1 *usr_41.txt* For Vim version 7.1b. Last change: 2007 Apr 26
3 VIM USER MANUAL - by Bram Moolenaar
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.
16 |41.5| Executing an expression
17 |41.6| Using functions
18 |41.7| Defining a function
19 |41.8| Lists and Dictionaries
21 |41.10| Various remarks
22 |41.11| Writing a plugin
23 |41.12| Writing a filetype plugin
24 |41.13| Writing a compiler plugin
25 |41.14| Writing a plugin that loads quickly
26 |41.15| Writing library scripts
27 |41.16| Distributing Vim scripts
29 Next chapter: |usr_42.txt| Add new menus
30 Previous chapter: |usr_40.txt| Make new commands
31 Table of contents: |usr_toc.txt|
33 ==============================================================================
34 *41.1* Introduction *vim-script-intro* *script*
36 Your first experience with Vim scripts is the vimrc file. Vim reads it when
37 it starts up and executes the commands. You can set options to values you
38 prefer. And you can use any colon command in it (commands that start with a
39 ":"; these are sometimes referred to as Ex commands or command-line commands).
40 Syntax files are also Vim scripts. As are files that set options for a
41 specific file type. A complicated macro can be defined by a separate Vim
42 script file. You can think of other uses yourself.
44 Let's start with a simple example: >
53 The ":" characters are not really needed here. You only need to use
54 them when you type a command. In a Vim script file they can be left
55 out. We will use them here anyway to make clear these are colon
56 commands and make them stand out from Normal mode commands.
58 You can try out the examples by yanking the lines from the text here
59 and executing them with :@"
61 The output of the example code is:
68 In the first line the ":let" command assigns a value to a variable. The
71 :let {variable} = {expression}
73 In this case the variable name is "i" and the expression is a simple value,
75 The ":while" command starts a loop. The generic form is: >
81 The statements until the matching ":endwhile" are executed for as long as the
82 condition is true. The condition used here is the expression "i < 5". This
83 is true when the variable i is smaller than five.
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).
88 The ":echo" command prints its arguments. In this case the string "count is"
89 and the value of the variable i. Since i is one, this will print:
93 Then there is the ":let i += 1" command. This does the same thing as
94 ":let i = i + 1". This adds one to the variable i and assigns the new value
97 The example was given to explain the commands, but would you really want to
98 make such a loop it can be written much more compact: >
100 :for i in range(1, 4)
104 We won't explain how |:for| and |range()| work until later. Follow the links
105 if you are impatient.
108 THREE KINDS OF NUMBERS
110 Numbers can be decimal, hexadecimal or octal. A hexadecimal number starts
111 with "0x" or "0X". For example "0x1f" is decimal 31. An octal number starts
112 with a zero. "017" is decimal 15. Careful: don't put a zero before a decimal
113 number, it will be interpreted as an octal number!
114 The ":echo" command always prints decimal numbers. Example: >
119 A number is made negative with a minus sign. This also works for hexadecimal
120 and octal numbers. A minus sign is also used for subtraction. Compare this
121 with the previous example: >
126 White space in an expression is ignored. However, it's recommended to use it
127 for separating items, to make the expression easier to read. For example, to
128 avoid the confusion with a negative number above, put a space between the
129 minus sign and the following number: >
133 ==============================================================================
136 A variable name consists of ASCII letters, digits and the underscore. It
137 cannot start with a digit. Valid variable names are:
141 very_long_variable_name_with_underscores
145 Invalid names are "foo+bar" and "6var".
146 These variables are global. To see a list of currently defined variables
151 You can use global variables everywhere. This also means that when the
152 variable "count" is used in one script file, it might also be used in another
153 file. This leads to confusion at least, and real problems at worst. To avoid
154 this, you can use a variable local to a script file by prepending "s:". For
155 example, one script contains this code: >
163 Since "s:count" is local to this script, you can be sure that sourcing the
164 "other.vim" script will not change this variable. If "other.vim" also uses an
165 "s:count" variable, it will be a different copy, local to that script. More
166 about script-local variables here: |script-variable|.
168 There are more kinds of variables, see |internal-variables|. The most often
171 b:name variable local to a buffer
172 w:name variable local to a window
173 g:name global variable (also in a function)
174 v:name variable predefined by Vim
179 Variables take up memory and show up in the output of the ":let" command. To
180 delete a variable use the ":unlet" command. Example: >
184 This deletes the script-local variable "s:count" to free up the memory it
185 uses. If you are not sure if the variable exists, and don't want an error
186 message when it doesn't, append !: >
190 When a script finishes, the local variables used there will not be
191 automatically freed. The next time the script executes, it can still use the
192 old value. Example: >
194 :if !exists("s:call_count")
195 : let s:call_count = 0
197 :let s:call_count = s:call_count + 1
198 :echo "called" s:call_count "times"
200 The "exists()" function checks if a variable has already been defined. Its
201 argument is the name of the variable you want to check. Not the variable
202 itself! If you would do this: >
204 :if !exists(s:call_count)
206 Then the value of s:call_count will be used as the name of the variable that
207 exists() checks. That's not what you want.
208 The exclamation mark ! negates a value. When the value was true, it
209 becomes false. When it was false, it becomes true. You can read it as "not".
210 Thus "if !exists()" can be read as "if not exists()".
211 What Vim calls true is anything that is not zero. Zero is false.
213 Vim automatically converts a string to a number when it is looking for
214 a number. When using a string that doesn't start with a digit the
215 resulting number is zero. Thus look out for this: >
217 < The "true" will be interpreted as a zero, thus as false!
220 STRING VARIABLES AND CONSTANTS
222 So far only numbers were used for the variable value. Strings can be used as
223 well. Numbers and strings are the basic types of variables that Vim supports.
224 The type is dynamic, it is set each time when assigning a value to the
225 variable with ":let". More about types in |41.8|.
226 To assign a string value to a variable, you need to use a string constant.
227 There are two types of these. First the string in double quotes: >
233 If you want to include a double quote inside the string, put a backslash in
236 :let name = "\"peter\""
240 To avoid the need for a backslash, you can use a string in single quotes: >
242 :let name = '"peter"'
246 Inside a single-quote string all the characters are as they are. Only the
247 single quote itself is special: you need to use two to get one. A backslash
248 is taken literally, thus you can't use it to change the meaning of the
250 In double-quote strings it is possible to use special characters. Here are
263 The last two are just examples. The "\<name>" form can be used to include
264 the special key "name".
265 See |expr-quote| for the full list of special items in a string.
267 ==============================================================================
270 Vim has a rich, yet simple way to handle expressions. You can read the
271 definition here: |expression-syntax|. Here we will show the most common
273 The numbers, strings and variables mentioned above are expressions by
274 themselves. Thus everywhere an expression is expected, you can use a number,
275 string or variable. Other basic items in an expression are:
277 $NAME environment variable
283 :echo "The value of 'tabstop' is" &ts
284 :echo "Your home directory is" $HOME
287 The &name form can be used to save an option value, set it to a new value,
288 do something and restore the old value. Example: >
295 This makes sure the "The Start" pattern is used with the 'ignorecase' option
296 off. Still, it keeps the value that the user had set. (Another way to do
297 this would be to add "\C" to the pattern, see |/\C|.)
302 It becomes more interesting if we combine these basic items. Let's start with
303 mathematics on numbers:
311 The usual precedence is used. Example: >
316 Grouping is done with braces. No surprises here. Example: >
321 Strings can be concatenated with ".". Example: >
326 When the ":echo" command gets multiple arguments, it separates them with a
327 space. In the example the argument is a single expression, thus no space is
330 Borrowed from the C language is the conditional expression:
334 If "a" evaluates to true "b" is used, otherwise "c" is used. Example: >
337 :echo i > 5 ? "i is big" : "i is small"
340 The three parts of the constructs are always evaluated first, thus you could
345 ==============================================================================
348 The ":if" commands executes the following statements, until the matching
349 ":endif", only when a condition is met. The generic form is:
355 Only when the expression {condition} evaluates to true (non-zero) will the
356 {statements} be executed. These must still be valid commands. If they
357 contain garbage, Vim won't be able to find the ":endif".
358 You can also use ":else". The generic form for this is:
366 The second {statements} is only executed if the first one isn't.
367 Finally, there is ":elseif":
375 This works just like using ":else" and then "if", but without the need for an
377 A useful example for your vimrc file is checking the 'term' option and
378 doing something depending upon its value: >
381 : " Do stuff for xterm
382 :elseif &term == "vt100"
383 : " Do stuff for a vt100 terminal
385 : " Do something for other terminals
391 We already used some of them in the examples. These are the most often used
397 a >= b greater than or equal to
399 a <= b less than or equal to
401 The result is one if the condition is met and zero otherwise. An example: >
404 : echo "congratulations"
406 : echo "you are using an old version, upgrade!"
409 Here "v:version" is a variable defined by Vim, which has the value of the Vim
410 version. 600 is for version 6.0. Version 6.1 has the value 601. This is
411 very useful to write a script that works with multiple versions of Vim.
414 The logic operators work both for numbers and strings. When comparing two
415 strings, the mathematical difference is used. This compares byte values,
416 which may not be right for some languages.
417 When comparing a string with a number, the string is first converted to a
418 number. This is a bit tricky, because when a string doesn't look like a
419 number, the number zero is used. Example: >
425 This will echo "yes", because "one" doesn't look like a number, thus it is
426 converted to the number zero.
428 For strings there are two more items:
431 a !~ b does not match with
433 The left item "a" is used as a string. The right item "b" is used as a
434 pattern, like what's used for searching. Example: >
437 : echo "str contains a space"
440 : echo "str does not end in a full stop"
443 Notice the use of a single-quote string for the pattern. This is useful,
444 because backslashes would need to be doubled in a double-quote string and
445 patterns tend to contain many backslashes.
447 The 'ignorecase' option is used when comparing strings. When you don't want
448 that, append "#" to match case and "?" to ignore case. Thus "==?" compares
449 two strings to be equal while ignoring case. And "!~#" checks if a pattern
450 doesn't match, also checking the case of letters. For the full table see
456 The ":while" command was already mentioned. Two more statements can be used
457 in between the ":while" and the ":endwhile":
459 :continue Jump back to the start of the while loop; the
461 :break Jump forward to the ":endwhile"; the loop is
467 : call do_something()
477 The ":sleep" command makes Vim take a nap. The "50m" specifies fifty
478 milliseconds. Another example is ":sleep 4", which sleeps for four seconds.
480 Even more looping can be done with the ":for" command, see below in |41.8|.
482 ==============================================================================
483 *41.5* Executing an expression
485 So far the commands in the script were executed by Vim directly. The
486 ":execute" command allows executing the result of an expression. This is a
487 very powerful way to build commands and execute them.
488 An example is to jump to a tag, which is contained in a variable: >
490 :execute "tag " . tag_name
492 The "." is used to concatenate the string "tag " with the value of variable
493 "tag_name". Suppose "tag_name" has the value "get_cmd", then the command that
494 will be executed is: >
498 The ":execute" command can only execute colon commands. The ":normal" command
499 executes Normal mode commands. However, its argument is not an expression but
500 the literal command characters. Example: >
504 This jumps to the first line and formats all lines with the "=" operator.
505 To make ":normal" work with an expression, combine ":execute" with it.
508 :execute "normal " . normal_commands
510 The variable "normal_commands" must contain the Normal mode commands.
511 Make sure that the argument for ":normal" is a complete command. Otherwise
512 Vim will run into the end of the argument and abort the command. For example,
513 if you start Insert mode, you must leave Insert mode as well. This works: >
515 :execute "normal Inew text \<Esc>"
517 This inserts "new text " in the current line. Notice the use of the special
518 key "\<Esc>". This avoids having to enter a real <Esc> character in your
521 If you don't want to execute a string but evaluate it to get its expression
522 value, you can use the eval() function: >
524 :let optname = "path"
525 :let optval = eval('&' . optname)
527 A "&" character is prepended to "path", thus the argument to eval() is
528 "&path". The result will then be the value of the 'path' option.
529 The same thing can be done with: >
530 :exe 'let optval = &' . optname
532 ==============================================================================
533 *41.6* Using functions
535 Vim defines many functions and provides a large amount of functionality that
536 way. A few examples will be given in this section. You can find the whole
537 list here: |functions|.
539 A function is called with the ":call" command. The parameters are passed in
540 between braces, separated by commas. Example: >
542 :call search("Date: ", "W")
544 This calls the search() function, with arguments "Date: " and "W". The
545 search() function uses its first argument as a search pattern and the second
546 one as flags. The "W" flag means the search doesn't wrap around the end of
549 A function can be called in an expression. Example: >
551 :let line = getline(".")
552 :let repl = substitute(line, '\a', "*", "g")
553 :call setline(".", repl)
555 The getline() function obtains a line from the current buffer. Its argument
556 is a specification of the line number. In this case "." is used, which means
557 the line where the cursor is.
558 The substitute() function does something similar to the ":substitute"
559 command. The first argument is the string on which to perform the
560 substitution. The second argument is the pattern, the third the replacement
561 string. Finally, the last arguments are the flags.
562 The setline() function sets the line, specified by the first argument, to a
563 new string, the second argument. In this example the line under the cursor is
564 replaced with the result of the substitute(). Thus the effect of the three
565 statements is equal to: >
569 Using the functions becomes more interesting when you do more work before and
570 after the substitute() call.
573 FUNCTIONS *function-list*
575 There are many functions. We will mention them here, grouped by what they are
576 used for. You can find an alphabetical list here: |functions|. Use CTRL-] on
577 the function name to jump to detailed help on it.
580 nr2char() get a character by its ASCII value
581 char2nr() get ASCII value of a character
582 str2nr() convert a string to a number
583 printf() format a string according to % items
584 escape() escape characters in a string with a '\'
585 tr() translate characters from one set to another
586 strtrans() translate a string to make it printable
587 tolower() turn a string to lowercase
588 toupper() turn a string to uppercase
589 match() position where a pattern matches in a string
590 matchend() position where a pattern match ends in a string
591 matchstr() match of a pattern in a string
592 matchlist() like matchstr() and also return submatches
593 stridx() first index of a short string in a long string
594 strridx() last index of a short string in a long string
595 strlen() length of a string
596 substitute() substitute a pattern match with a string
597 submatch() get a specific match in a ":substitute"
598 strpart() get part of a string
599 expand() expand special keywords
600 iconv() convert text from one encoding to another
601 byteidx() byte index of a character in a string
602 repeat() repeat a string multiple times
603 eval() evaluate a string expression
606 get() get an item without error for wrong index
607 len() number of items in a List
608 empty() check if List is empty
609 insert() insert an item somewhere in a List
610 add() append an item to a List
611 extend() append a List to a List
612 remove() remove one or more items from a List
613 copy() make a shallow copy of a List
614 deepcopy() make a full copy of a List
615 filter() remove selected items from a List
616 map() change each List item
618 reverse() reverse the order of a List
619 split() split a String into a List
620 join() join List items into a String
621 range() return a List with a sequence of numbers
622 string() String representation of a List
623 call() call a function with List as arguments
624 index() index of a value in a List
625 max() maximum value in a List
626 min() minimum value in a List
627 count() count number of times a value appears in a List
628 repeat() repeat a List multiple times
630 Dictionary manipulation:
631 get() get an entry without an error for a wrong key
632 len() number of entries in a Dictionary
633 has_key() check whether a key appears in a Dictionary
634 empty() check if Dictionary is empty
635 remove() remove an entry from a Dictionary
636 extend() add entries from one Dictionary to another
637 filter() remove selected entries from a Dictionary
638 map() change each Dictionary entry
639 keys() get List of Dictionary keys
640 values() get List of Dictionary values
641 items() get List of Dictionary key-value pairs
642 copy() make a shallow copy of a Dictionary
643 deepcopy() make a full copy of a Dictionary
644 string() String representation of a Dictionary
645 max() maximum value in a Dictionary
646 min() minimum value in a Dictionary
647 count() count number of times a value appears
650 type() type of a variable
651 islocked() check if a variable is locked
652 function() get a Funcref for a function name
653 getbufvar() get a variable value from a specific buffer
654 setbufvar() set a variable in a specific buffer
655 getwinvar() get a variable from specific window
656 gettabwinvar() get a variable from specific window & tab page
657 setwinvar() set a variable in a specific window
658 settabwinvar() set a variable in a specific window & tab page
659 garbagecollect() possibly free memory
661 Cursor and mark position:
662 col() column number of the cursor or a mark
663 virtcol() screen column of the cursor or a mark
664 line() line number of the cursor or mark
665 wincol() window column number of the cursor
666 winline() window line number of the cursor
667 cursor() position the cursor at a line/column
668 getpos() get position of cursor, mark, etc.
669 setpos() set position of cursor, mark, etc.
670 byte2line() get line number at a specific byte count
671 line2byte() byte count at a specific line
672 diff_filler() get the number of filler lines above a line
674 Working with text in the current buffer:
675 getline() get a line or list of lines from the buffer
676 setline() replace a line in the buffer
677 append() append line or list of lines in the buffer
678 indent() indent of a specific line
679 cindent() indent according to C indenting
680 lispindent() indent according to Lisp indenting
681 nextnonblank() find next non-blank line
682 prevnonblank() find previous non-blank line
683 search() find a match for a pattern
684 searchpos() find a match for a pattern
685 searchpair() find the other end of a start/skip/end
686 searchpairpos() find the other end of a start/skip/end
687 searchdecl() search for the declaration of a name
689 System functions and manipulation of files:
690 glob() expand wildcards
691 globpath() expand wildcards in a number of directories
692 findfile() find a file in a list of directories
693 finddir() find a directory in a list of directories
694 resolve() find out where a shortcut points to
695 fnamemodify() modify a file name
696 pathshorten() shorten directory names in a path
697 simplify() simplify a path without changing its meaning
698 executable() check if an executable program exists
699 filereadable() check if a file can be read
700 filewritable() check if a file can be written to
701 getfperm() get the permissions of a file
702 getftype() get the kind of a file
703 isdirectory() check if a directory exists
704 getfsize() get the size of a file
705 getcwd() get the current working directory
706 haslocaldir() check if current window used |:lcd|
707 tempname() get the name of a temporary file
708 mkdir() create a new directory
709 delete() delete a file
710 rename() rename a file
711 system() get the result of a shell command
712 hostname() name of the system
713 readfile() read a file into a List of lines
714 writefile() write a List of lines into a file
717 getftime() get last modification time of a file
718 localtime() get current time in seconds
719 strftime() convert time to a string
720 reltime() get the current or elapsed time accurately
721 reltimestr() convert reltime() result to a string
723 Buffers, windows and the argument list:
724 argc() number of entries in the argument list
725 argidx() current position in the argument list
726 argv() get one entry from the argument list
727 bufexists() check if a buffer exists
728 buflisted() check if a buffer exists and is listed
729 bufloaded() check if a buffer exists and is loaded
730 bufname() get the name of a specific buffer
731 bufnr() get the buffer number of a specific buffer
732 tabpagebuflist() return List of buffers in a tab page
733 tabpagenr() get the number of a tab page
734 tabpagewinnr() like winnr() for a specified tab page
735 winnr() get the window number for the current window
736 bufwinnr() get the window number of a specific buffer
737 winbufnr() get the buffer number of a specific window
738 getbufline() get a list of lines from the specified buffer
741 getcmdline() get the current command line
742 getcmdpos() get position of the cursor in the command line
743 setcmdpos() set position of the cursor in the command line
744 getcmdtype() return the current command-line type
746 Quickfix and location lists:
747 getqflist() list of quickfix errors
748 setqflist() modify a quickfix list
749 getloclist() list of location list items
750 setloclist() modify a location list
752 Insert mode completion:
753 complete() set found matches
754 complete_add() add to found matches
755 complete_check() check if completion should be aborted
756 pumvisible() check if the popup menu is displayed
759 foldclosed() check for a closed fold at a specific line
760 foldclosedend() like foldclosed() but return the last line
761 foldlevel() check for the fold level at a specific line
762 foldtext() generate the line displayed for a closed fold
763 foldtextresult() get the text displayed for a closed fold
765 Syntax and highlighting:
766 hlexists() check if a highlight group exists
767 hlID() get ID of a highlight group
768 synID() get syntax ID at a specific position
769 synIDattr() get a specific attribute of a syntax ID
770 synIDtrans() get translated syntax ID
771 diff_hlID() get highlight ID for diff mode at a position
772 matcharg() get info about |:match| arguments
775 spellbadword() locate badly spelled word at or after cursor
776 spellsuggest() return suggested spelling corrections
777 soundfold() return the sound-a-like equivalent of a word
780 histadd() add an item to a history
781 histdel() delete an item from a history
782 histget() get an item from a history
783 histnr() get highest index of a history list
786 browse() put up a file requester
787 browsedir() put up a directory requester
788 confirm() let the user make a choice
789 getchar() get a character from the user
790 getcharmod() get modifiers for the last typed character
791 input() get a line from the user
792 inputlist() let the user pick an entry from a list
793 inputsecret() get a line from the user without showing it
794 inputdialog() get a line from the user in a dialog
795 inputsave() save and clear typeahead
796 inputrestore() restore typeahead
799 getfontname() get name of current font being used
800 getwinposx() X position of the GUI Vim window
801 getwinposy() Y position of the GUI Vim window
804 serverlist() return the list of server names
805 remote_send() send command characters to a Vim server
806 remote_expr() evaluate an expression in a Vim server
807 server2client() send a reply to a client of a Vim server
808 remote_peek() check if there is a reply from a Vim server
809 remote_read() read a reply from a Vim server
810 foreground() move the Vim window to the foreground
811 remote_foreground() move the Vim server window to the foreground
813 Window size and position:
814 winheight() get height of a specific window
815 winwidth() get width of a specific window
816 winrestcmd() return command to restore window sizes
817 winsaveview() get view of current window
818 winrestview() restore saved view of current window
821 mode() get current editing mode
822 visualmode() last visual mode used
823 hasmapto() check if a mapping exists
824 mapcheck() check if a matching mapping exists
825 maparg() get rhs of a mapping
826 exists() check if a variable, function, etc. exists
827 has() check if a feature is supported in Vim
828 changenr() return number of most recent change
829 cscope_connection() check if a cscope connection exists
830 did_filetype() check if a FileType autocommand was used
831 eventhandler() check if invoked by an event handler
833 libcall() call a function in an external library
834 libcallnr() idem, returning a number
836 getreg() get contents of a register
837 getregtype() get type of a register
838 setreg() set contents and type of a register
840 taglist() get list of matching tags
841 tagfiles() get a list of tags files
843 ==============================================================================
844 *41.7* Defining a function
846 Vim enables you to define your own functions. The basic function declaration
849 :function {name}({var1}, {var2}, ...)
854 Function names must begin with a capital letter.
856 Let's define a short function to return the smaller of two numbers. It starts
859 :function Min(num1, num2)
861 This tells Vim that the function is named "Min" and it takes two arguments:
863 The first thing you need to do is to check to see which number is smaller:
867 The special prefix "a:" tells Vim that the variable is a function argument.
868 Let's assign the variable "smaller" the value of the smallest number: >
871 : let smaller = a:num1
873 : let smaller = a:num2
876 The variable "smaller" is a local variable. Variables used inside a function
877 are local unless prefixed by something like "g:", "a:", or "s:".
880 To access a global variable from inside a function you must prepend
881 "g:" to it. Thus "g:count" inside a function is used for the global
882 variable "count", and "count" is another variable, local to the
885 You now use the ":return" statement to return the smallest number to the user.
886 Finally, you end the function: >
891 The complete function definition is as follows: >
893 :function Min(num1, num2)
895 : let smaller = a:num1
897 : let smaller = a:num2
902 For people who like short functions, this does the same thing: >
904 :function Min(num1, num2)
911 A user defined function is called in exactly the same way as a built-in
912 function. Only the name is different. The Min function can be used like
917 Only now will the function be executed and the lines be interpreted by Vim.
918 If there are mistakes, like using an undefined variable or function, you will
919 now get an error message. When defining the function these errors are not
922 When a function reaches ":endfunction" or ":return" is used without an
923 argument, the function returns zero.
925 To redefine a function that already exists, use the ! for the ":function"
928 :function! Min(num1, num2, num3)
933 The ":call" command can be given a line range. This can have one of two
934 meanings. When a function has been defined with the "range" keyword, it will
935 take care of the line range itself.
936 The function will be passed the variables "a:firstline" and "a:lastline".
937 These will have the line numbers from the range the function was called with.
940 :function Count_words() range
941 : let n = a:firstline
943 : while n <= a:lastline
944 : let count = count + Wordcount(getline(n))
947 : echo "found " . count . " words"
950 You can call this function with: >
952 :10,30call Count_words()
954 It will be executed once and echo the number of words.
955 The other way to use a line range is by defining a function without the
956 "range" keyword. The function will be called once for every line in the
957 range, with the cursor in that line. Example: >
960 : echo "line " . line(".") . " contains: " . getline(".")
963 If you call this function with: >
967 The function will be called six times.
970 VARIABLE NUMBER OF ARGUMENTS
972 Vim enables you to define functions that have a variable number of arguments.
973 The following command, for instance, defines a function that must have 1
974 argument (start) and can have up to 20 additional arguments: >
976 :function Show(start, ...)
978 The variable "a:1" contains the first optional argument, "a:2" the second, and
979 so on. The variable "a:0" contains the number of extra arguments.
982 :function Show(start, ...)
984 : echo "Show is " . a:start
988 : echo " Arg " . index . " is " . a:{index}
989 : let index = index + 1
994 This uses the ":echohl" command to specify the highlighting used for the
995 following ":echo" command. ":echohl None" stops it again. The ":echon"
996 command works like ":echo", but doesn't output a line break.
998 You can also use the a:000 variable, it is a List of all the "..." arguments.
1004 The ":function" command lists the names and arguments of all user-defined
1008 < function Show(start, ...) ~
1009 function GetVimIndent() ~
1010 function SetSyn(name) ~
1012 To see what a function does, use its name as an argument for ":function": >
1015 < 1 if &syntax == '' ~
1016 2 let &syntax = a:name ~
1023 The line number is useful for when you get an error message or when debugging.
1024 See |debug-scripts| about debugging mode.
1025 You can also set the 'verbose' option to 12 or higher to see all function
1026 calls. Set it to 15 or higher to see every executed line.
1031 To delete the Show() function: >
1035 You get an error when the function doesn't exist.
1040 Sometimes it can be useful to have a variable point to one function or
1041 another. You can do it with the function() function. It turns the name of a
1042 function into a reference: >
1044 :let result = 0 " or 1
1053 : let Afunc = function('Right')
1055 : let Afunc = function('Wrong')
1057 :echo call(Afunc, [])
1060 Note that the name of a variable that holds a function reference must start
1061 with a capital. Otherwise it could be confused with the name of a builtin
1063 The way to invoke a function that a variable refers to is with the call()
1064 function. Its first argument is the function reference, the second argument
1065 is a List with arguments.
1067 Function references are most useful in combination with a Dictionary, as is
1068 explained in the next section.
1070 ==============================================================================
1071 *41.8* Lists and Dictionaries
1073 So far we have used the basic types String and Number. Vim also supports two
1074 composite types: List and Dictionary.
1076 A List is an ordered sequence of things. The things can be any kind of value,
1077 thus you can make a List of numbers, a List of Lists and even a List of mixed
1078 items. To create a List with three strings: >
1080 :let alist = ['aap', 'mies', 'noot']
1082 The List items are enclosed in square brackets and separated by commas. To
1083 create an empty List: >
1087 You can add items to a List with the add() function: >
1090 :call add(alist, 'foo')
1091 :call add(alist, 'bar')
1095 List concatenation is done with +: >
1097 :echo alist + ['foo', 'bar']
1098 < ['foo', 'bar', 'foo', 'bar'] ~
1100 Or, if you want to extend a List directly: >
1102 :let alist = ['one']
1103 :call extend(alist, ['two', 'three'])
1105 < ['one', 'two', 'three'] ~
1107 Notice that using add() will have a different effect: >
1109 :let alist = ['one']
1110 :call add(alist, ['two', 'three'])
1112 < ['one', ['two', 'three']] ~
1114 The second argument of add() is added as a single item.
1119 One of the nice things you can do with a List is iterate over it: >
1121 :let alist = ['one', 'two', 'three']
1129 This will loop over each element in List "alist", assigning the value to
1130 variable "n". The generic form of a for loop is: >
1132 :for {varname} in {listexpression}
1136 To loop a certain number of times you need a List of a specific length. The
1137 range() function creates one for you: >
1146 Notice that the first item of the List that range() produces is zero, thus the
1147 last item is one less than the length of the list.
1148 You can also specify the maximum value, the stride and even go backwards: >
1150 :for a in range(8, 4, -2)
1157 A more useful example, looping over lines in the buffer: >
1159 :for line in getline(1, 20)
1160 : if line =~ "Date: "
1161 : echo matchstr(line, 'Date: \zs.*')
1165 This looks into lines 1 to 20 (inclusive) and echoes any date found in there.
1170 A Dictionary stores key-value pairs. You can quickly lookup a value if you
1171 know the key. A Dictionary is created with curly braces: >
1173 :let uk2nl = {'one': 'een', 'two': 'twee', 'three': 'drie'}
1175 Now you can lookup words by putting the key in square brackets: >
1180 The generic form for defining a Dictionary is: >
1182 {<key> : <value>, ...}
1184 An empty Dictionary is one without any keys: >
1188 The possibilities with Dictionaries are numerous. There are various functions
1189 for them as well. For example, you can obtain a list of the keys and loop
1192 :for key in keys(uk2nl)
1199 The will notice the keys are not ordered. You can sort the list to get a
1202 :for key in sort(keys(uk2nl))
1209 But you can never get back the order in which items are defined. For that you
1210 need to use a List, it stores items in an ordered sequence.
1213 DICTIONARY FUNCTIONS
1215 The items in a Dictionary can normally be obtained with an index in square
1221 A method that does the same, but without so many punctuation characters: >
1226 This only works for a key that is made of ASCII letters, digits and the
1227 underscore. You can also assign a new value this way: >
1229 :let uk2nl.four = 'vier'
1231 < {'three': 'drie', 'four': 'vier', 'one': 'een', 'two': 'twee'} ~
1233 And now for something special: you can directly define a function and store a
1234 reference to it in the dictionary: >
1236 :function uk2nl.translate(line) dict
1237 : return join(map(split(a:line), 'get(self, v:val, "???")'))
1240 Let's first try it out: >
1242 :echo uk2nl.translate('three two five one')
1243 < drie twee ??? een ~
1245 The first special thing you notice is the "dict" at the end of the ":function"
1246 line. This marks the function as being used from a Dictionary. The "self"
1247 local variable will then refer to that Dictionary.
1248 Now let's break up the complicated return command: >
1252 The split() function takes a string, chops it into white separated words
1253 and returns a list with these words. Thus in the example it returns: >
1255 :echo split('three two five one')
1256 < ['three', 'two', 'five', 'one'] ~
1258 This list is the first argument to the map() function. This will go through
1259 the list, evaluating its second argument with "v:val" set to the value of each
1260 item. This is a shortcut to using a for loop. This command: >
1262 :let alist = map(split(a:line), 'get(self, v:val, "???")')
1266 :let alist = split(a:line)
1267 :for idx in range(len(alist))
1268 : let alist[idx] = get(self, alist[idx], "???")
1271 The get() function checks if a key is present in a Dictionary. If it is, then
1272 the value is retrieved. If it isn't, then the default value is returned, in
1273 the example it's '???'. This is a convenient way to handle situations where a
1274 key may not be present and you don't want an error message.
1276 The join() function does the opposite of split(): it joins together a list of
1277 words, putting a space in between.
1278 This combination of split(), map() and join() is a nice way to filter a line
1279 of words in a very compact way.
1282 OBJECT ORIENTED PROGRAMMING
1284 Now that you can put both values and functions in a Dictionary, you can
1285 actually use a Dictionary like an object.
1286 Above we used a Dictionary for translating Dutch to English. We might want
1287 to do the same for other languages. Let's first make an object (aka
1288 Dictionary) that has the translate function, but no words to translate: >
1291 :function transdict.translate(line) dict
1292 : return join(map(split(a:line), 'get(self.words, v:val, "???")'))
1295 It's slightly different from the function above, using 'self.words' to lookup
1296 word translations. But we don't have a self.words. Thus you could call this
1299 Now we can instantiate a Dutch translation object: >
1301 :let uk2nl = copy(transdict)
1302 :let uk2nl.words = {'one': 'een', 'two': 'twee', 'three': 'drie'}
1303 :echo uk2nl.translate('three one')
1306 And a German translator: >
1308 :let uk2de = copy(transdict)
1309 :let uk2de.words = {'one': 'ein', 'two': 'zwei', 'three': 'drei'}
1310 :echo uk2de.translate('three one')
1313 You see that the copy() function is used to make a copy of the "transdict"
1314 Dictionary and then the copy is changed to add the words. The original
1315 remains the same, of course.
1317 Now you can go one step further, and use your preferred translator: >
1324 :echo trans.translate('one two three')
1327 Here "trans" refers to one of the two objects (Dictionaries). No copy is
1328 made. More about List and Dictionary identity can be found at |list-identity|
1329 and |dict-identity|.
1331 Now you might use a language that isn't supported. You can overrule the
1332 translate() function to do nothing: >
1334 :let uk2uk = copy(transdict)
1335 :function! uk2uk.translate(line)
1338 :echo uk2uk.translate('three one wladiwostok')
1339 < three one wladiwostok ~
1341 Notice that a ! was used to overwrite the existing function reference. Now
1342 use "uk2uk" when no recognized language is found: >
1346 :elseif $LANG =~ "nl"
1351 :echo trans.translate('one two three')
1354 For further reading see |Lists| and |Dictionaries|.
1356 ==============================================================================
1359 Let's start with an example: >
1362 : read ~/templates/pascal.tmpl
1364 : echo "Sorry, the Pascal template file cannot be found."
1367 The ":read" command will fail if the file does not exist. Instead of
1368 generating an error message, this code catches the error and gives the user a
1369 nice message instead.
1371 For the commands in between ":try" and ":endtry" errors are turned into
1372 exceptions. An exception is a string. In the case of an error the string
1373 contains the error message. And every error message has a number. In this
1374 case, the error we catch contains "E484:". This number is guaranteed to stay
1375 the same (the text may change, e.g., it may be translated).
1377 When the ":read" command causes another error, the pattern "E484:" will not
1378 match in it. Thus this exception will not be caught and result in the usual
1381 You might be tempted to do this: >
1384 : read ~/templates/pascal.tmpl
1386 : echo "Sorry, the Pascal template file cannot be found."
1389 This means all errors are caught. But then you will not see errors that are
1390 useful, such as "E21: Cannot make changes, 'modifiable' is off".
1392 Another useful mechanism is the ":finally" command: >
1394 :let tmp = tempname()
1396 : exe ".,$write " . tmp
1397 : exe "!filter " . tmp
1399 : exe "$read " . tmp
1404 This filters the lines from the cursor until the end of the file through the
1405 "filter" command, which takes a file name argument. No matter if the
1406 filtering works, something goes wrong in between ":try" and ":finally" or the
1407 user cancels the filtering by pressing CTRL-C, the "call delete(tmp)" is
1408 always executed. This makes sure you don't leave the temporary file behind.
1410 More information about exception handling can be found in the reference
1411 manual: |exception-handling|.
1413 ==============================================================================
1414 *41.10* Various remarks
1416 Here is a summary of items that apply to Vim scripts. They are also mentioned
1417 elsewhere, but form a nice checklist.
1419 The end-of-line character depends on the system. For Unix a single <NL>
1420 character is used. For MS-DOS, Windows, OS/2 and the like, <CR><LF> is used.
1421 This is important when using mappings that end in a <CR>. See |:source_crnl|.
1426 Blank lines are allowed and ignored.
1428 Leading whitespace characters (blanks and TABs) are always ignored. The
1429 whitespaces between parameters (e.g. between the 'set' and the 'cpoptions' in
1430 the example below) are reduced to one blank character and plays the role of a
1431 separator, the whitespaces after the last (visible) character may or may not
1432 be ignored depending on the situation, see below.
1434 For a ":set" command involving the "=" (equal) sign, such as in: >
1436 :set cpoptions =aABceFst
1438 the whitespace immediately before the "=" sign is ignored. But there can be
1439 no whitespace after the "=" sign!
1441 To include a whitespace character in the value of an option, it must be
1442 escaped by a "\" (backslash) as in the following example: >
1444 :set tags=my\ nice\ file
1446 The same example written as >
1448 :set tags=my nice file
1450 will issue an error, because it is interpreted as: >
1459 The character " (the double quote mark) starts a comment. Everything after
1460 and including this character until the end-of-line is considered a comment and
1461 is ignored, except for commands that don't consider comments, as shown in
1462 examples below. A comment can start on any character position on the line.
1464 There is a little "catch" with comments for some commands. Examples: >
1466 :abbrev dev development " shorthand
1467 :map <F3> o#include " insert include
1468 :execute cmd " do it
1469 :!ls *.c " list C files
1471 The abbreviation 'dev' will be expanded to 'development " shorthand'. The
1472 mapping of <F3> will actually be the whole line after the 'o# ....' including
1473 the '" insert include'. The "execute" command will give an error. The "!"
1474 command will send everything after it to the shell, causing an error for an
1475 unmatched '"' character.
1476 There can be no comment after ":map", ":abbreviate", ":execute" and "!"
1477 commands (there are a few more commands with this restriction). For the
1478 ":map", ":abbreviate" and ":execute" commands there is a trick: >
1480 :abbrev dev development|" shorthand
1481 :map <F3> o#include|" insert include
1482 :execute cmd |" do it
1484 With the '|' character the command is separated from the next one. And that
1485 next command is only a comment. For the last command you need to do two
1486 things: |:execute| and use '|': >
1487 :exe '!ls *.c' |" list C files
1489 Notice that there is no white space before the '|' in the abbreviation and
1490 mapping. For these commands, any character until the end-of-line or '|' is
1491 included. As a consequence of this behavior, you don't always see that
1492 trailing whitespace is included: >
1496 To spot these problems, you can set the 'list' option when editing vimrc
1499 For Unix there is one special way to comment a line, that allows making a Vim
1500 script executable: >
1501 #!/usr/bin/env vim -S
1502 echo "this is a Vim script"
1505 The "#" command by itself lists a line with the line number. Adding an
1506 exclamation mark changes it into doing nothing, so that you can add the shell
1507 command to execute the rest of the file. |:#!| |-S|
1512 Even bigger problem arises in the following example: >
1517 Here the unmap command will not work, because it tries to unmap ",ab ". This
1518 does not exist as a mapped sequence. An error will be issued, which is very
1519 hard to identify, because the ending whitespace character in ":unmap ,ab " is
1522 And this is the same as what happens when one uses a comment after an 'unmap'
1525 :unmap ,ab " comment
1527 Here the comment part will be ignored. However, Vim will try to unmap
1528 ',ab ', which does not exist. Rewrite it as: >
1530 :unmap ,ab| " comment
1535 Sometimes you want to make a change and go back to where cursor was.
1536 Restoring the relative position would also be nice, so that the same line
1537 appears at the top of the window.
1538 This example yanks the current line, puts it above the first line in the
1539 file and then restores the view: >
1541 map ,p ma"aYHmbgg"aP`bzt`a
1545 < ma set mark a at cursor position
1546 "aY yank current line into register a
1547 Hmb go to top line in window and set mark b there
1548 gg go to first line in file
1549 "aP put the yanked line above it
1550 `b go back to top line in display
1551 zt position the text in the window as before
1552 `a go back to saved cursor position
1557 To avoid your function names to interfere with functions that you get from
1558 others, use this scheme:
1559 - Prepend a unique string before each function name. I often use an
1560 abbreviation. For example, "OW_" is used for the option window functions.
1561 - Put the definition of your functions together in a file. Set a global
1562 variable to indicate that the functions have been loaded. When sourcing the
1563 file again, first unload the functions.
1566 " This is the XXX package
1568 if exists("XXX_loaded")
1574 ... body of function ...
1578 ... body of function ...
1583 ==============================================================================
1584 *41.11* Writing a plugin *write-plugin*
1586 You can write a Vim script in such a way that many people can use it. This is
1587 called a plugin. Vim users can drop your script in their plugin directory and
1588 use its features right away |add-plugin|.
1590 There are actually two types of plugins:
1592 global plugins: For all types of files.
1593 filetype plugins: Only for files of a specific type.
1595 In this section the first type is explained. Most items are also relevant for
1596 writing filetype plugins. The specifics for filetype plugins are in the next
1597 section |write-filetype-plugin|.
1602 First of all you must choose a name for your plugin. The features provided
1603 by the plugin should be clear from its name. And it should be unlikely that
1604 someone else writes a plugin with the same name but which does something
1605 different. And please limit the name to 8 characters, to avoid problems on
1606 old Windows systems.
1608 A script that corrects typing mistakes could be called "typecorr.vim". We
1609 will use it here as an example.
1611 For the plugin to work for everybody, it should follow a few guidelines. This
1612 will be explained step-by-step. The complete example plugin is at the end.
1617 Let's start with the body of the plugin, the lines that do the actual work: >
1620 15 iabbrev otehr other
1621 16 iabbrev wnat want
1622 17 iabbrev synchronisation
1623 18 \ synchronization
1626 The actual list should be much longer, of course.
1628 The line numbers have only been added to explain a few things, don't put them
1629 in your plugin file!
1634 You will probably add new corrections to the plugin and soon have several
1635 versions laying around. And when distributing this file, people will want to
1636 know who wrote this wonderful plugin and where they can send remarks.
1637 Therefore, put a header at the top of your plugin: >
1639 1 " Vim global plugin for correcting typing mistakes
1640 2 " Last Change: 2000 Oct 15
1641 3 " Maintainer: Bram Moolenaar <Bram@vim.org>
1643 About copyright and licensing: Since plugins are very useful and it's hardly
1644 worth restricting their distribution, please consider making your plugin
1645 either public domain or use the Vim |license|. A short note about this near
1646 the top of the plugin should be sufficient. Example: >
1648 4 " License: This file is placed in the public domain.
1651 LINE CONTINUATION, AVOIDING SIDE EFFECTS *use-cpo-save*
1653 In line 18 above, the line-continuation mechanism is used |line-continuation|.
1654 Users with 'compatible' set will run into trouble here, they will get an error
1655 message. We can't just reset 'compatible', because that has a lot of side
1656 effects. To avoid this, we will set the 'cpoptions' option to its Vim default
1657 value and restore it later. That will allow the use of line-continuation and
1658 make the script work for most people. It is done like this: >
1660 11 let s:save_cpo = &cpo
1663 42 let &cpo = s:save_cpo
1665 We first store the old value of 'cpoptions' in the s:save_cpo variable. At
1666 the end of the plugin this value is restored.
1668 Notice that a script-local variable is used |s:var|. A global variable could
1669 already be in use for something else. Always use script-local variables for
1670 things that are only used in the script.
1675 It's possible that a user doesn't always want to load this plugin. Or the
1676 system administrator has dropped it in the system-wide plugin directory, but a
1677 user has his own plugin he wants to use. Then the user must have a chance to
1678 disable loading this specific plugin. This will make it possible: >
1680 6 if exists("loaded_typecorr")
1683 9 let loaded_typecorr = 1
1685 This also avoids that when the script is loaded twice it would cause error
1686 messages for redefining functions and cause trouble for autocommands that are
1692 Now let's make the plugin more interesting: We will add a mapping that adds a
1693 correction for the word under the cursor. We could just pick a key sequence
1694 for this mapping, but the user might already use it for something else. To
1695 allow the user to define which keys a mapping in a plugin uses, the <Leader>
1698 22 map <unique> <Leader>a <Plug>TypecorrAdd
1700 The "<Plug>TypecorrAdd" thing will do the work, more about that further on.
1702 The user can set the "mapleader" variable to the key sequence that he wants
1703 this mapping to start with. Thus if the user has done: >
1707 the mapping will define "_a". If the user didn't do this, the default value
1708 will be used, which is a backslash. Then a map for "\a" will be defined.
1710 Note that <unique> is used, this will cause an error message if the mapping
1711 already happened to exist. |:map-<unique>|
1713 But what if the user wants to define his own key sequence? We can allow that
1714 with this mechanism: >
1716 21 if !hasmapto('<Plug>TypecorrAdd')
1717 22 map <unique> <Leader>a <Plug>TypecorrAdd
1720 This checks if a mapping to "<Plug>TypecorrAdd" already exists, and only
1721 defines the mapping from "<Leader>a" if it doesn't. The user then has a
1722 chance of putting this in his vimrc file: >
1724 map ,c <Plug>TypecorrAdd
1726 Then the mapped key sequence will be ",c" instead of "_a" or "\a".
1731 If a script gets longer, you often want to break up the work in pieces. You
1732 can use functions or mappings for this. But you don't want these functions
1733 and mappings to interfere with the ones from other scripts. For example, you
1734 could define a function Add(), but another script could try to define the same
1735 function. To avoid this, we define the function local to the script by
1736 prepending it with "s:".
1738 We will define a function that adds a new typing correction: >
1740 30 function s:Add(from, correct)
1741 31 let to = input("type the correction for " . a:from . ": ")
1742 32 exe ":iabbrev " . a:from . " " . to
1746 Now we can call the function s:Add() from within this script. If another
1747 script also defines s:Add(), it will be local to that script and can only
1748 be called from the script it was defined in. There can also be a global Add()
1749 function (without the "s:"), which is again another function.
1751 <SID> can be used with mappings. It generates a script ID, which identifies
1752 the current script. In our typing correction plugin we use it like this: >
1754 24 noremap <unique> <script> <Plug>TypecorrAdd <SID>Add
1756 28 noremap <SID>Add :call <SID>Add(expand("<cword>"), 1)<CR>
1758 Thus when a user types "\a", this sequence is invoked: >
1760 \a -> <Plug>TypecorrAdd -> <SID>Add -> :call <SID>Add()
1762 If another script would also map <SID>Add, it would get another script ID and
1763 thus define another mapping.
1765 Note that instead of s:Add() we use <SID>Add() here. That is because the
1766 mapping is typed by the user, thus outside of the script. The <SID> is
1767 translated to the script ID, so that Vim knows in which script to look for
1770 This is a bit complicated, but it's required for the plugin to work together
1771 with other plugins. The basic rule is that you use <SID>Add() in mappings and
1772 s:Add() in other places (the script itself, autocommands, user commands).
1774 We can also add a menu entry to do the same as the mapping: >
1776 26 noremenu <script> Plugin.Add\ Correction <SID>Add
1778 The "Plugin" menu is recommended for adding menu items for plugins. In this
1779 case only one item is used. When adding more items, creating a submenu is
1780 recommended. For example, "Plugin.CVS" could be used for a plugin that offers
1781 CVS operations "Plugin.CVS.checkin", "Plugin.CVS.checkout", etc.
1783 Note that in line 28 ":noremap" is used to avoid that any other mappings cause
1784 trouble. Someone may have remapped ":call", for example. In line 24 we also
1785 use ":noremap", but we do want "<SID>Add" to be remapped. This is why
1786 "<script>" is used here. This only allows mappings which are local to the
1787 script. |:map-<script>| The same is done in line 26 for ":noremenu".
1791 <SID> AND <Plug> *using-<Plug>*
1793 Both <SID> and <Plug> are used to avoid that mappings of typed keys interfere
1794 with mappings that are only to be used from other mappings. Note the
1795 difference between using <SID> and <Plug>:
1797 <Plug> is visible outside of the script. It is used for mappings which the
1798 user might want to map a key sequence to. <Plug> is a special code
1799 that a typed key will never produce.
1800 To make it very unlikely that other plugins use the same sequence of
1801 characters, use this structure: <Plug> scriptname mapname
1802 In our example the scriptname is "Typecorr" and the mapname is "Add".
1803 This results in "<Plug>TypecorrAdd". Only the first character of
1804 scriptname and mapname is uppercase, so that we can see where mapname
1807 <SID> is the script ID, a unique identifier for a script.
1808 Internally Vim translates <SID> to "<SNR>123_", where "123" can be any
1809 number. Thus a function "<SID>Add()" will have a name "<SNR>11_Add()"
1810 in one script, and "<SNR>22_Add()" in another. You can see this if
1811 you use the ":function" command to get a list of functions. The
1812 translation of <SID> in mappings is exactly the same, that's how you
1813 can call a script-local function from a mapping.
1818 Now let's add a user command to add a correction: >
1820 38 if !exists(":Correct")
1821 39 command -nargs=1 Correct :call s:Add(<q-args>, 0)
1824 The user command is defined only if no command with the same name already
1825 exists. Otherwise we would get an error here. Overriding the existing user
1826 command with ":command!" is not a good idea, this would probably make the user
1827 wonder why the command he defined himself doesn't work. |:command|
1832 When a variable starts with "s:" it is a script variable. It can only be used
1833 inside a script. Outside the script it's not visible. This avoids trouble
1834 with using the same variable name in different scripts. The variables will be
1835 kept as long as Vim is running. And the same variables are used when sourcing
1836 the same script again. |s:var|
1838 The fun is that these variables can also be used in functions, autocommands
1839 and user commands that are defined in the script. In our example we can add
1840 a few lines to count the number of corrections: >
1844 30 function s:Add(from, correct)
1846 34 let s:count = s:count + 1
1847 35 echo s:count . " corrections now"
1850 First s:count is initialized to 4 in the script itself. When later the
1851 s:Add() function is called, it increments s:count. It doesn't matter from
1852 where the function was called, since it has been defined in the script, it
1853 will use the local variables from this script.
1858 Here is the resulting complete example: >
1860 1 " Vim global plugin for correcting typing mistakes
1861 2 " Last Change: 2000 Oct 15
1862 3 " Maintainer: Bram Moolenaar <Bram@vim.org>
1863 4 " License: This file is placed in the public domain.
1865 6 if exists("loaded_typecorr")
1868 9 let loaded_typecorr = 1
1870 11 let s:save_cpo = &cpo
1874 15 iabbrev otehr other
1875 16 iabbrev wnat want
1876 17 iabbrev synchronisation
1877 18 \ synchronization
1880 21 if !hasmapto('<Plug>TypecorrAdd')
1881 22 map <unique> <Leader>a <Plug>TypecorrAdd
1883 24 noremap <unique> <script> <Plug>TypecorrAdd <SID>Add
1885 26 noremenu <script> Plugin.Add\ Correction <SID>Add
1887 28 noremap <SID>Add :call <SID>Add(expand("<cword>"), 1)<CR>
1889 30 function s:Add(from, correct)
1890 31 let to = input("type the correction for " . a:from . ": ")
1891 32 exe ":iabbrev " . a:from . " " . to
1892 33 if a:correct | exe "normal viws\<C-R>\" \b\e" | endif
1893 34 let s:count = s:count + 1
1894 35 echo s:count . " corrections now"
1897 38 if !exists(":Correct")
1898 39 command -nargs=1 Correct :call s:Add(<q-args>, 0)
1901 42 let &cpo = s:save_cpo
1903 Line 33 wasn't explained yet. It applies the new correction to the word under
1904 the cursor. The |:normal| command is used to use the new abbreviation. Note
1905 that mappings and abbreviations are expanded here, even though the function
1906 was called from a mapping defined with ":noremap".
1908 Using "unix" for the 'fileformat' option is recommended. The Vim scripts will
1909 then work everywhere. Scripts with 'fileformat' set to "dos" do not work on
1910 Unix. Also see |:source_crnl|. To be sure it is set right, do this before
1913 :set fileformat=unix
1916 DOCUMENTATION *write-local-help*
1918 It's a good idea to also write some documentation for your plugin. Especially
1919 when its behavior can be changed by the user. See |add-local-help| for how
1922 Here is a simple example for a plugin help file, called "typecorr.txt": >
1924 1 *typecorr.txt* Plugin for correcting typing mistakes
1926 3 If you make typing mistakes, this plugin will have them corrected
1929 6 There are currently only a few corrections. Add your own if you like.
1932 9 <Leader>a or <Plug>TypecorrAdd
1933 10 Add a correction for the word under the cursor.
1937 14 Add a correction for {word}.
1939 16 *typecorr-settings*
1940 17 This plugin doesn't have any settings.
1942 The first line is actually the only one for which the format matters. It will
1943 be extracted from the help file to be put in the "LOCAL ADDITIONS:" section of
1944 help.txt |local-additions|. The first "*" must be in the first column of the
1945 first line. After adding your help file do ":help" and check that the entries
1948 You can add more tags inside ** in your help file. But be careful not to use
1949 existing help tags. You would probably use the name of your plugin in most of
1950 them, like "typecorr-settings" in the example.
1952 Using references to other parts of the help in || is recommended. This makes
1953 it easy for the user to find associated help.
1956 FILETYPE DETECTION *plugin-filetype*
1958 If your filetype is not already detected by Vim, you should create a filetype
1959 detection snippet in a separate file. It is usually in the form of an
1960 autocommand that sets the filetype when the file name matches a pattern.
1963 au BufNewFile,BufRead *.foo set filetype=foofoo
1965 Write this single-line file as "ftdetect/foofoo.vim" in the first directory
1966 that appears in 'runtimepath'. For Unix that would be
1967 "~/.vim/ftdetect/foofoo.vim". The convention is to use the name of the
1968 filetype for the script name.
1970 You can make more complicated checks if you like, for example to inspect the
1971 contents of the file to recognize the language. Also see |new-filetype|.
1974 SUMMARY *plugin-special*
1976 Summary of special things to use in a plugin:
1978 s:name Variables local to the script.
1980 <SID> Script-ID, used for mappings and functions local to
1983 hasmapto() Function to test if the user already defined a mapping
1984 for functionality the script offers.
1986 <Leader> Value of "mapleader", which the user defines as the
1987 keys that plugin mappings start with.
1989 :map <unique> Give a warning if a mapping already exists.
1991 :noremap <script> Use only mappings local to the script, not global
1994 exists(":Cmd") Check if a user command already exists.
1996 ==============================================================================
1997 *41.12* Writing a filetype plugin *write-filetype-plugin* *ftplugin*
1999 A filetype plugin is like a global plugin, except that it sets options and
2000 defines mappings for the current buffer only. See |add-filetype-plugin| for
2001 how this type of plugin is used.
2003 First read the section on global plugins above |41.11|. All that is said there
2004 also applies to filetype plugins. There are a few extras, which are explained
2005 here. The essential thing is that a filetype plugin should only have an
2006 effect on the current buffer.
2011 If you are writing a filetype plugin to be used by many people, they need a
2012 chance to disable loading it. Put this at the top of the plugin: >
2014 " Only do this when not done yet for this buffer
2015 if exists("b:did_ftplugin")
2018 let b:did_ftplugin = 1
2020 This also needs to be used to avoid that the same plugin is executed twice for
2021 the same buffer (happens when using an ":edit" command without arguments).
2023 Now users can disable loading the default plugin completely by making a
2024 filetype plugin with only this line: >
2026 let b:did_ftplugin = 1
2028 This does require that the filetype plugin directory comes before $VIMRUNTIME
2031 If you do want to use the default plugin, but overrule one of the settings,
2032 you can write the different setting in a script: >
2034 setlocal textwidth=70
2036 Now write this in the "after" directory, so that it gets sourced after the
2037 distributed "vim.vim" ftplugin |after-directory|. For Unix this would be
2038 "~/.vim/after/ftplugin/vim.vim". Note that the default plugin will have set
2039 "b:did_ftplugin", but it is ignored here.
2044 To make sure the filetype plugin only affects the current buffer use the >
2048 command to set options. And only set options which are local to a buffer (see
2049 the help for the option to check that). When using |:setlocal| for global
2050 options or options local to a window, the value will change for many buffers,
2051 and that is not what a filetype plugin should do.
2053 When an option has a value that is a list of flags or items, consider using
2054 "+=" and "-=" to keep the existing value. Be aware that the user may have
2055 changed an option value already. First resetting to the default value and
2056 then changing it often a good idea. Example: >
2058 :setlocal formatoptions& formatoptions+=ro
2063 To make sure mappings will only work in the current buffer use the >
2067 command. This needs to be combined with the two-step mapping explained above.
2068 An example of how to define functionality in a filetype plugin: >
2070 if !hasmapto('<Plug>JavaImport')
2071 map <buffer> <unique> <LocalLeader>i <Plug>JavaImport
2073 noremap <buffer> <unique> <Plug>JavaImport oimport ""<Left><Esc>
2075 |hasmapto()| is used to check if the user has already defined a map to
2076 <Plug>JavaImport. If not, then the filetype plugin defines the default
2077 mapping. This starts with |<LocalLeader>|, which allows the user to select
2078 the key(s) he wants filetype plugin mappings to start with. The default is a
2080 "<unique>" is used to give an error message if the mapping already exists or
2081 overlaps with an existing mapping.
2082 |:noremap| is used to avoid that any other mappings that the user has defined
2083 interferes. You might want to use ":noremap <script>" to allow remapping
2084 mappings defined in this script that start with <SID>.
2086 The user must have a chance to disable the mappings in a filetype plugin,
2087 without disabling everything. Here is an example of how this is done for a
2088 plugin for the mail filetype: >
2090 " Add mappings, unless the user didn't want this.
2091 if !exists("no_plugin_maps") && !exists("no_mail_maps")
2092 " Quote text by inserting "> "
2093 if !hasmapto('<Plug>MailQuote')
2094 vmap <buffer> <LocalLeader>q <Plug>MailQuote
2095 nmap <buffer> <LocalLeader>q <Plug>MailQuote
2097 vnoremap <buffer> <Plug>MailQuote :s/^/> /<CR>
2098 nnoremap <buffer> <Plug>MailQuote :.,$s/^/> /<CR>
2101 Two global variables are used:
2102 no_plugin_maps disables mappings for all filetype plugins
2103 no_mail_maps disables mappings for a specific filetype
2108 To add a user command for a specific file type, so that it can only be used in
2109 one buffer, use the "-buffer" argument to |:command|. Example: >
2111 :command -buffer Make make %:r.s
2116 A filetype plugin will be sourced for each buffer of the type it's for. Local
2117 script variables |s:var| will be shared between all invocations. Use local
2118 buffer variables |b:var| if you want a variable specifically for one buffer.
2123 When defining a function, this only needs to be done once. But the filetype
2124 plugin will be sourced every time a file with this filetype will be opened.
2125 This construct make sure the function is only defined once: >
2127 :if !exists("*s:Func")
2128 : function s:Func(arg)
2134 UNDO *undo_ftplugin*
2136 When the user does ":setfiletype xyz" the effect of the previous filetype
2137 should be undone. Set the b:undo_ftplugin variable to the commands that will
2138 undo the settings in your filetype plugin. Example: >
2140 let b:undo_ftplugin = "setlocal fo< com< tw< commentstring<"
2141 \ . "| unlet b:match_ignorecase b:match_words b:match_skip"
2143 Using ":setlocal" with "<" after the option name resets the option to its
2144 global value. That is mostly the best way to reset the option value.
2146 This does require removing the "C" flag from 'cpoptions' to allow line
2147 continuation, as mentioned above |use-cpo-save|.
2152 The filetype must be included in the file name |ftplugin-name|. Use one of
2155 .../ftplugin/stuff.vim
2156 .../ftplugin/stuff_foo.vim
2157 .../ftplugin/stuff/bar.vim
2159 "stuff" is the filetype, "foo" and "bar" are arbitrary names.
2162 SUMMARY *ftplugin-special*
2164 Summary of special things to use in a filetype plugin:
2166 <LocalLeader> Value of "maplocalleader", which the user defines as
2167 the keys that filetype plugin mappings start with.
2169 :map <buffer> Define a mapping local to the buffer.
2171 :noremap <script> Only remap mappings defined in this script that start
2174 :setlocal Set an option for the current buffer only.
2176 :command -buffer Define a user command local to the buffer.
2178 exists("*s:Func") Check if a function was already defined.
2180 Also see |plugin-special|, the special things used for all plugins.
2182 ==============================================================================
2183 *41.13* Writing a compiler plugin *write-compiler-plugin*
2185 A compiler plugin sets options for use with a specific compiler. The user can
2186 load it with the |:compiler| command. The main use is to set the
2187 'errorformat' and 'makeprg' options.
2189 Easiest is to have a look at examples. This command will edit all the default
2192 :next $VIMRUNTIME/compiler/*.vim
2194 Use |:next| to go to the next plugin file.
2196 There are two special items about these files. First is a mechanism to allow
2197 a user to overrule or add to the default file. The default files start with: >
2199 :if exists("current_compiler")
2202 :let current_compiler = "mine"
2204 When you write a compiler file and put it in your personal runtime directory
2205 (e.g., ~/.vim/compiler for Unix), you set the "current_compiler" variable to
2206 make the default file skip the settings.
2208 The second mechanism is to use ":set" for ":compiler!" and ":setlocal" for
2209 ":compiler". Vim defines the ":CompilerSet" user command for this. However,
2210 older Vim versions don't, thus your plugin should define it then. This is an
2213 if exists(":CompilerSet") != 2
2214 command -nargs=* CompilerSet setlocal <args>
2216 CompilerSet errorformat& " use the default 'errorformat'
2217 CompilerSet makeprg=nmake
2219 When you write a compiler plugin for the Vim distribution or for a system-wide
2220 runtime directory, use the mechanism mentioned above. When
2221 "current_compiler" was already set by a user plugin nothing will be done.
2223 When you write a compiler plugin to overrule settings from a default plugin,
2224 don't check "current_compiler". This plugin is supposed to be loaded
2225 last, thus it should be in a directory at the end of 'runtimepath'. For Unix
2226 that could be ~/.vim/after/compiler.
2228 ==============================================================================
2229 *41.14* Writing a plugin that loads quickly *write-plugin-quickload*
2231 A plugin may grow and become quite long. The startup delay may become
2232 noticeable, while you hardly every use the plugin. Then it's time for a
2235 The basic idea is that the plugin is loaded twice. The first time user
2236 commands and mappings are defined that offer the functionality. The second
2237 time the functions that implement the functionality are defined.
2239 It may sound surprising that quickload means loading a script twice. What we
2240 mean is that it loads quickly the first time, postponing the bulk of the
2241 script to the second time, which only happens when you actually use it. When
2242 you always use the functionality it actually gets slower!
2244 Note that since Vim 7 there is an alternative: use the |autoload|
2245 functionality |41.15|.
2247 The following example shows how it's done: >
2249 " Vim global plugin for demonstrating quick loading
2250 " Last Change: 2005 Feb 25
2251 " Maintainer: Bram Moolenaar <Bram@vim.org>
2252 " License: This file is placed in the public domain.
2254 if !exists("s:did_load")
2255 command -nargs=* BNRead call BufNetRead(<f-args>)
2256 map <F19> :call BufNetWrite('something')<CR>
2259 exe 'au FuncUndefined BufNet* source ' . expand('<sfile>')
2263 function BufNetRead(...)
2264 echo 'BufNetRead(' . string(a:000) . ')'
2265 " read functionality here
2268 function BufNetWrite(...)
2269 echo 'BufNetWrite(' . string(a:000) . ')'
2270 " write functionality here
2273 When the script is first loaded "s:did_load" is not set. The commands between
2274 the "if" and "endif" will be executed. This ends in a |:finish| command, thus
2275 the rest of the script is not executed.
2277 The second time the script is loaded "s:did_load" exists and the commands
2278 after the "endif" are executed. This defines the (possible long)
2279 BufNetRead() and BufNetWrite() functions.
2281 If you drop this script in your plugin directory Vim will execute it on
2282 startup. This is the sequence of events that happens:
2284 1. The "BNRead" command is defined and the <F19> key is mapped when the script
2285 is sourced at startup. A |FuncUndefined| autocommand is defined. The
2286 ":finish" command causes the script to terminate early.
2288 2. The user types the BNRead command or presses the <F19> key. The
2289 BufNetRead() or BufNetWrite() function will be called.
2291 3. Vim can't find the function and triggers the |FuncUndefined| autocommand
2292 event. Since the pattern "BufNet*" matches the invoked function, the
2293 command "source fname" will be executed. "fname" will be equal to the name
2294 of the script, no matter where it is located, because it comes from
2295 expanding "<sfile>" (see |expand()|).
2297 4. The script is sourced again, the "s:did_load" variable exists and the
2298 functions are defined.
2300 Notice that the functions that are loaded afterwards match the pattern in the
2301 |FuncUndefined| autocommand. You must make sure that no other plugin defines
2302 functions that match this pattern.
2304 ==============================================================================
2305 *41.15* Writing library scripts *write-library-script*
2307 Some functionality will be required in several places. When this becomes more
2308 than a few lines you will want to put it in one script and use it from many
2309 scripts. We will call that one script a library script.
2311 Manually loading a library script is possible, so long as you avoid loading it
2312 when it's already done. You can do this with the |exists()| function.
2315 if !exists('*MyLibFunction')
2316 runtime library/mylibscript.vim
2318 call MyLibFunction(arg)
2320 Here you need to know that MyLibFunction() is defined in a script
2321 "library/mylibscript.vim" in one of the directories in 'runtimepath'.
2323 To make this a bit simpler Vim offers the autoload mechanism. Then the
2324 example looks like this: >
2326 call mylib#myfunction(arg)
2328 That's a lot simpler, isn't it? Vim will recognize the function name and when
2329 it's not defined search for the script "autoload/mylib.vim" in 'runtimepath'.
2330 That script must define the "mylib#myfunction()" function.
2332 You can put many other functions in the mylib.vim script, you are free to
2333 organize your functions in library scripts. But you must use function names
2334 where the part before the '#' matches the script name. Otherwise Vim would
2335 not know what script to load.
2337 If you get really enthusiastic and write lots of library scripts, you may
2338 want to use subdirectories. Example: >
2340 call netlib#ftp#read('somefile')
2342 For Unix the library script used for this could be:
2344 ~/.vim/autoload/netlib/ftp.vim
2346 Where the function is defined like this: >
2348 function netlib#ftp#read(fname)
2349 " Read the file fname through ftp
2352 Notice that the name the function is defined with is exactly the same as the
2353 name used for calling the function. And the part before the last '#'
2354 exactly matches the subdirectory and script name.
2356 You can use the same mechanism for variables: >
2358 let weekdays = dutch#weekdays
2360 This will load the script "autoload/dutch.vim", which should contain something
2363 let dutch#weekdays = ['zondag', 'maandag', 'dinsdag', 'woensdag',
2364 \ 'donderdag', 'vrijdag', 'zaterdag']
2366 Further reading: |autoload|.
2368 ==============================================================================
2369 *41.16* Distributing Vim scripts *distribute-script*
2371 Vim users will look for scripts on the Vim website: http://www.vim.org.
2372 If you made something that is useful for others, share it!
2374 Vim scripts can be used on any system. There might not be a tar or gzip
2375 command. If you want to pack files together and/or compress them the "zip"
2376 utility is recommended.
2378 For utmost portability use Vim itself to pack scripts together. This can be
2379 done with the Vimball utility. See |vimball|.
2381 It's good if you add a line to allow automatic updating. See |glvs-plugins|.
2383 ==============================================================================
2385 Next chapter: |usr_42.txt| Add new menus
2387 Copyright: see |manual-copyright| vim:tw=78:ts=8:ft=help:norl: