return indent(prevlnum) - shiftwidth()
  endif

  " TODO: The following edge-case is still indented incorrectly:
  " case =>
  "         if (foo) {
  "                 bar;
  "         };
  " | // cursor is incorrectly deindented by one shiftwidth.
  "
  " This only happens if the {} block is the first statement in the case body.
  " If `case` is typed, the case will also be incorrectly deindented by one
  " shiftwidth. Are you having fun yet?

  " Deindent cases.
  if line =~# '\v^\s*case'
    " If the previous line was also a case, don't do any special indenting.
    if prevline =~# '\v^\s*case'
      return indent(prevlnum)
    end

    " If the previous line was a multiline case, deindent by one shiftwidth.
    if prevline =~# '\v\=\>\s*(//.*)?$'
      return indent(prevlnum) - shiftwidth()
    endif

    " If the previous line started a block, deindent by one shiftwidth.
    " This handles the first case in a switch/match block.
    if prevline =~# '\v\{\s*(//.*)?$'
      return FloorCindent(v:lnum) - shiftwidth()
    end

    " If the previous line ended in a semicolon and the line before that wasn't
    " a case, deindent by one shiftwidth.
    if prevline =~# '\v;\s*(//.*)?$' && prevprevline !~# '\v\=\>\s*(//.*)?$'
      return FloorCindent(v:lnum) - shiftwidth()
    end

    let l:indent = FloorCindent(v:lnum)

    " If a normal cindent would indent the same amount as the previous line,
    " deindent by one shiftwidth. This fixes some issues with `case let` blocks.
    if l:indent == indent(prevlnum)
      return l:indent - shiftwidth()
    endif

    " Otherwise, do a normal cindent.
    return l:indent
  endif

  " Don't indent an extra shiftwidth for cases which span multiple lines.
  if prevline =~# '\v\=\>\s*(//.*)?$' && prevline !~# '\v^\s*case\W'
    return indent(prevlnum)
  endif

  " Indent the body of a case.
  " If the previous line ended in a semicolon and the line before that was a
  " case, don't do any special indenting.
  if prevline =~# '\v;\s*(//.*)?$' && prevprevline =~# '\v\=\>\s*(//.*)?$' && line !~# '\v^\s*}'
    return indent(prevlnum)
  endif

  let l:indent = FloorCindent(v:lnum)

  " If the previous line was a case and a normal cindent wouldn't indent, indent
  " an extra shiftwidth.
  if prevline =~# '\v\=\>\s*(//.*)?$' && l:indent == indent(prevlnum)
    return l:indent + shiftwidth()
  endif

  " If everything above is false, do a normal cindent.
  return l:indent
endfunction

" vim: tabstop=2 shiftwidth=2 expandtab