rust.vim (10366B)
1 " Vim indent file 2 " Language: Rust 3 " Author: Chris Morgan <me@chrismorgan.info> 4 " Last Change: 2023-09-11 5 " 2024 Jul 04 by Vim Project: use shiftwidth() instead of hard-coding shifted values #15138 6 " 2025 Dec 29 by Vim Project: clean up 7 " 2025 Dec 31 by Vim Project: correcly indent after nested array literal #19042 8 " 2026 Jan 28 by Vim Project: fix indentation when a string literal contains 'if' #19265 9 10 " For bugs, patches and license go to https://github.com/rust-lang/rust.vim 11 " Note: upstream seems umaintained: https://github.com/rust-lang/rust.vim/issues/502 12 13 " Only load this indent file when no other was loaded. 14 if exists("b:did_indent") 15 finish 16 endif 17 let b:did_indent = 1 18 19 setlocal cindent 20 setlocal cinoptions=L0,(s,Ws,J1,j1,m1 21 setlocal cinkeys=0{,0},!^F,o,O,0[,0],0(,0) 22 " Don't think cinwords will actually do anything at all... never mind 23 setlocal cinwords=for,if,else,while,loop,impl,mod,unsafe,trait,struct,enum,fn,extern,macro 24 25 " Some preliminary settings 26 setlocal nolisp " Make sure lisp indenting doesn't supersede us 27 setlocal autoindent " indentexpr isn't much help otherwise 28 " Also do indentkeys, otherwise # gets shoved to column 0 :-/ 29 setlocal indentkeys=0{,0},!^F,o,O,0[,0],0(,0) 30 31 setlocal indentexpr=GetRustIndent(v:lnum) 32 33 let b:undo_indent = "setlocal cindent< cinoptions< cinkeys< cinwords< lisp< autoindent< indentkeys< indentexpr<" 34 35 " Only define the function once. 36 if exists("*GetRustIndent") 37 finish 38 endif 39 40 " vint: -ProhibitAbbreviationOption 41 let s:save_cpo = &cpo 42 set cpo&vim 43 " vint: +ProhibitAbbreviationOption 44 45 " Come here when loading the script the first time. 46 47 function! s:get_line_trimmed(lnum) 48 " Get the line and remove a trailing comment. 49 " Use syntax highlighting attributes when possible. 50 " NOTE: this is not accurate; /* */ or a line continuation could trick it 51 let line = getline(a:lnum) 52 let line_len = strlen(line) 53 if has('syntax_items') 54 " If the last character in the line is a comment, do a binary search for 55 " the start of the comment. synID() is slow, a linear search would take 56 " too long on a long line. 57 if synIDattr(synID(a:lnum, line_len, 1), "name") =~? 'Comment\|Todo' 58 let min = 1 59 let max = line_len 60 while min < max 61 let col = (min + max) / 2 62 if synIDattr(synID(a:lnum, col, 1), "name") =~? 'Comment\|Todo' 63 let max = col 64 else 65 let min = col + 1 66 endif 67 endwhile 68 let line = strpart(line, 0, min - 1) 69 endif 70 return substitute(line, "\s*$", "", "") 71 else 72 " Sorry, this is not complete, nor fully correct (e.g. string "//"). 73 " Such is life. 74 return substitute(line, "\s*//.*$", "", "") 75 endif 76 endfunction 77 78 function! s:is_string_comment(lnum, col) 79 if has('syntax_items') 80 for id in synstack(a:lnum, a:col) 81 let synname = synIDattr(id, "name") 82 if synname ==# "rustString" || synname =~# "^rustComment" 83 return 1 84 endif 85 endfor 86 else 87 " without syntax, let's not even try 88 return 0 89 endif 90 endfunction 91 92 function GetRustIndent(lnum) 93 " Starting assumption: cindent (called at the end) will do it right 94 " normally. We just want to fix up a few cases. 95 96 let line = getline(a:lnum) 97 98 if has('syntax_items') 99 let synname = synIDattr(synID(a:lnum, 1, 1), "name") 100 if synname ==# "rustString" 101 " If the start of the line is in a string, don't change the indent 102 return -1 103 elseif synname =~? '\(Comment\|Todo\)' 104 \ && line !~# '^\s*/\*' " not /* opening line 105 if synname =~? "CommentML" " multi-line 106 if line !~# '^\s*\*' && getline(a:lnum - 1) =~# '^\s*/\*' 107 " This is (hopefully) the line after a /*, and it has no 108 " leader, so the correct indentation is that of the 109 " previous line. 110 return GetRustIndent(a:lnum - 1) 111 endif 112 endif 113 " If it's in a comment, let cindent take care of it now. This is 114 " for cases like "/*" where the next line should start " * ", not 115 " "* " as the code below would otherwise cause for module scope 116 " Fun fact: " /*\n*\n*/" takes two calls to get right! 117 return cindent(a:lnum) 118 endif 119 endif 120 121 " cindent gets second and subsequent match patterns/struct members wrong, 122 " as it treats the comma as indicating an unfinished statement:: 123 " 124 " match a { 125 " b => c, 126 " d => e, 127 " f => g, 128 " }; 129 130 " Search backwards for the previous non-empty line. 131 let prevlinenum = prevnonblank(a:lnum - 1) 132 let prevline = s:get_line_trimmed(prevlinenum) 133 while prevlinenum > 1 && prevline !~# '[^[:blank:]]' 134 let prevlinenum = prevnonblank(prevlinenum - 1) 135 let prevline = s:get_line_trimmed(prevlinenum) 136 endwhile 137 138 " A standalone '{', '}', or 'where' 139 let l:standalone_open = line =~# '\V\^\s\*{\s\*\$' 140 let l:standalone_close = line =~# '\V\^\s\*}\s\*\$' 141 let l:standalone_where = line =~# '\V\^\s\*where\s\*\$' 142 if l:standalone_open || l:standalone_close || l:standalone_where 143 let l:orig_line = line('.') 144 let l:orig_col = col('.') 145 let l:i = 0 146 while 1 147 " ToDo: we can search for more items than 'fn' and 'if'. 148 let [l:found_line, l:col, l:submatch] = 149 \ searchpos('\<\(fn\|if\)\>', 'bWp') 150 if l:found_line ==# 0 || !s:is_string_comment(l:found_line, l:col) 151 break 152 endif 153 let l:i += 1 154 " Limit to 10 iterations as a failsafe against endless looping. 155 if l:i >= 10 156 let l:found_line = 0 157 break 158 endif 159 endwhile 160 call cursor(l:orig_line, l:orig_col) 161 if l:found_line !=# 0 162 " Now we count the number of '{' and '}' in between the match 163 " locations and the current line (there is probably a better 164 " way to compute this). 165 let l:i = l:found_line 166 let l:search_line = strpart(getline(l:i), l:col - 1) 167 let l:opens = 0 168 let l:closes = 0 169 while l:i < a:lnum 170 let l:search_line2 = substitute(l:search_line, '\V{', '', 'g') 171 let l:opens += strlen(l:search_line) - strlen(l:search_line2) 172 let l:search_line3 = substitute(l:search_line2, '\V}', '', 'g') 173 let l:closes += strlen(l:search_line2) - strlen(l:search_line3) 174 let l:i += 1 175 let l:search_line = getline(l:i) 176 endwhile 177 if l:standalone_open || l:standalone_where 178 if l:opens ==# l:closes 179 return indent(l:found_line) 180 endif 181 else 182 " Expect to find just one more close than an open 183 if l:opens ==# l:closes + 1 184 return indent(l:found_line) 185 endif 186 endif 187 endif 188 endif 189 190 " A standalone 'where' adds a shift. 191 let l:standalone_prevline_where = prevline =~# '\V\^\s\*where\s\*\$' 192 if l:standalone_prevline_where 193 return indent(prevlinenum) + shiftwidth() 194 endif 195 196 " Handle where clauses nicely: subsequent values should line up nicely. 197 if prevline[len(prevline) - 1] ==# "," 198 \ && prevline =~# '^\s*where\s' 199 return indent(prevlinenum) + 6 200 endif 201 202 let l:last_prevline_character = prevline[len(prevline) - 1] 203 204 " A line that ends with '.<expr>;' is probably an end of a long list 205 " of method operations. 206 if prevline =~# '\V\^\s\*.' && l:last_prevline_character ==# ';' 207 call cursor(a:lnum - 1, 1) 208 let l:scope_start = searchpair('{\|(', '', '}\|)', 'nbW', 209 \ 's:is_string_comment(line("."), col("."))') 210 if l:scope_start != 0 && l:scope_start < a:lnum 211 return indent(l:scope_start) + shiftwidth() 212 endif 213 endif 214 215 " Prevent cindent from becoming confused when pairing square brackets, as 216 " in 217 " 218 " let arr = [[u8; 4]; 2] = [ 219 " [0; 4], 220 " [1, 3, 5, 9], 221 " ]; 222 " | ← indentation placed here 223 " 224 " for which it calculates too much indentation in the line following the 225 " close of the array. 226 if prevline =~# '^\s*\]' && l:last_prevline_character ==# ';' 227 \ && line !~# '^\s*}' 228 return indent(prevlinenum) 229 endif 230 231 if l:last_prevline_character ==# "," 232 \ && s:get_line_trimmed(a:lnum) !~# '^\s*[\[\]{})]' 233 \ && prevline !~# '^\s*fn\s' 234 \ && prevline !~# '([^()]\+,$' 235 \ && s:get_line_trimmed(a:lnum) !~# '^\s*\S\+\s*=>' 236 " Oh ho! The previous line ended in a comma! I bet cindent will try to 237 " take this too far... For now, let's normally use the previous line's 238 " indent. 239 240 " One case where this doesn't work out is where *this* line contains 241 " square or curly brackets; then we normally *do* want to be indenting 242 " further. 243 " 244 " Another case where we don't want to is one like a function 245 " definition with arguments spread over multiple lines: 246 " 247 " fn foo(baz: Baz, 248 " baz: Baz) // <-- cindent gets this right by itself 249 " 250 " Another case is similar to the previous, except calling a function 251 " instead of defining it, or any conditional expression that leaves 252 " an open paren: 253 " 254 " foo(baz, 255 " baz); 256 " 257 " if baz && (foo || 258 " bar) { 259 " 260 " Another case is when the current line is a new match arm. 261 " 262 " There are probably other cases where we don't want to do this as 263 " well. Add them as needed. 264 return indent(prevlinenum) 265 endif 266 267 " Fall back on cindent, which does it mostly right 268 return cindent(a:lnum) 269 endfunction 270 271 " vint: -ProhibitAbbreviationOption 272 let &cpo = s:save_cpo 273 unlet s:save_cpo 274 " vint: +ProhibitAbbreviationOption 275 276 " vim: set et sw=4 sts=4 ts=8: