1*indent.txt* For Vim version 7.0aa. Last change: 2004 Sep 02 2 3 4 VIM REFERENCE MANUAL by Bram Moolenaar 5 6 7This file is about indenting C programs and other files. 8 91. Indenting C programs |C-indenting| 102. Indenting by expression |indent-expression| 11 12============================================================================== 131. Indenting C programs *C-indenting* 14 15The basics for C indenting are explained in section |30.2| of the user manual. 16 17Vim has options for automatically indenting C program files. These options 18affect only the indent and do not perform other formatting. For comment 19formatting, see |format-comments|. 20 21Note that this will not work when the |+smartindent| or |+cindent| features 22have been disabled at compile time. 23 24There are in fact four methods available for indentation: 25'autoindent' uses the indent from the previous line. 26'smartindent' is like 'autoindent' but also recognizes some C syntax to 27 increase/reduce the indent where appropriate. 28'cindent' Works more cleverly than the other two and is configurable to 29 different indenting styles. 30'indentexpr' The most flexible of all: Evaluates an expression to compute 31 the indent of a line. When non-empty this method overrides 32 the other ones. See |indent-expression|. 33The rest of this section describes the 'cindent' option. 34 35Note that 'cindent' indenting does not work for every code scenario. Vim 36is not a C compiler: it does not recognize all syntax. 37 38These four options control C program indenting: 39'cindent' Enables Vim to perform C program indenting automatically. 40'cinkeys' Specifies which keys trigger reindenting in insert mode. 41'cinoptions' Sets your preferred indent style. 42'cinwords' Defines keywords that start an extra indent in the next line. 43 44If 'lisp' is not on and 'equalprg' is empty, the "=" operator indents using 45Vim's built-in algorithm rather than calling an external program. 46 47See |autocommand| for how to set the 'cindent' option automatically for C code 48files and reset it for others. 49 50 *cinkeys-format* *indentkeys-format* 51The 'cinkeys' option is a string that controls Vim's indenting in response to 52typing certain characters or commands in certain contexts. Note that this not 53only triggers C-indenting. When 'indentexpr' is not empty 'indentkeys' is 54used instead. The format of 'cinkeys' and 'indentkeys' is equal. 55 56The default is "0{,0},0),:,0#,!^F,o,O,e" which specifies that indenting occurs 57as follows: 58 59 "0{" if you type '{' as the first character in a line 60 "0}" if you type '}' as the first character in a line 61 "0)" if you type ')' as the first character in a line 62 ":" if you type ':' after a label or case statement 63 "0#" if you type '#' as the first character in a line 64 "!^F" if you type CTRL-F (which is not inserted) 65 "o" if you type a <CR> anywhere or use the "o" command (not in 66 insert mode!) 67 "O" if you use the "O" command (not in insert mode!) 68 "e" if you type the second 'e' for an "else" at the start of a 69 line 70 71Characters that can precede each key: 72! When a '!' precedes the key, Vim will not insert the key but will 73 instead reindent the current line. This allows you to define a 74 command key for reindenting the current line. CTRL-F is the default 75 key for this. Be careful if you define CTRL-I for this because CTRL-I 76 is the ASCII code for <Tab>. 77* When a '*' precedes the key, Vim will reindent the line before 78 inserting the key. If 'cinkeys' contains "*<Return>", Vim reindents 79 the current line before opening a new line. 800 When a zero precedes the key (but appears after '!' or '*') Vim will 81 reindent the line only if the key is the first character you type in 82 the line. When used before "=" Vim will only reindent the line if 83 there is only white space before the word. 84 85When neither '!' nor '*' precedes the key, Vim reindents the line after you 86type the key. So ';' sets the indentation of a line which includes the ';'. 87 88Special key names: 89<> Angle brackets mean spelled-out names of keys. For example: "<Up>", 90 "<Ins>" (see |key-notation|). 91^ Letters preceded by a caret (^) are control characters. For example: 92 "^F" is CTRL-F. 93o Reindent a line when you use the "o" command or when Vim opens a new 94 line below the current one (e.g., when you type <Enter> in insert 95 mode). 96O Reindent a line when you use the "O" command. 97e Reindent a line that starts with "else" when you type the second 'e'. 98: Reindent a line when a ':' is typed which is after a label or case 99 statement. Don't reindent for a ":" in "class::method" for C++. To 100 Reindent for any ":", use "<:>". 101=word Reindent when typing the last character of "word". "word" may 102 actually be part of another word. Thus "=end" would cause reindenting 103 when typing the "d" in "endif" or "endwhile". But not when typing 104 "bend". Also reindent when completion produces a word that starts 105 with "word". "0=word" reindents when there is only white space before 106 the word. 107=~word Like =word, but ignore case. 108 109If you really want to reindent when you type 'o', 'O', 'e', '0', '<', '>', 110'*', ':' or '!', use "<o>", "<O>", "<e>", "<0>", "<<>", "<>>", "<*>", "<:>" or 111"<!>", respectively, for those keys. 112 113For an emacs-style indent mode where lines aren't indented every time you 114press Enter but only if you press Tab, I suggest: 115 :set cinkeys=0{,0},:,0#,!<Tab>,!^F 116You might also want to switch off 'autoindent' then. 117 118Note: If you change the current line's indentation manually, Vim ignores the 119cindent settings for that line. This prevents vim from reindenting after you 120have changed the indent by typing <BS>, <Tab>, or <Space> in the indent or 121used CTRL-T or CTRL-D. 122 123 *cinoptions-values* 124The 'cinoptions' option sets how Vim performs indentation. In the list below, 125"N" represents a number of your choice (the number can be negative). When 126there is an 's' after the number, Vim multiplies the number by 'shiftwidth': 127"1s" is 'shiftwidth', "2s" is two times 'shiftwidth', etc. You can use a 128decimal point, too: "-0.5s" is minus half a 'shiftwidth'. The examples below 129assume a 'shiftwidth' of 4. 130 131 >N Amount added for "normal" indent. Used after a line that should 132 increase the indent (lines starting with "if", an opening brace, 133 etc.). (default 'shiftwidth'). 134 135 cino= cino=>2 cino=>2s > 136 if (cond) if (cond) if (cond) 137 { { { 138 foo; foo; foo; 139 } } } 140< 141 eN Add N to the prevailing indent inside a set of braces if the 142 opening brace at the End of the line (more precise: is not the 143 first character in a line). This is useful if you want a 144 different indent when the '{' is at the start of the line from 145 when '{' is at the end of the line. (default 0). 146 147 cino= cino=e2 cino=e-2 > 148 if (cond) { if (cond) { if (cond) { 149 foo; foo; foo; 150 } } } 151 else else else 152 { { { 153 bar; bar; bar; 154 } } } 155< 156 nN Add N to the prevailing indent for a statement after an "if", 157 "while", etc., if it is NOT inside a set of braces. This is 158 useful if you want a different indent when there is no '{' 159 before the statement from when there is a '{' before it. 160 (default 0). 161 162 cino= cino=n2 cino=n-2 > 163 if (cond) if (cond) if (cond) 164 foo; foo; foo; 165 else else else 166 { { { 167 bar; bar; bar; 168 } } } 169< 170 fN Place the first opening brace of a function or other block in 171 column N. This applies only for an opening brace that is not 172 inside other braces and is at the start of the line. What comes 173 after the brace is put relative to this brace. (default 0). 174 175 cino= cino=f.5s cino=f1s > 176 func() func() func() 177 { { { 178 int foo; int foo; int foo; 179< 180 {N Place opening braces N characters from the prevailing indent. 181 This applies only for opening braces that are inside other 182 braces. (default 0). 183 184 cino= cino={.5s cino={1s > 185 if (cond) if (cond) if (cond) 186 { { { 187 foo; foo; foo; 188< 189 }N Place closing braces N characters from the matching opening 190 brace. (default 0). 191 192 cino= cino={2,}-0.5s cino=}2 > 193 if (cond) if (cond) if (cond) 194 { { { 195 foo; foo; foo; 196 } } } 197< 198 ^N Add N to the prevailing indent inside a set of braces if the 199 opening brace is in column 0. This can specify a different 200 indent for whole of a function (some may like to set it to a 201 negative number). (default 0). 202 203 cino= cino=^-2 cino=^-s > 204 func() func() func() 205 { { { 206 if (cond) if (cond) if (cond) 207 { { { 208 a = b; a = b; a = b; 209 } } } 210 } } } 211< 212 :N Place case labels N characters from the indent of the switch(). 213 (default 'shiftwidth'). 214 215 cino= cino=:0 > 216 switch (x) switch(x) 217 { { 218 case 1: case 1: 219 a = b; a = b; 220 default: default: 221 } } 222< 223 =N Place statements occurring after a case label N characters from 224 the indent of the label. (default 'shiftwidth'). 225 226 cino= cino==10 > 227 case 11: case 11: a = a + 1; 228 a = a + 1; b = b + 1; 229< 230 lN If N != 0 Vim will align with a case label instead of the 231 statement after it in the same line. 232 233 cino= cino=l1 > 234 switch (a) { switch (a) { 235 case 1: { case 1: { 236 break; break; 237 } } 238< 239 bN If N != 0 Vim will align a final "break" with the case label, 240 so that case..break looks like a sort of block. (default: 0). 241 242 cino= cino=b1 > 243 switch (x) switch(x) 244 { { 245 case 1: case 1: 246 a = b; a = b; 247 break; break; 248 249 default: default: 250 a = 0; a = 0; 251 break; break; 252 } } 253< 254 gN Place C++ scope declarations N characters from the indent of the 255 block they are in. (default 'shiftwidth'). A scope declaration 256 can be "public:", "protected:" or "private:". 257 258 cino= cino=g0 > 259 { { 260 public: public: 261 a = b; a = b; 262 private: private: 263 } } 264< 265 hN Place statements occurring after a C++ scope declaration N 266 characters from the indent of the label. (default 267 'shiftwidth'). 268 269 cino= cino=h10 > 270 public: public: a = a + 1; 271 a = a + 1; b = b + 1; 272< 273 pN Parameter declarations for K&R-style function declarations will 274 be indented N characters from the margin. (default 275 'shiftwidth'). 276 277 cino= cino=p0 cino=p2s > 278 func(a, b) func(a, b) func(a, b) 279 int a; int a; int a; 280 char b; char b; char b; 281< 282 tN Indent a function return type declaration N characters from the 283 margin. (default 'shiftwidth'). 284 285 cino= cino=t0 cino=t7 > 286 int int int 287 func() func() func() 288< 289 iN Indent C++ base class declarations and contructor 290 initializations, if they start in a new line (otherwise they 291 are aligned at the right side of the ':'). 292 (default 'shiftwidth'). 293 294 cino= cino=i0 > 295 class MyClass : class MyClass : 296 public BaseClass public BaseClass 297 {} {} 298 MyClass::MyClass() : MyClass::MyClass() : 299 BaseClass(3) BaseClass(3) 300 {} {} 301< 302 +N Indent a continuation line (a line that spills onto the next) N 303 additional characters. (default 'shiftwidth'). 304 305 cino= cino=+10 > 306 a = b + 9 * a = b + 9 * 307 c; c; 308< 309 cN Indent comment lines after the comment opener, when there is no 310 other text with which to align, N characters from the comment 311 opener. (default 3). See also |format-comments|. 312 313 cino= cino=c5 > 314 /* /* 315 text. text. 316 */ */ 317< 318 CN When N is non-zero, indent comment lines by the amount specified 319 with the c flag above even if there is other text behind the 320 comment opener. (default 0). 321 322 cino=c0 cino=c0,C1 > 323 /******** /******** 324 text. text. 325 ********/ ********/ 326< (Example uses ":set comments& comments-=s1:/* comments^=s0:/*") 327 328 /N Indent comment lines N characters extra. (default 0). 329 cino= cino=/4 > 330 a = b; a = b; 331 /* comment */ /* comment */ 332 c = d; c = d; 333< 334 (N When in unclosed parentheses, indent N characters from the line 335 with the unclosed parentheses. Add a 'shiftwidth' for every 336 unclosed parentheses. When N is 0 or the unclosed parentheses 337 is the first non-white character in its line, line up with the 338 next non-white character after the unclosed parentheses. 339 (default 'shiftwidth' * 2). 340 341 cino= cino=(0 > 342 if (c1 && (c2 || if (c1 && (c2 || 343 c3)) c3)) 344 foo; foo; 345 if (c1 && if (c1 && 346 (c2 || c3)) (c2 || c3)) 347 { { 348< 349 uN Same as (N, but for one level deeper. (default 'shiftwidth'). 350 351 cino= cino=u2 > 352 if (c123456789 if (c123456789 353 && (c22345 && (c22345 354 || c3)) || c3)) 355< 356 UN When N is non-zero, do not ignore the indenting specified by 357 ( or u in case that the unclosed parentheses is the first 358 non-white character in its line. (default 0). 359 360 cino= or cino=(s cino=(s,U1 > 361 c = c1 && c = c1 && 362 ( ( 363 c2 || c2 || 364 c3 c3 365 ) && c4; ) && c4; 366< 367 wN When in unclosed parentheses and N is non-zero and either 368 using "(0" or "u0", respectively, or using "U0" and the unclosed 369 parentheses is the first non-white character in its line, line 370 up with the character immediately after the unclosed parentheses 371 rather than the first non-white character. (default 0). 372 373 cino=(0 cino=(0,w1 > 374 if ( c1 if ( c1 375 && ( c2 && ( c2 376 || c3)) || c3)) 377 foo; foo; 378< 379 WN When in unclosed parentheses and N is non-zero and either 380 using "(0" or "u0", respectively and the unclosed parentheses is 381 the last non-white character in its line and it is not the 382 closing parentheses, indent the following line N characters 383 relative to the outer context (i.e. start of the line or the 384 next unclosed parentheses). (default: 0). 385 386 cino=(0 cino=(0,W4 > 387 a_long_line( a_long_line( 388 argument, argument, 389 argument); argument); 390 a_short_line(argument, a_short_line(argument, 391 argument); argument); 392< 393 mN When N is non-zero, line up a line starting with a closing 394 parentheses with the first character of the line with the 395 matching opening parentheses. (default 0). 396 397 cino=(s cino=(s,m1 > 398 c = c1 && ( c = c1 && ( 399 c2 || c2 || 400 c3 c3 401 ) && c4; ) && c4; 402 if ( if ( 403 c1 && c2 c1 && c2 404 ) ) 405 foo; foo; 406< 407 *java-cinoptions* *java-indenting* 408 jN Indent java anonymous classes correctly. The value 'N' is 409 currently unused but must be non-zero (e.g. 'j1'). 'j1' will 410 indent for example the following code snippet correctly: > 411 412 object.add(new ChangeListener() { 413 public void stateChanged(ChangeEvent e) { 414 do_something(); 415 } 416 }); 417< 418 )N Vim searches for unclosed parentheses at most N lines away. 419 This limits the time needed to search for parentheses. (default 420 20 lines). 421 422 *N Vim searches for unclosed comments at most N lines away. This 423 limits the time needed to search for the start of a comment. 424 (default 30 lines). 425 426 427The defaults, spelled out in full, are: 428 cinoptions=>s,e0,n0,f0,{0,}0,^0,:s,=s,l0,b0,gs,hs,ps,ts,is,+s,c3,C0, 429 /0,(2s,us,U0,w0,W0,m0,j0,)20,*30 430 431Vim puts a line in column 1 if: 432- It starts with '#' (preprocessor directives), if 'cinkeys' contains '#'. 433- It starts with a label (a keyword followed by ':', other than "case" and 434 "default"). 435- Any combination of indentations causes the line to have less than 0 436 indentation. 437 438============================================================================== 4392. Indenting by expression *indent-expression* 440 441The basics for using flexible indenting are explained in section |30.3| of the 442user manual. 443 444If you want to write your own indent file, it must set the 'indentexpr' 445option. Setting the 'indentkeys' option is often useful. See the 446$VIMRUNTIME/indent directory for examples. 447 448 449REMARKS ABOUT SPECIFIC INDENT FILES ~ 450 451 452FORTRAN *fortran-indent* 453 454Block if, select case, and where constructs are indented. Comments, labelled 455statements and continuation lines are indented if the Fortran is in free 456source form, whereas they are not indented if the Fortran is in fixed source 457form because of the left margin requirements. Hence manual indent corrections 458will be necessary for labelled statements and continuation lines when fixed 459source form is being used. For further discussion of the method used for the 460detection of source format see |fortran-syntax|. 461 462Do loops ~ 463All do loops are left unindented by default. Do loops can be unstructured in 464Fortran with (possibly multiple) loops ending on a labelled executable 465statement of almost arbitrary type. Correct indentation requires 466compiler-quality parsing. Old code with do loops ending on labelled statements 467of arbitrary type can be indented with elaborate programs such as Tidy 468(http://www.unb.ca/chem/ajit/f_tidy.htm). Structured do/continue loops are 469also left unindented because continue statements are also used for purposes 470other than ending a do loop. Programs such as Tidy can convert structured 471do/continue loops to the do/enddo form. Do loops of the do/enddo variety can 472be indented. If you use only structured loops of the do/enddo form, you should 473declare this by setting the fortran_do_enddo variable in your .vimrc as 474follows > 475 476 let fortran_do_enddo=1 477 478in which case do loops will be indented. If all your loops are of do/enddo 479type only in, say, .f90 files, then you should set a buffer flag with an 480autocommand such as > 481 482 au! BufRead,BufNewFile *.f90 let b:fortran_do_enddo=1 483 484to get do loops indented in .f90 files and left alone in Fortran files with 485other extensions such as .for. 486 487 488VERILOG *verilog-indent* 489 490General block statements such as if, for, case, always, initial, function, 491specify and begin, etc., are indented. The module block statements (first 492level blocks) are not indented by default. you can turn on the indent with 493setting a variable in the .vimrc as follows: > 494 495 let b:verilog_indent_modules = 1 496 497then the module blocks will be indented. To stop this, remove the variable: > 498 499 :unlet b:verilog_indent_modules 500 501To set the variable only for Verilog file. The following statements can be 502used: > 503 504 au BufReadPost * if exists("b:current_syntax") 505 au BufReadPost * if b:current_syntax == "verilog" 506 au BufReadPost * let b:verilog_indent_modules = 1 507 au BufReadPost * endif 508 au BufReadPost * endif 509 510Furthermore, setting the variable b:verilog_indent_width to change the 511indenting width (default is 'shiftwidth'): > 512 513 let b:verilog_indent_width = 4 514 let b:verilog_indent_width = &sw * 2 515 516In addition, you can turn the verbose mode for debug issue: > 517 518 let b:verilog_indent_verbose = 1 519 520Make sure to do ":set cmdheight=2" first to allow the display of the message. 521 522 523VIM *vim-indent* 524 525For indenting Vim scripts there is one variable that specifies the amount of 526indent for a continuation line, a line that starts with a backslash: > 527 528 :let g:vim_indent_cont = &sw * 3 529 530Three times shiftwidth is the default value. 531 532 533 vim:tw=78:ts=8:ft=help:norl: 534