dbarnett@google.com | 4882d60 | 2014-04-12 06:08:42 +0000 | [diff] [blame] | 1 | <?xml version = '1.0'?> |
| 2 | <?xml-stylesheet type="text/xsl" href="styleguide.xsl"?> |
| 3 | <GUIDE title="Google Vimscript Guide"> |
| 4 | <p class="revision"> |
| 5 | |
| 6 | Revision 1.1 |
| 7 | </p> |
| 8 | |
| 9 | |
| 10 | <address> |
| 11 | Nate Soares<br/> |
| 12 | Joshua Hoak<br/> |
| 13 | David Barnett<br/> |
| 14 | </address> |
| 15 | |
| 16 | <OVERVIEW> |
| 17 | <CATEGORY title="Background"> |
| 18 | <p> |
| 19 | This is the in-depth vimscript guide. If you're just a casual user |
| 20 | looking to write a plugin, the |
| 21 | <a href="vimscriptguide.html">abbreviated style guide</a> is for you. |
| 22 | </p> |
| 23 | <p> |
| 24 | This rather rotund guide dives into justifications and clarifications. |
| 25 | It provides an idealized set of rules that are rather too draconian to |
| 26 | push on casual scripters. |
| 27 | </p> |
| 28 | |
| 29 | <p> |
| 30 | It's for users who want to know why certain decisions were made in the |
| 31 | abbreviated guide and who want to learn a thing or two about using |
| 32 | vimscript safely. |
| 33 | </p> |
| 34 | <p> |
| 35 | Fair warning: Vimscript is a maddening abyss. When you gaze into it, it |
| 36 | gazes also into you. Proceed with caution. |
| 37 | </p> |
| 38 | </CATEGORY> |
| 39 | </OVERVIEW> |
| 40 | |
| 41 | <CATEGORY title="Portability"> |
| 42 | <p> |
| 43 | Vim is highly configurable. Users can change many of the default |
| 44 | settings, including the case sensitivity, the regular expression rules, |
| 45 | the substitution rules, and more. In order for your vimscript to work |
| 46 | for all users, follow these guidelines: |
| 47 | </p> |
| 48 | <ul> |
| 49 | <li> |
| 50 | Always prefix regular expressions with one of <code>\m</code>, |
| 51 | <code>\v</code>, <code>\M</code>, or <code>\V</code> (prefer |
| 52 | tersity) |
| 53 | <ul> |
| 54 | <li> |
| 55 | Users can change the global "magic level" of regular expressions. |
| 56 | This changes how atoms are parsed in regular expressions, |
| 57 | including <code>.</code>, <code>*</code>, and <code>{</code>. |
| 58 | </li> |
| 59 | <li> |
| 60 | Even if your regular expression does not contain characters which |
| 61 | are affected by the <code>magic</code> setting you must prefix it |
| 62 | with one of the magic control atoms. This future-proofs your |
| 63 | regular expression against other devs modifying it and forgetting |
| 64 | to add the control atom. |
| 65 | </li> |
| 66 | <li> |
| 67 | If you have no opinion about what type of regular expression to |
| 68 | use, prefer the one which makes your regular expression most |
| 69 | concise. |
| 70 | </li> |
| 71 | </ul> |
| 72 | </li> |
| 73 | <li> |
| 74 | Avoid using <code>:s[ubstitute]</code> in scripts. |
| 75 | <ul> |
| 76 | <li> |
| 77 | <code>:substitute</code> moves the cursor. |
| 78 | </li> |
| 79 | <li> |
| 80 | <code>:substitute</code> outputs an error message when the match |
| 81 | does not exist. |
| 82 | </li> |
| 83 | <li> |
| 84 | The meaning of the <code>g</code> flag depends upon the |
| 85 | <code>gdefault</code> setting. If you do use |
| 86 | <code>:substitute</code> you must save <code>gdefault</code>, set |
| 87 | it to <code>0</code> or <code>1</code>, perform the substitution, |
| 88 | and then restore it. |
| 89 | </li> |
| 90 | <li> |
| 91 | Script authors who want a safe way to replace text in the buffer |
| 92 | are encouraged to use <code>maktaba#buffer#Replace</code>. |
| 93 | </li> |
| 94 | </ul> |
| 95 | </li> |
| 96 | <li> |
| 97 | Always use case-explicit operators for strings (<code>=~#</code> and |
| 98 | <code>=~?</code>, never <code>=~</code>). |
| 99 | <ul> |
| 100 | <li> |
| 101 | This also applies to <code>!~ == != > >= <</code> and |
| 102 | <code><=</code> |
| 103 | </li> |
| 104 | <li> |
| 105 | This only applies for strings. <code>==</code> and |
| 106 | <code>>=</code> are fine for numbers, but <code>==#</code> and |
| 107 | <code>>=#</code> must be used for strings. |
| 108 | </li> |
| 109 | <li> |
| 110 | The behavior of <code>=~</code> and friends is dependant upon the |
| 111 | <code>ignorecase</code> setting. |
| 112 | </li> |
| 113 | <li> |
| 114 | You may break this rule when you explicitly want to obey the |
| 115 | user's <code>ignorecase</code> setting. Be prepared to justify |
| 116 | your reasoning. |
| 117 | </li> |
| 118 | </ul> |
| 119 | </li> |
| 120 | <li> |
| 121 | When using regular expressions as arguments to functions, prepend them |
| 122 | with <code>\c</code> or <code>\C</code>. |
| 123 | <ul> |
| 124 | <li> |
| 125 | This forces case to be either explicitly matched or ignored. |
| 126 | </li> |
| 127 | <li> |
| 128 | This is recommended, but not required, when comparing regexes with |
| 129 | operators that specify case sensitivity (<code>=~#</code>, etc.). |
| 130 | </li> |
| 131 | <li> |
| 132 | This rule applies when your regexes are matching syntax, external |
| 133 | APIs, external messages, and most other cases. |
| 134 | </li> |
| 135 | <li> |
| 136 | It does not apply when matching text in the buffer. When matching |
| 137 | text in the buffer you should honor the <code>ignorecase</code> |
| 138 | setting. |
| 139 | </li> |
| 140 | <li> |
| 141 | You may also ignore this rule any time that you explicitly want to |
| 142 | honor the <code>ignorecase</code> setting. Be prepared to justify |
| 143 | your reasoning. |
| 144 | </li> |
| 145 | </ul> |
| 146 | </li> |
| 147 | <li> |
| 148 | Always use <code>normal!</code> instead of <code>normal</code>. |
| 149 | <ul> |
| 150 | <li> |
| 151 | If you forgo the <code>!</code> the command will use the user's |
| 152 | key mappings and you have literally no idea what your macro will |
| 153 | do. |
| 154 | </li> |
| 155 | </ul> |
| 156 | </li> |
| 157 | <li> |
| 158 | Always use the <code>noremap</code> family of commands. |
| 159 | <ul> |
| 160 | <li> |
| 161 | Your plugins generally shouldn't introduce mappings, but if they |
| 162 | do, the <code>map</code> command respects the users existing |
| 163 | mappings and could do anything. |
| 164 | </li> |
| 165 | </ul> |
| 166 | </li> |
| 167 | <li> |
| 168 | When using <code>catch</code>, match the error code rather than the |
| 169 | error text. |
| 170 | <ul> |
| 171 | <li> |
| 172 | The error text may be locale-dependant. |
| 173 | </li> |
| 174 | <li> |
| 175 | See <code>:help error-messages</code>. |
| 176 | </li> |
| 177 | </ul> |
| 178 | </li> |
| 179 | </ul> |
| 180 | <p> |
| 181 | In general, guard all commands and functions against user settings. |
| 182 | </p> |
| 183 | |
| 184 | </CATEGORY> |
| 185 | <CATEGORY title="Language Guide"> |
| 186 | <ul> |
| 187 | |
| 188 | |
| 189 | <li> |
| 190 | Line continuations: <strong>Yes</strong> |
| 191 | <ul> |
| 192 | |
| 193 | <li> |
| 194 | Plugins that support vi compatibility mode must save and restore |
| 195 | compatibility options as described in the |
| 196 | <strong>Errata section</strong> so line continuations work properly. |
| 197 | </li> |
| 198 | </ul> |
| 199 | </li> |
| 200 | <li> |
| 201 | Exceptions: <strong>Yes, with caution</strong> |
| 202 | <ul> |
| 203 | <li> |
| 204 | Always use an error code in thrown exception messages. |
| 205 | </li> |
| 206 | <li> |
| 207 | Prefer the <code>maktaba#error</code> codes found in |
| 208 | <code>maktaba</code>. |
| 209 | </li> |
| 210 | <li> |
| 211 | Fall back to the vim error codes. See |
| 212 | <code>:help error-messages</code>. |
| 213 | </li> |
| 214 | <li> |
| 215 | Generate custom error messages using |
| 216 | <code>maktaba#error#Message</code>. |
| 217 | </li> |
| 218 | </ul> |
| 219 | </li> |
| 220 | <li> |
| 221 | Global Variables: <strong>As configuration only</strong> |
| 222 | <ul> |
| 223 | <li> |
| 224 | See the plugin guide. |
| 225 | </li> |
| 226 | </ul> |
| 227 | </li> |
| 228 | <li> |
| 229 | Messaging: <strong>As little as possible.</strong> |
| 230 | <ul> |
| 231 | <li> |
| 232 | Loud scripts are annoying. |
| 233 | </li> |
| 234 | <li> |
| 235 | Message the user when an error has occured. |
| 236 | </li> |
| 237 | <li> |
| 238 | Message the user when an operation which takes a long time has |
| 239 | begun work. |
| 240 | </li> |
| 241 | <li> |
| 242 | Avoid messaging otherwise. |
| 243 | </li> |
| 244 | </ul> |
| 245 | </li> |
| 246 | <li> |
| 247 | Type checking: |
| 248 | <strong>Use strict and explicit checks where possible.</strong> |
| 249 | <ul> |
| 250 | <li> |
| 251 | Vimscript has unsafe, unintuitive behavior when dealing with some |
| 252 | types. For instance, <code>0 == 'foo'</code> evaluates to true. |
| 253 | </li> |
| 254 | <li> |
| 255 | Use strict comparison operators where possible. When comparing |
| 256 | against a string literal, use the <code>is#</code> operator. |
| 257 | Otherwise, prefer <code>maktaba#value#IsEqual</code> or check |
| 258 | <code>type()</code> explicitly. |
| 259 | </li> |
| 260 | <li> |
| 261 | Check variable types explicitly before using them. Use functions |
| 262 | from <code>maktaba#ensure</code>, or check |
| 263 | <code>maktaba#value</code> or <code>type()</code> and throw your own |
| 264 | errors. |
| 265 | </li> |
| 266 | <li> |
| 267 | Use <code>:unlet</code> for variables that may change types, |
| 268 | particularly those assigned inside loops. |
| 269 | </li> |
| 270 | </ul> |
| 271 | </li> |
| 272 | <li> |
| 273 | FuncRefs: <strong>No in most cases.</strong> |
| 274 | <ul> |
| 275 | <li> |
| 276 | FuncRefs have inconsistently enforced naming restrictions. |
| 277 | (Functions can have names that FuncRefs can not.) |
| 278 | </li> |
| 279 | <li> |
| 280 | FuncRefs have inconsistent ability to be reassigned (in Vim |
| 281 | 7.2 and before you must unlet a FuncRef before assigning it). |
| 282 | </li> |
| 283 | <li> |
| 284 | In most instances where a FuncRef is needed a string works |
| 285 | just as well: just pass the string that you would use to make |
| 286 | the FuncRef. |
| 287 | </li> |
| 288 | <li> |
| 289 | Consider using <code>maktaba#function</code> instead to create and |
| 290 | manipulate handles to functions. |
| 291 | </li> |
| 292 | </ul> |
| 293 | </li> |
| 294 | <li> |
| 295 | Python: <strong>Sparingly</strong> |
| 296 | <ul> |
| 297 | |
| 298 | <li> |
| 299 | Hurts code reuse since python code embedded in python plugins is |
| 300 | awkward to share between plugins. |
| 301 | </li> |
| 302 | <li> |
| 303 | Using python introduces python language version dependencies, which |
| 304 | are likely to get stale. |
| 305 | </li> |
| 306 | <li> |
| 307 | Exception: It's reasonable to use python for plugin functionality |
| 308 | that needs to do work in the background, as vimscript can not do |
| 309 | this. |
| 310 | </li> |
| 311 | </ul> |
| 312 | </li> |
| 313 | <li> |
| 314 | Ruby: <strong>No</strong> |
| 315 | <ul> |
| 316 | <li> |
| 317 | We can not assume ruby interoperability. |
| 318 | </li> |
| 319 | <li> |
| 320 | You shouldn't depend upon the version of the ruby language that the |
| 321 | user has installed. |
| 322 | </li> |
| 323 | </ul> |
| 324 | </li> |
| 325 | <li> |
| 326 | Lua: <strong>No</strong> |
| 327 | <ul> |
| 328 | <li> |
| 329 | For the same reasons an Ruby. |
| 330 | </li> |
| 331 | </ul> |
| 332 | </li> |
| 333 | <li> |
| 334 | Dict Functions: <strong>Encouraged</strong> |
| 335 | <ul> |
| 336 | <li> |
| 337 | Vimscript can attach functions to dictionaries. Such functions |
| 338 | have access to the <code>self</code> parameter which access |
| 339 | the dict state. |
| 340 | </li> |
| 341 | <li> |
| 342 | Use these where you would use a class in python. |
| 343 | </li> |
| 344 | <li> |
| 345 | Do not over-use this feature; it is not necessary for helper |
| 346 | functions or API functions, only for encapsulated objects. |
| 347 | </li> |
| 348 | </ul> |
| 349 | </li> |
| 350 | </ul> |
| 351 | <p> |
| 352 | All other language features are fair game. |
| 353 | </p> |
| 354 | </CATEGORY> |
| 355 | <CATEGORY title="Structure"> |
| 356 | <ul> |
| 357 | <li> |
| 358 | Provided functionality should be packed into modular plugins. |
| 359 | <ul> |
| 360 | <li> |
| 361 | Every function in your plugin should be specific to your |
| 362 | plugin. |
| 363 | </li> |
| 364 | <li> |
| 365 | General utility functions should be abstracted into library plugins. |
| 366 | </li> |
| 367 | <li> |
| 368 | Manage dependencies with <code>maktaba</code>. |
| 369 | </li> |
| 370 | </ul> |
| 371 | </li> |
| 372 | <li> |
| 373 | <code>plugin-names-like-this</code> |
| 374 | <ul> |
| 375 | <li> |
| 376 | Plugin names should be descriptive and concise. |
| 377 | </li> |
| 378 | |
| 379 | |
| 380 | </ul> |
| 381 | </li> |
| 382 | <li> |
| 383 | Each plugin must consist of one directory (or code repository), sharing |
| 384 | a name with the plugin (with a "vim-" prefix or ".vim" suffix if |
| 385 | desired). |
| 386 | </li> |
| 387 | <li> |
| 388 | Plugin metadata should be declared in the addon-info.json format (see |
Ackermann Yuriy | acb4f90 | 2016-04-01 21:36:44 +1300 | [diff] [blame] | 389 | the <a href="https://github.com/MarcWeber/vim-addon-manager/blob/master/doc/vim-addon-manager-additional-documentation.txt">VAM documentation</a> for details). |
dbarnett@google.com | 4882d60 | 2014-04-12 06:08:42 +0000 | [diff] [blame] | 390 | </li> |
| 391 | <li> |
| 392 | Functions should go in the <code>autoload/</code> subdirectory of |
| 393 | your plugin. |
| 394 | <ul> |
| 395 | <li> |
| 396 | This allows them to be late-loaded, which speeds up startup |
| 397 | time. |
| 398 | </li> |
| 399 | <li> |
| 400 | This helps vim enforce namespacing conventions. |
| 401 | </li> |
| 402 | </ul> |
| 403 | </li> |
| 404 | <li> |
| 405 | Each file in the <code>plugin/</code> or <code>instant/</code> directory |
| 406 | should begin with the boilerplate |
| 407 | <CODE_SNIPPET> |
| 408 | let [s:plugin, s:enter] = maktaba#plugin#Enter(expand('<sfile>:p')) |
| 409 | if !s:enter |
| 410 | finish |
| 411 | endif |
| 412 | </CODE_SNIPPET> |
| 413 | (This prevents re-entry and allows users to selectively disable |
| 414 | functionality.) |
| 415 | </li> |
| 416 | <li> |
| 417 | User configuration should be via plugin flags defined in |
| 418 | <code>instant/flags.vim</code>. |
| 419 | <ul> |
| 420 | <li> |
| 421 | Define flags with |
| 422 | <code>call s:plugin.Flag('FLAGNAME', DEFAULT_VALUE)</code>. |
| 423 | </li> |
| 424 | <li> |
| 425 | Users can configure these flags using the <code>:Glaive</code> |
| 426 | command (see <a href="https://github.com/google/glaive">glaive</a>). |
| 427 | </li> |
| 428 | </ul> |
| 429 | </li> |
| 430 | <li> |
| 431 | Commands, autocommands, mappings, and settings changes should |
| 432 | occur either in the <code>plugin/</code> or the |
| 433 | <code>ftplugin/</code> subdirectories. |
| 434 | <ul> |
| 435 | <li> |
| 436 | All commands should be defined in <code>plugin/commands.vim</code> |
| 437 | or <code>ftplugin/</code> files. |
| 438 | </li> |
| 439 | <li> |
| 440 | Autocommands should be defined in <code>plugin/autocmds.vim</code>, |
| 441 | inside an augroup. |
| 442 | </li> |
| 443 | <li> |
| 444 | Mappings should be defined in <code>plugin/mappings.vim</code> and |
| 445 | will be disabled unless explicitly enabled by users. |
| 446 | </li> |
| 447 | <li> |
| 448 | If the plugin configures any standard vim settings, those should be |
| 449 | configured in <code>plugin/settings.vim</code> or |
| 450 | <code>instant/settings.vim</code>. |
| 451 | </li> |
| 452 | </ul> |
| 453 | </li> |
| 454 | <li> |
| 455 | Avoid using the <code>after/</code> subdirectory. |
| 456 | <ul> |
| 457 | <li> |
| 458 | <code>after/</code> should be reserved for the user. |
| 459 | </li> |
| 460 | <li> |
| 461 | It is difficult for the user to add their own overrides when |
| 462 | plugins use <code>after/</code>. |
| 463 | </li> |
| 464 | </ul> |
| 465 | </li> |
| 466 | </ul> |
| 467 | |
| 468 | <STYLEPOINT title="Libraries vs. Functionality"> |
| 469 | <SUMMARY> |
| 470 | Separate library-providing plugins from command-providing plugins. |
| 471 | </SUMMARY> |
| 472 | <BODY> |
| 473 | <p> |
| 474 | Many plugins provide either user functionality (commands, |
| 475 | autocommands, etc) or an API (of autoloaded functions) but not both. |
| 476 | This separation is encouraged, as it allows other plugins to pull in a |
| 477 | library without also pulling in commands, setting changes, and other |
| 478 | plugin functionality that affects the end user. |
| 479 | </p> |
| 480 | </BODY> |
| 481 | </STYLEPOINT> |
| 482 | |
| 483 | <STYLEPOINT title="Configuration"> |
| 484 | <SUMMARY> |
| 485 | Don't clobber user settings. Provide as much configurability as |
| 486 | possible: that's what Vim's all about. |
| 487 | </SUMMARY> |
| 488 | <BODY> |
| 489 | <ul> |
| 490 | <li> |
| 491 | Use maktaba flags for plugin configuration. Users can configure them |
| 492 | using the <code>:Glaive</code> command. |
| 493 | |
| 494 | </li> |
| 495 | <li> |
| 496 | Check if configuration variables exist before setting them. |
| 497 | <CODE_SNIPPET> |
| 498 | if !exists('g:myplugin_option') |
| 499 | let g:myplugin_option = 1 |
| 500 | endif |
| 501 | </CODE_SNIPPET> |
| 502 | </li> |
| 503 | </ul> |
| 504 | </BODY> |
| 505 | </STYLEPOINT> |
| 506 | </CATEGORY> |
| 507 | <CATEGORY title="Style Guide"> |
| 508 | <p> |
| 509 | Follow google-wide style conventions. Mimic google python style when |
| 510 | in doubt. |
| 511 | </p> |
| 512 | |
| 513 | |
| 514 | |
| 515 | <STYLEPOINT title="Documentation"> |
| 516 | <SUMMARY> |
| 517 | Use <a href="https://github.com/google/vimdoc">vimdoc</a>. |
| 518 | </SUMMARY> |
| 519 | <BODY> |
| 520 | <p> |
| 521 | Provide help files generated by |
| 522 | <a href="https://github.com/google/vimdoc">vimdoc</a>. Write |
| 523 | documentation in .vim files in conformance with the vimdoc standards |
| 524 | and include fields like "description" and "author" in the |
| 525 | addon-info.json file (see the |
Ackermann Yuriy | acb4f90 | 2016-04-01 21:36:44 +1300 | [diff] [blame] | 526 | <a href="https://github.com/MarcWeber/vim-addon-manager/blob/master/doc/vim-addon-manager-additional-documentation.txt">VAM documentation</a>). |
dbarnett@google.com | 4882d60 | 2014-04-12 06:08:42 +0000 | [diff] [blame] | 527 | </p> |
| 528 | </BODY> |
| 529 | </STYLEPOINT> |
| 530 | |
| 531 | <STYLEPOINT title="Whitespace"> |
| 532 | <SUMMARY> |
| 533 | Follow google-wide conventions. |
| 534 | </SUMMARY> |
| 535 | <BODY> |
| 536 | <ul> |
| 537 | <li> |
| 538 | Use two spaces for indents. |
| 539 | </li> |
| 540 | <li> |
| 541 | Do not use tabs. |
| 542 | </li> |
| 543 | <li> |
| 544 | Use spaces around operators except for arguments to commands. |
| 545 | <ul> |
| 546 | <li> |
| 547 | Using spaces around operators for commands is often invalid |
| 548 | syntax. This is inconsistently enforced by vimscript. To be |
| 549 | safe, always omit whitespace around arguments to commands. |
| 550 | </li> |
| 551 | <li> |
| 552 | <CODE_SNIPPET> |
| 553 | let s:variable = "concatenated " . "strings" |
| 554 | command -range=% MyCommand |
| 555 | </CODE_SNIPPET> |
| 556 | <BAD_CODE_SNIPPET> |
| 557 | let s:variable="concatenated "."strings" |
| 558 | command -range = % MyCommand |
| 559 | </BAD_CODE_SNIPPET> |
| 560 | </li> |
| 561 | </ul> |
| 562 | </li> |
| 563 | <li> |
| 564 | Do not introduce trailing whitespace. |
| 565 | <ul> |
| 566 | <li> |
| 567 | You need not go out of your way to remove it. |
| 568 | </li> |
| 569 | </ul> |
| 570 | </li> |
| 571 | <li> |
| 572 | Restrict lines to 80 columns wide. |
| 573 | </li> |
| 574 | <li> |
| 575 | Indent continued lines by two tabs (four spaces). |
| 576 | </li> |
| 577 | <li> |
| 578 | Do not waste whitespace aligning common segments of similar |
| 579 | commands. It is both difficult and expensive to maintain. |
| 580 | <ul> |
| 581 | <li> |
| 582 | <CODE_SNIPPET> |
| 583 | command -bang MyCommand call myplugin#foo() |
| 584 | command MyCommand2 call myplugin#bar() |
| 585 | </CODE_SNIPPET> |
| 586 | <BAD_CODE_SNIPPET> |
| 587 | command -bang MyCommand call myplugin#foo() |
| 588 | command MyCommand2 call myplugin#bar() |
| 589 | </BAD_CODE_SNIPPET> |
| 590 | </li> |
| 591 | </ul> |
| 592 | </li> |
| 593 | </ul> |
| 594 | <SUBSECTION title="Line Continuations"> |
| 595 | <ul start="7"> |
| 596 | <li> |
| 597 | Prefer line continuations on semantic boundaries. |
| 598 | <ul> |
| 599 | <li> |
| 600 | <CODE_SNIPPET> |
| 601 | command SomeLongCommand |
| 602 | \ call some#function() |
| 603 | </CODE_SNIPPET> |
| 604 | <BAD_CODE_SNIPPET> |
| 605 | command SomeLongCommand call |
| 606 | \ some#function() |
| 607 | </BAD_CODE_SNIPPET> |
| 608 | </li> |
| 609 | <li> |
| 610 | Use your best judgement. |
| 611 | </li> |
| 612 | </ul> |
| 613 | </li> |
| 614 | <li> |
| 615 | Place one space after the backslash denoting a line continuation. |
| 616 | <ul> |
| 617 | <li> |
| 618 | When continuing a multi-line command a pipe can be substituted |
| 619 | for this space as necessary, as follows: |
| 620 | <CODE_SNIPPET> |
| 621 | autocommand BufEnter <buffer> |
| 622 | \ if !empty(s:var) |
| 623 | \| call some#function() |
| 624 | \|else |
| 625 | \| call some#function(s:var) |
| 626 | \|endif |
| 627 | </CODE_SNIPPET> |
| 628 | </li> |
| 629 | </ul> |
| 630 | </li> |
| 631 | <li> |
| 632 | Do not continue multi-line commands when you can avoid it. Prefer |
| 633 | function calls. |
| 634 | </li> |
| 635 | </ul> |
| 636 | </SUBSECTION> |
| 637 | <SUBSECTION title="Comments"> |
| 638 | <ul> |
| 639 | <li> |
| 640 | Place a space after the <code>"</code> before the comment text. |
| 641 | <ul> |
| 642 | <li> |
| 643 | <CODE_SNIPPET> |
| 644 | " I am a line comment. |
| 645 | call call(s:my_function) |
| 646 | </CODE_SNIPPET> |
| 647 | </li> |
| 648 | </ul> |
| 649 | </li> |
| 650 | <li> |
| 651 | Do not use inline comments. |
| 652 | <ul> |
| 653 | <li> |
| 654 | Some commands treat them as comments and others as unclosed |
| 655 | quotes. There are many edge cases. It's difficult to get |
| 656 | right and difficult to maintain. |
| 657 | </li> |
| 658 | <li> |
| 659 | Where you would use an inline comment, put a line comment on |
| 660 | the line above. |
| 661 | </li> |
| 662 | </ul> |
| 663 | </li> |
| 664 | <li> |
| 665 | When leaving blank lines in comments, include the quote in the |
| 666 | blank line. |
| 667 | <ul> |
| 668 | <li> |
| 669 | <CODE_SNIPPET> |
| 670 | " I am one continuous |
| 671 | " |
| 672 | " comment block |
| 673 | </CODE_SNIPPET> |
| 674 | </li> |
| 675 | </ul> |
| 676 | </li> |
| 677 | </ul> |
| 678 | </SUBSECTION> |
| 679 | </BODY> |
| 680 | </STYLEPOINT> |
| 681 | |
| 682 | <STYLEPOINT title="Variables"> |
| 683 | <SUMMARY> |
| 684 | <p> |
| 685 | <code>plugin-names-like-this</code>, |
| 686 | <code>FunctionNamesLikeThis</code>, |
| 687 | <code>CommandNamesLikeThis</code>, |
| 688 | <code>augroup_names_like_this</code>, |
| 689 | <code>variable_names_like_this</code>. |
| 690 | </p> |
| 691 | <p> |
| 692 | Prefix all variables with their scope. |
| 693 | </p> |
| 694 | </SUMMARY> |
| 695 | <BODY> |
| 696 | <ul> |
| 697 | <li> |
| 698 | <code>variable_names_like_this</code> |
| 699 | <ul> |
| 700 | <li> |
| 701 | FuncRef variables count as functions and should be named like |
| 702 | functions. |
| 703 | </li> |
| 704 | <li> |
| 705 | This (pathological) convention is enforced by vim itself. |
| 706 | </li> |
| 707 | </ul> |
| 708 | </li> |
| 709 | <li> |
| 710 | Prefix global variables with <code>g:</code> |
| 711 | <ul> |
| 712 | <li> |
| 713 | Vimscript allows you to create global variables without |
| 714 | prefixing them. |
| 715 | </li> |
| 716 | <li> |
| 717 | It is very bad practice to introduce non-prefixed global |
| 718 | variables into scope. |
| 719 | </li> |
| 720 | <li> |
| 721 | Global variables should only be used for plugin configuration. |
| 722 | </li> |
| 723 | <li> |
| 724 | This does not apply to functions defined in |
| 725 | <code>autoload</code> directories. |
| 726 | </li> |
| 727 | </ul> |
| 728 | </li> |
| 729 | <li> |
| 730 | Prefix script-local variables with <code>s:</code> |
| 731 | <ul> |
| 732 | <li> |
| 733 | This prevents namespace collisions between plugins. |
| 734 | </li> |
| 735 | <li> |
| 736 | This also applies to script-local functions. |
| 737 | </li> |
| 738 | </ul> |
| 739 | </li> |
| 740 | <li> |
| 741 | Prefix function arguments with <code>a:</code> |
| 742 | <ul> |
| 743 | <li> |
| 744 | This is enforced by vim itself. |
| 745 | </li> |
| 746 | </ul> |
| 747 | </li> |
| 748 | <li> |
| 749 | Prefix function-local variables with <code>l:</code> |
| 750 | <ul> |
| 751 | <li> |
| 752 | This is not enforced by vimscript but is good practice. |
| 753 | </li> |
| 754 | <li> |
| 755 | It helps you remember that all other variables must be |
| 756 | prefixed with scope. |
| 757 | </li> |
| 758 | <li> |
| 759 | <code>l:</code> disambiguates between function-local and |
| 760 | vim-predefined variables. For example, <code>count</code> |
| 761 | refers to |
| 762 | <code>v:count</code>, not <code>l:count</code>. |
| 763 | </li> |
| 764 | <li> |
| 765 | It future proofs your scripts against the introduction of new |
| 766 | vim-predefined variables. |
| 767 | </li> |
| 768 | </ul> |
| 769 | </li> |
| 770 | <li> |
| 771 | Prefix pre-defined vim variables with <code>v:</code> |
| 772 | <ul> |
| 773 | <li> |
| 774 | This is not enforced by vimscript but is good practice. |
| 775 | </li> |
| 776 | <li> |
| 777 | It provides context as to where the (undeclared) variable is |
| 778 | coming from. |
| 779 | </li> |
| 780 | <li> |
| 781 | It reminds you that the variable can not be assigned to. |
| 782 | </li> |
| 783 | </ul> |
| 784 | </li> |
| 785 | <li> |
| 786 | Prefix buffer-local variables with <code>b:</code> |
| 787 | <ul> |
| 788 | <li> |
| 789 | This is useful for plugins that keep per-buffer state. |
| 790 | </li> |
| 791 | </ul> |
| 792 | </li> |
| 793 | </ul> |
| 794 | </BODY> |
| 795 | </STYLEPOINT> |
| 796 | |
| 797 | <STYLEPOINT title="Strings"> |
| 798 | <SUMMARY> |
| 799 | Prefer single quotes. |
| 800 | </SUMMARY> |
| 801 | <BODY> |
| 802 | <p> |
| 803 | Prefer single quoted strings. Specifically, in order of precedence: |
| 804 | </p> |
| 805 | <ul> |
| 806 | <li> |
| 807 | Always use single quotes for regular expressions. |
| 808 | <ul> |
| 809 | <li> |
| 810 | <code>'\s*'</code> is not the same as <code>"\s*"</code> |
| 811 | </li> |
| 812 | <li> |
| 813 | Single quotes will prevent the need for excessive backslashes. |
| 814 | </li> |
| 815 | <li> |
| 816 | Double single quotes escape to one single quote in single |
| 817 | quoted strings: <code>'example ('')'</code> represents the |
| 818 | string |
| 819 | <code>example (')</code> |
| 820 | </li> |
| 821 | </ul> |
| 822 | </li> |
| 823 | <li> |
| 824 | If your string requires escape characters (<code>\n</code>, |
| 825 | <code>\t</code>, etc.) use double quotes. |
| 826 | <ul> |
| 827 | <li> |
| 828 | Escapes can not be expressed in single quoted strings. |
| 829 | </li> |
| 830 | <li> |
| 831 | Remember that <code>'\n'</code> in a regex does not represent a |
| 832 | newline, but rather "\n". You only need to use double quotes |
| 833 | when you want to embed the represented character itself (e.g. a |
| 834 | newline) in the string. |
| 835 | </li> |
| 836 | </ul> |
| 837 | </li> |
| 838 | <li> |
| 839 | If your string contains no escapes nor single quotes, use single |
| 840 | quoted strings. |
| 841 | <ul> |
| 842 | <li> |
| 843 | Most strings in vimscript are regexes, so this provides maximum |
| 844 | consistency. |
| 845 | </li> |
| 846 | </ul> |
| 847 | </li> |
| 848 | <li> |
| 849 | If your non-regex string contains single quotes but no double |
| 850 | quotes, use double quotes. |
| 851 | <ul> |
| 852 | <li> |
| 853 | Don't bother escaping strings if you don't have to. |
| 854 | </li> |
| 855 | <li> |
| 856 | This is similar to the python string rules. |
| 857 | </li> |
| 858 | </ul> |
| 859 | </li> |
| 860 | <li> |
| 861 | If your string contains both single and double quotes, use whichever |
| 862 | quoting style requires less escaping. |
| 863 | <ul> |
| 864 | <li> |
| 865 | Break ties in favor of single quotes. |
| 866 | </li> |
| 867 | </ul> |
| 868 | </li> |
| 869 | </ul> |
| 870 | </BODY> |
| 871 | </STYLEPOINT> |
| 872 | |
| 873 | <STYLEPOINT title="Settings"> |
| 874 | <SUMMARY> |
| 875 | Prefer long names. Set settings locally. |
| 876 | </SUMMARY> |
| 877 | <BODY> |
| 878 | <ul start="6"> |
| 879 | <li> |
| 880 | Prefer long names of built in settings (i.e. <code>tabstop</code> |
| 881 | over |
| 882 | <code>ts</code>). |
| 883 | </li> |
| 884 | <li> |
| 885 | Set local settings unless you explicitly want to set global |
| 886 | settings. |
| 887 | <ul> |
| 888 | <li> |
| 889 | Use <code>setlocal</code> and <code>&l:</code> instead of |
| 890 | <code>set</code> and <code>&</code>. |
| 891 | </li> |
| 892 | </ul> |
| 893 | </li> |
| 894 | </ul> |
| 895 | </BODY> |
| 896 | </STYLEPOINT> |
| 897 | </CATEGORY> |
| 898 | <CATEGORY title="Usage Guide"> |
| 899 | <p> |
| 900 | Vim plugins should provide any or all of the following: |
| 901 | <strong>Commands,</strong> <strong>Autocommands,</strong> |
| 902 | <strong>Functions,</strong> <strong>Statusline Flags, and</strong> |
| 903 | <strong>Mappings.</strong> |
| 904 | </p> |
| 905 | |
| 906 | <STYLEPOINT title="Commands"> |
| 907 | <SUMMARY> |
| 908 | <ul> |
| 909 | <li>Define in <code>plugin/commands.vim</code>.</li> |
| 910 | <li>CommandNamesLikeThis.</li> |
| 911 | <li>Prefer semantic names to a unified prefix.</li> |
| 912 | <li>Do not use <code>[!]</code></li> |
| 913 | <li>Extract logic into functions.</li> |
| 914 | </ul> |
| 915 | </SUMMARY> |
| 916 | <BODY> |
| 917 | <ul> |
| 918 | <li> |
| 919 | <code>CommandNamesLikeThis</code> |
| 920 | </li> |
| 921 | <li> |
| 922 | Commands should be defined in one block with no whitespace between |
| 923 | them. |
| 924 | <ul> |
| 925 | <li> |
| 926 | Name commands semantically at the expense of a common prefix. |
| 927 | </li> |
| 928 | <li> |
| 929 | <BAD_CODE_SNIPPET> |
| 930 | command WhitespaceFixTrailing |
| 931 | command WhitespaceFixIndentation |
| 932 | </BAD_CODE_SNIPPET> |
| 933 | <CODE_SNIPPET> |
| 934 | command FixTrailingWhitespace |
| 935 | command FixIndentation |
| 936 | </CODE_SNIPPET> |
| 937 | </li> |
| 938 | </ul> |
| 939 | </li> |
| 940 | <li> |
| 941 | Use <code>command</code> without a bang. |
| 942 | <ul> |
| 943 | <li> |
| 944 | This notifies users to command name conflicts immediately at |
| 945 | startup. |
| 946 | </li> |
| 947 | <li> |
| 948 | Command name collisions are an error and should not fail |
| 949 | silently. |
| 950 | </li> |
| 951 | <li> |
| 952 | Plugins are guarded against re-entry, so a single vim session |
| 953 | should never attempt to re-define defined commands. |
| 954 | </li> |
| 955 | </ul> |
| 956 | </li> |
| 957 | <li> |
| 958 | Do not put logic in commands. |
| 959 | <ul> |
| 960 | <li> |
| 961 | Delegate to functions instead. |
| 962 | </li> |
| 963 | <li> |
| 964 | Pass non-argument command parameters (<code><bang></code>, |
| 965 | <code><register></code>, etc.) before argument parameters |
| 966 | (<code><f-args></code>, etc.). |
| 967 | </li> |
| 968 | <li> |
| 969 | Otherwise variable-length argument functions are difficult to |
| 970 | implement. |
| 971 | </li> |
| 972 | </ul> |
| 973 | </li> |
| 974 | <li> |
| 975 | Do not autoload commands. |
