summaryrefslogtreecommitdiffstats
path: root/runtime/doc/repeat.txt
diff options
context:
space:
mode:
Diffstat (limited to 'runtime/doc/repeat.txt')
-rw-r--r--runtime/doc/repeat.txt1037
1 files changed, 1037 insertions, 0 deletions
diff --git a/runtime/doc/repeat.txt b/runtime/doc/repeat.txt
new file mode 100644
index 0000000..03a2799
--- /dev/null
+++ b/runtime/doc/repeat.txt
@@ -0,0 +1,1037 @@
+*repeat.txt* For Vim version 8.1. Last change: 2018 Dec 18
+
+
+ VIM REFERENCE MANUAL by Bram Moolenaar
+
+
+Repeating commands, Vim scripts and debugging *repeating*
+
+Chapter 26 of the user manual introduces repeating |usr_26.txt|.
+
+1. Single repeats |single-repeat|
+2. Multiple repeats |multi-repeat|
+3. Complex repeats |complex-repeat|
+4. Using Vim scripts |using-scripts|
+5. Using Vim packages |packages|
+6. Creating Vim packages |package-create|
+7. Debugging scripts |debug-scripts|
+8. Profiling |profiling|
+
+==============================================================================
+1. Single repeats *single-repeat*
+
+ *.*
+. Repeat last change, with count replaced with [count].
+ Also repeat a yank command, when the 'y' flag is
+ included in 'cpoptions'. Does not repeat a
+ command-line command.
+
+Simple changes can be repeated with the "." command. Without a count, the
+count of the last change is used. If you enter a count, it will replace the
+last one. |v:count| and |v:count1| will be set.
+
+If the last change included a specification of a numbered register, the
+register number will be incremented. See |redo-register| for an example how
+to use this.
+
+Note that when repeating a command that used a Visual selection, the same SIZE
+of area is used, see |visual-repeat|.
+
+ *@:*
+@: Repeat last command-line [count] times.
+ {not available when compiled without the
+ |+cmdline_hist| feature}
+
+
+==============================================================================
+2. Multiple repeats *multi-repeat*
+
+ *:g* *:global* *E148*
+:[range]g[lobal]/{pattern}/[cmd]
+ Execute the Ex command [cmd] (default ":p") on the
+ lines within [range] where {pattern} matches.
+
+:[range]g[lobal]!/{pattern}/[cmd]
+ Execute the Ex command [cmd] (default ":p") on the
+ lines within [range] where {pattern} does NOT match.
+
+ *:v* *:vglobal*
+:[range]v[global]/{pattern}/[cmd]
+ Same as :g!.
+
+Instead of the '/' which surrounds the {pattern}, you can use any other
+single byte character, but not an alphabetic character, '\', '"' or '|'.
+This is useful if you want to include a '/' in the search pattern or
+replacement string.
+
+For the definition of a pattern, see |pattern|.
+
+NOTE [cmd] may contain a range; see |collapse| and |edit-paragraph-join| for
+examples.
+
+The global commands work by first scanning through the [range] lines and
+marking each line where a match occurs (for a multi-line pattern, only the
+start of the match matters).
+In a second scan the [cmd] is executed for each marked line, as if the cursor
+was in that line. For ":v" and ":g!" the command is executed for each not
+marked line. If a line is deleted its mark disappears.
+The default for [range] is the whole buffer (1,$). Use "CTRL-C" to interrupt
+the command. If an error message is given for a line, the command for that
+line is aborted and the global command continues with the next marked or
+unmarked line.
+ *E147*
+When the command is used recursively, it only works on one line. Giving a
+range is then not allowed. This is useful to find all lines that match a
+pattern and do not match another pattern: >
+ :g/found/v/notfound/{cmd}
+This first finds all lines containing "found", but only executes {cmd} when
+there is no match for "notfound".
+
+To execute a non-Ex command, you can use the `:normal` command: >
+ :g/pat/normal {commands}
+Make sure that {commands} ends with a whole command, otherwise Vim will wait
+for you to type the rest of the command for each match. The screen will not
+have been updated, so you don't know what you are doing. See |:normal|.
+
+The undo/redo command will undo/redo the whole global command at once.
+The previous context mark will only be set once (with "''" you go back to
+where the cursor was before the global command).
+
+The global command sets both the last used search pattern and the last used
+substitute pattern (this is vi compatible). This makes it easy to globally
+replace a string:
+ :g/pat/s//PAT/g
+This replaces all occurrences of "pat" with "PAT". The same can be done with:
+ :%s/pat/PAT/g
+Which is two characters shorter!
+
+When using "global" in Ex mode, a special case is using ":visual" as a
+command. This will move to a matching line, go to Normal mode to let you
+execute commands there until you use |Q| to return to Ex mode. This will be
+repeated for each matching line. While doing this you cannot use ":global".
+To abort this type CTRL-C twice.
+
+==============================================================================
+3. Complex repeats *complex-repeat*
+
+ *q* *recording*
+q{0-9a-zA-Z"} Record typed characters into register {0-9a-zA-Z"}
+ (uppercase to append). The 'q' command is disabled
+ while executing a register, and it doesn't work inside
+ a mapping and |:normal|.
+
+ Note: If the register being used for recording is also
+ used for |y| and |p| the result is most likely not
+ what is expected, because the put will paste the
+ recorded macro and the yank will overwrite the
+ recorded macro. {Vi: no recording}
+
+q Stops recording. (Implementation note: The 'q' that
+ stops recording is not stored in the register, unless
+ it was the result of a mapping) {Vi: no recording}
+
+ *@*
+@{0-9a-z".=*+} Execute the contents of register {0-9a-z".=*+} [count]
+ times. Note that register '%' (name of the current
+ file) and '#' (name of the alternate file) cannot be
+ used.
+ The register is executed like a mapping, that means
+ that the difference between 'wildchar' and 'wildcharm'
+ applies.
+ For "@=" you are prompted to enter an expression. The
+ result of the expression is then executed.
+ See also |@:|. {Vi: only named registers}
+
+ *@@* *E748*
+@@ Repeat the previous @{0-9a-z":*} [count] times.
+
+:[addr]*{0-9a-z".=+} *:@* *:star*
+:[addr]@{0-9a-z".=*+} Execute the contents of register {0-9a-z".=*+} as an Ex
+ command. First set cursor at line [addr] (default is
+ current line). When the last line in the register does
+ not have a <CR> it will be added automatically when
+ the 'e' flag is present in 'cpoptions'.
+ Note that the ":*" command is only recognized when the
+ '*' flag is present in 'cpoptions'. This is NOT the
+ default when 'nocompatible' is used.
+ For ":@=" the last used expression is used. The
+ result of evaluating the expression is executed as an
+ Ex command.
+ Mappings are not recognized in these commands.
+ {Vi: only in some versions} Future: Will execute the
+ register for each line in the address range.
+
+ *:@:*
+:[addr]@: Repeat last command-line. First set cursor at line
+ [addr] (default is current line). {not in Vi}
+
+:[addr]@ *:@@*
+:[addr]@@ Repeat the previous :@{0-9a-z"}. First set cursor at
+ line [addr] (default is current line). {Vi: only in
+ some versions}
+
+==============================================================================
+4. Using Vim scripts *using-scripts*
+
+For writing a Vim script, see chapter 41 of the user manual |usr_41.txt|.
+
+ *:so* *:source* *load-vim-script*
+:so[urce] {file} Read Ex commands from {file}. These are commands that
+ start with a ":".
+ Triggers the |SourcePre| autocommand.
+
+:so[urce]! {file} Read Vim commands from {file}. These are commands
+ that are executed from Normal mode, like you type
+ them.
+ When used after |:global|, |:argdo|, |:windo|,
+ |:bufdo|, in a loop or when another command follows
+ the display won't be updated while executing the
+ commands.
+ {not in Vi}
+
+ *:ru* *:runtime*
+:ru[ntime][!] [where] {file} ..
+ Read Ex commands from {file} in each directory given
+ by 'runtimepath' and/or 'packpath'. There is no error
+ for non-existing files.
+
+ Example: >
+ :runtime syntax/c.vim
+
+< There can be multiple {file} arguments, separated by
+ spaces. Each {file} is searched for in the first
+ directory from 'runtimepath', then in the second
+ directory, etc. Use a backslash to include a space
+ inside {file} (although it's better not to use spaces
+ in file names, it causes trouble).
+
+ When [!] is included, all found files are sourced.
+ When it is not included only the first found file is
+ sourced.
+
+ When [where] is omitted only 'runtimepath' is used.
+ Other values:
+ START search under "start" in 'packpath'
+ OPT search under "opt" in 'packpath'
+ PACK search under "start" and "opt" in
+ 'packpath'
+ ALL first use 'runtimepath', then search
+ under "start" and "opt" in 'packpath'
+
+ When {file} contains wildcards it is expanded to all
+ matching files. Example: >
+ :runtime! plugin/*.vim
+< This is what Vim uses to load the plugin files when
+ starting up. This similar command: >
+ :runtime plugin/*.vim
+< would source the first file only.
+
+ When 'verbose' is one or higher, there is a message
+ when no file could be found.
+ When 'verbose' is two or higher, there is a message
+ about each searched file.
+ {not in Vi}
+
+ *:pa* *:packadd* *E919*
+:pa[ckadd][!] {name} Search for an optional plugin directory in 'packpath'
+ and source any plugin files found. The directory must
+ match:
+ pack/*/opt/{name} ~
+ The directory is added to 'runtimepath' if it wasn't
+ there yet.
+ If the directory pack/*/opt/{name}/after exists it is
+ added at the end of 'runtimepath'.
+
+ If loading packages from "pack/*/start" was skipped,
+ then this directory is searched first:
+ pack/*/start/{name} ~
+
+ Note that {name} is the directory name, not the name
+ of the .vim file. All the files matching the pattern
+ pack/*/opt/{name}/plugin/**/*.vim ~
+ will be sourced. This allows for using subdirectories
+ below "plugin", just like with plugins in
+ 'runtimepath'.
+
+ If the filetype detection was not enabled yet (this
+ is usually done with a "syntax enable" or "filetype
+ on" command in your .vimrc file), this will also look
+ for "{name}/ftdetect/*.vim" files.
+
+ When the optional ! is added no plugin files or
+ ftdetect scripts are loaded, only the matching
+ directories are added to 'runtimepath'. This is
+ useful in your .vimrc. The plugins will then be
+ loaded during initialization, see |load-plugins|.
+
+ Also see |pack-add|.
+ {only available when compiled with |+eval|}
+
+ *:packl* *:packloadall*
+:packl[oadall][!] Load all packages in the "start" directory under each
+ entry in 'packpath'.
+
+ First all the directories found are added to
+ 'runtimepath', then the plugins found in the
+ directories are sourced. This allows for a plugin to
+ depend on something of another plugin, e.g. an
+ "autoload" directory. See |packload-two-steps| for
+ how this can be useful.
+
+ This is normally done automatically during startup,
+ after loading your .vimrc file. With this command it
+ can be done earlier.
+
+ Packages will be loaded only once. After this command
+ it won't happen again. When the optional ! is added
+ this command will load packages even when done before.
+
+ An error only causes sourcing the script where it
+ happens to be aborted, further plugins will be loaded.
+ See |packages|.
+ {only available when compiled with |+eval|}
+
+:scripte[ncoding] [encoding] *:scripte* *:scriptencoding* *E167*
+ Specify the character encoding used in the script.
+ The following lines will be converted from [encoding]
+ to the value of the 'encoding' option, if they are
+ different. Examples: >
+ scriptencoding iso-8859-5
+ scriptencoding cp932
+<
+ When [encoding] is empty, no conversion is done. This
+ can be used to restrict conversion to a sequence of
+ lines: >
+ scriptencoding euc-jp
+ ... lines to be converted ...
+ scriptencoding
+ ... not converted ...
+
+< When conversion isn't supported by the system, there
+ is no error message and no conversion is done. When a
+ line can't be converted there is no error and the
+ original line is kept.
+
+ Don't use "ucs-2" or "ucs-4", scripts cannot be in
+ these encodings (they would contain NUL bytes).
+ When a sourced script starts with a BOM (Byte Order
+ Mark) in utf-8 format Vim will recognize it, no need
+ to use ":scriptencoding utf-8" then.
+
+ If you set the 'encoding' option in your |.vimrc|,
+ `:scriptencoding` must be placed after that. E.g.: >
+ set encoding=utf-8
+ scriptencoding utf-8
+<
+ When compiled without the |+multi_byte| feature this
+ command is ignored.
+ {not in Vi}
+
+ *:scr* *:scriptnames*
+:scr[iptnames] List all sourced script names, in the order they were
+ first sourced. The number is used for the script ID
+ |<SID>|.
+ {not in Vi} {not available when compiled without the
+ |+eval| feature}
+
+:scr[iptnames][!] {scriptId} *:script*
+ Edit script {scriptId}. Although ":scriptnames name"
+ works, using ":script name" is recommended.
+ When the current buffer can't be |abandon|ed and the !
+ is not present, the command fails.
+
+ *:fini* *:finish* *E168*
+:fini[sh] Stop sourcing a script. Can only be used in a Vim
+ script file. This is a quick way to skip the rest of
+ the file. If it is used after a |:try| but before the
+ matching |:finally| (if present), the commands
+ following the ":finally" up to the matching |:endtry|
+ are executed first. This process applies to all
+ nested ":try"s in the script. The outermost ":endtry"
+ then stops sourcing the script. {not in Vi}
+
+All commands and command sequences can be repeated by putting them in a named
+register and then executing it. There are two ways to get the commands in the
+register:
+- Use the record command "q". You type the commands once, and while they are
+ being executed they are stored in a register. Easy, because you can see
+ what you are doing. If you make a mistake, "p"ut the register into the
+ file, edit the command sequence, and then delete it into the register
+ again. You can continue recording by appending to the register (use an
+ uppercase letter).
+- Delete or yank the command sequence into the register.
+
+Often used command sequences can be put under a function key with the ':map'
+command.
+
+An alternative is to put the commands in a file, and execute them with the
+':source!' command. Useful for long command sequences. Can be combined with
+the ':map' command to put complicated commands under a function key.
+
+The ':source' command reads Ex commands from a file line by line. You will
+have to type any needed keyboard input. The ':source!' command reads from a
+script file character by character, interpreting each character as if you
+typed it.
+
+Example: When you give the ":!ls" command you get the |hit-enter| prompt. If
+you ':source' a file with the line "!ls" in it, you will have to type the
+<Enter> yourself. But if you ':source!' a file with the line ":!ls" in it,
+the next characters from that file are read until a <CR> is found. You will
+not have to type <CR> yourself, unless ":!ls" was the last line in the file.
+
+It is possible to put ':source[!]' commands in the script file, so you can
+make a top-down hierarchy of script files. The ':source' command can be
+nested as deep as the number of files that can be opened at one time (about
+15). The ':source!' command can be nested up to 15 levels deep.
+
+You can use the "<sfile>" string (literally, this is not a special key) inside
+of the sourced file, in places where a file name is expected. It will be
+replaced by the file name of the sourced file. For example, if you have a
+"other.vimrc" file in the same directory as your ".vimrc" file, you can source
+it from your ".vimrc" file with this command: >
+ :source <sfile>:h/other.vimrc
+
+In script files terminal-dependent key codes are represented by
+terminal-independent two character codes. This means that they can be used
+in the same way on different kinds of terminals. The first character of a
+key code is 0x80 or 128, shown on the screen as "~@". The second one can be
+found in the list |key-notation|. Any of these codes can also be entered
+with CTRL-V followed by the three digit decimal code. This does NOT work for
+the <t_xx> termcap codes, these can only be used in mappings.
+
+ *:source_crnl* *W15*
+MS-DOS, Win32 and OS/2: Files that are read with ":source" normally have
+<CR><NL> <EOL>s. These always work. If you are using a file with <NL> <EOL>s
+(for example, a file made on Unix), this will be recognized if 'fileformats'
+is not empty and the first line does not end in a <CR>. This fails if the
+first line has something like ":map <F1> :help^M", where "^M" is a <CR>. If
+the first line ends in a <CR>, but following ones don't, you will get an error
+message, because the <CR> from the first lines will be lost.
+
+Mac Classic: Files that are read with ":source" normally have <CR> <EOL>s.
+These always work. If you are using a file with <NL> <EOL>s (for example, a
+file made on Unix), this will be recognized if 'fileformats' is not empty and
+the first line does not end in a <CR>. Be careful not to use a file with <NL>
+linebreaks which has a <CR> in first line.
+
+On other systems, Vim expects ":source"ed files to end in a <NL>. These
+always work. If you are using a file with <CR><NL> <EOL>s (for example, a
+file made on MS-DOS), all lines will have a trailing <CR>. This may cause
+problems for some commands (e.g., mappings). There is no automatic <EOL>
+detection, because it's common to start with a line that defines a mapping
+that ends in a <CR>, which will confuse the automaton.
+
+ *line-continuation*
+Long lines in a ":source"d Ex command script file can be split by inserting
+a line continuation symbol "\" (backslash) at the start of the next line.
+There can be white space before the backslash, which is ignored.
+
+Example: the lines >
+ :set comments=sr:/*,mb:*,el:*/,
+ \://,
+ \b:#,
+ \:%,
+ \n:>,
+ \fb:-
+are interpreted as if they were given in one line:
+ :set comments=sr:/*,mb:*,el:*/,://,b:#,:%,n:>,fb:-
+
+All leading whitespace characters in the line before a backslash are ignored.
+Note however that trailing whitespace in the line before it cannot be
+inserted freely; it depends on the position where a command is split up
+whether additional whitespace is allowed or not.
+
+When a space is required it's best to put it right after the backslash. A
+space at the end of a line is hard to see and may be accidentally deleted. >
+ :syn match Comment
+ \ "very long regexp"
+ \ keepend
+
+There is a problem with the ":append" and ":insert" commands: >
+ :1append
+ \asdf
+ .
+The backslash is seen as a line-continuation symbol, thus this results in the
+command: >
+ :1appendasdf
+ .
+To avoid this, add the 'C' flag to the 'cpoptions' option: >
+ :set cpo+=C
+ :1append
+ \asdf
+ .
+ :set cpo-=C
+
+Note that when the commands are inside a function, you need to add the 'C'
+flag when defining the function, it is not relevant when executing it. >
+ :set cpo+=C
+ :function Foo()
+ :1append
+ \asdf
+ .
+ :endfunction
+ :set cpo-=C
+<
+ *line-continuation-comment*
+To add a comment in between the lines start with '"\ '. Notice the space
+after the backslash. Example: >
+ let array = [
+ "\ first entry comment
+ \ 'first',
+ "\ second entry comment
+ \ 'second',
+ \ ]
+
+Rationale:
+ Most programs work with a trailing backslash to indicate line
+ continuation. Using this in Vim would cause incompatibility with Vi.
+ For example for this Vi mapping: >
+ :map xx asdf\
+< Therefore the unusual leading backslash is used.
+
+ Starting a comment in a continuation line results in all following
+ continuation lines to be part of the comment. Since it was like this
+ for a long time, when making it possible to add a comment halfway a
+ sequence of continuation lines, it was not possible to use \", since
+ that was a valid continuation line. Using '"\ ' comes closest, even
+ though it may look a bit weird. Requiring the space after the
+ backslash is to make it very unlikely this is a normal comment line.
+
+==============================================================================
+5. Using Vim packages *packages*
+
+A Vim package is a directory that contains one or more plugins. The
+advantages over normal plugins:
+- A package can be downloaded as an archive and unpacked in its own directory.
+ Thus the files are not mixed with files of other plugins. That makes it
+ easy to update and remove.
+- A package can be a git, mercurial, etc. repository. That makes it really
+ easy to update.
+- A package can contain multiple plugins that depend on each other.
+- A package can contain plugins that are automatically loaded on startup and
+ ones that are only loaded when needed with `:packadd`.
+
+
+Using a package and loading automatically ~
+
+Let's assume your Vim files are in the "~/.vim" directory and you want to add a
+package from a zip archive "/tmp/foopack.zip":
+ % mkdir -p ~/.vim/pack/foo
+ % cd ~/.vim/pack/foo
+ % unzip /tmp/foopack.zip
+
+The directory name "foo" is arbitrary, you can pick anything you like.
+
+You would now have these files under ~/.vim:
+ pack/foo/README.txt
+ pack/foo/start/foobar/plugin/foo.vim
+ pack/foo/start/foobar/syntax/some.vim
+ pack/foo/opt/foodebug/plugin/debugger.vim
+
+When Vim starts up, after processing your .vimrc, it scans all directories in
+'packpath' for plugins under the "pack/*/start" directory. First all those
+directories are added to 'runtimepath'. Then all the plugins are loaded.
+See |packload-two-steps| for how these two steps can be useful.
+
+In the example Vim will find "pack/foo/start/foobar/plugin/foo.vim" and adds
+"~/.vim/pack/foo/start/foobar" to 'runtimepath'.
+
+If the "foobar" plugin kicks in and sets the 'filetype' to "some", Vim will
+find the syntax/some.vim file, because its directory is in 'runtimepath'.
+
+Vim will also load ftdetect files, if there are any.
+
+Note that the files under "pack/foo/opt" are not loaded automatically, only the
+ones under "pack/foo/start". See |pack-add| below for how the "opt" directory
+is used.
+
+Loading packages automatically will not happen if loading plugins is disabled,
+see |load-plugins|.
+
+To load packages earlier, so that 'runtimepath' gets updated: >
+ :packloadall
+This also works when loading plugins is disabled. The automatic loading will
+only happen once.
+
+If the package has an "after" directory, that directory is added to the end of
+'runtimepath', so that anything there will be loaded later.
+
+
+Using a single plugin and loading it automatically ~
+
+If you don't have a package but a single plugin, you need to create the extra
+directory level:
+ % mkdir -p ~/.vim/pack/foo/start/foobar
+ % cd ~/.vim/pack/foo/start/foobar
+ % unzip /tmp/someplugin.zip
+
+You would now have these files:
+ pack/foo/start/foobar/plugin/foo.vim
+ pack/foo/start/foobar/syntax/some.vim
+
+From here it works like above.
+
+
+Optional plugins ~
+ *pack-add*
+To load an optional plugin from a pack use the `:packadd` command: >
+ :packadd foodebug
+This searches for "pack/*/opt/foodebug" in 'packpath' and will find
+~/.vim/pack/foo/opt/foodebug/plugin/debugger.vim and source it.
+
+This could be done if some conditions are met. For example, depending on
+whether Vim supports a feature or a dependency is missing.
+
+You can also load an optional plugin at startup, by putting this command in
+your |.vimrc|: >
+ :packadd! foodebug
+The extra "!" is so that the plugin isn't loaded if Vim was started with
+|--noplugin|.
+
+It is perfectly normal for a package to only have files in the "opt"
+directory. You then need to load each plugin when you want to use it.
+
+
+Where to put what ~
+
+Since color schemes, loaded with `:colorscheme`, are found below
+"pack/*/start" and "pack/*/opt", you could put them anywhere. We recommend
+you put them below "pack/*/opt", for example
+".vim/pack/mycolors/opt/dark/colors/very_dark.vim".
+
+Filetype plugins should go under "pack/*/start", so that they are always
+found. Unless you have more than one plugin for a file type and want to
+select which one to load with `:packadd`. E.g. depending on the compiler
+version: >
+ if foo_compiler_version > 34
+ packadd foo_new
+ else
+ packadd foo_old
+ endif
+
+The "after" directory is most likely not useful in a package. It's not
+disallowed though.
+
+==============================================================================
+6. Creating Vim packages *package-create*
+
+This assumes you write one or more plugins that you distribute as a package.
+
+If you have two unrelated plugins you would use two packages, so that Vim
+users can chose what they include or not. Or you can decide to use one
+package with optional plugins, and tell the user to add the ones he wants with
+`:packadd`.
+
+Decide how you want to distribute the package. You can create an archive or
+you could use a repository. An archive can be used by more users, but is a
+bit harder to update to a new version. A repository can usually be kept
+up-to-date easily, but it requires a program like "git" to be available.
+You can do both, github can automatically create an archive for a release.
+
+Your directory layout would be like this:
+ start/foobar/plugin/foo.vim " always loaded, defines commands
+ start/foobar/plugin/bar.vim " always loaded, defines commands
+ start/foobar/autoload/foo.vim " loaded when foo command used
+ start/foobar/doc/foo.txt " help for foo.vim
+ start/foobar/doc/tags " help tags
+ opt/fooextra/plugin/extra.vim " optional plugin, defines commands
+ opt/fooextra/autoload/extra.vim " loaded when extra command used
+ opt/fooextra/doc/extra.txt " help for extra.vim
+ opt/fooextra/doc/tags " help tags
+
+This allows for the user to do: >
+ mkdir ~/.vim/pack/myfoobar
+ cd ~/.vim/pack/myfoobar
+ git clone https://github.com/you/foobar.git
+
+Here "myfoobar" is a name that the user can choose, the only condition is that
+it differs from other packages.
+
+In your documentation you explain what the plugins do, and tell the user how
+to load the optional plugin: >
+ :packadd! fooextra
+
+You could add this packadd command in one of your plugins, to be executed when
+the optional plugin is needed.
+
+Run the `:helptags` command to generate the doc/tags file. Including this
+generated file in the package means that the user can drop the package in his
+pack directory and the help command works right away. Don't forget to re-run
+the command after changing the plugin help: >
+ :helptags path/start/foobar/doc
+ :helptags path/opt/fooextra/doc
+
+
+Dependencies between plugins ~
+ *packload-two-steps*
+Suppose you have two plugins that depend on the same functionality. You can
+put the common functionality in an autoload directory, so that it will be
+found automatically. Your package would have these files:
+
+ pack/foo/start/one/plugin/one.vim >
+ call foolib#getit()
+< pack/foo/start/two/plugin/two.vim >
+ call foolib#getit()
+< pack/foo/start/lib/autoload/foolib.vim >
+ func foolib#getit()
+
+This works, because loading packages will first add all found directories to
+'runtimepath' before sourcing the plugins.
+
+==============================================================================
+7. Debugging scripts *debug-scripts*
+
+Besides the obvious messages that you can add to your scripts to find out what
+they are doing, Vim offers a debug mode. This allows you to step through a
+sourced file or user function and set breakpoints.
+
+NOTE: The debugging mode is far from perfect. Debugging will have side
+effects on how Vim works. You cannot use it to debug everything. For
+example, the display is messed up by the debugging messages.
+{Vi does not have a debug mode}
+
+An alternative to debug mode is setting the 'verbose' option. With a bigger
+number it will give more verbose messages about what Vim is doing.
+
+
+STARTING DEBUG MODE *debug-mode*
+
+To enter debugging mode use one of these methods:
+1. Start Vim with the |-D| argument: >
+ vim -D file.txt
+< Debugging will start as soon as the first vimrc file is sourced. This is
+ useful to find out what is happening when Vim is starting up. A side
+ effect is that Vim will switch the terminal mode before initialisations
+ have finished, with unpredictable results.
+ For a GUI-only version (Windows, Macintosh) the debugging will start as
+ soon as the GUI window has been opened. To make this happen early, add a
+ ":gui" command in the vimrc file.
+ *:debug*
+2. Run a command with ":debug" prepended. Debugging will only be done while
+ this command executes. Useful for debugging a specific script or user
+ function. And for scripts and functions used by autocommands. Example: >
+ :debug edit test.txt.gz
+
+3. Set a breakpoint in a sourced file or user function. You could do this in
+ the command line: >
+ vim -c "breakadd file */explorer.vim" .
+< This will run Vim and stop in the first line of the "explorer.vim" script.
+ Breakpoints can also be set while in debugging mode.
+
+In debugging mode every executed command is displayed before it is executed.
+Comment lines, empty lines and lines that are not executed are skipped. When
+a line contains two commands, separated by "|", each command will be displayed
+separately.
+
+
+DEBUG MODE
+
+Once in debugging mode, the usual Ex commands can be used. For example, to
+inspect the value of a variable: >
+ echo idx
+When inside a user function, this will print the value of the local variable
+"idx". Prepend "g:" to get the value of a global variable: >
+ echo g:idx
+All commands are executed in the context of the current function or script.
+You can also set options, for example setting or resetting 'verbose' will show
+what happens, but you might want to set it just before executing the lines you
+are interested in: >
+ :set verbose=20
+
+Commands that require updating the screen should be avoided, because their
+effect won't be noticed until after leaving debug mode. For example: >
+ :help
+won't be very helpful.
+
+There is a separate command-line history for debug mode.
+
+The line number for a function line is relative to the start of the function.
+If you have trouble figuring out where you are, edit the file that defines
+the function in another Vim, search for the start of the function and do
+"99j". Replace "99" with the line number.
+
+Additionally, these commands can be used:
+ *>cont*
+ cont Continue execution until the next breakpoint is hit.
+ *>quit*
+ quit Abort execution. This is like using CTRL-C, some
+ things might still be executed, doesn't abort
+ everything. Still stops at the next breakpoint.
+ *>next*
+ next Execute the command and come back to debug mode when
+ it's finished. This steps over user function calls
+ and sourced files.
+ *>step*
+ step Execute the command and come back to debug mode for
+ the next command. This steps into called user
+ functions and sourced files.
+ *>interrupt*
+ interrupt This is like using CTRL-C, but unlike ">quit" comes
+ back to debug mode for the next command that is
+ executed. Useful for testing |:finally| and |:catch|
+ on interrupt exceptions.
+ *>finish*
+ finish Finish the current script or user function and come
+ back to debug mode for the command after the one that
+ sourced or called it.
+ *>bt*
+ *>backtrace*
+ *>where*
+ backtrace Show the call stacktrace for current debugging session.
+ bt
+ where
+ *>frame*
+ frame N Goes to N backtrace level. + and - signs make movement
+ relative. E.g., ":frame +3" goes three frames up.
+ *>up*
+ up Goes one level up from call stacktrace.
+ *>down*
+ down Goes one level down from call stacktrace.
+
+About the additional commands in debug mode:
+- There is no command-line completion for them, you get the completion for the
+ normal Ex commands only.
+- You can shorten them, up to a single character, unless more than one command
+ starts with the same letter. "f" stands for "finish", use "fr" for "frame".
+- Hitting <CR> will repeat the previous one. When doing another command, this
+ is reset (because it's not clear what you want to repeat).
+- When you want to use the Ex command with the same name, prepend a colon:
+ ":cont", ":next", ":finish" (or shorter).
+
+The backtrace shows the hierarchy of function calls, e.g.:
+ >bt ~
+ 3 function One[3] ~
+ 2 Two[3] ~
+ ->1 Three[3] ~
+ 0 Four ~
+ line 1: let four = 4 ~
+
+The "->" points to the current frame. Use "up", "down" and "frame N" to
+select another frame.
+
+In the current frame you can evaluate the local function variables. There is
+no way to see the command at the current line yet.
+
+
+DEFINING BREAKPOINTS
+ *:breaka* *:breakadd*
+:breaka[dd] func [lnum] {name}
+ Set a breakpoint in a function. Example: >
+ :breakadd func Explore
+< Doesn't check for a valid function name, thus the breakpoint
+ can be set before the function is defined.
+
+:breaka[dd] file [lnum] {name}
+ Set a breakpoint in a sourced file. Example: >
+ :breakadd file 43 .vimrc
+
+:breaka[dd] here
+ Set a breakpoint in the current line of the current file.
+ Like doing: >
+ :breakadd file <cursor-line> <current-file>
+< Note that this only works for commands that are executed when
+ sourcing the file, not for a function defined in that file.
+
+:breaka[dd] expr {expression}
+ Sets a breakpoint, that will break whenever the {expression}
+ evaluates to a different value. Example: >
+ :breakadd expr g:lnum
+
+< Will break, whenever the global variable lnum changes.
+ Note if you watch a |script-variable| this will break
+ when switching scripts, since the script variable is only
+ valid in the script where it has been defined and if that
+ script is called from several other scripts, this will stop
+ whenever that particular variable will become visible or
+ unaccessible again.
+
+The [lnum] is the line number of the breakpoint. Vim will stop at or after
+this line. When omitted line 1 is used.
+
+ *:debug-name*
+{name} is a pattern that is matched with the file or function name. The
+pattern is like what is used for autocommands. There must be a full match (as
+if the pattern starts with "^" and ends in "$"). A "*" matches any sequence
+of characters. 'ignorecase' is not used, but "\c" can be used in the pattern
+to ignore case |/\c|. Don't include the () for the function name!
+
+The match for sourced scripts is done against the full file name. If no path
+is specified the current directory is used. Examples: >
+ breakadd file explorer.vim
+matches "explorer.vim" in the current directory. >
+ breakadd file *explorer.vim
+matches ".../plugin/explorer.vim", ".../plugin/iexplorer.vim", etc. >
+ breakadd file */explorer.vim
+matches ".../plugin/explorer.vim" and "explorer.vim" in any other directory.
+
+The match for functions is done against the name as it's shown in the output
+of ":function". For local functions this means that something like "<SNR>99_"
+is prepended.
+
+Note that functions are first loaded and later executed. When they are loaded
+the "file" breakpoints are checked, when they are executed the "func"
+breakpoints.
+
+
+DELETING BREAKPOINTS
+ *:breakd* *:breakdel* *E161*
+:breakd[el] {nr}
+ Delete breakpoint {nr}. Use |:breaklist| to see the number of
+ each breakpoint.
+
+:breakd[el] *
+ Delete all breakpoints.
+
+:breakd[el] func [lnum] {name}
+ Delete a breakpoint in a function.
+
+:breakd[el] file [lnum] {name}
+ Delete a breakpoint in a sourced file.
+
+:breakd[el] here
+ Delete a breakpoint at the current line of the current file.
+
+When [lnum] is omitted, the first breakpoint in the function or file is
+deleted.
+The {name} must be exactly the same as what was typed for the ":breakadd"
+command. "explorer", "*explorer.vim" and "*explorer*" are different.
+
+
+LISTING BREAKPOINTS
+ *:breakl* *:breaklist*
+:breakl[ist]
+ List all breakpoints.
+
+
+OBSCURE
+
+ *:debugg* *:debuggreedy*
+:debugg[reedy]
+ Read debug mode commands from the normal input stream, instead
+ of getting them directly from the user. Only useful for test
+ scripts. Example: >
+ echo 'q^Mq' | vim -e -s -c debuggreedy -c 'breakadd file script.vim' -S script.vim
+
+:0debugg[reedy]
+ Undo ":debuggreedy": get debug mode commands directly from the
+ user, don't use typeahead for debug commands.
+
+==============================================================================
+8. Profiling *profile* *profiling*
+
+Profiling means that Vim measures the time that is spent on executing
+functions and/or scripts. The |+profile| feature is required for this.
+It is only included when Vim was compiled with "huge" features.
+{Vi does not have profiling}
+
+You can also use the |reltime()| function to measure time. This only requires
+the |+reltime| feature, which is present more often.
+
+For profiling syntax highlighting see |:syntime|.
+
+For example, to profile the one_script.vim script file: >
+ :profile start /tmp/one_script_profile
+ :profile file one_script.vim
+ :source one_script.vim
+ :exit
+
+
+:prof[ile] start {fname} *:prof* *:profile* *E750*
+ Start profiling, write the output in {fname} upon exit.
+ "~/" and environment variables in {fname} will be expanded.
+ If {fname} already exists it will be silently overwritten.
+ The variable |v:profiling| is set to one.
+
+:prof[ile] pause
+ Don't profile until the following ":profile continue". Can be
+ used when doing something that should not be counted (e.g., an
+ external command). Does not nest.
+
+:prof[ile] continue
+ Continue profiling after ":profile pause".
+
+:prof[ile] func {pattern}
+ Profile function that matches the pattern {pattern}.
+ See |:debug-name| for how {pattern} is used.
+
+:prof[ile][!] file {pattern}
+ Profile script file that matches the pattern {pattern}.
+ See |:debug-name| for how {pattern} is used.
+ This only profiles the script itself, not the functions
+ defined in it.
+ When the [!] is added then all functions defined in the script
+ will also be profiled.
+ Note that profiling only starts when the script is loaded
+ after this command. A :profile command in the script itself
+ won't work.
+
+
+:profd[el] ... *:profd* *:profdel*
+ Stop profiling for the arguments specified. See |:breakdel|
+ for the arguments.
+
+
+You must always start with a ":profile start fname" command. The resulting
+file is written when Vim exits. Here is an example of the output, with line
+numbers prepended for the explanation:
+
+ 1 FUNCTION Test2() ~
+ 2 Called 1 time ~
+ 3 Total time: 0.155251 ~
+ 4 Self time: 0.002006 ~
+ 5 ~
+ 6 count total (s) self (s) ~
+ 7 9 0.000096 for i in range(8) ~
+ 8 8 0.153655 0.000410 call Test3() ~
+ 9 8 0.000070 endfor ~
+ 10 " Ask a question ~
+ 11 1 0.001341 echo input("give me an answer: ") ~
+
+The header (lines 1-4) gives the time for the whole function. The "Total"
+time is the time passed while the function was executing. The "Self" time is
+the "Total" time reduced by time spent in:
+- other user defined functions
+- sourced scripts
+- executed autocommands
+- external (shell) commands
+
+Lines 7-11 show the time spent in each executed line. Lines that are not
+executed do not count. Thus a comment line is never counted.
+
+The Count column shows how many times a line was executed. Note that the
+"for" command in line 7 is executed one more time as the following lines.
+That is because the line is also executed to detect the end of the loop.
+
+The time Vim spends waiting for user input isn't counted at all. Thus how
+long you take to respond to the input() prompt is irrelevant.
+
+Profiling should give a good indication of where time is spent, but keep in
+mind there are various things that may clobber the results:
+
+- The accuracy of the time measured depends on the gettimeofday() system
+ function. It may only be as accurate as 1/100 second, even though the times
+ are displayed in micro seconds.
+
+- Real elapsed time is measured, if other processes are busy they may cause
+ delays at unpredictable moments. You may want to run the profiling several
+ times and use the lowest results.
+
+- If you have several commands in one line you only get one time. Split the
+ line to see the time for the individual commands.
+
+- The time of the lines added up is mostly less than the time of the whole
+ function. There is some overhead in between.
+
+- Functions that are deleted before Vim exits will not produce profiling
+ information. You can check the |v:profiling| variable if needed: >
+ :if !v:profiling
+ : delfunc MyFunc
+ :endif
+<
+- Profiling may give weird results on multi-processor systems, when sleep
+ mode kicks in or the processor frequency is reduced to save power.
+
+- The "self" time is wrong when a function is used recursively.
+
+
+ vim:tw=78:ts=8:noet:ft=help:norl: