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date | Sun, 13 Jun 2004 20:20:40 +0000 |
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1 *usr_41.txt* For Vim version 7.0aa. Last change: 2004 May 06 | |
2 | |
3 VIM USER MANUAL - by Bram Moolenaar | |
4 | |
5 Write a Vim script | |
6 | |
7 | |
8 The Vim script language is used for the startup vimrc file, syntax files, and | |
9 many other things. This chapter explains the items that can be used in a Vim | |
10 script. There are a lot of them, thus this is a long chapter. | |
11 | |
12 |41.1| Introduction | |
13 |41.2| Variables | |
14 |41.3| Expressions | |
15 |41.4| Conditionals | |
16 |41.5| Executing an expression | |
17 |41.6| Using functions | |
18 |41.7| Defining a function | |
19 |41.8| Exceptions | |
20 |41.9| Various remarks | |
21 |41.10| Writing a plugin | |
22 |41.11| Writing a filetype plugin | |
23 |41.12| Writing a compiler plugin | |
24 | |
25 Next chapter: |usr_42.txt| Add new menus | |
26 Previous chapter: |usr_40.txt| Make new commands | |
27 Table of contents: |usr_toc.txt| | |
28 | |
29 ============================================================================== | |
30 *41.1* Introduction *vim-script-intro* | |
31 | |
32 Your first experience with Vim scripts is the vimrc file. Vim reads it when | |
33 it starts up and executes the commands. You can set options to values you | |
34 prefer. And you can use any colon command in it (commands that start with a | |
35 ":"; these are sometimes referred to as Ex commands or command-line commands). | |
36 Syntax files are also Vim scripts. As are files that set options for a | |
37 specific file type. A complicated macro can be defined by a separate Vim | |
38 script file. You can think of other uses yourself. | |
39 | |
40 Let's start with a simple example: > | |
41 | |
42 :let i = 1 | |
43 :while i < 5 | |
44 : echo "count is" i | |
45 : let i = i + 1 | |
46 :endwhile | |
47 < | |
48 Note: | |
49 The ":" characters are not really needed here. You only need to use | |
50 them when you type a command. In a Vim script file they can be left | |
51 out. We will use them here anyway to make clear these are colon | |
52 commands and make them stand out from Normal mode commands. | |
53 | |
54 The ":let" command assigns a value to a variable. The generic form is: > | |
55 | |
56 :let {variable} = {expression} | |
57 | |
58 In this case the variable name is "i" and the expression is a simple value, | |
59 the number one. | |
60 The ":while" command starts a loop. The generic form is: > | |
61 | |
62 :while {condition} | |
63 : {statements} | |
64 :endwhile | |
65 | |
66 The statements until the matching ":endwhile" are executed for as long as the | |
67 condition is true. The condition used here is the expression "i < 5". This | |
68 is true when the variable i is smaller than five. | |
69 The ":echo" command prints its arguments. In this case the string "count | |
70 is" and the value of the variable i. Since i is one, this will print: | |
71 | |
72 count is 1 ~ | |
73 | |
74 Then there is another ":let i =" command. The value used is the expression "i | |
75 + 1". This adds one to the variable i and assigns the new value to the same | |
76 variable. | |
77 The output of the example code is: | |
78 | |
79 count is 1 ~ | |
80 count is 2 ~ | |
81 count is 3 ~ | |
82 count is 4 ~ | |
83 | |
84 Note: | |
85 If you happen to write a while loop that keeps on running, you can | |
86 interrupt it by pressing CTRL-C (CTRL-Break on MS-Windows). | |
87 | |
88 | |
89 THREE KINDS OF NUMBERS | |
90 | |
91 Numbers can be decimal, hexadecimal or octal. A hexadecimal number starts | |
92 with "0x" or "0X". For example "0x1f" is 31. An octal number starts with a | |
93 zero. "017" is 15. Careful: don't put a zero before a decimal number, it | |
94 will be interpreted as an octal number! | |
95 The ":echo" command always prints decimal numbers. Example: > | |
96 | |
97 :echo 0x7f 036 | |
98 < 127 30 ~ | |
99 | |
100 A number is made negative with a minus sign. This also works for hexadecimal | |
101 and octal numbers. A minus sign is also for subtraction. Compare this with | |
102 the previous example: > | |
103 | |
104 :echo 0x7f -036 | |
105 < 97 ~ | |
106 | |
107 White space in an expression is ignored. However, it's recommended to use it | |
108 for separating items, to make the expression easier to read. For example, to | |
109 avoid the confusion with a negative number, put a space between the minus sign | |
110 and the following number: > | |
111 | |
112 :echo 0x7f - 036 | |
113 | |
114 ============================================================================== | |
115 *41.2* Variables | |
116 | |
117 A variable name consists of ASCII letters, digits and the underscore. It | |
118 cannot start with a digit. Valid variable names are: | |
119 | |
120 counter | |
121 _aap3 | |
122 very_long_variable_name_with_underscores | |
123 FuncLength | |
124 LENGTH | |
125 | |
126 Invalid names are "foo+bar" and "6var". | |
127 These variables are global. To see a list of currently defined variables | |
128 use this command: > | |
129 | |
130 :let | |
131 | |
132 You can use global variables everywhere. This also means that when the | |
133 variable "count" is used in one script file, it might also be used in another | |
134 file. This leads to confusion at least, and real problems at worst. To avoid | |
135 this, you can use a variable local to a script file by prepending "s:". For | |
136 example, one script contains this code: > | |
137 | |
138 :let s:count = 1 | |
139 :while s:count < 5 | |
140 : source other.vim | |
141 : let s:count = s:count + 1 | |
142 :endwhile | |
143 | |
144 Since "s:count" is local to this script, you can be sure that sourcing the | |
145 "other.vim" script will not change this variable. If "other.vim" also uses an | |
146 "s:count" variable, it will be a different copy, local to that script. More | |
147 about script-local variables here: |script-variable|. | |
148 | |
149 There are more kinds of variables, see |internal-variables|. The most often | |
150 used ones are: | |
151 | |
152 b:name variable local to a buffer | |
153 w:name variable local to a window | |
154 g:name global variable (also in a function) | |
155 v:name variable predefined by Vim | |
156 | |
157 | |
158 DELETING VARIABLES | |
159 | |
160 Variables take up memory and show up in the output of the ":let" command. To | |
161 delete a variable use the ":unlet" command. Example: > | |
162 | |
163 :unlet s:count | |
164 | |
165 This deletes the script-local variable "s:count" to free up the memory it | |
166 uses. If you are not sure if the variable exists, and don't want an error | |
167 message when it doesn't, append !: > | |
168 | |
169 :unlet! s:count | |
170 | |
171 When a script finishes, the local variables used there will not be | |
172 automatically freed. The next time the script executes, it can still use the | |
173 old value. Example: > | |
174 | |
175 :if !exists("s:call_count") | |
176 : let s:call_count = 0 | |
177 :endif | |
178 :let s:call_count = s:call_count + 1 | |
179 :echo "called" s:call_count "times" | |
180 | |
181 The "exists()" function checks if a variable has already been defined. Its | |
182 argument is the name of the variable you want to check. Not the variable | |
183 itself! If you would do this: > | |
184 | |
185 :if !exists(s:call_count) | |
186 | |
187 Then the value of s:call_count will be used as the name of the variable that | |
188 exists() checks. That's not what you want. | |
189 The exclamation mark ! negates a value. When the value was true, it | |
190 becomes false. When it was false, it becomes true. You can read it as "not". | |
191 Thus "if !exists()" can be read as "if not exists()". | |
192 What Vim calls true is anything that is not zero. Only zero is false. | |
193 | |
194 | |
195 STRING VARIABLES AND CONSTANTS | |
196 | |
197 So far only numbers were used for the variable value. Strings can be used as | |
198 well. Numbers and strings are the only two types of variables that Vim | |
199 supports. The type is dynamic, it is set each time when assigning a value to | |
200 the variable with ":let". | |
201 To assign a string value to a variable, you need to use a string constant. | |
202 There are two types of these. First the string in double quotes: > | |
203 | |
204 :let name = "peter" | |
205 :echo name | |
206 < peter ~ | |
207 | |
208 If you want to include a double quote inside the string, put a backslash in | |
209 front of it: > | |
210 | |
211 :let name = "\"peter\"" | |
212 :echo name | |
213 < "peter" ~ | |
214 | |
215 To avoid the need for a backslash, you can use a string in single quotes: > | |
216 | |
217 :let name = '"peter"' | |
218 :echo name | |
219 < "peter" ~ | |
220 | |
221 Inside a single-quote string all the characters are taken literally. The | |
222 drawback is that it's impossible to include a single quote. A backslash is | |
223 taken literally as well, thus you can't use it to change the meaning of the | |
224 character after it. | |
225 In double-quote strings it is possible to use special characters. Here are | |
226 a few useful ones: | |
227 | |
228 \t <Tab> | |
229 \n <NL>, line break | |
230 \r <CR>, <Enter> | |
231 \e <Esc> | |
232 \b <BS>, backspace | |
233 \" " | |
234 \\ \, backslash | |
235 \<Esc> <Esc> | |
236 \<C-W> CTRL-W | |
237 | |
238 The last two are just examples. The "\<name>" form can be used to include | |
239 the special key "name". | |
240 See |expr-quote| for the full list of special items in a string. | |
241 | |
242 ============================================================================== | |
243 *41.3* Expressions | |
244 | |
245 Vim has a rich, yet simple way to handle expressions. You can read the | |
246 definition here: |expression-syntax|. Here we will show the most common | |
247 items. | |
248 The numbers, strings and variables mentioned above are expressions by | |
249 themselves. Thus everywhere an expression is expected, you can use a number, | |
250 string or variable. Other basic items in an expression are: | |
251 | |
252 $NAME environment variable | |
253 &name option | |
254 @r register | |
255 | |
256 Examples: > | |
257 | |
258 :echo "The value of 'tabstop' is" &ts | |
259 :echo "Your home directory is" $HOME | |
260 :if @a > 5 | |
261 | |
262 The &name form can be used to save an option value, set it to a new value, | |
263 do something and restore the old value. Example: > | |
264 | |
265 :let save_ic = &ic | |
266 :set noic | |
267 :/The Start/,$delete | |
268 :let &ic = save_ic | |
269 | |
270 This makes sure the "The Start" pattern is used with the 'ignorecase' option | |
271 off. Still, it keeps the value that the user had set. | |
272 | |
273 | |
274 MATHEMATICS | |
275 | |
276 It becomes more interesting if we combine these basic items. Let's start with | |
277 mathematics on numbers: | |
278 | |
279 a + b add | |
280 a - b subtract | |
281 a * b multiply | |
282 a / b divide | |
283 a % b modulo | |
284 | |
285 The usual precedence is used. Example: > | |
286 | |
287 :echo 10 + 5 * 2 | |
288 < 20 ~ | |
289 | |
290 Grouping is done with braces. No surprises here. Example: > | |
291 | |
292 :echo (10 + 5) * 2 | |
293 < 30 ~ | |
294 | |
295 Strings can be concatenated with ".". Example: > | |
296 | |
297 :echo "foo" . "bar" | |
298 < foobar ~ | |
299 | |
300 When the ":echo" command gets multiple arguments, it separates them with a | |
301 space. In the example the argument is a single expression, thus no space is | |
302 inserted. | |
303 | |
304 Borrowed from the C language is the conditional expression: | |
305 | |
306 a ? b : c | |
307 | |
308 If "a" evaluates to true "b" is used, otherwise "c" is used. Example: > | |
309 | |
310 :let i = 4 | |
311 :echo i > 5 ? "i is big" : "i is small" | |
312 < i is small ~ | |
313 | |
314 The three parts of the constructs are always evaluated first, thus you could | |
315 see it work as: | |
316 | |
317 (a) ? (b) : (c) | |
318 | |
319 ============================================================================== | |
320 *41.4* Conditionals | |
321 | |
322 The ":if" commands executes the following statements, until the matching | |
323 ":endif", only when a condition is met. The generic form is: | |
324 | |
325 :if {condition} | |
326 {statements} | |
327 :endif | |
328 | |
329 Only when the expression {condition} evaluates to true (non-zero) will the | |
330 {statements} be executed. These must still be valid commands. If they | |
331 contain garbage, Vim won't be able to find the ":endif". | |
332 You can also use ":else". The generic form for this is: | |
333 | |
334 :if {condition} | |
335 {statements} | |
336 :else | |
337 {statements} | |
338 :endif | |
339 | |
340 The second {statements} is only executed if the first one isn't. | |
341 Finally, there is ":elseif": | |
342 | |
343 :if {condition} | |
344 {statements} | |
345 :elseif {condition} | |
346 {statements} | |
347 :endif | |
348 | |
349 This works just like using ":else" and then "if", but without the need for an | |
350 extra ":endif". | |
351 A useful example for your vimrc file is checking the 'term' option and | |
352 doing something depending upon its value: > | |
353 | |
354 :if &term == "xterm" | |
355 : " Do stuff for xterm | |
356 :elseif &term == "vt100" | |
357 : " Do stuff for a vt100 terminal | |
358 :else | |
359 : " Do something for other terminals | |
360 :endif | |
361 | |
362 | |
363 LOGIC OPERATIONS | |
364 | |
365 We already used some of them in the examples. These are the most often used | |
366 ones: | |
367 | |
368 a == b equal to | |
369 a != b not equal to | |
370 a > b greater than | |
371 a >= b greater than or equal to | |
372 a < b less than | |
373 a <= b less than or equal to | |
374 | |
375 The result is one if the condition is met and zero otherwise. An example: > | |
376 | |
377 :if v:version >= 600 | |
378 : echo "congratulations" | |
379 :else | |
380 : echo "you are using an old version, upgrade!" | |
381 :endif | |
382 | |
383 Here "v:version" is a variable defined by Vim, which has the value of the Vim | |
384 version. 600 is for version 6.0. Version 6.1 has the value 601. This is | |
385 very useful to write a script that works with multiple versions of Vim. | |
386 |v:version| | |
387 | |
388 The logic operators work both for numbers and strings. When comparing two | |
389 strings, the mathematical difference is used. This compares byte values, | |
390 which may not be right for some languages. | |
391 When comparing a string with a number, the string is first converted to a | |
392 number. This is a bit tricky, because when a string doesn't look like a | |
393 number, the number zero is used. Example: > | |
394 | |
395 :if 0 == "one" | |
396 : echo "yes" | |
397 :endif | |
398 | |
399 This will echo "yes", because "one" doesn't look like a number, thus it is | |
400 converted to the number zero. | |
401 | |
402 For strings there are two more items: | |
403 | |
404 a =~ b matches with | |
405 a !~ b does not match with | |
406 | |
407 The left item "a" is used as a string. The right item "b" is used as a | |
408 pattern, like what's used for searching. Example: > | |
409 | |
410 :if str =~ " " | |
411 : echo "str contains a space" | |
412 :endif | |
413 :if str !~ '\.$' | |
414 : echo "str does not end in a full stop" | |
415 :endif | |
416 | |
417 Notice the use of a single-quote string for the pattern. This is useful, | |
418 because backslashes need to be doubled in a double-quote string and patterns | |
419 tend to contain many backslashes. | |
420 | |
421 The 'ignorecase' option is used when comparing strings. When you don't want | |
422 that, append "#" to match case and "?" to ignore case. Thus "==?" compares | |
423 two strings to be equal while ignoring case. And "!~#" checks if a pattern | |
424 doesn't match, also checking the case of letters. For the full table see | |
425 |expr-==|. | |
426 | |
427 | |
428 MORE LOOPING | |
429 | |
430 The ":while" command was already mentioned. Two more statements can be used | |
431 in between the ":while" and the ":endwhile": | |
432 | |
433 :continue Jump back to the start of the while loop; the | |
434 loop continues. | |
435 :break Jump forward to the ":endwhile"; the loop is | |
436 discontinued. | |
437 | |
438 Example: > | |
439 | |
440 :while counter < 40 | |
441 : call do_something() | |
442 : if skip_flag | |
443 : continue | |
444 : endif | |
445 : if finished_flag | |
446 : break | |
447 : endif | |
448 : sleep 50m | |
449 :endwhile | |
450 | |
451 The ":sleep" command makes Vim take a nap. The "50m" specifies fifty | |
452 milliseconds. Another example is ":sleep 4", which sleeps for four seconds. | |
453 | |
454 ============================================================================== | |
455 *41.5* Executing an expression | |
456 | |
457 So far the commands in the script were executed by Vim directly. The | |
458 ":execute" command allows executing the result of an expression. This is a | |
459 very powerful way to build commands and execute them. | |
460 An example is to jump to a tag, which is contained in a variable: > | |
461 | |
462 :execute "tag " . tag_name | |
463 | |
464 The "." is used to concatenate the string "tag " with the value of variable | |
465 "tag_name". Suppose "tag_name" has the value "get_cmd", then the command that | |
466 will be executed is: > | |
467 | |
468 :tag get_cmd | |
469 | |
470 The ":execute" command can only execute colon commands. The ":normal" command | |
471 executes Normal mode commands. However, its argument is not an expression but | |
472 the literal command characters. Example: > | |
473 | |
474 :normal gg=G | |
475 | |
476 This jumps to the first line and formats all lines with the "=" operator. | |
477 To make ":normal" work with an expression, combine ":execute" with it. | |
478 Example: > | |
479 | |
480 :execute "normal " . normal_commands | |
481 | |
482 The variable "normal_commands" must contain the Normal mode commands. | |
483 Make sure that the argument for ":normal" is a complete command. Otherwise | |
484 Vim will run into the end of the argument and abort the command. For example, | |
485 if you start Insert mode, you must leave Insert mode as well. This works: > | |
486 | |
487 :execute "normal Inew text \<Esc>" | |
488 | |
489 This inserts "new text " in the current line. Notice the use of the special | |
490 key "\<Esc>". This avoids having to enter a real <Esc> character in your | |
491 script. | |
492 | |
493 ============================================================================== | |
494 *41.6* Using functions | |
495 | |
496 Vim defines many functions and provides a large amount of functionality that | |
497 way. A few examples will be given in this section. You can find the whole | |
498 list here: |functions|. | |
499 | |
500 A function is called with the ":call" command. The parameters are passed in | |
501 between braces, separated by commas. Example: > | |
502 | |
503 :call search("Date: ", "W") | |
504 | |
505 This calls the search() function, with arguments "Date: " and "W". The | |
506 search() function uses its first argument as a search pattern and the second | |
507 one as flags. The "W" flag means the search doesn't wrap around the end of | |
508 the file. | |
509 | |
510 A function can be called in an expression. Example: > | |
511 | |
512 :let line = getline(".") | |
513 :let repl = substitute(line, '\a', "*", "g") | |
514 :call setline(".", repl) | |
515 | |
516 The getline() function obtains a line from the current file. Its argument is | |
517 a specification of the line number. In this case "." is used, which means the | |
518 line where the cursor is. | |
519 The substitute() function does something similar to the ":substitute" | |
520 command. The first argument is the string on which to perform the | |
521 substitution. The second argument is the pattern, the third the replacement | |
522 string. Finally, the last arguments are the flags. | |
523 The setline() function sets the line, specified by the first argument, to a | |
524 new string, the second argument. In this example the line under the cursor is | |
525 replaced with the result of the substitute(). Thus the effect of the three | |
526 statements is equal to: > | |
527 | |
528 :substitute/\a/*/g | |
529 | |
530 Using the functions becomes more interesting when you do more work before and | |
531 after the substitute() call. | |
532 | |
533 | |
534 FUNCTIONS *function-list* | |
535 | |
536 There are many functions. We will mention them here, grouped by what they are | |
537 used for. You can find an alphabetical list here: |functions|. Use CTRL-] on | |
538 the function name to jump to detailed help on it. | |
539 | |
540 String manipulation: | |
541 char2nr() get ASCII value of a character | |
542 nr2char() get a character by its ASCII value | |
543 escape() escape characters in a string with a '\' | |
544 strtrans() translate a string to make it printable | |
545 tolower() turn a string to lowercase | |
546 toupper() turn a string to uppercase | |
547 match() position where a pattern matches in a string | |
548 matchend() position where a pattern match ends in a string | |
549 matchstr() match of a pattern in a string | |
550 stridx() first index of a short string in a long string | |
551 strridx() last index of a short string in a long string | |
552 strlen() length of a string | |
553 substitute() substitute a pattern match with a string | |
554 submatch() get a specific match in a ":substitute" | |
555 strpart() get part of a string | |
556 expand() expand special keywords | |
557 type() type of a variable | |
558 iconv() convert text from one encoding to another | |
559 | |
560 Working with text in the current buffer: | |
561 byte2line() get line number at a specific byte count | |
562 line2byte() byte count at a specific line | |
563 col() column number of the cursor or a mark | |
564 virtcol() screen column of the cursor or a mark | |
565 line() line number of the cursor or mark | |
566 wincol() window column number of the cursor | |
567 winline() window line number of the cursor | |
568 cursor() position the cursor at a line/column | |
569 getline() get a line from the buffer | |
570 setline() replace a line in the buffer | |
571 append() append {string} below line {lnum} | |
572 indent() indent of a specific line | |
573 cindent() indent according to C indenting | |
574 lispindent() indent according to Lisp indenting | |
575 nextnonblank() find next non-blank line | |
576 prevnonblank() find previous non-blank line | |
577 search() find a match for a pattern | |
578 searchpair() find the other end of a start/skip/end | |
579 | |
580 System functions and manipulation of files: | |
581 browse() put up a file requester | |
582 glob() expand wildcards | |
583 globpath() expand wildcards in a number of directories | |
584 resolve() find out where a shortcut points to | |
585 fnamemodify() modify a file name | |
586 executable() check if an executable program exists | |
587 filereadable() check if a file can be read | |
588 filewritable() check if a file can be written to | |
589 isdirectory() check if a directory exists | |
590 getcwd() get the current working directory | |
591 getfsize() get the size of a file | |
592 getftime() get last modification time of a file | |
593 localtime() get current time | |
594 strftime() convert time to a string | |
595 tempname() get the name of a temporary file | |
596 delete() delete a file | |
597 rename() rename a file | |
598 system() get the result of a shell command | |
599 hostname() name of the system | |
600 | |
601 Buffers, windows and the argument list: | |
602 argc() number of entries in the argument list | |
603 argidx() current position in the argument list | |
604 argv() get one entry from the argument list | |
605 bufexists() check if a buffer exists | |
606 buflisted() check if a buffer exists and is listed | |
607 bufloaded() check if a buffer exists and is loaded | |
608 bufname() get the name of a specific buffer | |
609 bufnr() get the buffer number of a specific buffer | |
610 winnr() get the window number for the current window | |
611 bufwinnr() get the window number of a specific buffer | |
612 winbufnr() get the buffer number of a specific window | |
613 getbufvar() get a variable value from a specific buffer | |
614 setbufvar() set a variable in a specific buffer | |
615 getwinvar() get a variable value from a specific window | |
616 setwinvar() set a variable in a specific window | |
617 | |
618 Folding: | |
619 foldclosed() check for a closed fold at a specific line | |
620 foldclosedend() like foldclosed() but return the last line | |
621 foldlevel() check for the fold level at a specific line | |
622 foldtext() generate the line displayed for a closed fold | |
623 | |
624 Syntax highlighting: | |
625 hlexists() check if a highlight group exists | |
626 hlID() get ID of a highlight group | |
627 synID() get syntax ID at a specific position | |
628 synIDattr() get a specific attribute of a syntax ID | |
629 synIDtrans() get translated syntax ID | |
630 | |
631 History: | |
632 histadd() add an item to a history | |
633 histdel() delete an item from a history | |
634 histget() get an item from a history | |
635 histnr() get highest index of a history list | |
636 | |
637 Interactive: | |
638 confirm() let the user make a choice | |
639 getchar() get a character from the user | |
640 getcharmod() get modifiers for the last typed character | |
641 input() get a line from the user | |
642 inputsecret() get a line from the user without showing it | |
643 inputdialog() get a line from the user in a dialog | |
644 inputresave save and clear typeahead | |
645 inputrestore() restore typeahead | |
646 | |
647 Vim server: | |
648 serverlist() return the list of server names | |
649 remote_send() send command characters to a Vim server | |
650 remote_expr() evaluate an expression in a Vim server | |
651 server2client() send a reply to a client of a Vim server | |
652 remote_peek() check if there is a reply from a Vim server | |
653 remote_read() read a reply from a Vim server | |
654 foreground() move the Vim window to the foreground | |
655 remote_foreground() move the Vim server window to the foreground | |
656 | |
657 Various: | |
658 mode() get current editing mode | |
659 visualmode() last visual mode used | |
660 hasmapto() check if a mapping exists | |
661 mapcheck() check if a matching mapping exists | |
662 maparg() get rhs of a mapping | |
663 exists() check if a variable, function, etc. exists | |
664 has() check if a feature is supported in Vim | |
665 cscope_connection() check if a cscope connection exists | |
666 did_filetype() check if a FileType autocommand was used | |
667 eventhandler() check if invoked by an event handler | |
668 getwinposx() X position of the GUI Vim window | |
669 getwinposy() Y position of the GUI Vim window | |
670 winheight() get height of a specific window | |
671 winwidth() get width of a specific window | |
672 libcall() call a function in an external library | |
673 libcallnr() idem, returning a number | |
674 getreg() get contents of a register | |
675 getregtype() get type of a register | |
676 setreg() set contents and type of a register | |
677 | |
678 ============================================================================== | |
679 *41.7* Defining a function | |
680 | |
681 Vim enables you to define your own functions. The basic function declaration | |
682 begins as follows: > | |
683 | |
684 :function {name}({var1}, {var2}, ...) | |
685 : {body} | |
686 :endfunction | |
687 < | |
688 Note: | |
689 Function names must begin with a capital letter. | |
690 | |
691 Let's define a short function to return the smaller of two numbers. It starts | |
692 with this line: > | |
693 | |
694 :function Min(num1, num2) | |
695 | |
696 This tells Vim that the function is named "Min" and it takes two arguments: | |
697 "num1" and "num2". | |
698 The first thing you need to do is to check to see which number is smaller: | |
699 > | |
700 : if a:num1 < a:num2 | |
701 | |
702 The special prefix "a:" tells Vim that the variable is a function argument. | |
703 Let's assign the variable "smaller" the value of the smallest number: > | |
704 | |
705 : if a:num1 < a:num2 | |
706 : let smaller = a:num1 | |
707 : else | |
708 : let smaller = a:num2 | |
709 : endif | |
710 | |
711 The variable "smaller" is a local variable. Variables used inside a function | |
712 are local unless prefixed by something like "g:", "a:", or "s:". | |
713 | |
714 Note: | |
715 To access a global variable from inside a function you must prepend | |
716 "g:" to it. Thus "g:count" inside a function is used for the global | |
717 variable "count", and "count" is another variable, local to the | |
718 function. | |
719 | |
720 You now use the ":return" statement to return the smallest number to the user. | |
721 Finally, you end the function: > | |
722 | |
723 : return smaller | |
724 :endfunction | |
725 | |
726 The complete function definition is as follows: > | |
727 | |
728 :function Min(num1, num2) | |
729 : if a:num1 < a:num2 | |
730 : let smaller = a:num1 | |
731 : else | |
732 : let smaller = a:num2 | |
733 : endif | |
734 : return smaller | |
735 :endfunction | |
736 | |
737 A user defined function is called in exactly the same way as a builtin | |
738 function. Only the name is different. The Min function can be used like | |
739 this: > | |
740 | |
741 :echo Min(5, 8) | |
742 | |
743 Only now will the function be executed and the lines be interpreted by Vim. | |
744 If there are mistakes, like using an undefined variable or function, you will | |
745 now get an error message. When defining the function these errors are not | |
746 detected. | |
747 | |
748 When a function reaches ":endfunction" or ":return" is used without an | |
749 argument, the function returns zero. | |
750 | |
751 To redefine a function that already exists, use the ! for the ":function" | |
752 command: > | |
753 | |
754 :function! Min(num1, num2, num3) | |
755 | |
756 | |
757 USING A RANGE | |
758 | |
759 The ":call" command can be given a line range. This can have one of two | |
760 meanings. When a function has been defined with the "range" keyword, it will | |
761 take care of the line range itself. | |
762 The function will be passed the variables "a:firstline" and "a:lastline". | |
763 These will have the line numbers from the range the function was called with. | |
764 Example: > | |
765 | |
766 :function Count_words() range | |
767 : let n = a:firstline | |
768 : let count = 0 | |
769 : while n <= a:lastline | |
770 : let count = count + Wordcount(getline(n)) | |
771 : let n = n + 1 | |
772 : endwhile | |
773 : echo "found " . count . " words" | |
774 :endfunction | |
775 | |
776 You can call this function with: > | |
777 | |
778 :10,30call Count_words() | |
779 | |
780 It will be executed once and echo the number of words. | |
781 The other way to use a line range is by defining a function without the | |
782 "range" keyword. The function will be called once for every line in the | |
783 range, with the cursor in that line. Example: > | |
784 | |
785 :function Number() | |
786 : echo "line " . line(".") . " contains: " . getline(".") | |
787 :endfunction | |
788 | |
789 If you call this function with: > | |
790 | |
791 :10,15call Number() | |
792 | |
793 The function will be called six times. | |
794 | |
795 | |
796 VARIABLE NUMBER OF ARGUMENTS | |
797 | |
798 Vim enables you to define functions that have a variable number of arguments. | |
799 The following command, for instance, defines a function that must have 1 | |
800 argument (start) and can have up to 20 additional arguments: > | |
801 | |
802 :function Show(start, ...) | |
803 | |
804 The variable "a:1" contains the first optional argument, "a:2" the second, and | |
805 so on. The variable "a:0" contains the number of extra arguments. | |
806 For example: > | |
807 | |
808 :function Show(start, ...) | |
809 : echohl Title | |
810 : echo "Show is " . a:start | |
811 : echohl None | |
812 : let index = 1 | |
813 : while index <= a:0 | |
814 : echo " Arg " . index . " is " . a:{index} | |
815 : let index = index + 1 | |
816 : endwhile | |
817 : echo "" | |
818 :endfunction | |
819 | |
820 This uses the ":echohl" command to specify the highlighting used for the | |
821 following ":echo" command. ":echohl None" stops it again. The ":echon" | |
822 command works like ":echo", but doesn't output a line break. | |
823 | |
824 | |
825 LISTING FUNCTIONS | |
826 | |
827 The ":function" command lists the names and arguments of all user-defined | |
828 functions: > | |
829 | |
830 :function | |
831 < function Show(start, ...) ~ | |
832 function GetVimIndent() ~ | |
833 function SetSyn(name) ~ | |
834 | |
835 To see what a function does, use its name as an argument for ":function": > | |
836 | |
837 :function SetSyn | |
838 < 1 if &syntax == '' ~ | |
839 2 let &syntax = a:name ~ | |
840 3 endif ~ | |
841 endfunction ~ | |
842 | |
843 | |
844 DEBUGGING | |
845 | |
846 The line number is useful for when you get an error message or when debugging. | |
847 See |debug-scripts| about debugging mode. | |
848 You can also set the 'verbose' option to 12 or higher to see all function | |
849 calls. Set it to 15 or higher to see every executed line. | |
850 | |
851 | |
852 DELETING A FUNCTION | |
853 | |
854 To delete the Show() function: > | |
855 | |
856 :delfunction Show | |
857 | |
858 You get an error when the function doesn't exist. | |
859 | |
860 ============================================================================== | |
861 *41.8* Exceptions | |
862 | |
863 Let's start with an example: > | |
864 | |
865 :try | |
866 : read ~/templates/pascal.tmpl | |
867 :catch /E484:/ | |
868 : echo "Sorry, the Pascal template file cannot be found." | |
869 :endtry | |
870 | |
871 The ":read" command will fail if the file does not exist. Instead of | |
872 generating an error message, this code catches the error and gives the user a | |
873 nice message instead. | |
874 | |
875 For the commands in between ":try" and ":endtry" errors are turned into | |
876 exceptions. An exception is a string. In the case of an error the string | |
877 contains the error message. And every error message has a number. In this | |
878 case, the error we catch contains "E484:". This number is guaranteed to stay | |
879 the same (the text may change, e.g., it may be translated). | |
880 | |
881 When the ":read" command causes another error, the pattern "E484:" will not | |
882 match in it. Thus this exception will not be caught and result in the usual | |
883 error message. | |
884 | |
885 You might be tempted to do this: > | |
886 | |
887 :try | |
888 : read ~/templates/pascal.tmpl | |
889 :catch | |
890 : echo "Sorry, the Pascal template file cannot be found." | |
891 :endtry | |
892 | |
893 This means all errors are caught. But then you will not see errors that are | |
894 useful, such as "E21: Cannot make changes, 'modifiable' is off". | |
895 | |
896 Another useful mechanism is the ":finally" command: > | |
897 | |
898 :let tmp = tempname() | |
899 :try | |
900 : exe ".,$write " . tmp | |
901 : exe "!filter " . tmp | |
902 : .,$delete | |
903 : exe "$read " . tmp | |
904 :finally | |
905 : call delete(tmp) | |
906 :endtry | |
907 | |
908 This filters the lines from the cursor until the end of the file through the | |
909 "filter" command, which takes a file name argument. No matter if the | |
910 filtering works, something goes wrong in between ":try" and ":finally" or the | |
911 user cancels the filtering by pressing CTRL-C, the "call delete(tmp)" is | |
912 always executed. This makes sure you don't leave the temporary file behind. | |
913 | |
914 More information about exception handling can be found in the reference | |
915 manual: |exception-handling|. | |
916 | |
917 ============================================================================== | |
918 *41.9* Various remarks | |
919 | |
920 Here is a summary of items that apply to Vim scripts. They are also mentioned | |
921 elsewhere, but form a nice checklist. | |
922 | |
923 The end-of-line character depends on the system. For Unix a single <NL> | |
924 character is used. For MS-DOS, Windows, OS/2 and the like, <CR><LF> is used. | |
925 This is important when using mappings that end in a <CR>. See |:source_crnl|. | |
926 | |
927 | |
928 WHITE SPACE | |
929 | |
930 Blank lines are allowed and ignored. | |
931 | |
932 Leading whitespace characters (blanks and TABs) are always ignored. The | |
933 whitespaces between parameters (e.g. between the 'set' and the 'cpoptions' in | |
934 the example below) are reduced to one blank character and plays the role of a | |
935 separator, the whitespaces after the last (visible) character may or may not | |
936 be ignored depending on the situation, see below. | |
937 | |
938 For a ":set" command involving the "=" (equal) sign, such as in: > | |
939 | |
940 :set cpoptions =aABceFst | |
941 | |
942 the whitespace immediately before the "=" sign is ignored. But there can be | |
943 no whitespace after the "=" sign! | |
944 | |
945 To include a whitespace character in the value of an option, it must be | |
946 escaped by a "\" (backslash) as in the following example: > | |
947 | |
948 :set tags=my\ nice\ file | |
949 | |
950 The same example written as > | |
951 | |
952 :set tags=my nice file | |
953 | |
954 will issue an error, because it is interpreted as: > | |
955 | |
956 :set tags=my | |
957 :set nice | |
958 :set file | |
959 | |
960 | |
961 COMMENTS | |
962 | |
963 The character " (the double quote mark) starts a comment. Everything after | |
964 and including this character until the end-of-line is considered a comment and | |
965 is ignored, except for commands that don't consider comments, as shown in | |
966 examples below. A comment can start on any character position on the line. | |
967 | |
968 There is a little "catch" with comments for some commands. Examples: > | |
969 | |
970 :abbrev dev development " shorthand | |
971 :map <F3> o#include " insert include | |
972 :execute cmd " do it | |
973 :!ls *.c " list C files | |
974 | |
975 The abbreviation 'dev' will be expanded to 'development " shorthand'. The | |
976 mapping of <F3> will actually be the whole line after the 'o# ....' including | |
977 the '" insert include'. The "execute" command will give an error. The "!" | |
978 command will send everything after it to the shell, causing an error for an | |
979 unmatched '"' character. | |
980 There can be no comment after ":map", ":abbreviate", ":execute" and "!" | |
981 commands (there are a few more commands with this restriction). For the | |
982 ":map", ":abbreviate" and ":execute" commands there is a trick: > | |
983 | |
984 :abbrev dev development|" shorthand | |
985 :map <F3> o#include|" insert include | |
986 :execute cmd |" do it | |
987 | |
988 With the '|' character the command is separated from the next one. And that | |
989 next command is only a comment. | |
990 | |
991 Notice that there is no white space before the '|' in the abbreviation and | |
992 mapping. For these commands, any character until the end-of-line or '|' is | |
993 included. As a consequence of this behavior, you don't always see that | |
994 trailing whitespace is included: > | |
995 | |
996 :map <F4> o#include | |
997 | |
998 To avoid these problems, you can set the 'list' option when editing vimrc | |
999 files. | |
1000 | |
1001 | |
1002 PITFALLS | |
1003 | |
1004 Even bigger problem arises in the following example: > | |
1005 | |
1006 :map ,ab o#include | |
1007 :unmap ,ab | |
1008 | |
1009 Here the unmap command will not work, because it tries to unmap ",ab ". This | |
1010 does not exist as a mapped sequence. An error will be issued, which is very | |
1011 hard to identify, because the ending whitespace character in ":unmap ,ab " is | |
1012 not visible. | |
1013 | |
1014 And this is the same as what happens when one uses a comment after an 'unmap' | |
1015 command: > | |
1016 | |
1017 :unmap ,ab " comment | |
1018 | |
1019 Here the comment part will be ignored. However, Vim will try to unmap | |
1020 ',ab ', which does not exist. Rewrite it as: > | |
1021 | |
1022 :unmap ,ab| " comment | |
1023 | |
1024 | |
1025 RESTORING THE VIEW | |
1026 | |
1027 Sometimes you want to make a change and go back to where cursor was. | |
1028 Restoring the relative position would also be nice, so that the same line | |
1029 appears at the top of the window. | |
1030 This example yanks the current line, puts it above the first line in the | |
1031 file and then restores the view: > | |
1032 | |
1033 map ,p ma"aYHmbgg"aP`bzt`a | |
1034 | |
1035 What this does: > | |
1036 ma"aYHmbgg"aP`bzt`a | |
1037 < ma set mark a at cursor position | |
1038 "aY yank current line into register a | |
1039 Hmb go to top line in window and set mark b there | |
1040 gg go to first line in file | |
1041 "aP put the yanked line above it | |
1042 `b go back to top line in display | |
1043 zt position the text in the window as before | |
1044 `a go back to saved cursor position | |
1045 | |
1046 | |
1047 PACKAGING | |
1048 | |
1049 To avoid your function names to interfere with functions that you get from | |
1050 others, use this scheme: | |
1051 - Prepend a unique string before each function name. I often use an | |
1052 abbreviation. For example, "OW_" is used for the option window functions. | |
1053 - Put the definition of your functions together in a file. Set a global | |
1054 variable to indicate that the functions have been loaded. When sourcing the | |
1055 file again, first unload the functions. | |
1056 Example: > | |
1057 | |
1058 " This is the XXX package | |
1059 | |
1060 if exists("XXX_loaded") | |
1061 delfun XXX_one | |
1062 delfun XXX_two | |
1063 endif | |
1064 | |
1065 function XXX_one(a) | |
1066 ... body of function ... | |
1067 endfun | |
1068 | |
1069 function XXX_two(b) | |
1070 ... body of function ... | |
1071 endfun | |
1072 | |
1073 let XXX_loaded = 1 | |
1074 | |
1075 ============================================================================== | |
1076 *41.10* Writing a plugin *write-plugin* | |
1077 | |
1078 You can write a Vim script in such a way that many people can use it. This is | |
1079 called a plugin. Vim users can drop your script in their plugin directory and | |
1080 use its features right away |add-plugin|. | |
1081 | |
1082 There are actually two types of plugins: | |
1083 | |
1084 global plugins: For all types of files. | |
1085 filetype plugins: Only for files of a specific type. | |
1086 | |
1087 In this section the first type is explained. Most items are also relevant for | |
1088 writing filetype plugins. The specifics for filetype plugins are in the next | |
1089 section |write-filetype-plugin|. | |
1090 | |
1091 | |
1092 NAME | |
1093 | |
1094 First of all you must choose a name for your plugin. The features provided | |
1095 by the plugin should be clear from its name. And it should be unlikely that | |
1096 someone else writes a plugin with the same name but which does something | |
1097 different. And please limit the name to 8 characters, to avoid problems on | |
1098 old Windows systems. | |
1099 | |
1100 A script that corrects typing mistakes could be called "typecorr.vim". We | |
1101 will use it here as an example. | |
1102 | |
1103 For the plugin to work for everybody, it should follow a few guidelines. This | |
1104 will be explained step-by-step. The complete example plugin is at the end. | |
1105 | |
1106 | |
1107 BODY | |
1108 | |
1109 Let's start with the body of the plugin, the lines that do the actual work: > | |
1110 | |
1111 14 iabbrev teh the | |
1112 15 iabbrev otehr other | |
1113 16 iabbrev wnat want | |
1114 17 iabbrev synchronisation | |
1115 18 \ synchronization | |
1116 19 let s:count = 4 | |
1117 | |
1118 The actual list should be much longer, of course. | |
1119 | |
1120 The line numbers have only been added to explain a few things, don't put them | |
1121 in your plugin file! | |
1122 | |
1123 | |
1124 HEADER | |
1125 | |
1126 You will probably add new corrections to the plugin and soon have several | |
1127 versions laying around. And when distributing this file, people will want to | |
1128 know who wrote this wonderful plugin and where they can send remarks. | |
1129 Therefore, put a header at the top of your plugin: > | |
1130 | |
1131 1 " Vim global plugin for correcting typing mistakes | |
1132 2 " Last Change: 2000 Oct 15 | |
1133 3 " Maintainer: Bram Moolenaar <Bram@vim.org> | |
1134 | |
1135 About copyright and licensing: Since plugins are very useful and it's hardly | |
1136 worth restricting their distribution, please consider making your plugin | |
1137 either public domain or use the Vim |license|. A short note about this near | |
1138 the top of the plugin should be sufficient. Example: > | |
1139 | |
1140 4 " License: This file is placed in the public domain. | |
1141 | |
1142 | |
1143 LINE CONTINUATION, AVOIDING SIDE EFFECTS *use-cpo-save* | |
1144 | |
1145 In line 18 above, the line-continuation mechanism is used |line-continuation|. | |
1146 Users with 'compatible' set will run into trouble here, they will get an error | |
1147 message. We can't just reset 'compatible', because that has a lot of side | |
1148 effects. To avoid this, we will set the 'cpoptions' option to its Vim default | |
1149 value and restore it later. That will allow the use of line-continuation and | |
1150 make the script work for most people. It is done like this: > | |
1151 | |
1152 11 let s:save_cpo = &cpo | |
1153 12 set cpo&vim | |
1154 .. | |
1155 42 let &cpo = s:save_cpo | |
1156 | |
1157 We first store the old value of 'cpoptions' in the s:save_cpo variable. At | |
1158 the end of the plugin this value is restored. | |
1159 | |
1160 Notice that a script-local variable is used |s:var|. A global variable could | |
1161 already be in use for something else. Always use script-local variables for | |
1162 things that are only used in the script. | |
1163 | |
1164 | |
1165 NOT LOADING | |
1166 | |
1167 It's possible that a user doesn't always want to load this plugin. Or the | |
1168 system administrator has dropped it in the system-wide plugin directory, but a | |
1169 user has his own plugin he wants to use. Then the user must have a chance to | |
1170 disable loading this specific plugin. This will make it possible: > | |
1171 | |
1172 6 if exists("loaded_typecorr") | |
1173 7 finish | |
1174 8 endif | |
1175 9 let loaded_typecorr = 1 | |
1176 | |
1177 This also avoids that when the script is loaded twice it would cause error | |
1178 messages for redefining functions and cause trouble for autocommands that are | |
1179 added twice. | |
1180 | |
1181 | |
1182 MAPPING | |
1183 | |
1184 Now let's make the plugin more interesting: We will add a mapping that adds a | |
1185 correction for the word under the cursor. We could just pick a key sequence | |
1186 for this mapping, but the user might already use it for something else. To | |
1187 allow the user to define which keys a mapping in a plugin uses, the <Leader> | |
1188 item can be used: > | |
1189 | |
1190 22 map <unique> <Leader>a <Plug>TypecorrAdd | |
1191 | |
1192 The "<Plug>TypecorrAdd" thing will do the work, more about that further on. | |
1193 | |
1194 The user can set the "mapleader" variable to the key sequence that he wants | |
1195 this mapping to start with. Thus if the user has done: > | |
1196 | |
1197 let mapleader = "_" | |
1198 | |
1199 the mapping will define "_a". If the user didn't do this, the default value | |
1200 will be used, which is a backslash. Then a map for "\a" will be defined. | |
1201 | |
1202 Note that <unique> is used, this will cause an error message if the mapping | |
1203 already happened to exist. |:map-<unique>| | |
1204 | |
1205 But what if the user wants to define his own key sequence? We can allow that | |
1206 with this mechanism: > | |
1207 | |
1208 21 if !hasmapto('<Plug>TypecorrAdd') | |
1209 22 map <unique> <Leader>a <Plug>TypecorrAdd | |
1210 23 endif | |
1211 | |
1212 This checks if a mapping to "<Plug>TypecorrAdd" already exists, and only | |
1213 defines the mapping from "<Leader>a" if it doesn't. The user then has a | |
1214 chance of putting this in his vimrc file: > | |
1215 | |
1216 map ,c <Plug>TypecorrAdd | |
1217 | |
1218 Then the mapped key sequence will be ",c" instead of "_a" or "\a". | |
1219 | |
1220 | |
1221 PIECES | |
1222 | |
1223 If a script gets longer, you often want to break up the work in pieces. You | |
1224 can use functions or mappings for this. But you don't want these functions | |
1225 and mappings to interfere with the ones from other scripts. For example, you | |
1226 could define a function Add(), but another script could try to define the same | |
1227 function. To avoid this, we define the function local to the script by | |
1228 prepending it with "s:". | |
1229 | |
1230 We will define a function that adds a new typing correction: > | |
1231 | |
1232 30 function s:Add(from, correct) | |
1233 31 let to = input("type the correction for " . a:from . ": ") | |
1234 32 exe ":iabbrev " . a:from . " " . to | |
1235 .. | |
1236 36 endfunction | |
1237 | |
1238 Now we can call the function s:Add() from within this script. If another | |
1239 script also defines s:Add(), it will be local to that script and can only | |
1240 be called from the script it was defined in. There can also be a global Add() | |
1241 function (without the "s:"), which is again another function. | |
1242 | |
1243 <SID> can be used with mappings. It generates a script ID, which identifies | |
1244 the current script. In our typing correction plugin we use it like this: > | |
1245 | |
1246 24 noremap <unique> <script> <Plug>TypecorrAdd <SID>Add | |
1247 .. | |
1248 28 noremap <SID>Add :call <SID>Add(expand("<cword>"), 1)<CR> | |
1249 | |
1250 Thus when a user types "\a", this sequence is invoked: > | |
1251 | |
1252 \a -> <Plug>TypecorrAdd -> <SID>Add -> :call <SID>Add() | |
1253 | |
1254 If another script would also map <SID>Add, it would get another script ID and | |
1255 thus define another mapping. | |
1256 | |
1257 Note that instead of s:Add() we use <SID>Add() here. That is because the | |
1258 mapping is typed by the user, thus outside of the script. The <SID> is | |
1259 translated to the script ID, so that Vim knows in which script to look for | |
1260 the Add() function. | |
1261 | |
1262 This is a bit complicated, but it's required for the plugin to work together | |
1263 with other plugins. The basic rule is that you use <SID>Add() in mappings and | |
1264 s:Add() in other places (the script itself, autocommands, user commands). | |
1265 | |
1266 We can also add a menu entry to do the same as the mapping: > | |
1267 | |
1268 26 noremenu <script> Plugin.Add\ Correction <SID>Add | |
1269 | |
1270 The "Plugin" menu is recommended for adding menu items for plugins. In this | |
1271 case only one item is used. When adding more items, creating a submenu is | |
1272 recommended. For example, "Plugin.CVS" could be used for a plugin that offers | |
1273 CVS operations "Plugin.CVS.checkin", "Plugin.CVS.checkout", etc. | |
1274 | |
1275 Note that in line 28 ":noremap" is used to avoid that any other mappings cause | |
1276 trouble. Someone may have remapped ":call", for example. In line 24 we also | |
1277 use ":noremap", but we do want "<SID>Add" to be remapped. This is why | |
1278 "<script>" is used here. This only allows mappings which are local to the | |
1279 script. |:map-<script>| The same is done in line 26 for ":noremenu". | |
1280 |:menu-<script>| | |
1281 | |
1282 | |
1283 <SID> AND <Plug> *using-<Plug>* | |
1284 | |
1285 Both <SID> and <Plug> are used to avoid that mappings of typed keys interfere | |
1286 with mappings that are only to be used from other mappings. Note the | |
1287 difference between using <SID> and <Plug>: | |
1288 | |
1289 <Plug> is visible outside of the script. It is used for mappings which the | |
1290 user might want to map a key sequence to. <Plug> is a special code | |
1291 that a typed key will never produce. | |
1292 To make it very unlikely that other plugins use the same sequence of | |
1293 characters, use this structure: <Plug> scriptname mapname | |
1294 In our example the scriptname is "Typecorr" and the mapname is "Add". | |
1295 This results in "<Plug>TypecorrAdd". Only the first character of | |
1296 scriptname and mapname is uppercase, so that we can see where mapname | |
1297 starts. | |
1298 | |
1299 <SID> is the script ID, a unique identifier for a script. | |
1300 Internally Vim translates <SID> to "<SNR>123_", where "123" can be any | |
1301 number. Thus a function "<SID>Add()" will have a name "<SNR>11_Add()" | |
1302 in one script, and "<SNR>22_Add()" in another. You can see this if | |
1303 you use the ":function" command to get a list of functions. The | |
1304 translation of <SID> in mappings is exactly the same, that's how you | |
1305 can call a script-local function from a mapping. | |
1306 | |
1307 | |
1308 USER COMMAND | |
1309 | |
1310 Now let's add a user command to add a correction: > | |
1311 | |
1312 38 if !exists(":Correct") | |
1313 39 command -nargs=1 Correct :call s:Add(<q-args>, 0) | |
1314 40 endif | |
1315 | |
1316 The user command is defined only if no command with the same name already | |
1317 exists. Otherwise we would get an error here. Overriding the existing user | |
1318 command with ":command!" is not a good idea, this would probably make the user | |
1319 wonder why the command he defined himself doesn't work. |:command| | |
1320 | |
1321 | |
1322 SCRIPT VARIABLES | |
1323 | |
1324 When a variable starts with "s:" it is a script variable. It can only be used | |
1325 inside a script. Outside the script it's not visible. This avoids trouble | |
1326 with using the same variable name in different scripts. The variables will be | |
1327 kept as long as Vim is running. And the same variables are used when sourcing | |
1328 the same script again. |s:var| | |
1329 | |
1330 The fun is that these variables can also be used in functions, autocommands | |
1331 and user commands that are defined in the script. In our example we can add | |
1332 a few lines to count the number of corrections: > | |
1333 | |
1334 19 let s:count = 4 | |
1335 .. | |
1336 30 function s:Add(from, correct) | |
1337 .. | |
1338 34 let s:count = s:count + 1 | |
1339 35 echo s:count . " corrections now" | |
1340 36 endfunction | |
1341 | |
1342 First s:count is initialized to 4 in the script itself. When later the | |
1343 s:Add() function is called, it increments s:count. It doesn't matter from | |
1344 where the function was called, since it has been defined in the script, it | |
1345 will use the local variables from this script. | |
1346 | |
1347 | |
1348 THE RESULT | |
1349 | |
1350 Here is the resulting complete example: > | |
1351 | |
1352 1 " Vim global plugin for correcting typing mistakes | |
1353 2 " Last Change: 2000 Oct 15 | |
1354 3 " Maintainer: Bram Moolenaar <Bram@vim.org> | |
1355 4 " License: This file is placed in the public domain. | |
1356 5 | |
1357 6 if exists("loaded_typecorr") | |
1358 7 finish | |
1359 8 endif | |
1360 9 let loaded_typecorr = 1 | |
1361 10 | |
1362 11 let s:save_cpo = &cpo | |
1363 12 set cpo&vim | |
1364 13 | |
1365 14 iabbrev teh the | |
1366 15 iabbrev otehr other | |
1367 16 iabbrev wnat want | |
1368 17 iabbrev synchronisation | |
1369 18 \ synchronization | |
1370 19 let s:count = 4 | |
1371 20 | |
1372 21 if !hasmapto('<Plug>TypecorrAdd') | |
1373 22 map <unique> <Leader>a <Plug>TypecorrAdd | |
1374 23 endif | |
1375 24 noremap <unique> <script> <Plug>TypecorrAdd <SID>Add | |
1376 25 | |
1377 26 noremenu <script> Plugin.Add\ Correction <SID>Add | |
1378 27 | |
1379 28 noremap <SID>Add :call <SID>Add(expand("<cword>"), 1)<CR> | |
1380 29 | |
1381 30 function s:Add(from, correct) | |
1382 31 let to = input("type the correction for " . a:from . ": ") | |
1383 32 exe ":iabbrev " . a:from . " " . to | |
1384 33 if a:correct | exe "normal viws\<C-R>\" \b\e" | endif | |
1385 34 let s:count = s:count + 1 | |
1386 35 echo s:count . " corrections now" | |
1387 36 endfunction | |
1388 37 | |
1389 38 if !exists(":Correct") | |
1390 39 command -nargs=1 Correct :call s:Add(<q-args>, 0) | |
1391 40 endif | |
1392 41 | |
1393 42 let &cpo = s:save_cpo | |
1394 | |
1395 Line 33 wasn't explained yet. It applies the new correction to the word under | |
1396 the cursor. The |:normal| command is used to use the new abbreviation. Note | |
1397 that mappings and abbreviations are expanded here, even though the function | |
1398 was called from a mapping defined with ":noremap". | |
1399 | |
1400 Using "unix" for the 'fileformat' option is recommended. The Vim scripts will | |
1401 then work everywhere. Scripts with 'fileformat' set to "dos" do not work on | |
1402 Unix. Also see |:source_crnl|. To be sure it is set right, do this before | |
1403 writing the file: > | |
1404 | |
1405 :set fileformat=unix | |
1406 | |
1407 | |
1408 DOCUMENTATION *write-local-help* | |
1409 | |
1410 It's a good idea to also write some documentation for your plugin. Especially | |
1411 when its behavior can be changed by the user. See |add-local-help| for how | |
1412 they are installed. | |
1413 | |
1414 Here is a simple example for a plugin help file, called "typecorr.txt": > | |
1415 | |
1416 1 *typecorr.txt* Plugin for correcting typing mistakes | |
1417 2 | |
1418 3 If you make typing mistakes, this plugin will have them corrected | |
1419 4 automatically. | |
1420 5 | |
1421 6 There are currently only a few corrections. Add your own if you like. | |
1422 7 | |
1423 8 Mappings: | |
1424 9 <Leader>a or <Plug>TypecorrAdd | |
1425 10 Add a correction for the word under the cursor. | |
1426 11 | |
1427 12 Commands: | |
1428 13 :Correct {word} | |
1429 14 Add a correction for {word}. | |
1430 15 | |
1431 16 *typecorr-settings* | |
1432 17 This plugin doesn't have any settings. | |
1433 | |
1434 The first line is actually the only one for which the format matters. It will | |
1435 be extracted from the help file to be put in the "LOCAL ADDITIONS:" section of | |
1436 help.txt |local-additions|. The first "*" must be in the first column of the | |
1437 first line. After adding your help file do ":help" and check that the entries | |
1438 line up nicely. | |
1439 | |
1440 You can add more tags inside ** in your help file. But be careful not to use | |
1441 existing help tags. You would probably use the name of your plugin in most of | |
1442 them, like "typecorr-settings" in the example. | |
1443 | |
1444 Using references to other parts of the help in || is recommended. This makes | |
1445 it easy for the user to find associated help. | |
1446 | |
1447 | |
1448 FILETYPE DETECTION *plugin-filetype* | |
1449 | |
1450 If your filetype is not already detected by Vim, you should create a filetype | |
1451 detection snippet in a separate file. It is usually in the form of an | |
1452 autocommand that sets the filetype when the file name matches a pattern. | |
1453 Example: > | |
1454 | |
1455 au BufNewFile,BufRead *.foo set filetype=foofoo | |
1456 | |
1457 Write this single-line file as "ftdetect/foofoo.vim" in the first directory | |
1458 that appears in 'runtimepath'. For Unix that would be | |
1459 "~/.vim/ftdetect/foofoo.vim". The convention is to use the name of the | |
1460 filetype for the script name. | |
1461 | |
1462 You can make more complicated checks if you like, for example to inspect the | |
1463 contents of the file to recognize the language. Also see |new-filetype|. | |
1464 | |
1465 | |
1466 SUMMARY *plugin-special* | |
1467 | |
1468 Summary of special things to use in a plugin: | |
1469 | |
1470 s:name Variables local to the script. | |
1471 | |
1472 <SID> Script-ID, used for mappings and functions local to | |
1473 the script. | |
1474 | |
1475 hasmapto() Function to test if the user already defined a mapping | |
1476 for functionality the script offers. | |
1477 | |
1478 <Leader> Value of "mapleader", which the user defines as the | |
1479 keys that plugin mappings start with. | |
1480 | |
1481 :map <unique> Give a warning if a mapping already exists. | |
1482 | |
1483 :noremap <script> Use only mappings local to the script, not global | |
1484 mappings. | |
1485 | |
1486 exists(":Cmd") Check if a user command already exists. | |
1487 | |
1488 ============================================================================== | |
1489 *41.11* Writing a filetype plugin *write-filetype-plugin* *ftplugin* | |
1490 | |
1491 A filetype plugin is like a global plugin, except that it sets options and | |
1492 defines mappings for the current buffer only. See |add-filetype-plugin| for | |
1493 how this type of plugin is used. | |
1494 | |
1495 First read the section on global plugins above |41.10|. All that is said there | |
1496 also applies to filetype plugins. There are a few extras, which are explained | |
1497 here. The essential thing is that a filetype plugin should only have an | |
1498 effect on the current buffer. | |
1499 | |
1500 | |
1501 DISABLING | |
1502 | |
1503 If you are writing a filetype plugin to be used by many people, they need a | |
1504 chance to disable loading it. Put this at the top of the plugin: > | |
1505 | |
1506 " Only do this when not done yet for this buffer | |
1507 if exists("b:did_ftplugin") | |
1508 finish | |
1509 endif | |
1510 let b:did_ftplugin = 1 | |
1511 | |
1512 This also needs to be used to avoid that the same plugin is executed twice for | |
1513 the same buffer (happens when using an ":edit" command without arguments). | |
1514 | |
1515 Now users can disable loading the default plugin completely by making a | |
1516 filetype plugin with only this line: > | |
1517 | |
1518 let b:did_ftplugin = 1 | |
1519 | |
1520 This does require that the filetype plugin directory comes before $VIMRUNTIME | |
1521 in 'runtimepath'! | |
1522 | |
1523 If you do want to use the default plugin, but overrule one of the settings, | |
1524 you can write the different setting in a script: > | |
1525 | |
1526 setlocal textwidth=70 | |
1527 | |
1528 Now write this in the "after" directory, so that it gets sourced after the | |
1529 distributed "vim.vim" ftplugin |after-directory|. For Unix this would be | |
1530 "~/.vim/after/ftplugin/vim.vim". Note that the default plugin will have set | |
1531 "b:did_ftplugin", but it is ignored here. | |
1532 | |
1533 | |
1534 OPTIONS | |
1535 | |
1536 To make sure the filetype plugin only affects the current buffer use the > | |
1537 | |
1538 :setlocal | |
1539 | |
1540 command to set options. And only set options which are local to a buffer (see | |
1541 the help for the option to check that). When using |:setlocal| for global | |
1542 options or options local to a window, the value will change for many buffers, | |
1543 and that is not what a filetype plugin should do. | |
1544 | |
1545 When an option has a value that is a list of flags or items, consider using | |
1546 "+=" and "-=" to keep the existing value. Be aware that the user may have | |
1547 changed an option value already. First resetting to the default value and | |
1548 then changing it often a good idea. Example: > | |
1549 | |
1550 :setlocal formatoptions& formatoptions+=ro | |
1551 | |
1552 | |
1553 MAPPINGS | |
1554 | |
1555 To make sure mappings will only work in the current buffer use the > | |
1556 | |
1557 :map <buffer> | |
1558 | |
1559 command. This needs to be combined with the two-step mapping explained above. | |
1560 An example of how to define functionality in a filetype plugin: > | |
1561 | |
1562 if !hasmapto('<Plug>JavaImport') | |
1563 map <buffer> <unique> <LocalLeader>i <Plug>JavaImport | |
1564 endif | |
1565 noremap <buffer> <unique> <Plug>JavaImport oimport ""<Left><Esc> | |
1566 | |
1567 |hasmapto()| is used to check if the user has already defined a map to | |
1568 <Plug>JavaImport. If not, then the filetype plugin defines the default | |
1569 mapping. This starts with |<LocalLeader>|, which allows the user to select | |
1570 the key(s) he wants filetype plugin mappings to start with. The default is a | |
1571 backslash. | |
1572 "<unique>" is used to give an error message if the mapping already exists or | |
1573 overlaps with an existing mapping. | |
1574 |:noremap| is used to avoid that any other mappings that the user has defined | |
1575 interferes. You might want to use ":noremap <script>" to allow remapping | |
1576 mappings defined in this script that start with <SID>. | |
1577 | |
1578 The user must have a chance to disable the mappings in a filetype plugin, | |
1579 without disabling everything. Here is an example of how this is done for a | |
1580 plugin for the mail filetype: > | |
1581 | |
1582 " Add mappings, unless the user didn't want this. | |
1583 if !exists("no_plugin_maps") && !exists("no_mail_maps") | |
1584 " Quote text by inserting "> " | |
1585 if !hasmapto('<Plug>MailQuote') | |
1586 vmap <buffer> <LocalLeader>q <Plug>MailQuote | |
1587 nmap <buffer> <LocalLeader>q <Plug>MailQuote | |
1588 endif | |
1589 vnoremap <buffer> <Plug>MailQuote :s/^/> /<CR> | |
1590 nnoremap <buffer> <Plug>MailQuote :.,$s/^/> /<CR> | |
1591 endif | |
1592 | |
1593 Two global variables are used: | |
1594 no_plugin_maps disables mappings for all filetype plugins | |
1595 no_mail_maps disables mappings for a specific filetype | |
1596 | |
1597 | |
1598 USER COMMANDS | |
1599 | |
1600 To add a user command for a specific file type, so that it can only be used in | |
1601 one buffer, use the "-buffer" argument to |:command|. Example: > | |
1602 | |
1603 :command -buffer Make make %:r.s | |
1604 | |
1605 | |
1606 VARIABLES | |
1607 | |
1608 A filetype plugin will be sourced for each buffer of the type it's for. Local | |
1609 script variables |s:var| will be shared between all invocations. Use local | |
1610 buffer variables |b:var| if you want a variable specifically for one buffer. | |
1611 | |
1612 | |
1613 FUNCTIONS | |
1614 | |
1615 When defining a function, this only needs to be done once. But the filetype | |
1616 plugin will be sourced every time a file with this filetype will be opened. | |
1617 This construct make sure the function is only defined once: > | |
1618 | |
1619 :if !exists("*s:Func") | |
1620 : function s:Func(arg) | |
1621 : ... | |
1622 : endfunction | |
1623 :endif | |
1624 < | |
1625 | |
1626 UNDO *undo_ftplugin* | |
1627 | |
1628 When the user does ":setfiletype xyz" the effect of the previous filetype | |
1629 should be undone. Set the b:undo_ftplugin variable to the commands that will | |
1630 undo the settings in your filetype plugin. Example: > | |
1631 | |
1632 let b:undo_ftplugin = "setlocal fo< com< tw< commentstring<" | |
1633 \ . "| unlet b:match_ignorecase b:match_words b:match_skip" | |
1634 | |
1635 Using ":setlocal" with "<" after the option name resets the option to its | |
1636 global value. That is mostly the best way to reset the option value. | |
1637 | |
1638 This does require removing the "C" flag from 'cpoptions' to allow line | |
1639 continuation, as mentioned above |use-cpo-save|. | |
1640 | |
1641 | |
1642 FILE NAME | |
1643 | |
1644 The filetype must be included in the file name |ftplugin-name|. Use one of | |
1645 these three forms: | |
1646 | |
1647 .../ftplugin/stuff.vim | |
1648 .../ftplugin/stuff_foo.vim | |
1649 .../ftplugin/stuff/bar.vim | |
1650 | |
1651 "stuff" is the filetype, "foo" and "bar" are arbitrary names. | |
1652 | |
1653 | |
1654 SUMMARY *ftplugin-special* | |
1655 | |
1656 Summary of special things to use in a filetype plugin: | |
1657 | |
1658 <LocalLeader> Value of "maplocalleader", which the user defines as | |
1659 the keys that filetype plugin mappings start with. | |
1660 | |
1661 :map <buffer> Define a mapping local to the buffer. | |
1662 | |
1663 :noremap <script> Only remap mappings defined in this script that start | |
1664 with <SID>. | |
1665 | |
1666 :setlocal Set an option for the current buffer only. | |
1667 | |
1668 :command -buffer Define a user command local to the buffer. | |
1669 | |
1670 exists("*s:Func") Check if a function was already defined. | |
1671 | |
1672 Also see |plugin-special|, the special things used for all plugins. | |
1673 | |
1674 ============================================================================== | |
1675 *41.12* Writing a compiler plugin *write-compiler-plugin* | |
1676 | |
1677 A compiler plugin sets options for use with a specific compiler. The user can | |
1678 load it with the |:compiler| command. The main use is to set the | |
1679 'errorformat' and 'makeprg' options. | |
1680 | |
1681 Easiest is to have a look at examples. This command will edit all the default | |
1682 compiler plugins: > | |
1683 | |
1684 :next $VIMRUNTIME/compiler/*.vim | |
1685 | |
1686 Use |:next| to go to the next plugin file. | |
1687 | |
1688 There are two special items about these files. First is a mechanism to allow | |
1689 a user to overrule or add to the default file. The default files start with: > | |
1690 | |
1691 :if exists("current_compiler") | |
1692 : finish | |
1693 :endif | |
1694 :let current_compiler = "mine" | |
1695 | |
1696 When you write a compiler file and put it in your personal runtime directory | |
1697 (e.g., ~/.vim/compiler for Unix), you set the "current_compiler" variable to | |
1698 make the default file skip the settings. | |
1699 | |
1700 The second mechanism is to use ":set" for ":compiler!" and ":setlocal" for | |
1701 ":compiler". Vim defines the ":CompilerSet" user command for this. However, | |
1702 older Vim versions don't, thus your plugin should define it then. This is an | |
1703 example: > | |
1704 | |
1705 if exists(":CompilerSet") != 2 | |
1706 command -nargs=* CompilerSet setlocal <args> | |
1707 endif | |
1708 CompilerSet errorformat& " use the default 'errorformat' | |
1709 CompilerSet makeprg=nmake | |
1710 | |
1711 When you write a compiler plugin for the Vim distribution or for a system-wide | |
1712 runtime directory, use the mechanism mentioned above. When | |
1713 "current_compiler" was already set by a user plugin nothing will be done. | |
1714 | |
1715 When you write a compiler plugin to overrule settings from a default plugin, | |
1716 don't check "current_compiler". This plugin is supposed to be loaded | |
1717 last, thus it should be in a directory at the end of 'runtimepath'. For Unix | |
1718 that could be ~/.vim/after/compiler. | |
1719 | |
1720 ============================================================================== | |
1721 | |
1722 Next chapter: |usr_42.txt| Add new menus | |
1723 | |
1724 Copyright: see |manual-copyright| vim:tw=78:ts=8:ft=help:norl: |