| 976 | <ul> |
| 977 | <li> |
| 978 | Autoloaded commands will not be available until after a function |
| 979 | in the same file is called. |
| 980 | </li> |
| 981 | <li> |
| 982 | Commands intended to be used in the .vimrc should be defined in |
| 983 | a <code>instant/commands.vim</code> file in plugins using |
| 984 | maktaba, or explicitly installed via an autoload function in |
| 985 | non-maktaba plugins. |
| 986 | </li> |
| 987 | </ul> |
| 988 | </li> |
| 989 | </ul> |
| 990 | <SUBSECTION title="Conventions"> |
| 991 | <ul> |
| 992 | <li> |
| 993 | Pass <code><bang></code> to functions with |
| 994 | <code>'<bang>' == '!'</code>. |
| 995 | <ul> |
| 996 | <li> |
| 997 | The function should receive a boolean parameter, not a string. |
| 998 | </li> |
| 999 | </ul> |
| 1000 | </li> |
| 1001 | </ul> |
| 1002 | </SUBSECTION> |
| 1003 | </BODY> |
| 1004 | </STYLEPOINT> |
| 1005 | |
| 1006 | <STYLEPOINT title="Autocommands"> |
| 1007 | <SUMMARY> |
| 1008 | <ul> |
| 1009 | <li>Define in <code>plugin/autocmds.vim</code>.</li> |
| 1010 | <li>Use augroups.</li> |
| 1011 | <li>augroup_names_like_this.</li> |
| 1012 | <li>Clear the augroup first.</li> |
| 1013 | <li>Extract logic into functions.</li> |
| 1014 | </ul> |
| 1015 | </SUMMARY> |
| 1016 | <BODY> |
| 1017 | <ul> |
| 1018 | <li> |
| 1019 | All autocommands should be defined in the |
| 1020 | <code>plugin/autocmds.vim</code> file. |
| 1021 | <ul> |
| 1022 | <li> |
| 1023 | This allows users to disable your autocommands with |
| 1024 | <code>Glaive myplugin !plugin[autocmds]</code>. |
| 1025 | </li> |
| 1026 | </ul> |
| 1027 | </li> |
| 1028 | <li> |
| 1029 | Declare all autocommands in an <code>augroup</code> block. |
| 1030 | <ul> |
| 1031 | <li> |
| 1032 | This allows your autocommands to be cleared with |
| 1033 | <code>autocmd!</code>. |
| 1034 | </li> |
| 1035 | <li> |
| 1036 | If your plugin only has one <code>augroup</code>, the |
| 1037 | <code>augroup</code> name should be the same as your plugin |
| 1038 | name, with underscores in place of any hyphens. |
| 1039 | </li> |
| 1040 | <li> |
| 1041 | Otherwise <code>augroup</code> names should start with your |
| 1042 | plugin name followed by an underscore. |
| 1043 | </li> |
| 1044 | </ul> |
| 1045 | </li> |
| 1046 | <li> |
| 1047 | Do not put logic in autocommands. |
| 1048 | <ul> |
| 1049 | <li> |
| 1050 | Delegate to functions instead. |
| 1051 | </li> |
| 1052 | </ul> |
| 1053 | </li> |
| 1054 | <li> |
| 1055 | When creating a new <code>augroup</code>, clear it with |
| 1056 | <code>autocmd!</code> |
| 1057 | <ul> |
| 1058 | <li> |
| 1059 | This allows your plugins to be re-enterable. |
| 1060 | </li> |
| 1061 | </ul> |
| 1062 | </li> |
| 1063 | </ul> |
| 1064 | </BODY> |
| 1065 | </STYLEPOINT> |
| 1066 | |
| 1067 | <STYLEPOINT title="Functions"> |
| 1068 | <SUMMARY> |
| 1069 | <ul> |
| 1070 | <li>FunctionNamesLikeThis.</li> |
| 1071 | <li>Autoload all functions.</li> |
| 1072 | <li>Prefix script-local functions with <code>s:</code></li> |
| 1073 | <li>Use <code>[!]</code>.</li> |
| 1074 | <li>Use <code>[abort]</code>.</li> |
| 1075 | </ul> |
| 1076 | </SUMMARY> |
| 1077 | <BODY> |
| 1078 | <ul> |
| 1079 | <li> |
| 1080 | <code>FunctionNamesLikeThis</code> |
| 1081 | </li> |
| 1082 | <li> |
| 1083 | Prefix all script-local functions with <code>s:</code> |
| 1084 | </li> |
| 1085 | <li> |
| 1086 | Do not provide global functions. Use autoloaded functions instead. |
| 1087 | </li> |
| 1088 | <li> |
| 1089 | Place two blank lines between top-level functions. |
| 1090 | </li> |
| 1091 | <li> |
| 1092 | Declare all functions with <code>abort</code>. |
| 1093 | <ul> |
| 1094 | <li> |
| 1095 | If you do not do this, the function's behavior depends upon |
| 1096 | whether it is called within a <code>try..endtry</code> block |
| 1097 | somewhere on the stack. |
| 1098 | </li> |
| 1099 | <li> |
| 1100 | The <code>abort</code> keyword forces the function to act |
| 1101 | consistently. |
| 1102 | </li> |
| 1103 | <li> |
| 1104 | Without it, the function may (or may not) attempt to continue |
| 1105 | execution after an error occurs. |
| 1106 | </li> |
| 1107 | </ul> |
| 1108 | </li> |
| 1109 | <li> |
| 1110 | Use <code>function!</code> with a bang. |
| 1111 | <ul> |
| 1112 | <li> |
| 1113 | This allows developers to re-source their scripts and have the |
| 1114 | functions reloaded without complaint. |
| 1115 | </li> |
| 1116 | <li> |
| 1117 | Function names should never collide because functions should |
| 1118 | always be either script-local or defined in an |
| 1119 | <code>autoload</code> directory. |
| 1120 | </li> |
| 1121 | <li> |
| 1122 | Failing to use a bang in any function in an autoload file will |
| 1123 | lead to cryptic errors if vim tries to re-source the file |
| 1124 | (e.g., if you refer to an nonexistent autoload function). |
| 1125 | </li> |
| 1126 | </ul> |
| 1127 | </li> |
| 1128 | <li> |
| 1129 | Use <code>...</code> for optional arguments, not for lists of |
| 1130 | arguments. |
| 1131 | <ul> |
| 1132 | <li> |
| 1133 | Vimscript functions take at most 20 arguments. |
| 1134 | </li> |
| 1135 | <li> |
| 1136 | Lists have no such length restriction. |
| 1137 | </li> |
| 1138 | <li> |
| 1139 | Your function is likely to break when given too many arguments |
| 1140 | if you use <code>...</code> for a list of arguments. |
| 1141 | </li> |
| 1142 | </ul> |
| 1143 | </li> |
| 1144 | <li> |
| 1145 | Throw exceptions rather than printing errors. |
| 1146 | <ul> |
| 1147 | <li> |
| 1148 | Printed errors can not be caught. |
| 1149 | </li> |
| 1150 | <li> |
| 1151 | Top-level functions expecting errors may catch them and print |
| 1152 | error messages, but even those should throw their own errors |
| 1153 | when they choke. |
| 1154 | </li> |
| 1155 | </ul> |
| 1156 | </li> |
| 1157 | </ul> |
| 1158 | </BODY> |
| 1159 | </STYLEPOINT> |
| 1160 | |
| 1161 | <STYLEPOINT title="Mappings"> |
| 1162 | <SUMMARY> |
| 1163 | <ul> |
| 1164 | <li> |
| 1165 | Provide opt-in key mappings in <code>plugin/mappings.vim</code>. |
| 1166 | </li> |
| 1167 | <li> |
| 1168 | <code><Plug></code> mappings can be defined in |
| 1169 | <code>plugin/plugs.vim</code> (unlike mappings.vim, plugs.vim is |
| 1170 | opt-out). |
| 1171 | </li> |
| 1172 | </ul> |
| 1173 | </SUMMARY> |
| 1174 | <BODY> |
| 1175 | <ul> |
| 1176 | <li> |
| 1177 | Define key mappings in <code>plugin/mappings.vim</code>, using |
| 1178 | <code>maktaba#plugin#MapPrefix</code> to get a prefix. |
| 1179 | <ul> |
| 1180 | <li> |
| 1181 | Mappings defined in the special <code>plugin/mappings.vim</code> |
| 1182 | file will be disabled by default (by the standard |
| 1183 | <code>maktaba#plugin#Enter()</code> boilerplate). |
| 1184 | </li> |
| 1185 | <li> |
| 1186 | Users can enable key mappings with |
| 1187 | <code>Glaive myplugin plugin[mappings]</code>. |
| 1188 | </li> |
| 1189 | </ul> |
| 1190 | </li> |
| 1191 | <li> |
| 1192 | Make all mappings with <code><unique></code>. |
| 1193 | <ul> |
| 1194 | <li> |
| 1195 | This will inform the user when they have a mapping conflict |
| 1196 | instead of silently clobbering their existing mappings. |
| 1197 | </li> |
| 1198 | </ul> |
| 1199 | </li> |
| 1200 | <li> |
| 1201 | You may provide pseudo-mappings using <code><Plug></code> and |
| 1202 | your plugin's name in <code>plugin/plugs.vim</code> (separate from |
| 1203 | standard key mappings). |
| 1204 | <ul> |
| 1205 | <li> |
| 1206 | <code><Plug></code> is a sequence which can not be typed. |
| 1207 | </li> |
| 1208 | <li> |
| 1209 | You can do something like |
| 1210 | <code>noremap <Plug>namespace#MappingName |
| 1211 | some_key_sequence</code> |
| 1212 | and then users can do |
| 1213 | <code>noremap <leader>x |
| 1214 | <Plug>namespace#MappingName</code> |
| 1215 | to take advantage of your pseudo-mapping. |
| 1216 | </li> |
| 1217 | <li> |
| 1218 | Pseudo-mappings should <strong>not</strong> be in |
| 1219 | <code>plugin/mappings.vim</code> or they will be disabled by |
| 1220 | default. |
| 1221 | </li> |
| 1222 | <li> |
| 1223 | Such pseudo-mappings should be named <code><Plug></code> |
| 1224 | followed by your plugin name, a pound sign, and a unique mapping |
| 1225 | name (CamelCased like a function). |
| 1226 | </li> |
| 1227 | </ul> |
| 1228 | </li> |
| 1229 | <li> |
| 1230 | Always use the <code>noremap</code> family of commands. Never use |
| 1231 | the <code>map</code> family. |
| 1232 | <ul> |
| 1233 | <li> |
| 1234 | <code>map</code> depends upon the user's existing mappings, and |
| 1235 | could do anything. |
| 1236 | </li> |
| 1237 | </ul> |
| 1238 | </li> |
| 1239 | <li> |
| 1240 | Only use <code>noremap</code> for commands that both make a motion |
| 1241 | and take a range. |
| 1242 | <ul> |
| 1243 | <li> |
| 1244 | <code>noremap</code> makes mappings in normal, visual, and |
| 1245 | operator-pending modes. |
| 1246 | </li> |
| 1247 | <li> |
| 1248 | If you don't want all these use <code>nnoremap</code> |
| 1249 | <code>onoremap</code> or <code>vnoremap</code> explicitly. |
| 1250 | </li> |
| 1251 | </ul> |
| 1252 | </li> |
| 1253 | <li> |
| 1254 | Always use <code><SID></code> in place of <code>s:</code> when |
| 1255 | accessing script locals in mappings. |
| 1256 | <ul> |
| 1257 | <li> |
| 1258 | Using <code>s:</code> will often fail as the mapping attempts to |
| 1259 | type a literal s and colon. |
| 1260 | </li> |
| 1261 | </ul> |
| 1262 | </li> |
| 1263 | </ul> |
| 1264 | </BODY> |
| 1265 | </STYLEPOINT> |
| 1266 | </CATEGORY> |
| 1267 | <CATEGORY title="Conventions"> |
| 1268 | <STYLEPOINT title="Dependency Checking"> |
| 1269 | <SUMMARY> |
| 1270 | Declare dependencies in addon-info.json and use <code>maktaba</code>. |
| 1271 | </SUMMARY> |
| 1272 | <BODY> |
| 1273 | <p> |
| 1274 | Declaring dependencies in addon-info.json allows conformant plugin |
| 1275 | managers (like VAM) to ensure dependencies are installed. See the |
Ackermann Yuriy | acb4f90 | 2016-04-01 21:36:44 +1300 | [diff] [blame] | 1276 | <a href="https://github.com/MarcWeber/vim-addon-manager/blob/master/doc/vim-addon-manager-additional-documentation.txt">VAM documentation</a> for details. |
dbarnett@google.com | 4882d60 | 2014-04-12 06:08:42 +0000 | [diff] [blame] | 1277 | </p> |
| 1278 | <p> |
| 1279 | Calling <code>maktaba#library#Require</code> from dependent code at |
| 1280 | runtime ensures that dependencies have been installed and that they |
| 1281 | don't include unsafe non-library files. |
| 1282 | </p> |
| 1283 | </BODY> |
| 1284 | </STYLEPOINT> |
| 1285 | |
| 1286 | <STYLEPOINT title="Statusline Flags"> |
| 1287 | <SUMMARY> |
| 1288 | Use <code><plugin-name>#status#Status()</code> or its |
| 1289 | finer-grained variants to provide statusline flags. |
| 1290 | </SUMMARY> |
| 1291 | <BODY> |
| 1292 | <p> |
| 1293 | Following is a convention for exposing statusline flags to the user. A |
| 1294 | plugin should never modify the user's statusline except for when that |
| 1295 | is the only purpose of the plugin (powerline, etc.). |
| 1296 | </p> |
| 1297 | <ul> |
| 1298 | <li> |
| 1299 | Provide the |
| 1300 | <code class="green">Info</code>, |
| 1301 | <code class="yellow">Alert</code>, |
| 1302 | <code class="orange">Warning</code>, and |
| 1303 | <code class="red">Error</code> functions under the |
| 1304 | <code><plugin-name>#status</code> namespace. |
| 1305 | </li> |
| 1306 | <li> |
| 1307 | <code class="green">Info</code> should provide information about the |
| 1308 | state of the buffer. |
| 1309 | <ul> |
| 1310 | <li> |
| 1311 | Example: The current git branch. |
| 1312 | </li> |
| 1313 | </ul> |
| 1314 | </li> |
| 1315 | <li> |
| 1316 | <code class="yellow">Alert</code> should provide a quiet reminder |
| 1317 | that the buffer is non-standard. |
| 1318 | <ul> |
| 1319 | <li> |
| 1320 | Example: The readonly setting is on. |
| 1321 | </li> |
| 1322 | </ul> |
| 1323 | </li> |
| 1324 | <li> |
| 1325 | <code class="orange">Warning</code> should provide a warning about |
| 1326 | the current state of the buffer. |
| 1327 | <ul> |
| 1328 | <li> |
| 1329 | Example: The file has been edited elsewhere. |
| 1330 | </li> |
| 1331 | </ul> |
| 1332 | </li> |
| 1333 | <li> |
| 1334 | <code class="red">Error</code> should bring to attention a loud |
| 1335 | issue with the buffer. |
| 1336 | <ul> |
| 1337 | <li> |
| 1338 | Example: The file does not pass the syntax checker. |
| 1339 | </li> |
| 1340 | </ul> |
| 1341 | </li> |
| 1342 | <li> |
| 1343 | By following these conventions, users can easily build up their own |
| 1344 | statusline customizing the verbosity and colors to their tastes. |
| 1345 | </li> |
| 1346 | <li> |
| 1347 | All functions should take no arguments and should return either |
| 1348 | empty strings or strings enclosed by square brackets, e.g. |
| 1349 | <code>[Google]</code>. For example: |
| 1350 | <ul> |
| 1351 | <li> |
| 1352 | A trailing whitespace plugin might return <code>[$]</code> if |
| 1353 | the file contains trailing whitespace |
| 1354 | </li> |
| 1355 | <li> |
| 1356 | A prose writing plugin might return <code>[write]</code> if vim |
| 1357 | is in writing mode. |
| 1358 | </li> |
| 1359 | </ul> |
| 1360 | </li> |
| 1361 | <li> |
| 1362 | Consider providing the |
| 1363 | <code><plugin-name>#status#Status</code> function. |
| 1364 | <ul> |
| 1365 | <li> |
| 1366 | It should return the first non-empty of <code>Error</code>, |
| 1367 | <code>Warning</code>, <code>Alert</code>, or <code>Info</code>. |
| 1368 | </li> |
| 1369 | <li> |
| 1370 | This is useful for users who want only the most relevant flag |
| 1371 | and do not have a colored statusline. |
| 1372 | </li> |
| 1373 | </ul> |
| 1374 | </li> |
| 1375 | </ul> |
| 1376 | </BODY> |
| 1377 | </STYLEPOINT> |
| 1378 | </CATEGORY> |
| 1379 | <CATEGORY title="Forbidden Commands"> |
| 1380 | <p> |
| 1381 | These are commands which can only be used by a limited number of |
| 1382 | plugins, and should not in general be used by yours. |
| 1383 | </p> |
| 1384 | <ul> |
| 1385 | <li> |
| 1386 | Do not use <code>:match :2match</code> or <code>:3match</code> |
| 1387 | <ul> |
| 1388 | <li> |
| 1389 | These are reserved for the user and for vim itself. |
| 1390 | </li> |
| 1391 | <li> |
dbarnett@google.com | 4052f39 | 2014-11-15 02:14:20 +0000 | [diff] [blame] | 1392 | Use <code>matchadd()</code> to create a matchlevel unique to your |
dbarnett@google.com | 4882d60 | 2014-04-12 06:08:42 +0000 | [diff] [blame] | 1393 | plugin. |
| 1394 | </li> |
| 1395 | </ul> |
| 1396 | </li> |
| 1397 | <li> |
| 1398 | Do not use <code>echoerr</code>. |
| 1399 | <ul> |
| 1400 | <li> |
| 1401 | <code>echoerr</code> does not print the red error message that you |
| 1402 | might think it does. |
| 1403 | </li> |
| 1404 | <li> |
| 1405 | <code>echoerr</code> prints an error message as well as context |
| 1406 | about the code where <code>echoerr</code> was called. |
| 1407 | </li> |
| 1408 | <li> |
| 1409 | <code>echoerr</code> is best suited for debugging. |
| 1410 | </li> |
| 1411 | <li> |
| 1412 | Use <code>echohl</code> in tandem with <code>echomsg</code> if |
| 1413 | you want the red error bar. |
| 1414 | </li> |
| 1415 | </ul> |
| 1416 | </li> |
| 1417 | <li> |
| 1418 | Use <code>echomsg</code> instead of <code>echo</code>. |
| 1419 | <ul> |
| 1420 | <li> |
| 1421 | <code>echomsg</code> messages can be reviewed with the |
| 1422 | <code>:messages</code> command. |
| 1423 | </li> |
| 1424 | <li> |
| 1425 | <code>echo</code> messages disappear permanently on redraw, which |
| 1426 | can be very annoying to users who failed to read the message in |
| 1427 | time. |
| 1428 | </li> |
| 1429 | </ul> |
| 1430 | </li> |
| 1431 | </ul> |
| 1432 | </CATEGORY> |
| 1433 | <CATEGORY title="Layout"> |
| 1434 | <p> |
| 1435 | Lay out <code>plugin/</code> files in the following sections, if |
| 1436 | applicable, separated by two blank lines: |
| 1437 | </p> |
| 1438 | <ul> |
| 1439 | <li> |
| 1440 | Declaration of script constants |
| 1441 | </li> |
| 1442 | <li> |
| 1443 | Declaration of configuration variables |
| 1444 | </li> |
| 1445 | <li> |
| 1446 | Other declarations (commands in <code>commands.vim</code> file, |
| 1447 | autocommands in <code>autocmds.vim</code> file, etc.) |
| 1448 | </li> |
| 1449 | </ul> |
| 1450 | <p> |
| 1451 | Lay out <code>autoload/</code> files in the following sections, if |
| 1452 | applicable, separated by two blank lines: |
| 1453 | </p> |
| 1454 | <ul> |
| 1455 | <li> |
| 1456 | <code>maktaba#library#Require</code> calls |
| 1457 | </li> |
| 1458 | <li> |
| 1459 | Script-local variables |
| 1460 | </li> |
| 1461 | <li> |
| 1462 | Script-local functions |
| 1463 | </li> |
| 1464 | <li> |
| 1465 | Private autoloaded functions |
| 1466 | </li> |
| 1467 | <li> |
| 1468 | Public autoloaded functions |
| 1469 | </li> |
| 1470 | </ul> |
| 1471 | <p> |
| 1472 | This is recommended convention and is not enforced. |
| 1473 | </p> |
| 1474 | |
| 1475 | </CATEGORY> |
| 1476 | <CATEGORY title="Recommended Shortcuts"> |
| 1477 | |
| 1478 | <p> |
| 1479 | Use the following shortcuts: |
| 1480 | </p> |
| 1481 | <ul> |
| 1482 | <li> |
| 1483 | <code>catch</code> over <code>catch /.*/</code> |
| 1484 | </li> |
| 1485 | <li> |
| 1486 | <code>return</code> over <code>return 0</code> when the return value |
| 1487 | has no semantic purpose. |
| 1488 | </li> |
| 1489 | </ul> |
| 1490 | |
| 1491 | </CATEGORY> |
| 1492 | <CATEGORY title="Errata"> |
| 1493 | <p> |
| 1494 | This section plumbs some of the darker corners of vimscript, explaining |
| 1495 | the language pathologies that you wish you didn't have to know. |
| 1496 | |
| 1497 | </p> |
| 1498 | |
| 1499 | <STYLEPOINT title="Compatibility Mode"> |
| 1500 | <SUMMARY> |
| 1501 | If you don't support vi-compatibility mode, fail gracefully. |
| 1502 | </SUMMARY> |
| 1503 | <BODY> |
| 1504 | <p> |
| 1505 | When <code>compatible</code> is set, many vim features are not |
| 1506 | available. The vim feature which most commonly affects vimscript |
| 1507 | authors is line continuations. |
| 1508 | </p> |
| 1509 | <p> |
| 1510 | If you want your plugin to work in vim with vi compatibility on, you |
| 1511 | will need to save the compatibility options at the beginning of each |
| 1512 | plugin file, clear them, and restore them at the end of each plugin |
| 1513 | file. See <code>:help use-cpo-save</code> for details. |
| 1514 | </p> |
| 1515 | <p> |
| 1516 | Plugins that depend on maktaba generally don't need to worry about |
| 1517 | compatible mode since maktaba currently just disables it, printing a |
| 1518 | warning. |
| 1519 | </p> |
| 1520 | </BODY> |
| 1521 | </STYLEPOINT> |
| 1522 | </CATEGORY> |
| 1523 | |
| 1524 | <p align="right"> |
| 1525 | Revision 1.1 |
| 1526 | </p> |
| 1527 | |
| 1528 | |
| 1529 | <address> |
| 1530 | Nate Soares<br/> |
| 1531 | Joshua Hoak<br/> |
| 1532 | David Barnett<br/> |
| 1533 | </address> |
| 1534 | </GUIDE> |