xref: /vim-8.2.3635/runtime/doc/eval.txt (revision ab79bcba)

*eval.txt*      For Vim version 7.0aa.  Last change: 2004 Jul 18


		  VIM REFERENCE MANUAL    by Bram Moolenaar


Expression evaluation			*expression* *expr* *E15* *eval*

Using expressions is introduced in chapter 41 of the user manual |usr_41.txt|.

Note: Expression evaluation can be disabled at compile time.  If this has been
done, the features in this document are not available.  See |+eval| and the
last chapter below.

1.  Variables		|variables|
2.  Expression syntax	|expression-syntax|
3.  Internal variable	|internal-variables|
4.  Builtin Functions	|functions|
5.  Defining functions	|user-functions|
6.  Curly braces names	|curly-braces-names|
7.  Commands		|expression-commands|
8.  Exception handling	|exception-handling|
9.  Examples		|eval-examples|
10. No +eval feature	|no-eval-feature|
11. The sandbox		|eval-sandbox|

{Vi does not have any of these commands}

==============================================================================
1. Variables						*variables*

There are two types of variables:

Number		a 32 bit signed number.
String		a NUL terminated string of 8-bit unsigned characters.

These are converted automatically, depending on how they are used.

Conversion from a Number to a String is by making the ASCII representation of
the Number.  Examples: >
	Number 123	-->	String "123"
	Number 0	-->	String "0"
	Number -1	-->	String "-1"

Conversion from a String to a Number is done by converting the first digits
to a number.  Hexadecimal "0xf9" and Octal "017" numbers are recognized.  If
the String doesn't start with digits, the result is zero.  Examples: >
	String "456"	-->	Number 456
	String "6bar"	-->	Number 6
	String "foo"	-->	Number 0
	String "0xf1"	-->	Number 241
	String "0100"	-->	Number 64
	String "-8"	-->	Number -8
	String "+8"	-->	Number 0

To force conversion from String to Number, add zero to it: >
	:echo "0100" + 0

For boolean operators Numbers are used.  Zero is FALSE, non-zero is TRUE.

Note that in the command >
	:if "foo"
"foo" is converted to 0, which means FALSE.  To test for a non-empty string,
use strlen(): >
	:if strlen("foo")

If you need to know the type of a variable or expression, use the |type()|
function.

When the '!' flag is included in the 'viminfo' option, global variables that
start with an uppercase letter, and don't contain a lowercase letter, are
stored in the viminfo file |viminfo-file|.

When the 'sessionoptions' option contains "global", global variables that
start with an uppercase letter and contain at least one lowercase letter are
stored in the session file |session-file|.

variable name		can be stored where ~
my_var_6		not
My_Var_6		session file
MY_VAR_6		viminfo file


It's possible to form a variable name with curly braces, see
|curly-braces-names|.

==============================================================================
2. Expression syntax					*expression-syntax*

Expression syntax summary, from least to most significant:

|expr1| expr2 ? expr1 : expr1	if-then-else

|expr2|	expr3 || expr3 ..	logical OR

|expr3|	expr4 && expr4 ..	logical AND

|expr4|	expr5 == expr5		equal
	expr5 != expr5		not equal
	expr5 >	 expr5		greater than
	expr5 >= expr5		greater than or equal
	expr5 <	 expr5		smaller than
	expr5 <= expr5		smaller than or equal
	expr5 =~ expr5		regexp matches
	expr5 !~ expr5		regexp doesn't match

	expr5 ==? expr5		equal, ignoring case
	expr5 ==# expr5		equal, match case
	etc.			As above, append ? for ignoring case, # for
				matching case

|expr5|	expr6 +	 expr6 ..	number addition
	expr6 -	 expr6 ..	number subtraction
	expr6 .	 expr6 ..	string concatenation

|expr6|	expr7 *	 expr7 ..	number multiplication
	expr7 /	 expr7 ..	number division
	expr7 %	 expr7 ..	number modulo

|expr7|	! expr7			logical NOT
	- expr7			unary minus
	+ expr7			unary plus
	expr8

|expr8|	expr9[expr1]		index in String

|expr9|	number			number constant
	"string"		string constant
	'string'		literal string constant
	&option			option value
	(expr1)			nested expression
	variable		internal variable
	va{ria}ble		internal variable with curly braces
	$VAR			environment variable
	@r			contents of register 'r'
	function(expr1, ...)	function call
	func{ti}on(expr1, ...)	function call with curly braces


".." indicates that the operations in this level can be concatenated.
Example: >
	&nu || &list && &shell == "csh"

All expressions within one level are parsed from left to right.


expr1							*expr1* *E109*
-----

expr2 ? expr1 : expr1

The expression before the '?' is evaluated to a number.  If it evaluates to
non-zero, the result is the value of the expression between the '?' and ':',
otherwise the result is the value of the expression after the ':'.
Example: >
	:echo lnum == 1 ? "top" : lnum

Since the first expression is an "expr2", it cannot contain another ?:.  The
other two expressions can, thus allow for recursive use of ?:.
Example: >
	:echo lnum == 1 ? "top" : lnum == 1000 ? "last" : lnum

To keep this readable, using |line-continuation| is suggested: >
	:echo lnum == 1
	:\	? "top"
	:\	: lnum == 1000
	:\		? "last"
	:\		: lnum


expr2 and expr3						*expr2* *expr3*
---------------

					*expr-barbar* *expr-&&*
The "||" and "&&" operators take one argument on each side.  The arguments
are (converted to) Numbers.  The result is:

	 input				 output ~
n1		n2		n1 || n2	n1 && n2 ~
zero		zero		zero		zero
zero		non-zero	non-zero	zero
non-zero	zero		non-zero	zero
non-zero	non-zero	non-zero	non-zero

The operators can be concatenated, for example: >

	&nu || &list && &shell == "csh"

Note that "&&" takes precedence over "||", so this has the meaning of: >

	&nu || (&list && &shell == "csh")

Once the result is known, the expression "short-circuits", that is, further
arguments are not evaluated.  This is like what happens in C.  For example: >

	let a = 1
	echo a || b

This is valid even if there is no variable called "b" because "a" is non-zero,
so the result must be non-zero.  Similarly below: >

	echo exists("b") && b == "yes"

This is valid whether "b" has been defined or not.  The second clause will
only be evaluated if "b" has been defined.


expr4							*expr4*
-----

expr5 {cmp} expr5

Compare two expr5 expressions, resulting in a 0 if it evaluates to false, or 1
if it evaluates to true.

			*expr-==*  *expr-!=*  *expr->*   *expr->=*
			*expr-<*   *expr-<=*  *expr-=~*  *expr-!~*
			*expr-==#* *expr-!=#* *expr->#*  *expr->=#*
			*expr-<#*  *expr-<=#* *expr-=~#* *expr-!~#*
			*expr-==?* *expr-!=?* *expr->?*  *expr->=?*
			*expr-<?*  *expr-<=?* *expr-=~?* *expr-!~?*
		use 'ignorecase'    match case	   ignore case ~
equal			==		==#		==?
not equal		!=		!=#		!=?
greater than		>		>#		>?
greater than or equal	>=		>=#		>=?
smaller than		<		<#		<?
smaller than or equal	<=		<=#		<=?
regexp matches		=~		=~#		=~?
regexp doesn't match	!~		!~#		!~?

Examples:
"abc" ==# "Abc"	  evaluates to 0
"abc" ==? "Abc"	  evaluates to 1
"abc" == "Abc"	  evaluates to 1 if 'ignorecase' is set, 0 otherwise

When comparing a String with a Number, the String is converted to a Number,
and the comparison is done on Numbers.  This means that "0 == 'x'" is TRUE,
because 'x' converted to a Number is zero.

When comparing two Strings, this is done with strcmp() or stricmp().  This
results in the mathematical difference (comparing byte values), not
necessarily the alphabetical difference in the local language.

When using the operators with a trailing '#", or the short version and
'ignorecase' is off, the comparing is done with strcmp().

When using the operators with a trailing '?', or the short version and
'ignorecase' is set, the comparing is done with stricmp().

The "=~" and "!~" operators match the lefthand argument with the righthand
argument, which is used as a pattern.  See |pattern| for what a pattern is.
This matching is always done like 'magic' was set and 'cpoptions' is empty, no
matter what the actual value of 'magic' or 'cpoptions' is.  This makes scripts
portable.  To avoid backslashes in the regexp pattern to be doubled, use a
single-quote string, see |literal-string|.
Since a string is considered to be a single line, a multi-line pattern
(containing \n, backslash-n) will not match.  However, a literal NL character
can be matched like an ordinary character.  Examples:
	"foo\nbar" =~ "\n"	evaluates to 1
	"foo\nbar" =~ "\\n"	evaluates to 0


expr5 and expr6						*expr5* *expr6*
---------------
expr6 +	 expr6 ..	number addition		*expr-+*
expr6 -	 expr6 ..	number subtraction	*expr--*
expr6 .	 expr6 ..	string concatenation	*expr-.*

expr7 *	 expr7 ..	number multiplication	*expr-star*
expr7 /	 expr7 ..	number division		*expr-/*
expr7 %	 expr7 ..	number modulo		*expr-%*

For all, except ".", Strings are converted to Numbers.

Note the difference between "+" and ".":
	"123" + "456" = 579
	"123" . "456" = "123456"

When the righthand side of '/' is zero, the result is 0x7fffffff.
When the righthand side of '%' is zero, the result is 0.


expr7							*expr7*
-----
! expr7			logical NOT		*expr-!*
- expr7			unary minus		*expr-unary--*
+ expr7			unary plus		*expr-unary-+*

For '!' non-zero becomes zero, zero becomes one.
For '-' the sign of the number is changed.
For '+' the number is unchanged.

A String will be converted to a Number first.

These three can be repeated and mixed.  Examples:
	!-1	    == 0
	!!8	    == 1
	--9	    == 9


expr8							*expr8*
-----
expr9[expr1]		index in String		*expr-[]* *E111*

This results in a String that contains the expr1'th single byte from expr9.
expr9 is used as a String, expr1 as a Number.  Note that this doesn't work for
multi-byte encodings.

Note that index zero gives the first character.  This is like it works in C.
Careful: text column numbers start with one!  Example, to get the character
under the cursor: >
	:let c = getline(line("."))[col(".") - 1]

If the length of the String is less than the index, the result is an empty
String.

						*expr9*
number
------
number			number constant		*expr-number*

Decimal, Hexadecimal (starting with 0x or 0X), or Octal (starting with 0).


string							*expr-string* *E114*
------
"string"		string constant		*expr-quote*

Note that double quotes are used.

A string constant accepts these special characters:
\...	three-digit octal number (e.g., "\316")
\..	two-digit octal number (must be followed by non-digit)
\.	one-digit octal number (must be followed by non-digit)
\x..	byte specified with two hex numbers (e.g., "\x1f")
\x.	byte specified with one hex number (must be followed by non-hex char)
\X..	same as \x..
\X.	same as \x.
\u....  character specified with up to 4 hex numbers, stored according to the
	current value of 'encoding' (e.g., "\u02a4")
\U....	same as \u....
\b	backspace <BS>
\e	escape <Esc>
\f	formfeed <FF>
\n	newline <NL>
\r	return <CR>
\t	tab <Tab>
\\	backslash
\"	double quote
\<xxx>	Special key named "xxx".  e.g. "\<C-W>" for CTRL-W.

Note that "\000" and "\x00" force the end of the string.


literal-string						*literal-string* *E115*
---------------
'string'		literal string constant		*expr-'*

Note that single quotes are used.

This string is taken literally.  No backslashes are removed or have a special
meaning.  A literal-string cannot contain a single quote.  Use a normal string
for that.


option						*expr-option* *E112* *E113*
------
&option			option value, local value if possible
&g:option		global option value
&l:option		local option value

Examples: >
	echo "tabstop is " . &tabstop
	if &insertmode

Any option name can be used here.  See |options|.  When using the local value
and there is no buffer-local or window-local value, the global value is used
anyway.


register						*expr-register*
--------
@r			contents of register 'r'

The result is the contents of the named register, as a single string.
Newlines are inserted where required.  To get the contents of the unnamed
register use @" or @@.  The '=' register can not be used here.  See
|registers| for an explanation of the available registers.


nesting							*expr-nesting* *E110*
-------
(expr1)			nested expression


environment variable					*expr-env*
--------------------
$VAR			environment variable

The String value of any environment variable.  When it is not defined, the
result is an empty string.
						*expr-env-expand*
Note that there is a difference between using $VAR directly and using
expand("$VAR").  Using it directly will only expand environment variables that
are known inside the current Vim session.  Using expand() will first try using
the environment variables known inside the current Vim session.  If that
fails, a shell will be used to expand the variable.  This can be slow, but it
does expand all variables that the shell knows about.  Example: >
	:echo $version
	:echo expand("$version")
The first one probably doesn't echo anything, the second echoes the $version
variable (if your shell supports it).


internal variable					*expr-variable*
-----------------
variable		internal variable
See below |internal-variables|.


function call		*expr-function* *E116* *E117* *E118* *E119* *E120*
-------------
function(expr1, ...)	function call
See below |functions|.


==============================================================================
3. Internal variable				*internal-variables* *E121*
									*E461*
An internal variable name can be made up of letters, digits and '_'.  But it
cannot start with a digit.  It's also possible to use curly braces, see
|curly-braces-names|.

An internal variable is created with the ":let" command |:let|.
An internal variable is destroyed with the ":unlet" command |:unlet|.
Using a name that isn't an internal variable, or an internal variable that has
been destroyed, results in an error.

There are several name spaces for variables.  Which one is to be used is
specified by what is prepended:

		(nothing) In a function: local to a function; otherwise: global
|buffer-variable|    b:	  Local to the current buffer.
|window-variable|    w:	  Local to the current window.
|global-variable|    g:	  Global.
|local-variable|     l:	  Local to a function.
|script-variable|    s:	  Local to a |:source|'ed Vim script.
|function-argument|  a:	  Function argument (only inside a function).
|vim-variable|       v:	  Global, predefined by Vim.

						*buffer-variable* *b:var*
A variable name that is preceded with "b:" is local to the current buffer.
Thus you can have several "b:foo" variables, one for each buffer.
This kind of variable is deleted when the buffer is wiped out or deleted with
|:bdelete|.

One local buffer variable is predefined:
					*b:changedtick-variable* *changetick*
b:changedtick	The total number of changes to the current buffer.  It is
		incremented for each change.  An undo command is also a change
		in this case.  This can be used to perform an action only when
		the buffer has changed.  Example: >
		    :if my_changedtick != b:changedtick
		    :   let my_changedtick = b:changedtick
		    :   call My_Update()
		    :endif
<
						*window-variable* *w:var*
A variable name that is preceded with "w:" is local to the current window.  It
is deleted when the window is closed.

						*global-variable* *g:var*
Inside functions global variables are accessed with "g:".  Omitting this will
access a variable local to a function.  But "g:" can also be used in any other
place if you like.

						*local-variable* *l:var*
Inside functions local variables are accessed without prepending anything.
But you can also prepend "l:" if you like.

						*script-variable* *s:var*
In a Vim script variables starting with "s:" can be used.  They cannot be
accessed from outside of the scripts, thus are local to the script.

They can be used in:
- commands executed while the script is sourced
- functions defined in the script
- autocommands defined in the script
- functions and autocommands defined in functions and autocommands which were
  defined in the script (recursively)
- user defined commands defined in the script
Thus not in:
- other scripts sourced from this one
- mappings
- etc.

script variables can be used to avoid conflicts with global variable names.
Take this example:

	let s:counter = 0
	function MyCounter()
	  let s:counter = s:counter + 1
	  echo s:counter
	endfunction
	command Tick call MyCounter()

You can now invoke "Tick" from any script, and the "s:counter" variable in
that script will not be changed, only the "s:counter" in the script where
"Tick" was defined is used.

Another example that does the same: >

	let s:counter = 0
	command Tick let s:counter = s:counter + 1 | echo s:counter

When calling a function and invoking a user-defined command, the context for
script variables is set to the script where the function or command was
defined.

The script variables are also available when a function is defined inside a
function that is defined in a script.  Example: >

	let s:counter = 0
	function StartCounting(incr)
	  if a:incr
	    function MyCounter()
	      let s:counter = s:counter + 1
	    endfunction
	  else
	    function MyCounter()
	      let s:counter = s:counter - 1
	    endfunction
	  endif
	endfunction

This defines the MyCounter() function either for counting up or counting down
when calling StartCounting().  It doesn't matter from where StartCounting() is
called, the s:counter variable will be accessible in MyCounter().

When the same script is sourced again it will use the same script variables.
They will remain valid as long as Vim is running.  This can be used to
maintain a counter: >

	if !exists("s:counter")
	  let s:counter = 1
	  echo "script executed for the first time"
	else
	  let s:counter = s:counter + 1
	  echo "script executed " . s:counter . " times now"
	endif

Note that this means that filetype plugins don't get a different set of script
variables for each buffer.  Use local buffer variables instead |b:var|.


Predefined Vim variables:			*vim-variable* *v:var*

			*v:charconvert_from* *charconvert_from-variable*
v:charconvert_from
		The name of the character encoding of a file to be converted.
		Only valid while evaluating the 'charconvert' option.

			*v:charconvert_to* *charconvert_to-variable*
v:charconvert_to
		The name of the character encoding of a file after conversion.
		Only valid while evaluating the 'charconvert' option.

					*v:cmdarg* *cmdarg-variable*
v:cmdarg	This variable is used for two purposes:
		1. The extra arguments given to a file read/write command.
		   Currently these are "++enc=" and "++ff=".  This variable is
		   set before an autocommand event for a file read/write
		   command is triggered.  There is a leading space to make it
		   possible to append this variable directly after the
		   read/write command.  Note: The "+cmd" argument isn't
		   included here, because it will be executed anyway.
		2. When printing a PostScript file with ":hardcopy" this is
		   the argument for the ":hardcopy" command.  This can be used
		   in 'printexpr'.

					*v:cmdbang* *cmdbang-variable*
v:cmdbang	Set like v:cmdarg for a file read/write command.  When a "!"
		was used the value is 1, otherwise it is 0.  Note that this
		can only be used in autocommands.  For user commands |<bang>|
		can be used.

					*v:count* *count-variable*
v:count		The count given for the last Normal mode command.  Can be used
		to get the count before a mapping.  Read-only.  Example: >
	:map _x :<C-U>echo "the count is " . v:count<CR>
<		Note: The <C-U> is required to remove the line range that you
		get when typing ':' after a count.
		"count" also works, for backwards compatibility.

					*v:count1* *count1-variable*
v:count1	Just like "v:count", but defaults to one when no count is
		used.

						*v:ctype* *ctype-variable*
v:ctype		The current locale setting for characters of the runtime
		environment.  This allows Vim scripts to be aware of the
		current locale encoding.  Technical: it's the value of
		LC_CTYPE.  When not using a locale the value is "C".
		This variable can not be set directly, use the |:language|
		command.
		See |multi-lang|.

					*v:dying* *dying-variable*
v:dying		Normally zero.  When a deadly signal is caught it's set to
		one.  When multiple signals are caught the number increases.
		Can be used in an autocommand to check if Vim didn't
		terminate normally. {only works on Unix}
		Example: >
	:au VimLeave * if v:dying | echo "\nAAAAaaaarrrggghhhh!!!\n" | endif
<
					*v:errmsg* *errmsg-variable*
v:errmsg	Last given error message.  It's allowed to set this variable.
		Example: >
	:let v:errmsg = ""
	:silent! next
	:if v:errmsg != ""
	:  ... handle error
<		"errmsg" also works, for backwards compatibility.

					*v:exception* *exception-variable*
v:exception	The value of the exception most recently caught and not
		finished.  See also |v:throwpoint| and |throw-variables|.
		Example: >
	:try
	:  throw "oops"
	:catch /.*/
	:  echo "caught" v:exception
	:endtry
<		Output: "caught oops".

					*v:fname_in* *fname_in-variable*
v:fname_in	The name of the input file.  Only valid while evaluating:
			option		used for ~
			'charconvert'	file to be converted
			'diffexpr'	original file
			'patchexpr'	original file
			'printexpr'	file to be printed

					*v:fname_out* *fname_out-variable*
v:fname_out	The name of the output file.  Only valid while
		evaluating:
			option		used for ~
			'charconvert'	resulting converted file (*)
			'diffexpr'	output of diff
			'patchexpr'	resulting patched file
		(*) When doing conversion for a write command (e.g., ":w
		file") it will be equal to v:fname_in.  When doing conversion
		for a read command (e.g., ":e file") it will be a temporary
		file and different from v:fname_in.

					*v:fname_new* *fname_new-variable*
v:fname_new	The name of the new version of the file.  Only valid while
		evaluating 'diffexpr'.

					*v:fname_diff* *fname_diff-variable*
v:fname_diff	The name of the diff (patch) file.  Only valid while
		evaluating 'patchexpr'.

					*v:folddashes* *folddashes-variable*
v:folddashes	Used for 'foldtext': dashes representing foldlevel of a closed
		fold.
		Read-only. |fold-foldtext|

					*v:foldlevel* *foldlevel-variable*
v:foldlevel	Used for 'foldtext': foldlevel of closed fold.
		Read-only. |fold-foldtext|

					*v:foldend* *foldend-variable*
v:foldend	Used for 'foldtext': last line of closed fold.
		Read-only. |fold-foldtext|

					*v:foldstart* *foldstart-variable*
v:foldstart	Used for 'foldtext': first line of closed fold.
		Read-only. |fold-foldtext|

					*v:insertmode* *insertmode-variable*
v:insertmode	Used for the |InsertEnter| and |InsertChange| autocommand
		events.  Values:
			i	Insert mode
			r	Replace mode
			v	Virtual Replace mode

						*v:lang* *lang-variable*
v:lang		The current locale setting for messages of the runtime
		environment.  This allows Vim scripts to be aware of the
		current language.  Technical: it's the value of LC_MESSAGES.
		The value is system dependent.
		This variable can not be set directly, use the |:language|
		command.
		It can be different from |v:ctype| when messages are desired
		in a different language than what is used for character
		encoding.  See |multi-lang|.

						*v:lc_time* *lc_time-variable*
v:lc_time	The current locale setting for time messages of the runtime
		environment.  This allows Vim scripts to be aware of the
		current language.  Technical: it's the value of LC_TIME.
		This variable can not be set directly, use the |:language|
		command.  See |multi-lang|.

						*v:lnum* *lnum-variable*
v:lnum		Line number for the 'foldexpr' and 'indentexpr' expressions.
		Only valid while one of these expressions is being evaluated.
		Read-only. |fold-expr| 'indentexpr'

					*v:prevcount* *prevcount-variable*
v:prevcount	The count given for the last but one Normal mode command.
		This is the v:count value of the previous command.  Useful if
		you want to cancel Visual mode and then use the count. >
			:vmap % <Esc>:call MyFilter(v:prevcount)<CR>
<		Read-only.

					*v:progname* *progname-variable*
v:progname	Contains the name (with path removed) with which Vim was
		invoked.  Allows you to do special initialisations for "view",
		"evim" etc., or any other name you might symlink to Vim.
		Read-only.

					*v:register* *register-variable*
v:register	The name of the register supplied to the last normal mode
		command.  Empty if none were supplied. |getreg()| |setreg()|

					*v:servername* *servername-variable*
v:servername	The resulting registered |x11-clientserver| name if any.
		Read-only.

					*v:shell_error* *shell_error-variable*
v:shell_error	Result of the last shell command.  When non-zero, the last
		shell command had an error.  When zero, there was no problem.
		This only works when the shell returns the error code to Vim.
		The value -1 is often used when the command could not be
		executed.  Read-only.
		Example: >
	:!mv foo bar
	:if v:shell_error
	:  echo 'could not rename "foo" to "bar"!'
	:endif
<		"shell_error" also works, for backwards compatibility.

					*v:statusmsg* *statusmsg-variable*
v:statusmsg	Last given status message.  It's allowed to set this variable.

				*v:termresponse* *termresponse-variable*
v:termresponse	The escape sequence returned by the terminal for the |t_RV|
		termcap entry.  It is set when Vim receives an escape sequence
		that starts with ESC [ or CSI and ends in a 'c', with only
		digits, ';' and '.' in between.
		When this option is set, the TermResponse autocommand event is
		fired, so that you can react to the response from the
		terminal.
		The response from a new xterm is: "<Esc>[ Pp ; Pv ; Pc c".  Pp
		is the terminal type: 0 for vt100 and 1 for vt220.  Pv is the
		patch level (since this was introduced in patch 95, it's
		always 95 or bigger).  Pc is always zero.
		{only when compiled with |+termresponse| feature}

				*v:this_session* *this_session-variable*
v:this_session	Full filename of the last loaded or saved session file.  See
		|:mksession|.  It is allowed to set this variable.  When no
		session file has been saved, this variable is empty.
		"this_session" also works, for backwards compatibility.

					*v:throwpoint* *throwpoint-variable*
v:throwpoint	The point where the exception most recently caught and not
		finished was thrown.  Not set when commands are typed.  See
		also |v:exception| and |throw-variables|.
		Example: >
	:try
	:  throw "oops"
	:catch /.*/
	:  echo "Exception from" v:throwpoint
	:endtry
<		Output: "Exception from test.vim, line 2"

					*v:version* *version-variable*
v:version	Version number of Vim: Major version number times 100 plus
		minor version number.  Version 5.0 is 500.  Version 5.1 (5.01)
		is 501.  Read-only.  "version" also works, for backwards
		compatibility.
		Use |has()| to check if a certain patch was included, e.g.: >
			if has("patch123")
<		Note that patch numbers are specific to the version, thus both
		version 5.0 and 5.1 may have a patch 123, but these are
		completely different.

					*v:warningmsg* *warningmsg-variable*
v:warningmsg	Last given warning message.  It's allowed to set this variable.

==============================================================================
4. Builtin Functions					*functions*

See |function-list| for a list grouped by what the function is used for.

(Use CTRL-] on the function name to jump to the full explanation)

USAGE				RESULT	DESCRIPTION	~

append( {lnum}, {string})	Number  append {string} below line {lnum}
argc()				Number	number of files in the argument list
argidx()			Number  current index in the argument list
argv( {nr})			String	{nr} entry of the argument list
browse( {save}, {title}, {initdir}, {default})
				String	put up a file requester
bufexists( {expr})		Number	TRUE if buffer {expr} exists
buflisted( {expr})		Number  TRUE if buffer {expr} is listed
bufloaded( {expr})		Number  TRUE if buffer {expr} is loaded
bufname( {expr})		String	Name of the buffer {expr}
bufnr( {expr})			Number	Number of the buffer {expr}
bufwinnr( {expr})		Number	window number of buffer {expr}
byte2line( {byte})		Number	line number at byte count {byte}
byteidx( {expr}, {nr})		Number  byte index of {nr}'th char in {expr}
char2nr( {expr})		Number	ASCII value of first char in {expr}
cindent( {lnum})		Number  C indent for line {lnum}
col( {expr})			Number	column nr of cursor or mark
confirm( {msg} [, {choices} [, {default} [, {type}]]])
				Number	number of choice picked by user
cscope_connection( [{num} , {dbpath} [, {prepend}]])
				Number	checks existence of cscope connection
cursor( {lnum}, {col})		Number  position cursor at {lnum}, {col}
delete( {fname})		Number	delete file {fname}
did_filetype()			Number	TRUE if FileType autocommand event used
escape( {string}, {chars})	String	escape {chars} in {string} with '\'
eventhandler( )			Number  TRUE if inside an event handler
executable( {expr})		Number	1 if executable {expr} exists
exists( {expr})			Number	TRUE if {expr} exists
expand( {expr})			String	expand special keywords in {expr}
filereadable( {file})		Number	TRUE if {file} is a readable file
filewritable( {file})		Number	TRUE if {file} is a writable file
fnamemodify( {fname}, {mods})	String	modify file name
foldclosed( {lnum})		Number  first line of fold at {lnum} if closed
foldclosedend( {lnum})		Number  last line of fold at {lnum} if closed
foldlevel( {lnum})		Number	fold level at {lnum}
foldtext( )			String  line displayed for closed fold
foreground( )			Number	bring the Vim window to the foreground
getchar( [expr])		Number  get one character from the user
getcharmod( )			Number  modifiers for the last typed character
getbufvar( {expr}, {varname})		variable {varname} in buffer {expr}
getcmdline()			String	return the current command-line
getcmdpos()			Number	return cursor position in command-line
getcwd()			String	the current working directory
getfsize( {fname})		Number	size in bytes of file
getftime( {fname})		Number	last modification time of file
getline( {lnum})		String	line {lnum} from current buffer
getreg( [{regname}])		String  contents of register
getregtype( [{regname}])	String  type of register
getwinposx()			Number	X coord in pixels of GUI Vim window
getwinposy()			Number	Y coord in pixels of GUI Vim window
getwinvar( {nr}, {varname})		variable {varname} in window {nr}
glob( {expr})			String	expand file wildcards in {expr}
globpath( {path}, {expr})	String	do glob({expr}) for all dirs in {path}
has( {feature})			Number	TRUE if feature {feature} supported
hasmapto( {what} [, {mode}])	Number	TRUE if mapping to {what} exists
histadd( {history},{item})	String	add an item to a history
histdel( {history} [, {item}])	String	remove an item from a history
histget( {history} [, {index}])	String	get the item {index} from a history
histnr( {history})		Number	highest index of a history
hlexists( {name})		Number	TRUE if highlight group {name} exists
hlID( {name})			Number	syntax ID of highlight group {name}
hostname()			String	name of the machine Vim is running on
iconv( {expr}, {from}, {to})	String  convert encoding of {expr}
indent( {lnum})			Number  indent of line {lnum}
input( {prompt} [, {text}])	String	get input from the user
inputdialog( {p} [, {t} [, {c}]]) String  like input() but in a GUI dialog
inputrestore()			Number  restore typeahead
inputsave()			Number  save and clear typeahead
inputsecret( {prompt} [, {text}]) String  like input() but hiding the text
isdirectory( {directory})	Number	TRUE if {directory} is a directory
libcall( {lib}, {func}, {arg})	String  call {func} in library {lib} with {arg}
libcallnr( {lib}, {func}, {arg})  Number  idem, but return a Number
line( {expr})			Number	line nr of cursor, last line or mark
line2byte( {lnum})		Number	byte count of line {lnum}
lispindent( {lnum})		Number  Lisp indent for line {lnum}
localtime()			Number	current time
maparg( {name}[, {mode}])	String	rhs of mapping {name} in mode {mode}
mapcheck( {name}[, {mode}])	String	check for mappings matching {name}
match( {expr}, {pat}[, {start}])
				Number	position where {pat} matches in {expr}
matchend( {expr}, {pat}[, {start}])
				Number	position where {pat} ends in {expr}
matchstr( {expr}, {pat}[, {start}])
				String	match of {pat} in {expr}
mode()				String  current editing mode
nextnonblank( {lnum})		Number	line nr of non-blank line >= {lnum}
nr2char( {expr})		String	single char with ASCII value {expr}
prevnonblank( {lnum})		Number	line nr of non-blank line <= {lnum}
remote_expr( {server}, {string} [, {idvar}])
				String	send expression
remote_foreground( {server})	Number	bring Vim server to the foreground
remote_peek( {serverid} [, {retvar}])
				Number	check for reply string
remote_read( {serverid})	String	read reply string
remote_send( {server}, {string} [, {idvar}])
				String	send key sequence
rename( {from}, {to})		Number  rename (move) file from {from} to {to}
repeat( {expr}, {count})	String  repeat {expr} {count} times
resolve( {filename})		String  get filename a shortcut points to
search( {pattern} [, {flags}])	Number  search for {pattern}
searchpair( {start}, {middle}, {end} [, {flags} [, {skip}]])
				Number  search for other end of start/end pair
server2client( {clientid}, {string})
				Number	send reply string
serverlist()			String	get a list of available servers
setbufvar( {expr}, {varname}, {val})	set {varname} in buffer {expr} to {val}
setcmdpos( {pos})		Number	set cursor position in command-line
setline( {lnum}, {line})	Number	set line {lnum} to {line}
setreg( {n}, {v}[, {opt}])	Number  set register to value and type
setwinvar( {nr}, {varname}, {val})	set {varname} in window {nr} to {val}
simplify( {filename})		String  simplify filename as much as possible
strftime( {format}[, {time}])	String	time in specified format
stridx( {haystack}, {needle})	Number	first index of {needle} in {haystack}
strlen( {expr})			Number	length of the String {expr}
strpart( {src}, {start}[, {len}])
				String	{len} characters of {src} at {start}
strridx( {haystack}, {needle})	Number	last index of {needle} in {haystack}
strtrans( {expr})		String	translate string to make it printable
submatch( {nr})			String  specific match in ":substitute"
substitute( {expr}, {pat}, {sub}, {flags})
				String	all {pat} in {expr} replaced with {sub}
synID( {line}, {col}, {trans})	Number	syntax ID at {line} and {col}
synIDattr( {synID}, {what} [, {mode}])
				String	attribute {what} of syntax ID {synID}
synIDtrans( {synID})		Number	translated syntax ID of {synID}
system( {expr})			String	output of shell command {expr}
tempname()			String	name for a temporary file
tolower( {expr})		String	the String {expr} switched to lowercase
toupper( {expr})		String	the String {expr} switched to uppercase
tr( {src}, {fromstr}, {tostr})	String	translate chars of {src} in {fromstr}
					to chars in {tostr}
type( {name})			Number	type of variable {name}
virtcol( {expr})		Number	screen column of cursor or mark
visualmode( [expr])		String	last visual mode used
winbufnr( {nr})			Number	buffer number of window {nr}
wincol()			Number	window column of the cursor
winheight( {nr})		Number	height of window {nr}
winline()			Number	window line of the cursor
winnr()				Number	number of current window
winrestcmd()			String  returns command to restore window sizes
winwidth( {nr})			Number	width of window {nr}

append({lnum}, {string})				*append()*
		Append the text {string} after line {lnum} in the current
		buffer.  {lnum} can be zero, to insert a line before the first
		one.  Returns 1 for failure ({lnum} out of range) or 0 for
		success.

							*argc()*
argc()		The result is the number of files in the argument list of the
		current window.  See |arglist|.

							*argidx()*
argidx()	The result is the current index in the argument list.  0 is
		the first file.  argc() - 1 is the last one.  See |arglist|.

							*argv()*
argv({nr})	The result is the {nr}th file in the argument list of the
		current window.  See |arglist|.  "argv(0)" is the first one.
		Example: >
	:let i = 0
	:while i < argc()
	:  let f = escape(argv(i), '. ')
	:  exe 'amenu Arg.' . f . ' :e ' . f . '<CR>'
	:  let i = i + 1
	:endwhile
<
							*browse()*
browse({save}, {title}, {initdir}, {default})
		Put up a file requester.  This only works when "has("browse")"
		returns non-zero (only in some GUI versions).
		The input fields are:
		    {save}	when non-zero, select file to write
		    {title}	title for the requester
		    {initdir}	directory to start browsing in
		    {default}	default file name
		When the "Cancel" button is hit, something went wrong, or
		browsing is not possible, an empty string is returned.

bufexists({expr})					*bufexists()*
		The result is a Number, which is non-zero if a buffer called
		{expr} exists.
		If the {expr} argument is a number, buffer numbers are used.
		If the {expr} argument is a string it must match a buffer name
		exactly.  The name can be:
		- Relative to the current directory.
		- A full path.
		- The name of a buffer with 'filetype' set to "nofile".
		- A URL name.
		Unlisted buffers will be found.
		Note that help files are listed by their short name in the
		output of |:buffers|, but bufexists() requires using their
		long name to be able to find them.
		Use "bufexists(0)" to test for the existence of an alternate
		file name.
							*buffer_exists()*
		Obsolete name: buffer_exists().

buflisted({expr})					*buflisted()*
		The result is a Number, which is non-zero if a buffer called
		{expr} exists and is listed (has the 'buflisted' option set).
		The {expr} argument is used like with |bufexists()|.

bufloaded({expr})					*bufloaded()*
		The result is a Number, which is non-zero if a buffer called
		{expr} exists and is loaded (shown in a window or hidden).
		The {expr} argument is used like with |bufexists()|.

bufname({expr})						*bufname()*
		The result is the name of a buffer, as it is displayed by the
		":ls" command.
		If {expr} is a Number, that buffer number's name is given.
		Number zero is the alternate buffer for the current window.
		If {expr} is a String, it is used as a |file-pattern| to match
		with the buffer names.  This is always done like 'magic' is
		set and 'cpoptions' is empty.  When there is more than one
		match an empty string is returned.
		"" or "%" can be used for the current buffer, "#" for the
		alternate buffer.
		A full match is preferred, otherwise a match at the start, end
		or middle of the buffer name is accepted.
		Listed buffers are found first.  If there is a single match
		with a listed buffer, that one is returned.  Next unlisted
		buffers are searched for.
		If the {expr} is a String, but you want to use it as a buffer
		number, force it to be a Number by adding zero to it: >
			:echo bufname("3" + 0)
<		If the buffer doesn't exist, or doesn't have a name, an empty
		string is returned. >
	bufname("#")		alternate buffer name
	bufname(3)		name of buffer 3
	bufname("%")		name of current buffer
	bufname("file2")	name of buffer where "file2" matches.
<							*buffer_name()*
		Obsolete name: buffer_name().

							*bufnr()*
bufnr({expr})	The result is the number of a buffer, as it is displayed by
		the ":ls" command.  For the use of {expr}, see |bufname()|
		above.  If the buffer doesn't exist, -1 is returned.
		bufnr("$") is the last buffer: >
	:let last_buffer = bufnr("$")
<		The result is a Number, which is the highest buffer number
		of existing buffers.  Note that not all buffers with a smaller
		number necessarily exist, because ":bwipeout" may have removed
		them.  Use bufexists() to test for the existence of a buffer.
							*buffer_number()*
		Obsolete name: buffer_number().
							*last_buffer_nr()*
		Obsolete name for bufnr("$"): last_buffer_nr().

bufwinnr({expr})					*bufwinnr()*
		The result is a Number, which is the number of the first
		window associated with buffer {expr}.  For the use of {expr},
		see |bufname()| above.  If buffer {expr} doesn't exist or
		there is no such window, -1 is returned.  Example: >

	echo "A window containing buffer 1 is " . (bufwinnr(1))

<		The number can be used with |CTRL-W_w| and ":wincmd w"
		|:wincmd|.


byte2line({byte})					*byte2line()*
		Return the line number that contains the character at byte
		count {byte} in the current buffer.  This includes the
		end-of-line character, depending on the 'fileformat' option
		for the current buffer.  The first character has byte count
		one.
		Also see |line2byte()|, |go| and |:goto|.
		{not available when compiled without the |+byte_offset|
		feature}

byteidx({expr}, {nr})					*byteidx()*
		Return byte index of the {nr}'th character in the string
		{expr}.  Use zero for the first character, it returns zero.
		This function is only useful when there are multibyte
		characters, otherwise the returned value is equal to {nr}.
		Composing characters are counted as a separate character.
		Example : >
			echo matchstr(str, ".", byteidx(str, 3))
<		will display the fourth character.  Another way to do the
		same: >
			let s = strpart(str, byteidx(str, 3))
			echo strpart(s, 0, byteidx(s, 1))
<		If there are less than {nr} characters -1 is returned.
		If there are exactly {nr} characters the length of the string
		is returned.

char2nr({expr})						*char2nr()*
		Return number value of the first char in {expr}.  Examples: >
			char2nr(" ")		returns 32
			char2nr("ABC")		returns 65
<		The current 'encoding' is used.  Example for "utf-8": >
			char2nr("�")		returns 225
			char2nr("�"[0])		returns 195

cindent({lnum})						*cindent()*
		Get the amount of indent for line {lnum} according the C
		indenting rules, as with 'cindent'.
		The indent is counted in spaces, the value of 'tabstop' is
		relevant.  {lnum} is used just like in |getline()|.
		When {lnum} is invalid or Vim was not compiled the |+cindent|
		feature, -1 is returned.

							*col()*
col({expr})	The result is a Number, which is the column of the file
		position given with {expr}.  The accepted positions are:
		    .	    the cursor position
		    $	    the end of the cursor line (the result is the
			    number of characters in the cursor line plus one)
		    'x	    position of mark x (if the mark is not set, 0 is
			    returned)
		For the screen column position use |virtcol()|.
		Note that only marks in the current file can be used.
		Examples: >
			col(".")		column of cursor
			col("$")		length of cursor line plus one
			col("'t")		column of mark t
			col("'" . markname)	column of mark markname
<		The first column is 1.  0 is returned for an error.
		For the cursor position, when 'virtualedit' is active, the
		column is one higher if the cursor is after the end of the
		line.  This can be used to obtain the column in Insert mode: >
			:imap <F2> <C-O>:let save_ve = &ve<CR>
				\<C-O>:set ve=all<CR>
				\<C-O>:echo col(".") . "\n" <Bar>
				\let &ve = save_ve<CR>
<
						*confirm()*
confirm({msg} [, {choices} [, {default} [, {type}]]])
		Confirm() offers the user a dialog, from which a choice can be
		made.  It returns the number of the choice.  For the first
		choice this is 1.
		Note: confirm() is only supported when compiled with dialog
		support, see |+dialog_con| and |+dialog_gui|.
		{msg} is displayed in a |dialog| with {choices} as the
		alternatives.  When {choices} is missing or empty, "&OK" is
		used (and translated).
		{msg} is a String, use '\n' to include a newline.  Only on
		some systems the string is wrapped when it doesn't fit.
		{choices} is a String, with the individual choices separated
		by '\n', e.g. >
			confirm("Save changes?", "&Yes\n&No\n&Cancel")
<		The letter after the '&' is the shortcut key for that choice.
		Thus you can type 'c' to select "Cancel".  The shortcut does
		not need to be the first letter: >
			confirm("file has been modified", "&Save\nSave &All")
<		For the console, the first letter of each choice is used as
		the default shortcut key.
		The optional {default} argument is the number of the choice
		that is made if the user hits <CR>.  Use 1 to make the first
		choice the default one.  Use 0 to not set a default.  If
		{default} is omitted, 1 is used.
		The optional {type} argument gives the type of dialog.  This
		is only used for the icon of the Win32 GUI.  It can be one of
		these values: "Error", "Question", "Info", "Warning" or
		"Generic".  Only the first character is relevant.  When {type}
		is omitted, "Generic" is used.
		If the user aborts the dialog by pressing <Esc>, CTRL-C,
		or another valid interrupt key, confirm() returns 0.

		An example: >
   :let choice = confirm("What do you want?", "&Apples\n&Oranges\n&Bananas", 2)
   :if choice == 0
   :	echo "make up your mind!"
   :elseif choice == 3
   :	echo "tasteful"
   :else
   :	echo "I prefer bananas myself."
   :endif
<		In a GUI dialog, buttons are used.  The layout of the buttons
		depends on the 'v' flag in 'guioptions'.  If it is included,
		the buttons are always put vertically.  Otherwise,  confirm()
		tries to put the buttons in one horizontal line.  If they
		don't fit, a vertical layout is used anyway.  For some systems
		the horizontal layout is always used.

							*cscope_connection()*
cscope_connection([{num} , {dbpath} [, {prepend}]])
		Checks for the existence of a |cscope| connection.  If no
		parameters are specified, then the function returns:
			0, if cscope was not available (not compiled in), or
			   if there are no cscope connections;
			1, if there is at least one cscope connection.

		If parameters are specified, then the value of {num}
		determines how existence of a cscope connection is checked:

		{num}	Description of existence check
		-----	------------------------------
		0	Same as no parameters (e.g., "cscope_connection()").
		1	Ignore {prepend}, and use partial string matches for
			{dbpath}.
		2	Ignore {prepend}, and use exact string matches for
			{dbpath}.
		3	Use {prepend}, use partial string matches for both
			{dbpath} and {prepend}.
		4	Use {prepend}, use exact string matches for both
			{dbpath} and {prepend}.

		Note: All string comparisons are case sensitive!

		Examples.  Suppose we had the following (from ":cs show"): >

  # pid    database name			prepend path
  0 27664  cscope.out				/usr/local
<
		Invocation					Return Val ~
		----------					---------- >
		cscope_connection()					1
		cscope_connection(1, "out")				1
		cscope_connection(2, "out")				0
		cscope_connection(3, "out")				0
		cscope_connection(3, "out", "local")			1
		cscope_connection(4, "out")				0
		cscope_connection(4, "out", "local")			0
		cscope_connection(4, "cscope.out", "/usr/local")	1
<
cursor({lnum}, {col})					*cursor()*
		Positions the cursor at the column {col} in the line {lnum}.
		Does not change the jumplist.
		If {lnum} is greater than the number of lines in the buffer,
		the cursor will be positioned at the last line in the buffer.
		If {lnum} is zero, the cursor will stay in the current line.
		If {col} is greater than the number of characters in the line,
		the cursor will be positioned at the last character in the
		line.
		If {col} is zero, the cursor will stay in the current column.

							*delete()*
delete({fname})	Deletes the file by the name {fname}.  The result is a Number,
		which is 0 if the file was deleted successfully, and non-zero
		when the deletion failed.

							*did_filetype()*
did_filetype()	Returns non-zero when autocommands are being executed and the
		FileType event has been triggered at least once.  Can be used
		to avoid triggering the FileType event again in the scripts
		that detect the file type. |FileType|
		When editing another file, the counter is reset, thus this
		really checks if the FileType event has been triggered for the
		current buffer.  This allows an autocommand that starts
		editing another buffer to set 'filetype' and load a syntax
		file.

escape({string}, {chars})				*escape()*
		Escape the characters in {chars} that occur in {string} with a
		backslash.  Example: >
			:echo escape('c:\program files\vim', ' \')
<		results in: >
			c:\\program\ files\\vim
<
eventhandler()						*eventhandler()*
		Returns 1 when inside an event handler.  That is that Vim got
		interrupted while waiting for the user to type a character,
		e.g., when dropping a file on Vim.  This means interactive
		commands cannot be used.  Otherwise zero is returned.

executable({expr})					*executable()*
		This function checks if an executable with the name {expr}
		exists.  {expr} must be the name of the program without any
		arguments.
		executable() uses the value of $PATH and/or the normal
		searchpath for programs.		*PATHEXT*
		On MS-DOS and MS-Windows the ".exe", ".bat", etc. can
		optionally be included.  Then the extensions in $PATHEXT are
		tried.  Thus if "foo.exe" does not exist, "foo.exe.bat" can be
		found.  If $PATHEXT is not set then ".exe;.com;.bat;.cmd" is
		used.  A dot by itself can be used in $PATHEXT to try using
		the name without an extension.  When 'shell' looks like a
		Unix shell, then the name is also tried without adding an
		extension.
		On MS-DOS and MS-Windows it only checks if the file exists and
		is not a directory, not if it's really executable.
		The result is a Number:
			1	exists
			0	does not exist
			-1	not implemented on this system

							*exists()*
exists({expr})	The result is a Number, which is non-zero if {expr} is
		defined, zero otherwise.  The {expr} argument is a string,
		which contains one of these:
			&option-name	Vim option (only checks if it exists,
					not if it really works)
			+option-name	Vim option that works.
			$ENVNAME	environment variable (could also be
					done by comparing with an empty
					string)
			*funcname	built-in function (see |functions|)
					or user defined function (see
					|user-functions|).
			varname		internal variable (see
					|internal-variables|).  Does not work
					for |curly-braces-names|.
			:cmdname	Ex command: built-in command, user
					command or command modifier |:command|.
					Returns:
					1  for match with start of a command
					2  full match with a command
					3  matches several user commands
					To check for a supported command
					always check the return value to be 2.
			#event		autocommand defined for this event
			#event#pattern	autocommand defined for this event and
					pattern (the pattern is taken
					literally and compared to the
					autocommand patterns character by
					character)
		For checking for a supported feature use |has()|.

		Examples: >
			exists("&shortname")
			exists("$HOSTNAME")
			exists("*strftime")
			exists("*s:MyFunc")
			exists("bufcount")
			exists(":Make")
			exists("#CursorHold");
			exists("#BufReadPre#*.gz")
<		There must be no space between the symbol (&/$/*/#) and the
		name.
		Note that the argument must be a string, not the name of the
		variable itself!  For example: >
			exists(bufcount)
<		This doesn't check for existence of the "bufcount" variable,
		but gets the contents of "bufcount", and checks if that
		exists.

expand({expr} [, {flag}])				*expand()*
		Expand wildcards and the following special keywords in {expr}.
		The result is a String.

		When there are several matches, they are separated by <NL>
		characters.  [Note: in version 5.0 a space was used, which
		caused problems when a file name contains a space]

		If the expansion fails, the result is an empty string.  A name
		for a non-existing file is not included.

		When {expr} starts with '%', '#' or '<', the expansion is done
		like for the |cmdline-special| variables with their associated
		modifiers.  Here is a short overview:

			%		current file name
			#		alternate file name
			#n		alternate file name n
			<cfile>		file name under the cursor
			<afile>		autocmd file name
			<abuf>		autocmd buffer number (as a String!)
			<amatch>	autocmd matched name
			<sfile>		sourced script file name
			<cword>		word under the cursor
			<cWORD>		WORD under the cursor
			<client>	the {clientid} of the last received
					message |server2client()|
		Modifiers:
			:p		expand to full path
			:h		head (last path component removed)
			:t		tail (last path component only)
			:r		root (one extension removed)
			:e		extension only

		Example: >
			:let &tags = expand("%:p:h") . "/tags"
<		Note that when expanding a string that starts with '%', '#' or
		'<', any following text is ignored.  This does NOT work: >
			:let doesntwork = expand("%:h.bak")
<		Use this: >
			:let doeswork = expand("%:h") . ".bak"
<		Also note that expanding "<cfile>" and others only returns the
		referenced file name without further expansion.  If "<cfile>"
		is "~/.cshrc", you need to do another expand() to have the
		"~/" expanded into the path of the home directory: >
			:echo expand(expand("<cfile>"))
<
		There cannot be white space between the variables and the
		following modifier.  The |fnamemodify()| function can be used
		to modify normal file names.

		When using '%' or '#', and the current or alternate file name
		is not defined, an empty string is used.  Using "%:p" in a
		buffer with no name, results in the current directory, with a
		'/' added.

		When {expr} does not start with '%', '#' or '<', it is
		expanded like a file name is expanded on the command line.
		'suffixes' and 'wildignore' are used, unless the optional
		{flag} argument is given and it is non-zero.  Names for
		non-existing files are included.

		Expand() can also be used to expand variables and environment
		variables that are only known in a shell.  But this can be
		slow, because a shell must be started.  See |expr-env-expand|.
		The expanded variable is still handled like a list of file
		names.  When an environment variable cannot be expanded, it is
		left unchanged.  Thus ":echo expand('$FOOBAR')" results in
		"$FOOBAR".

		See |glob()| for finding existing files.  See |system()| for
		getting the raw output of an external command.

filereadable({file})					*filereadable()*
		The result is a Number, which is TRUE when a file with the
		name {file} exists, and can be read.  If {file} doesn't exist,
		or is a directory, the result is FALSE.  {file} is any
		expression, which is used as a String.
							*file_readable()*
		Obsolete name: file_readable().

filewritable({file})					*filewritable()*
		The result is a Number, which is 1 when a file with the
		name {file} exists, and can be written.  If {file} doesn't
		exist, or is not writable, the result is 0.  If (file) is a
		directory, and we can write to it, the result is 2.

fnamemodify({fname}, {mods})				*fnamemodify()*
		Modify file name {fname} according to {mods}.  {mods} is a
		string of characters like it is used for file names on the
		command line.  See |filename-modifiers|.
		Example: >
			:echo fnamemodify("main.c", ":p:h")
<		results in: >
			/home/mool/vim/vim/src
<		Note: Environment variables and "~" don't work in {fname}, use
		|expand()| first then.

foldclosed({lnum})					*foldclosed()*
		The result is a Number.  If the line {lnum} is in a closed
		fold, the result is the number of the first line in that fold.
		If the line {lnum} is not in a closed fold, -1 is returned.

foldclosedend({lnum})					*foldclosedend()*
		The result is a Number.  If the line {lnum} is in a closed
		fold, the result is the number of the last line in that fold.
		If the line {lnum} is not in a closed fold, -1 is returned.

foldlevel({lnum})					*foldlevel()*
		The result is a Number, which is the foldlevel of line {lnum}
		in the current buffer.  For nested folds the deepest level is
		returned.  If there is no fold at line {lnum}, zero is
		returned.  It doesn't matter if the folds are open or closed.
		When used while updating folds (from 'foldexpr') -1 is
		returned for lines where folds are still to be updated and the
		foldlevel is unknown.  As a special case the level of the
		previous line is usually available.

							*foldtext()*
foldtext()	Returns a String, to be displayed for a closed fold.  This is
		the default function used for the 'foldtext' option and should
		only be called from evaluating 'foldtext'.  It uses the
		|v:foldstart|, |v:foldend| and |v:folddashes| variables.
		The returned string looks like this: >
			+-- 45 lines: abcdef
<		The number of dashes depends on the foldlevel.  The "45" is
		the number of lines in the fold.  "abcdef" is the text in the
		first non-blank line of the fold.  Leading white space, "//"
		or "/*" and the text from the 'foldmarker' and 'commentstring'
		options is removed.
		{not available when compiled without the |+folding| feature}

							*foreground()*
foreground()	Move the Vim window to the foreground.  Useful when sent from
		a client to a Vim server. |remote_send()|
		On Win32 systems this might not work, the OS does not always
		allow a window to bring itself to the foreground.  Use
		|remote_foreground()| instead.
		{only in the Win32, Athena, Motif and GTK GUI versions and the
		Win32 console version}

getchar([expr])						*getchar()*
		Get a single character from the user.  If it is an 8-bit
		character, the result is a number.  Otherwise a String is
		returned with the encoded character.  For a special key it's a
		sequence of bytes starting with 0x80 (decimal: 128).
		If [expr] is omitted, wait until a character is available.
		If [expr] is 0, only get a character when one is available.
		If [expr] is 1, only check if a character is available, it is
				not consumed.  If a normal character is
				available, it is returned, otherwise a
				non-zero value is returned.
		If a normal character available, it is returned as a Number.
		Use nr2char() to convert it to a String.
		The returned value is zero if no character is available.
		The returned value is a string of characters for special keys
		and when a modifier (shift, control, alt) was used.
		There is no prompt, you will somehow have to make clear to the
		user that a character has to be typed.
		There is no mapping for the character.
		Key codes are replaced, thus when the user presses the <Del>
		key you get the code for the <Del> key, not the raw character
		sequence.  Examples: >
			getchar() == "\<Del>"
			getchar() == "\<S-Left>"
<		This example redefines "f" to ignore case: >
			:nmap f :call FindChar()<CR>
			:function FindChar()
			:  let c = nr2char(getchar())
			:  while col('.') < col('$') - 1
			:    normal l
			:    if getline('.')[col('.') - 1] ==? c
			:      break
			:    endif
			:  endwhile
			:endfunction

getcharmod()						*getcharmod()*
		The result is a Number which is the state of the modifiers for
		the last obtained character with getchar() or in another way.
		These values are added together:
			2	shift
			4	control
			8	alt (meta)
			16	mouse double click
			32	mouse triple click
			64	mouse quadruple click
			128	Macintosh only: command
		Only the modifiers that have not been included in the
		character itself are obtained.  Thus Shift-a results in "A"
		with no modifier.

getbufvar({expr}, {varname})				*getbufvar()*
		The result is the value of option or local buffer variable
		{varname} in buffer {expr}.  Note that the name without "b:"
		must be used.
		This also works for a global or local window option, but it
		doesn't work for a global or local window variable.
		For the use of {expr}, see |bufname()| above.
		When the buffer or variable doesn't exist an empty string is
		returned, there is no error message.
		Examples: >
			:let bufmodified = getbufvar(1, "&mod")
			:echo "todo myvar = " . getbufvar("todo", "myvar")
<
getcmdline()						*getcmdline()*
		Return the current command-line.  Only works when the command
		line is being edited, thus requires use of |c_CTRL-\_e| or
		|c_CTRL-R_=|.
		Example: >
			:cmap <F7> <C-\>eescape(getcmdline(), ' \')<CR>
<		Also see |getcmdpos()| and |setcmdpos()|.

getcmdpos({pos})					*getcmdpos()*
		Return the position of the cursor in the command line as a
		byte count.  The first column is 1.
		Only works when editing the command line, thus requires use of
		|c_CTRL-\_e| or |c_CTRL-R_=|.  Returns 0 otherwise.
		Also see |setcmdpos()| and |getcmdline()|.

							*getcwd()*
getcwd()	The result is a String, which is the name of the current
		working directory.

getfsize({fname})					*getfsize()*
		The result is a Number, which is the size in bytes of the
		given file {fname}.
		If {fname} is a directory, 0 is returned.
		If the file {fname} can't be found, -1 is returned.

getftime({fname})					*getftime()*
		The result is a Number, which is the last modification time of
		the given file {fname}.  The value is measured as seconds
		since 1st Jan 1970, and may be passed to strftime().  See also
		|localtime()| and |strftime()|.
		If the file {fname} can't be found -1 is returned.

							*getline()*
getline({lnum}) The result is a String, which is line {lnum} from the current
		buffer.  Example: >
			getline(1)
<		When {lnum} is a String that doesn't start with a
		digit, line() is called to translate the String into a Number.
		To get the line under the cursor: >
			getline(".")
<		When {lnum} is smaller than 1 or bigger than the number of
		lines in the buffer, an empty string is returned.

getreg([{regname}])					*getreg()*
		The result is a String, which is the contents of register
		{regname}. Example: >
			:let cliptext = getreg('*')
<		getreg('=') returns the last evaluated value of the expression
		register. (For use in maps).
		If {regname} is not specified, |v:register| is used.

getregtype([{regname}])					*getregtype()*
		The result is a String, which is type of register {regname}.
		The value will be one of:
		    "v"			for |characterwise| text
		    "V"			for |linewise| text
		    "<CTRL-V>{width}"	for |blockwise-visual| text
		    0			for an empty or unknown register
		<CTRL-V> is one character with value 0x16.
		If {regname} is not specified, |v:register| is used.

							*getwinposx()*
getwinposx()	The result is a Number, which is the X coordinate in pixels of
		the left hand side of the GUI Vim window.  The result will be
		-1 if the information is not available.

							*getwinposy()*
getwinposy()	The result is a Number, which is the Y coordinate in pixels of
		the top of the GUI Vim window.  The result will be -1 if the
		information is not available.

getwinvar({nr}, {varname})				*getwinvar()*
		The result is the value of option or local window variable
		{varname} in window {nr}.
		This also works for a global or local buffer option, but it
		doesn't work for a global or local buffer variable.
		Note that the name without "w:" must be used.
		Examples: >
			:let list_is_on = getwinvar(2, '&list')
			:echo "myvar = " . getwinvar(1, 'myvar')
<
							*glob()*
glob({expr})	Expand the file wildcards in {expr}.  The result is a String.
		When there are several matches, they are separated by <NL>
		characters.
		If the expansion fails, the result is an empty string.
		A name for a non-existing file is not included.

		For most systems backticks can be used to get files names from
		any external command.  Example: >
			:let tagfiles = glob("`find . -name tags -print`")
			:let &tags = substitute(tagfiles, "\n", ",", "g")
<		The result of the program inside the backticks should be one
		item per line.  Spaces inside an item are allowed.

		See |expand()| for expanding special Vim variables.  See
		|system()| for getting the raw output of an external command.

globpath({path}, {expr})				*globpath()*
		Perform glob() on all directories in {path} and concatenate
		the results.  Example: >
			:echo globpath(&rtp, "syntax/c.vim")
<		{path} is a comma-separated list of directory names.  Each
		directory name is prepended to {expr} and expanded like with
		glob().  A path separator is inserted when needed.
		To add a comma inside a directory name escape it with a
		backslash.  Note that on MS-Windows a directory may have a
		trailing backslash, remove it if you put a comma after it.
		If the expansion fails for one of the directories, there is no
		error message.
		The 'wildignore' option applies: Names matching one of the
		patterns in 'wildignore' will be skipped.

							*has()*
has({feature})	The result is a Number, which is 1 if the feature {feature} is
		supported, zero otherwise.  The {feature} argument is a
		string.  See |feature-list| below.
		Also see |exists()|.

hasmapto({what} [, {mode}])				*hasmapto()*
		The result is a Number, which is 1 if there is a mapping that
		contains {what} in somewhere in the rhs (what it is mapped to)
		and this mapping exists in one of the modes indicated by
		{mode}.
		Both the global mappings and the mappings local to the current
		buffer are checked for a match.
		If no matching mapping is found 0 is returned.
		The following characters are recognized in {mode}:
			n	Normal mode
			v	Visual mode
			o	Operator-pending mode
			i	Insert mode
			l	Language-Argument ("r", "f", "t", etc.)
			c	Command-line mode
		When {mode} is omitted, "nvo" is used.

		This function is useful to check if a mapping already exists
		to a function in a Vim script.  Example: >
			:if !hasmapto('\ABCdoit')
			:   map <Leader>d \ABCdoit
			:endif
<		This installs the mapping to "\ABCdoit" only if there isn't
		already a mapping to "\ABCdoit".

histadd({history}, {item})				*histadd()*
		Add the String {item} to the history {history} which can be
		one of:					*hist-names*
			"cmd"	 or ":"	  command line history
			"search" or "/"   search pattern history
			"expr"   or "="   typed expression history
			"input"  or "@"	  input line history
		If {item} does already exist in the history, it will be
		shifted to become the newest entry.
		The result is a Number: 1 if the operation was successful,
		otherwise 0 is returned.

		Example: >
			:call histadd("input", strftime("%Y %b %d"))
			:let date=input("Enter date: ")
<		This function is not available in the |sandbox|.

histdel({history} [, {item}])				*histdel()*
		Clear {history}, ie. delete all its entries.  See |hist-names|
		for the possible values of {history}.

		If the parameter {item} is given as String, this is seen
		as regular expression.  All entries matching that expression
		will be removed from the history (if there are any).
		Upper/lowercase must match, unless "\c" is used |/\c|.
		If {item} is a Number, it will be interpreted as index, see
		|:history-indexing|.  The respective entry will be removed
		if it exists.

		The result is a Number: 1 for a successful operation,
		otherwise 0 is returned.

		Examples:
		Clear expression register history: >
			:call histdel("expr")
<
		Remove all entries starting with "*" from the search history: >
			:call histdel("/", '^\*')
<
		The following three are equivalent: >
			:call histdel("search", histnr("search"))
			:call histdel("search", -1)
			:call histdel("search", '^'.histget("search", -1).'$')
<
		To delete the last search pattern and use the last-but-one for
		the "n" command and 'hlsearch': >
			:call histdel("search", -1)
			:let @/ = histget("search", -1)

histget({history} [, {index}])				*histget()*
		The result is a String, the entry with Number {index} from
		{history}.  See |hist-names| for the possible values of
		{history}, and |:history-indexing| for {index}.  If there is
		no such entry, an empty String is returned.  When {index} is
		omitted, the most recent item from the history is used.

		Examples:
		Redo the second last search from history. >
			:execute '/' . histget("search", -2)

<		Define an Ex command ":H {num}" that supports re-execution of
		the {num}th entry from the output of |:history|. >
			:command -nargs=1 H execute histget("cmd", 0+<args>)
<
histnr({history})					*histnr()*
		The result is the Number of the current entry in {history}.
		See |hist-names| for the possible values of {history}.
		If an error occurred, -1 is returned.

		Example: >
			:let inp_index = histnr("expr")
<
hlexists({name})					*hlexists()*
		The result is a Number, which is non-zero if a highlight group
		called {name} exists.  This is when the group has been
		defined in some way.  Not necessarily when highlighting has
		been defined for it, it may also have been used for a syntax
		item.
							*highlight_exists()*
		Obsolete name: highlight_exists().

							*hlID()*
hlID({name})	The result is a Number, which is the ID of the highlight group
		with name {name}.  When the highlight group doesn't exist,
		zero is returned.
		This can be used to retrieve information about the highlight
		group.  For example, to get the background color of the
		"Comment" group: >
	:echo synIDattr(synIDtrans(hlID("Comment")), "bg")
<							*highlightID()*
		Obsolete name: highlightID().

hostname()						*hostname()*
		The result is a String, which is the name of the machine on
		which Vim is currently running. Machine names greater than
		256 characters long are truncated.

iconv({expr}, {from}, {to})				*iconv()*
		The result is a String, which is the text {expr} converted
		from encoding {from} to encoding {to}.
		When the conversion fails an empty string is returned.
		The encoding names are whatever the iconv() library function
		can accept, see ":!man 3 iconv".
		Most conversions require Vim to be compiled with the |+iconv|
		feature.  Otherwise only UTF-8 to latin1 conversion and back
		can be done.
		This can be used to display messages with special characters,
		no matter what 'encoding' is set to.  Write the message in
		UTF-8 and use: >
			echo iconv(utf8_str, "utf-8", &enc)
<		Note that Vim uses UTF-8 for all Unicode encodings, conversion
		from/to UCS-2 is automatically changed to use UTF-8.  You
		cannot use UCS-2 in a string anyway, because of the NUL bytes.
		{only available when compiled with the +multi_byte feature}

							*indent()*
indent({lnum})	The result is a Number, which is indent of line {lnum} in the
		current buffer.  The indent is counted in spaces, the value
		of 'tabstop' is relevant.  {lnum} is used just like in
		|getline()|.
		When {lnum} is invalid -1 is returned.

input({prompt} [, {text}])				*input()*
		The result is a String, which is whatever the user typed on
		the command-line.  The parameter is either a prompt string, or
		a blank string (for no prompt).  A '\n' can be used in the
		prompt to start a new line.  The highlighting set with
		|:echohl| is used for the prompt.  The input is entered just
		like a command-line, with the same editing commands and
		mappings.  There is a separate history for lines typed for
		input().
		If the optional {text} is present, this is used for the
		default reply, as if the user typed this.
		NOTE: This must not be used in a startup file, for the
		versions that only run in GUI mode (e.g., the Win32 GUI).
		Note: When input() is called from within a mapping it will
		consume remaining characters from that mapping, because a
		mapping is handled like the characters were typed.
		Use |inputsave()| before input() and |inputrestore()|
		after input() to avoid that.  Another solution is to avoid
		that further characters follow in the mapping, e.g., by using
		|:execute| or |:normal|.

		Example: >
			:if input("Coffee or beer? ") == "beer"
			:  echo "Cheers!"
			:endif
<		Example with default text: >
			:let color = input("Color? ", "white")
<		Example with a mapping: >
			:nmap \x :call GetFoo()<CR>:exe "/" . Foo<CR>
			:function GetFoo()
			:  call inputsave()
			:  let g:Foo = input("enter search pattern: ")
			:  call inputrestore()
			:endfunction

inputdialog({prompt} [, {text} [, {cancelreturn}]])		*inputdialog()*
		Like input(), but when the GUI is running and text dialogs are
		supported, a dialog window pops up to input the text.
		Example: >
			:let n = inputdialog("value for shiftwidth", &sw)
			:if n != ""
			:  let &sw = n
			:endif
<		When the dialog is cancelled {cancelreturn} is returned.  When
		omitted an empty string is returned.
		Hitting <Enter> works like pressing the OK button.  Hitting
		<Esc> works like pressing the Cancel button.

inputrestore()						*inputrestore()*
		Restore typeahead that was saved with a previous inputsave().
		Should be called the same number of times inputsave() is
		called.  Calling it more often is harmless though.
		Returns 1 when there is nothing to restore, 0 otherwise.

inputsave()						*inputsave()*
		Preserve typeahead (also from mappings) and clear it, so that
		a following prompt gets input from the user.  Should be
		followed by a matching inputrestore() after the prompt.  Can
		be used several times, in which case there must be just as
		many inputrestore() calls.
		Returns 1 when out of memory, 0 otherwise.

inputsecret({prompt} [, {text}])			*inputsecret()*
		This function acts much like the |input()| function with but
		two exceptions:
		a) the user's response will be displayed as a sequence of
		asterisks ("*") thereby keeping the entry secret, and
		b) the user's response will not be recorded on the input
		|history| stack.
		The result is a String, which is whatever the user actually
		typed on the command-line in response to the issued prompt.

isdirectory({directory})				*isdirectory()*
		The result is a Number, which is non-zero when a directory
		with the name {directory} exists.  If {directory} doesn't
		exist, or isn't a directory, the result is FALSE.  {directory}
		is any expression, which is used as a String.

						*libcall()* *E364* *E368*
libcall({libname}, {funcname}, {argument})
		Call function {funcname} in the run-time library {libname}
		with single argument {argument}.
		This is useful to call functions in a library that you
		especially made to be used with Vim.  Since only one argument
		is possible, calling standard library functions is rather
		limited.
		The result is the String returned by the function.  If the
		function returns NULL, this will appear as an empty string ""
		to Vim.
		If the function returns a number, use libcallnr()!
		If {argument} is a number, it is passed to the function as an
		int; if {argument} is a string, it is passed as a
		null-terminated string.
		This function will fail in |restricted-mode|.

		libcall() allows you to write your own 'plug-in' extensions to
		Vim without having to recompile the program.  It is NOT a
		means to call system functions!  If you try to do so Vim will
		very probably crash.

		For Win32, the functions you write must be placed in a DLL
		and use the normal C calling convention (NOT Pascal which is
		used in Windows System DLLs).  The function must take exactly
		one parameter, either a character pointer or a long integer,
		and must return a character pointer or NULL.  The character
		pointer returned must point to memory that will remain valid
		after the function has returned (e.g. in static data in the
		DLL).  If it points to allocated memory, that memory will
		leak away.  Using a static buffer in the function should work,
		it's then freed when the DLL is unloaded.

		WARNING: If the function returns a non-valid pointer, Vim may
		crash!  This also happens if the function returns a number,
		because Vim thinks it's a pointer.
		For Win32 systems, {libname} should be the filename of the DLL
		without the ".DLL" suffix.  A full path is only required if
		the DLL is not in the usual places.
		For Unix: When compiling your own plugins, remember that the
		object code must be compiled as position-independent ('PIC').
		{only in Win32 on some Unix versions, when the |+libcall|
		feature is present}
		Examples: >
			:echo libcall("libc.so", "getenv", "HOME")
			:echo libcallnr("/usr/lib/libc.so", "getpid", "")
<
							*libcallnr()*
libcallnr({libname}, {funcname}, {argument})
		Just like libcall(), but used for a function that returns an
		int instead of a string.
		{only in Win32 on some Unix versions, when the |+libcall|
		feature is present}
		Example (not very useful...): >
			:call libcallnr("libc.so", "printf", "Hello World!\n")
			:call libcallnr("libc.so", "sleep", 10)
<
							*line()*
line({expr})	The result is a Number, which is the line number of the file
		position given with {expr}.  The accepted positions are:
		    .	    the cursor position
		    $	    the last line in the current buffer
		    'x	    position of mark x (if the mark is not set, 0 is
			    returned)
		Note that only marks in the current file can be used.
		Examples: >
			line(".")		line number of the cursor
			line("'t")		line number of mark t
			line("'" . marker)	line number of mark marker
<							*last-position-jump*
		This autocommand jumps to the last known position in a file
		just after opening it, if the '" mark is set: >
	:au BufReadPost * if line("'\"") > 0 && line("'\"") <= line("$") | exe "normal g'\"" | endif

line2byte({lnum})					*line2byte()*
		Return the byte count from the start of the buffer for line
		{lnum}.  This includes the end-of-line character, depending on
		the 'fileformat' option for the current buffer.  The first
		line returns 1.
		This can also be used to get the byte count for the line just
		below the last line: >
			line2byte(line("$") + 1)
<		This is the file size plus one.
		When {lnum} is invalid, or the |+byte_offset| feature has been
		disabled at compile time, -1 is returned.
		Also see |byte2line()|, |go| and |:goto|.

lispindent({lnum})					*lispindent()*
		Get the amount of indent for line {lnum} according the lisp
		indenting rules, as with 'lisp'.
		The indent is counted in spaces, the value of 'tabstop' is
		relevant.  {lnum} is used just like in |getline()|.
		When {lnum} is invalid or Vim was not compiled the
		|+lispindent| feature, -1 is returned.

localtime()						*localtime()*
		Return the current time, measured as seconds since 1st Jan
		1970.  See also |strftime()| and |getftime()|.

maparg({name}[, {mode}])				*maparg()*
		Return the rhs of mapping {name} in mode {mode}.  When there
		is no mapping for {name}, an empty String is returned.
		These characters can be used for {mode}:
			"n"	Normal
			"v"	Visual
			"o"	Operator-pending
			"i"	Insert
			"c"	Cmd-line
			"l"	langmap |language-mapping|
			""	Normal, Visual and Operator-pending
		When {mode} is omitted, the modes from "" are used.
		The {name} can have special key names, like in the ":map"
		command.  The returned String has special characters
		translated like in the output of the ":map" command listing.
		The mappings local to the current buffer are checked first,
		then the global mappings.

mapcheck({name}[, {mode}])				*mapcheck()*
		Check if there is a mapping that matches with {name} in mode
		{mode}.  See |maparg()| for {mode} and special names in
		{name}.
		A match happens with a mapping that starts with {name} and
		with a mapping which is equal to the start of {name}.

			matches mapping "a"     "ab"    "abc" ~
		   mapcheck("a")	yes	yes	 yes
		   mapcheck("abc")	yes	yes	 yes
		   mapcheck("ax")	yes	no	 no
		   mapcheck("b")	no	no	 no

		The difference with maparg() is that mapcheck() finds a
		mapping that matches with {name}, while maparg() only finds a
		mapping for {name} exactly.
		When there is no mapping that starts with {name}, an empty
		String is returned.  If there is one, the rhs of that mapping
		is returned.  If there are several mappings that start with
		{name}, the rhs of one of them is returned.
		The mappings local to the current buffer are checked first,
		then the global mappings.
		This function can be used to check if a mapping can be added
		without being ambiguous.  Example: >
	:if mapcheck("_vv") == ""
	:   map _vv :set guifont=7x13<CR>
	:endif
<		This avoids adding the "_vv" mapping when there already is a
		mapping for "_v" or for "_vvv".

match({expr}, {pat}[, {start}])				*match()*
		The result is a Number, which gives the index (byte offset) in
		{expr} where {pat} matches.  A match at the first character
		returns zero.  If there is no match -1 is returned.  Example: >
			:echo match("testing", "ing")
<		results in "4".
		See |string-match| for how {pat} is used.
		If {start} is given, the search starts from index {start}.
		The result, however, is still the index counted from the
		first character. Example: >
			:echo match("testing", "ing", 2)
<		result is again "4". >
			:echo match("testing", "ing", 4)
<		result is again "4". >
			:echo match("testing", "t", 2)
<		result is "3".
		If {start} < 0, it will be set to 0.
		If {start} > strlen({expr}) -1 is returned.
		See |pattern| for the patterns that are accepted.
		The 'ignorecase' option is used to set the ignore-caseness of
		the pattern.  'smartcase' is NOT used.  The matching is always
		done like 'magic' is set and 'cpoptions' is empty.

matchend({expr}, {pat}[, {start}])			*matchend()*
		Same as match(), but return the index of first character after
		the match.  Example: >
			:echo matchend("testing", "ing")
<		results in "7".
		The {start}, if given, has the same meaning as for match(). >
			:echo matchend("testing", "ing", 2)
<		results in "7". >
			:echo matchend("testing", "ing", 5)
<		result is "-1".

matchstr({expr}, {pat}[, {start}])			*matchstr()*
		Same as match(), but return the matched string.  Example: >
			:echo matchstr("testing", "ing")
<		results in "ing".
		When there is no match "" is returned.
		The {start}, if given, has the same meaning as for match(). >
			:echo matchstr("testing", "ing", 2)
<		results in "ing". >
			:echo matchstr("testing", "ing", 5)
<		result is "".

							*mode()*
mode()		Return a string that indicates the current mode:
			n	Normal
			v	Visual by character
			V	Visual by line
			CTRL-V	Visual blockwise
			s	Select by character
			S	Select by line
			CTRL-S	Select blockwise
			i	Insert
			R	Replace
			c	Command-line
			r	Hit-enter prompt
		This is useful in the 'statusline' option.  In most other
		places it always returns "c" or "n".

nextnonblank({lnum})					*nextnonblank()*
		Return the line number of the first line at or below {lnum}
		that is not blank.  Example: >
			if getline(nextnonblank(1)) =~ "Java"
<		When {lnum} is invalid or there is no non-blank line at or
		below it, zero is returned.
		See also |prevnonblank()|.

nr2char({expr})						*nr2char()*
		Return a string with a single character, which has the number
		value {expr}.  Examples: >
			nr2char(64)		returns "@"
			nr2char(32)		returns " "
<		The current 'encoding' is used.  Example for "utf-8": >
			nr2char(300)		returns I with bow character
<		Note that a NUL character in the file is specified with
		nr2char(10), because NULs are represented with newline
		characters.  nr2char(0) is a real NUL and terminates the
		string, thus isn't very useful.

prevnonblank({lnum})					*prevnonblank()*
		Return the line number of the first line at or above {lnum}
		that is not blank.  Example: >
			let ind = indent(prevnonblank(v:lnum - 1))
<		When {lnum} is invalid or there is no non-blank line at or
		above it, zero is returned.
		Also see |nextnonblank()|.

							*remote_expr()* *E449*
remote_expr({server}, {string} [, {idvar}])
		Send the {string} to {server}.  The string is sent as an
		expression and the result is returned after evaluation.
		If {idvar} is present, it is taken as the name of a
		variable and a {serverid} for later use with
		remote_read() is stored there.
		See also |clientserver| |RemoteReply|.
		This function is not available in the |sandbox|.
		{only available when compiled with the |+clientserver| feature}
		Note: Any errors will cause a local error message to be issued
		and the result will be the empty string.
		Examples: >
			:echo remote_expr("gvim", "2+2")
			:echo remote_expr("gvim1", "b:current_syntax")
<

remote_foreground({server})				*remote_foreground()*
		Move the Vim server with the name {server} to the foreground.
		This works like: >
			remote_expr({server}, "foreground()")
<		Except that on Win32 systems the client does the work, to work
		around the problem that the OS doesn't always allow the server
		to bring itself to the foreground.
		This function is not available in the |sandbox|.
		{only in the Win32, Athena, Motif and GTK GUI versions and the
		Win32 console version}


remote_peek({serverid} [, {retvar}])		*remote_peek()*
		Returns a positive number if there are available strings
		from {serverid}.  Copies any reply string into the variable
		{retvar} if specified.  {retvar} must be a string with the
		name of a variable.
		Returns zero if none are available.
		Returns -1 if something is wrong.
		See also |clientserver|.
		This function is not available in the |sandbox|.
		{only available when compiled with the |+clientserver| feature}
		Examples: >
			:let repl = ""
			:echo "PEEK: ".remote_peek(id, "repl").": ".repl

remote_read({serverid})				*remote_read()*
		Return the oldest available reply from {serverid} and consume
		it.  It blocks until a reply is available.
		See also |clientserver|.
		This function is not available in the |sandbox|.
		{only available when compiled with the |+clientserver| feature}
		Example: >
			:echo remote_read(id)
<
							*remote_send()* *E241*
remote_send({server}, {string} [, {idvar}])
		Send the {string} to {server}.  The string is sent as
		input keys and the function returns immediately.
		If {idvar} is present, it is taken as the name of a
		variable and a {serverid} for later use with
		remote_read() is stored there.
		See also |clientserver| |RemoteReply|.
		This function is not available in the |sandbox|.
		{only available when compiled with the |+clientserver| feature}
		Note: Any errors will be reported in the server and may mess
		up the display.
		Examples: >
		:echo remote_send("gvim", ":DropAndReply ".file, "serverid").
		 \ remote_read(serverid)

		:autocmd NONE RemoteReply *
		 \ echo remote_read(expand("<amatch>"))
		:echo remote_send("gvim", ":sleep 10 | echo ".
		 \ 'server2client(expand("<client>"), "HELLO")<CR>')


rename({from}, {to})					*rename()*
		Rename the file by the name {from} to the name {to}.  This
		should also work to move files across file systems.  The
		result is a Number, which is 0 if the file was renamed
		successfully, and non-zero when the renaming failed.
		This function is not available in the |sandbox|.

repeat({expr}, {count})					*repeat()*
		Repeat {expr} {count} times and return the concatenated
		result.  Example: >
			:let seperator = repeat('-', 80)
<		When {count} is zero or negative the result is empty.

resolve({filename})					*resolve()* *E655*
		On MS-Windows, when {filename} is a shortcut (a .lnk file),
		returns the path the shortcut points to in a simplified form.
		On Unix, repeat resolving symbolic links in all path
		components of {filename} and return the simplified result.
		To cope with link cycles, resolving of symbolic links is
		stopped after 100 iterations.
		On other systems, return the simplified {filename}.
		The simplification step is done as by |simplify()|.
		resolve() keeps a leading path component specifying the
		current directory (provided the result is still a relative
		path name) and also keeps a trailing path separator.

search({pattern} [, {flags}])				*search()*
		Search for regexp pattern {pattern}.  The search starts at the
		cursor position.
		{flags} is a String, which can contain these character flags:
		'b'	search backward instead of forward
		'w'	wrap around the end of the file
		'W'	don't wrap around the end of the file
		If neither 'w' or 'W' is given, the 'wrapscan' option applies.

		When a match has been found its line number is returned, and
		the cursor will be positioned at the match.  If there is no
		match a 0 is returned and the cursor doesn't move.  No error
		message is given.

		Example (goes over all files in the argument list): >
		    :let n = 1
		    :while n <= argc()	    " loop over all files in arglist
		    :  exe "argument " . n
		    :  " start at the last char in the file and wrap for the
		    :  " first search to find match at start of file
		    :  normal G$
		    :  let flags = "w"
		    :  while search("foo", flags) > 0
		    :    s/foo/bar/g
		    :	 let flags = "W"
		    :  endwhile
		    :  update		    " write the file if modified
		    :  let n = n + 1
		    :endwhile
<
							*searchpair()*
searchpair({start}, {middle}, {end} [, {flags} [, {skip}]])
		Search for the match of a nested start-end pair.  This can be
		used to find the "endif" that matches an "if", while other
		if/endif pairs in between are ignored.
		The search starts at the cursor.  If a match is found, the
		cursor is positioned at it and the line number is returned.
		If no match is found 0 or -1 is returned and the cursor
		doesn't move.  No error message is given.

		{start}, {middle} and {end} are patterns, see |pattern|.  They
		must not contain \( \) pairs.  Use of \%( \) is allowed.  When
		{middle} is not empty, it is found when searching from either
		direction, but only when not in a nested start-end pair.  A
		typical use is: >
			searchpair('\<if\>', '\<else\>', '\<endif\>')
<		By leaving {middle} empty the "else" is skipped.

		{flags} are used like with |search()|.  Additionally:
		'n'	do Not move the cursor
		'r'	Repeat until no more matches found; will find the
			outer pair
		'm'	return number of Matches instead of line number with
			the match; will only be > 1 when 'r' is used.

		When a match for {start}, {middle} or {end} is found, the
		{skip} expression is evaluated with the cursor positioned on
		the start of the match.  It should return non-zero if this
		match is to be skipped.  E.g., because it is inside a comment
		or a string.
		When {skip} is omitted or empty, every match is accepted.
		When evaluating {skip} causes an error the search is aborted
		and -1 returned.

		The value of 'ignorecase' is used.  'magic' is ignored, the
		patterns are used like it's on.

		The search starts exactly at the cursor.  A match with
		{start}, {middle} or {end} at the next character, in the
		direction of searching, is the first one found.  Example: >
			if 1
			  if 2
			  endif 2
			endif 1
<		When starting at the "if 2", with the cursor on the "i", and
		searching forwards, the "endif 2" is found.  When starting on
		the character just before the "if 2", the "endif 1" will be
		found.  That's because the "if 2" will be found first, and
		then this is considered to be a nested if/endif from "if 2" to
		"endif 2".
		When searching backwards and {end} is more than one character,
		it may be useful to put "\zs" at the end of the pattern, so
		that when the cursor is inside a match with the end it finds
		the matching start.

		Example, to find the "endif" command in a Vim script: >

	:echo searchpair('\<if\>', '\<el\%[seif]\>', '\<en\%[dif]\>', 'W',
			\ 'getline(".") =~ "^\\s*\""')

<		The cursor must be at or after the "if" for which a match is
		to be found.  Note that single-quote strings are used to avoid
		having to double the backslashes.  The skip expression only
		catches comments at the start of a line, not after a command.
		Also, a word "en" or "if" halfway a line is considered a
		match.
		Another example, to search for the matching "{" of a "}": >

	:echo searchpair('{', '', '}', 'bW')

<		This works when the cursor is at or before the "}" for which a
		match is to be found.  To reject matches that syntax
		highlighting recognized as strings: >

	:echo searchpair('{', '', '}', 'bW',
	     \ 'synIDattr(synID(line("."), col("."), 0), "name") =~? "string"')
<
server2client( {clientid}, {string})			*server2client()*
		Send a reply string to {clientid}.  The most recent {clientid}
		that sent a string can be retrieved with expand("<client>").
		{only available when compiled with the |+clientserver| feature}
		Note:
		This id has to be stored before the next command can be
		received. Ie. before returning from the received command and
		before calling any commands that waits for input.
		See also |clientserver|.
		Example: >
			:echo server2client(expand("<client>"), "HELLO")
<
serverlist()					*serverlist()*
		Return a list of available server names, one per line.
		When there are no servers or the information is not available
		an empty string is returned.  See also |clientserver|.
		{only available when compiled with the |+clientserver| feature}
		Example: >
			:echo serverlist()
<
setbufvar({expr}, {varname}, {val})			*setbufvar()*
		Set option or local variable {varname} in buffer {expr} to
		{val}.
		This also works for a global or local window option, but it
		doesn't work for a global or local window variable.
		For a local window option the global value is unchanged.
		For the use of {expr}, see |bufname()| above.
		Note that the variable name without "b:" must be used.
		Examples: >
			:call setbufvar(1, "&mod", 1)
			:call setbufvar("todo", "myvar", "foobar")
<		This function is not available in the |sandbox|.

setcmdpos({pos})					*setcmdpos()*
		Set the cursor position in the command line to byte position
		{pos}.  The first position is 1.
		Use |getcmdpos()| to obtain the current position.
		Only works while editing the command line, thus you must use
		|c_CTRL-\_e| or |c_CTRL-R_=|.  The position is set after the
		command line is set to the expression.
		When the number is too big the cursor is put at the end of the
		line.  A number smaller than one has undefined results.
		Returns 0 when successful, 1 when not editing the command
		line.

setline({lnum}, {line})					*setline()*
		Set line {lnum} of the current buffer to {line}.  If this
		succeeds, 0 is returned.  If this fails (most likely because
		{lnum} is invalid) 1 is returned.  Example: >
			:call setline(5, strftime("%c"))
<		Note: The '[ and '] marks are not set.

							*setreg()*
setreg({regname}, {value} [,{options}])
		Set the register {regname} to {value}.
		If {options} contains "a" or {regname} is upper case,
		then the value is appended.
		{options} can also contains a register type specification:
		    "c" or "v"	      |characterwise| mode
		    "l" or "V"	      |linewise| mode
		    "b" or "<CTRL-V>" |blockwise-visual| mode
		If a number immediately follows "b" or "<CTRL-V>" then this is
		used as the width of the selection - if it is not specified
		then the width of the block is set to the number of characters
		in the longest line (counting a <TAB> as 1 character).

		If {options} contains no register settings, then the default
		is to use character mode unless {value} ends in a <NL>.
		Setting the '=' register is not possible.
		Returns zero for success, non-zero for failure.

		Examples: >
			:call setreg(v:register, @*)
			:call setreg('*', @%, 'ac')
			:call setreg('a', "1\n2\n3", 'b5')

<		This example shows using the functions to save and restore a
		register. >
			:let var_a = getreg('a')
			:let var_amode = getregtype('a')
			    ....
			:call setreg('a', var_a, var_amode)

<		You can also change the type of a register by appending
		nothing: >
			:call setreg('a', '', 'al')

setwinvar({nr}, {varname}, {val})			*setwinvar()*
		Set option or local variable {varname} in window {nr} to
		{val}.
		This also works for a global or local buffer option, but it
		doesn't work for a global or local buffer variable.
		For a local buffer option the global value is unchanged.
		Note that the variable name without "w:" must be used.
		Examples: >
			:call setwinvar(1, "&list", 0)
			:call setwinvar(2, "myvar", "foobar")
<		This function is not available in the |sandbox|.

simplify({filename})					*simplify()*
		Simplify the file name as much as possible without changing
		the meaning.  Shortcuts (on MS-Windows) or symbolic links (on
		Unix) are not resolved.  If the first path component in
		{filename} designates the current directory, this will be
		valid for the result as well.  A trailing path separator is
		not removed either.
		Example: >
			simplify("./dir/.././/file/") == "./file/"
<		Note: The combination "dir/.." is only removed if "dir" is
		a searchable directory or does not exist.  On Unix, it is also
		removed when "dir" is a symbolic link within the same
		directory.  In order to resolve all the involved symbolic
		links before simplifying the path name, use |resolve()|.

strftime({format} [, {time}])				*strftime()*
		The result is a String, which is a formatted date and time, as
		specified by the {format} string.  The given {time} is used,
		or the current time if no time is given.  The accepted
		{format} depends on your system, thus this is not portable!
		See the manual page of the C function strftime() for the
		format.  The maximum length of the result is 80 characters.
		See also |localtime()| and |getftime()|.
		The language can be changed with the |:language| command.
		Examples: >
		  :echo strftime("%c")		   Sun Apr 27 11:49:23 1997
		  :echo strftime("%Y %b %d %X")	   1997 Apr 27 11:53:25
		  :echo strftime("%y%m%d %T")	   970427 11:53:55
		  :echo strftime("%H:%M")	   11:55
		  :echo strftime("%c", getftime("file.c"))
						   Show mod time of file.c.
<
stridx({haystack}, {needle})				*stridx()*
		The result is a Number, which gives the index in {haystack} of
		the first occurrence of the String {needle} in the String
		{haystack}. The search is done case-sensitive. For advanced
		searches use |match()|.
		If the {needle} does not occur in {haystack} it returns -1.
		See also |strridx()|. Examples: >
		  :echo stridx("An Example", "Example")	     3
		  :echo stridx("Starting point", "Start")    0
		  :echo stridx("Starting point", "start")   -1
<
							*strlen()*
strlen({expr})	The result is a Number, which is the length of the String
		{expr} in bytes.  If you want to count the number of
		multi-byte characters use something like this: >

			:let len = strlen(substitute(str, ".", "x", "g"))

<		Composing characters are not counted.

strpart({src}, {start}[, {len}])			*strpart()*
		The result is a String, which is part of {src}, starting from
		byte {start}, with the length {len}.
		When non-existing bytes are included, this doesn't result in
		an error, the bytes are simply omitted.
		If {len} is missing, the copy continues from {start} till the
		end of the {src}. >
			strpart("abcdefg", 3, 2)    == "de"
			strpart("abcdefg", -2, 4)   == "ab"
			strpart("abcdefg", 5, 4)    == "fg"
			strpart("abcdefg", 3)       == "defg"
<		Note: To get the first character, {start} must be 0.  For
		example, to get three bytes under and after the cursor: >
			strpart(getline(line(".")), col(".") - 1, 3)
<
strridx({haystack}, {needle})				*strridx()*
		The result is a Number, which gives the index in {haystack} of
		the last occurrence of the String {needle} in the String
		{haystack}. The search is done case-sensitive. For advanced
		searches use |match()|.
		If the {needle} does not occur in {haystack} it returns -1.
		See also |stridx()|. Examples: >
		  :echo strridx("an angry armadillo", "an")	     3
<
strtrans({expr})					*strtrans()*
		The result is a String, which is {expr} with all unprintable
		characters translated into printable characters |'isprint'|.
		Like they are shown in a window.  Example: >
			echo strtrans(@a)
<		This displays a newline in register a as "^@" instead of
		starting a new line.

submatch({nr})						*submatch()*
		Only for an expression in a |:substitute| command.  Returns
		the {nr}'th submatch of the matched text.  When {nr} is 0
		the whole matched text is returned.
		Example: >
			:s/\d\+/\=submatch(0) + 1/
<		This finds the first number in the line and adds one to it.
		A line break is included as a newline character.

substitute({expr}, {pat}, {sub}, {flags})		*substitute()*
		The result is a String, which is a copy of {expr}, in which
		the first match of {pat} is replaced with {sub}.  This works
		like the ":substitute" command (without any flags).  But the
		matching with {pat} is always done like the 'magic' option is
		set and 'cpoptions' is empty (to make scripts portable).
		See |string-match| for how {pat} is used.
		And a "~" in {sub} is not replaced with the previous {sub}.
		Note that some codes in {sub} have a special meaning
		|sub-replace-special|.  For example, to replace something with
		"\n" (two characters), use "\\\\n" or '\\n'.
		When {pat} does not match in {expr}, {expr} is returned
		unmodified.
		When {flags} is "g", all matches of {pat} in {expr} are
		replaced.  Otherwise {flags} should be "".
		Example: >
			:let &path = substitute(&path, ",\\=[^,]*$", "", "")
<		This removes the last component of the 'path' option. >
			:echo substitute("testing", ".*", "\\U\\0", "")
<		results in "TESTING".

synID({line}, {col}, {trans})				*synID()*
		The result is a Number, which is the syntax ID at the position
		{line} and {col} in the current window.
		The syntax ID can be used with |synIDattr()| and
		|synIDtrans()| to obtain syntax information about text.
		{col} is 1 for the leftmost column, {line} is 1 for the first
		line.
		When {trans} is non-zero, transparent items are reduced to the
		item that they reveal.  This is useful when wanting to know
		the effective color.  When {trans} is zero, the transparent
		item is returned.  This is useful when wanting to know which
		syntax item is effective (e.g. inside parens).
		Warning: This function can be very slow.  Best speed is
		obtained by going through the file in forward direction.

		Example (echoes the name of the syntax item under the cursor): >
			:echo synIDattr(synID(line("."), col("."), 1), "name")
<
synIDattr({synID}, {what} [, {mode}])			*synIDattr()*
		The result is a String, which is the {what} attribute of
		syntax ID {synID}.  This can be used to obtain information
		about a syntax item.
		{mode} can be "gui", "cterm" or "term", to get the attributes
		for that mode.  When {mode} is omitted, or an invalid value is
		used, the attributes for the currently active highlighting are
		used (GUI, cterm or term).
		Use synIDtrans() to follow linked highlight groups.
		{what}		result
		"name"		the name of the syntax item
		"fg"		foreground color (GUI: color name used to set
				the color, cterm: color number as a string,
				term: empty string)
		"bg"		background color (like "fg")
		"fg#"		like "fg", but for the GUI and the GUI is
				running the name in "#RRGGBB" form
		"bg#"		like "fg#" for "bg"
		"bold"		"1" if bold
		"italic"	"1" if italic
		"reverse"	"1" if reverse
		"inverse"	"1" if inverse (= reverse)
		"underline"	"1" if underlined

		Example (echoes the color of the syntax item under the
		cursor): >
	:echo synIDattr(synIDtrans(synID(line("."), col("."), 1)), "fg")
<
synIDtrans({synID})					*synIDtrans()*
		The result is a Number, which is the translated syntax ID of
		{synID}.  This is the syntax group ID of what is being used to
		highlight the character.  Highlight links given with
		":highlight link" are followed.

							*system()*
system({expr})	Get the output of the shell command {expr}.  Note: newlines
		in {expr} may cause the command to fail.  The characters in
		'shellquote' and 'shellxquote' may also cause trouble.
		This is not to be used for interactive commands.
		The result is a String.  Example: >

			:let files = system("ls")

<		To make the result more system-independent, the shell output
		is filtered to replace <CR> with <NL> for Macintosh, and
		<CR><NL> with <NL> for DOS-like systems.
		The command executed is constructed using several options:
	'shell' 'shellcmdflag' 'shellxquote' {expr} 'shellredir' {tmp} 'shellxquote'
		({tmp} is an automatically generated file name).
		For Unix and OS/2 braces are put around {expr} to allow for
		concatenated commands.

		The resulting error code can be found in |v:shell_error|.
		This function will fail in |restricted-mode|.
		Unlike ":!cmd" there is no automatic check for changed files.
		Use |:checktime| to force a check.

tempname()					*tempname()* *temp-file-name*
		The result is a String, which is the name of a file that
		doesn't exist.  It can be used for a temporary file.  The name
		is different for at least 26 consecutive calls.  Example: >
			:let tmpfile = tempname()
			:exe "redir > " . tmpfile
<		For Unix, the file will be in a private directory (only
		accessible by the current user) to avoid security problems
		(e.g., a symlink attack or other people reading your file).
		When Vim exits the directory and all files in it are deleted.
		For MS-Windows forward slashes are used when the 'shellslash'
		option is set or when 'shellcmdflag' starts with '-'.

tolower({expr})						*tolower()*
		The result is a copy of the String given, with all uppercase
		characters turned into lowercase (just like applying |gu| to
		the string).

toupper({expr})						*toupper()*
		The result is a copy of the String given, with all lowercase
		characters turned into uppercase (just like applying |gU| to
		the string).

tr({src}, {fromstr}, {tostr})				*tr()*
		The result is a copy of the {src} string with all characters
		which appear in {fromstr} replaced by the character in that
		position in the {tostr} string.  Thus the first character in
		{fromstr} is translated into the first character in {tostr}
		and so on.  Exactly like the unix "tr" command.
		This code also deals with multibyte characters properly.

		Examples: >
			echo tr("hello there", "ht", "HT")
<		returns "Hello THere" >
			echo tr("<blob>", "<>", "{}")
<		returns "{blob}"

type({expr})						*type()*
		The result is a Number:
			0 if {expr} has the type Number
			1 if {expr} has the type String

virtcol({expr})						*virtcol()*
		The result is a Number, which is the screen column of the file
		position given with {expr}.  That is, the last screen position
		occupied by the character at that position, when the screen
		would be of unlimited width.  When there is a <Tab> at the
		position, the returned Number will be the column at the end of
		the <Tab>.  For example, for a <Tab> in column 1, with 'ts'
		set to 8, it returns 8.
		For the byte position use |col()|.
		When Virtual editing is active in the current mode, a position
		beyond the end of the line can be returned. |'virtualedit'|
		The accepted positions are:
		    .	    the cursor position
		    $	    the end of the cursor line (the result is the
			    number of displayed characters in the cursor line
			    plus one)
		    'x	    position of mark x (if the mark is not set, 0 is
			    returned)
		Note that only marks in the current file can be used.
		Examples: >
  virtcol(".")	   with text "foo^Lbar", with cursor on the "^L", returns 5
  virtcol("$")	   with text "foo^Lbar", returns 9
  virtcol("'t")    with text "    there", with 't at 'h', returns 6
<		The first column is 1.  0 is returned for an error.

visualmode([expr])						*visualmode()*
		The result is a String, which describes the last Visual mode
		used.  Initially it returns an empty string, but once Visual
		mode has been used, it returns "v", "V", or "<CTRL-V>" (a
		single CTRL-V character) for character-wise, line-wise, or
		block-wise Visual mode respectively.
		Example: >
			:exe "normal " . visualmode()
<		This enters the same Visual mode as before.  It is also useful
		in scripts if you wish to act differently depending on the
		Visual mode that was used.

		If an expression is supplied that results in a non-zero number
		or a non-empty string, then the Visual mode will be cleared
		and the old value is returned.  Note that " " and "0" are also
		non-empty strings, thus cause the mode to be cleared.

							*winbufnr()*
winbufnr({nr})	The result is a Number, which is the number of the buffer
		associated with window {nr}. When {nr} is zero, the number of
		the buffer in the current window is returned.  When window
		{nr} doesn't exist, -1 is returned.
		Example: >
  :echo "The file in the current window is " . bufname(winbufnr(0))
<
							*wincol()*
wincol()	The result is a Number, which is the virtual column of the
		cursor in the window.  This is counting screen cells from the
		left side of the window.  The leftmost column is one.

winheight({nr})						*winheight()*
		The result is a Number, which is the height of window {nr}.
		When {nr} is zero, the height of the current window is
		returned.  When window {nr} doesn't exist, -1 is returned.
		An existing window always has a height of zero or more.
		Examples: >
  :echo "The current window has " . winheight(0) . " lines."
<
							*winline()*
winline()	The result is a Number, which is the screen line of the cursor
		in the window.  This is counting screen lines from the top of
		the window.  The first line is one.

							*winnr()*
winnr()		The result is a Number, which is the number of the current
		window.  The top window has number 1.  The number can be used
		with |CTRL-W_w| and ":wincmd w" |:wincmd|.

							*winrestcmd()*
winrestcmd()	Returns a sequence of |:resize| commands that should restore
		the current window sizes.  Only works properly when no windows
		are opened or closed and the current window is unchanged.
		Example: >
			:let cmd = winrestcmd()
			:call MessWithWindowSizes()
			:exe cmd

winwidth({nr})						*winwidth()*
		The result is a Number, which is the width of window {nr}.
		When {nr} is zero, the width of the current window is
		returned.  When window {nr} doesn't exist, -1 is returned.
		An existing window always has a width of zero or more.
		Examples: >
  :echo "The current window has " . winwidth(0) . " columns."
  :if winwidth(0) <= 50
  :  exe "normal 50\<C-W>|"
  :endif
<

							*feature-list*
There are three types of features:
1.  Features that are only supported when they have been enabled when Vim
    was compiled |+feature-list|.  Example: >
	:if has("cindent")
2.  Features that are only supported when certain conditions have been met.
    Example: >
	:if has("gui_running")
<							*has-patch*
3.  Included patches.  First check |v:version| for the version of Vim.
    Then the "patch123" feature means that patch 123 has been included for
    this version.  Example (checking version 6.2.148 or later): >
	:if v:version > 602 || v:version == 602 && has("patch148")

all_builtin_terms	Compiled with all builtin terminals enabled.
amiga			Amiga version of Vim.
arabic			Compiled with Arabic support |Arabic|.
arp			Compiled with ARP support (Amiga).
autocmd			Compiled with autocommands support.
balloon_eval		Compiled with |balloon-eval| support.
beos			BeOS version of Vim.
browse			Compiled with |:browse| support, and browse() will
			work.
builtin_terms		Compiled with some builtin terminals.
byte_offset		Compiled with support for 'o' in 'statusline'
cindent			Compiled with 'cindent' support.
clientserver		Compiled with remote invocation support |clientserver|.
clipboard		Compiled with 'clipboard' support.
cmdline_compl		Compiled with |cmdline-completion| support.
cmdline_hist		Compiled with |cmdline-history| support.
cmdline_info		Compiled with 'showcmd' and 'ruler' support.
comments		Compiled with |'comments'| support.
cryptv			Compiled with encryption support |encryption|.
cscope			Compiled with |cscope| support.
compatible		Compiled to be very Vi compatible.
debug			Compiled with "DEBUG" defined.
dialog_con		Compiled with console dialog support.
dialog_gui		Compiled with GUI dialog support.
diff			Compiled with |vimdiff| and 'diff' support.
digraphs		Compiled with support for digraphs.
dnd			Compiled with support for the "~ register |quote_~|.
dos32			32 bits DOS (DJGPP) version of Vim.
dos16			16 bits DOS version of Vim.
ebcdic			Compiled on a machine with ebcdic character set.
emacs_tags		Compiled with support for Emacs tags.
eval			Compiled with expression evaluation support.  Always
			true, of course!
ex_extra		Compiled with extra Ex commands |+ex_extra|.
extra_search		Compiled with support for |'incsearch'| and
			|'hlsearch'|
farsi			Compiled with Farsi support |farsi|.
file_in_path		Compiled with support for |gf| and |<cfile>|
find_in_path		Compiled with support for include file searches
			|+find_in_path|.
fname_case		Case in file names matters (for Amiga, MS-DOS, and
			Windows this is not present).
folding			Compiled with |folding| support.
footer			Compiled with GUI footer support. |gui-footer|
fork			Compiled to use fork()/exec() instead of system().
gettext			Compiled with message translation |multi-lang|
gui			Compiled with GUI enabled.
gui_athena		Compiled with Athena GUI.
gui_beos		Compiled with BeOS GUI.
gui_gtk			Compiled with GTK+ GUI (any version).
gui_gtk2		Compiled with GTK+ 2 GUI (gui_gtk is also defined).
gui_kde			Compiled with KDE GUI |KVim|
gui_mac			Compiled with Macintosh GUI.
gui_motif		Compiled with Motif GUI.
gui_photon		Compiled with Photon GUI.
gui_win32		Compiled with MS Windows Win32 GUI.
gui_win32s		idem, and Win32s system being used (Windows 3.1)
gui_running		Vim is running in the GUI, or it will start soon.
hangul_input		Compiled with Hangul input support. |hangul|
iconv			Can use iconv() for conversion.
insert_expand		Compiled with support for CTRL-X expansion commands in
			Insert mode.
jumplist		Compiled with |jumplist| support.
keymap			Compiled with 'keymap' support.
langmap			Compiled with 'langmap' support.
libcall			Compiled with |libcall()| support.
linebreak		Compiled with 'linebreak', 'breakat' and 'showbreak'
			support.
lispindent		Compiled with support for lisp indenting.
listcmds		Compiled with commands for the buffer list |:files|
			and the argument list |arglist|.
localmap		Compiled with local mappings and abbr. |:map-local|
mac			Macintosh version of Vim.
macunix			Macintosh version of Vim, using Unix files (OS-X).
menu			Compiled with support for |:menu|.
mksession		Compiled with support for |:mksession|.
modify_fname		Compiled with file name modifiers. |filename-modifiers|
mouse			Compiled with support mouse.
mouseshape		Compiled with support for 'mouseshape'.
mouse_dec		Compiled with support for Dec terminal mouse.
mouse_gpm		Compiled with support for gpm (Linux console mouse)
mouse_netterm		Compiled with support for netterm mouse.
mouse_pterm		Compiled with support for qnx pterm mouse.
mouse_xterm		Compiled with support for xterm mouse.
multi_byte		Compiled with support for editing Korean et al.
multi_byte_ime		Compiled with support for IME input method.
multi_lang		Compiled with support for multiple languages.
mzscheme		Compiled with MzScheme interface |mzscheme|.
netbeans_intg		Compiled with support for |netbeans|.
ole			Compiled with OLE automation support for Win32.
os2			OS/2 version of Vim.
osfiletype		Compiled with support for osfiletypes |+osfiletype|
path_extra		Compiled with up/downwards search in 'path' and 'tags'
perl			Compiled with Perl interface.
postscript		Compiled with PostScript file printing.
printer			Compiled with |:hardcopy| support.
python			Compiled with Python interface.
qnx			QNX version of Vim.
quickfix		Compiled with |quickfix| support.
rightleft		Compiled with 'rightleft' support.
ruby			Compiled with Ruby interface |ruby|.
scrollbind		Compiled with 'scrollbind' support.
showcmd			Compiled with 'showcmd' support.
signs			Compiled with |:sign| support.
smartindent		Compiled with 'smartindent' support.
sniff			Compiled with SNiFF interface support.
statusline		Compiled with support for 'statusline', 'rulerformat'
			and special formats of 'titlestring' and 'iconstring'.
sun_workshop		Compiled with support for Sun |workshop|.
syntax			Compiled with syntax highlighting support.
syntax_items		There are active syntax highlighting items for the
			current buffer.
system			Compiled to use system() instead of fork()/exec().
tag_binary		Compiled with binary searching in tags files
			|tag-binary-search|.
tag_old_static		Compiled with support for old static tags
			|tag-old-static|.
tag_any_white		Compiled with support for any white characters in tags
			files |tag-any-white|.
tcl			Compiled with Tcl interface.
terminfo		Compiled with terminfo instead of termcap.
termresponse		Compiled with support for |t_RV| and |v:termresponse|.
textobjects		Compiled with support for |text-objects|.
tgetent			Compiled with tgetent support, able to use a termcap
			or terminfo file.
title			Compiled with window title support |'title'|.
toolbar			Compiled with support for |gui-toolbar|.
unix			Unix version of Vim.
user_commands		User-defined commands.
viminfo			Compiled with viminfo support.
vim_starting		True while initial source'ing takes place.
vertsplit		Compiled with vertically split windows |:vsplit|.
virtualedit		Compiled with 'virtualedit' option.
visual			Compiled with Visual mode.
visualextra		Compiled with extra Visual mode commands.
			|blockwise-operators|.
vms			VMS version of Vim.
vreplace		Compiled with |gR| and |gr| commands.
wildignore		Compiled with 'wildignore' option.
wildmenu		Compiled with 'wildmenu' option.
windows			Compiled with support for more than one window.
winaltkeys		Compiled with 'winaltkeys' option.
win16			Win16 version of Vim (MS-Windows 3.1).
win32			Win32 version of Vim (MS-Windows 95/98/ME/NT/2000/XP).
win64			Win64 version of Vim (MS-Windows 64 bit).
win32unix		Win32 version of Vim, using Unix files (Cygwin)
win95			Win32 version for MS-Windows 95/98/ME.
writebackup		Compiled with 'writebackup' default on.
xfontset		Compiled with X fontset support |xfontset|.
xim			Compiled with X input method support |xim|.
xsmp			Compiled with X session management support.
xsmp_interact		Compiled with interactive X session management support.
xterm_clipboard		Compiled with support for xterm clipboard.
xterm_save		Compiled with support for saving and restoring the
			xterm screen.
x11			Compiled with X11 support.

							*string-match*
Matching a pattern in a String

A regexp pattern as explained at |pattern| is normally used to find a match in
the buffer lines.  When a pattern is used to find a match in a String, almost
everything works in the same way.  The difference is that a String is handled
like it is one line.  When it contains a "\n" character, this is not seen as a
line break for the pattern.  It can be matched with a "\n" in the pattern, or
with ".".  Example: >
	:let a = "aaaa\nxxxx"
	:echo matchstr(a, "..\n..")
	aa
	xx
	:echo matchstr(a, "a.x")
	a
	x

Don't forget that "^" will only match at the first character of the String and
"$" at the last character of the string.  They don't match after or before a
"\n".

==============================================================================
5. Defining functions					*user-functions*

New functions can be defined.  These can be called just like builtin
functions.  The function executes a sequence of Ex commands.  Normal mode
commands can be executed with the |:normal| command.

The function name must start with an uppercase letter, to avoid confusion with
builtin functions.  To prevent from using the same name in different scripts
avoid obvious, short names.  A good habit is to start the function name with
the name of the script, e.g., "HTMLcolor()".

It's also possible to use curly braces, see |curly-braces-names|.

							*local-function*
A function local to a script must start with "s:".  A local script function
can only be called from within the script and from functions, user commands
and autocommands defined in the script.  It is also possible to call the
function from a mappings defined in the script, but then |<SID>| must be used
instead of "s:" when the mapping is expanded outside of the script.

					*:fu* *:function* *E128* *E129* *E123*
:fu[nction]		List all functions and their arguments.

:fu[nction] {name}	List function {name}.
							*E124* *E125*
:fu[nction][!] {name}([arguments]) [range] [abort]
			Define a new function by the name {name}.  The name
			must be made of alphanumeric characters and '_', and
			must start with a capital or "s:" (see above).
						*function-argument* *a:var*
			An argument can be defined by giving its name.  In the
			function this can then be used as "a:name" ("a:" for
			argument).
			Up to 20 arguments can be given, separated by commas.
			Finally, an argument "..." can be specified, which
			means that more arguments may be following.  In the
			function they can be used as "a:1", "a:2", etc.  "a:0"
			is set to the number of extra arguments (which can be
			0).
			When not using "...", the number of arguments in a
			function call must be equal to the number of named
			arguments.  When using "...", the number of arguments
			may be larger.
			It is also possible to define a function without any
			arguments.  You must still supply the () then.
			The body of the function follows in the next lines,
			until the matching |:endfunction|.  It is allowed to
			define another function inside a function body.
								*E127* *E122*
			When a function by this name already exists and [!] is
			not used an error message is given.  When [!] is used,
			an existing function is silently replaced.  Unless it
			is currently being executed, that is an error.
						*a:firstline* *a:lastline*
			When the [range] argument is added, the function is
			expected to take care of a range itself.  The range is
			passed as "a:firstline" and "a:lastline".  If [range]
			is excluded, ":{range}call" will call the function for
			each line in the range, with the cursor on the start
			of each line.  See |function-range-example|.
			When the [abort] argument is added, the function will
			abort as soon as an error is detected.
			The last used search pattern and the redo command "."
			will not be changed by the function.

					*:endf* *:endfunction* *E126* *E193*
:endf[unction]		The end of a function definition.  Must be on a line
			by its own, without other commands.

					*:delf* *:delfunction* *E130* *E131*
:delf[unction] {name}	Delete function {name}.

							*:retu* *:return* *E133*
:retu[rn] [expr]	Return from a function.  When "[expr]" is given, it is
			evaluated and returned as the result of the function.
			If "[expr]" is not given, the number 0 is returned.
			When a function ends without an explicit ":return",
			the number 0 is returned.
			Note that there is no check for unreachable lines,
			thus there is no warning if commands follow ":return".

			If the ":return" 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 inside the function.  The function
			returns at the outermost ":endtry".


Inside a function variables can be used.  These are local variables, which
will disappear when the function returns.  Global variables need to be
accessed with "g:".

Example: >
  :function Table(title, ...)
  :  echohl Title
  :  echo a:title
  :  echohl None
  :  let idx = 1
  :  while idx <= a:0
  :    echo a:{idx} . ' '
  :    let idx = idx + 1
  :  endwhile
  :  return idx
  :endfunction

This function can then be called with: >
  let lines = Table("Table", "line1", "line2")
  let lines = Table("Empty Table")

To return more than one value, pass the name of a global variable: >
  :function Compute(n1, n2, divname)
  :  if a:n2 == 0
  :    return "fail"
  :  endif
  :  let g:{a:divname} = a:n1 / a:n2
  :  return "ok"
  :endfunction

This function can then be called with: >
  :let success = Compute(13, 1324, "div")
  :if success == "ok"
  :  echo div
  :endif

An alternative is to return a command that can be executed.  This also works
with local variables in a calling function.  Example: >
  :function Foo()
  :  execute Bar()
  :  echo "line " . lnum . " column " . col
  :endfunction

  :function Bar()
  :  return "let lnum = " . line(".") . " | let col = " . col(".")
  :endfunction

The names "lnum" and "col" could also be passed as argument to Bar(), to allow
the caller to set the names.

							*:cal* *:call* *E107*
:[range]cal[l] {name}([arguments])
		Call a function.  The name of the function and its arguments
		are as specified with |:function|.  Up to 20 arguments can be
		used.
		Without a range and for functions that accept a range, the
		function is called once.  When a range is given the cursor is
		positioned at the start of the first line before executing the
		function.
		When a range is given and the function doesn't handle it
		itself, the function is executed for each line in the range,
		with the cursor in the first column of that line.  The cursor
		is left at the last line (possibly moved by the last function
		call).  The arguments are re-evaluated for each line.  Thus
		this works:
						*function-range-example*  >
	:function Mynumber(arg)
	:  echo line(".") . " " . a:arg
	:endfunction
	:1,5call Mynumber(getline("."))
<
		The "a:firstline" and "a:lastline" are defined anyway, they
		can be used to do something different at the start or end of
		the range.

		Example of a function that handles the range itself: >

	:function Cont() range
	:  execute (a:firstline + 1) . "," . a:lastline . 's/^/\t\\ '
	:endfunction
	:4,8call Cont()
<
		This function inserts the continuation character "\" in front
		of all the lines in the range, except the first one.

								*E132*
The recursiveness of user functions is restricted with the |'maxfuncdepth'|
option.

							*autoload-functions*
When using many or large functions, it's possible to automatically define them
only when they are used.  Use the FuncUndefined autocommand event with a
pattern that matches the function(s) to be defined.  Example: >

	:au FuncUndefined BufNet* source ~/vim/bufnetfuncs.vim

The file "~/vim/bufnetfuncs.vim" should then define functions that start with
"BufNet".  Also see |FuncUndefined|.

==============================================================================
6. Curly braces names					*curly-braces-names*

Wherever you can use a variable, you can use a "curly braces name" variable.
This is a regular variable name with one or more expressions wrapped in braces
{} like this: >
	my_{adjective}_variable

When Vim encounters this, it evaluates the expression inside the braces, puts
that in place of the expression, and re-interprets the whole as a variable
name.  So in the above example, if the variable "adjective" was set to
"noisy", then the reference would be to "my_noisy_variable", whereas if
"adjective" was set to "quiet", then it would be to "my_quiet_variable".

One application for this is to create a set of variables governed by an option
value.  For example, the statement >
	echo my_{&background}_message

would output the contents of "my_dark_message" or "my_light_message" depending
on the current value of 'background'.

You can use multiple brace pairs: >
	echo my_{adverb}_{adjective}_message
..or even nest them: >
	echo my_{ad{end_of_word}}_message
where "end_of_word" is either "verb" or "jective".

However, the expression inside the braces must evaluate to a valid single
variable name. e.g. this is invalid: >
	:let foo='a + b'
	:echo c{foo}d
.. since the result of expansion is "ca + bd", which is not a variable name.

						*curly-braces-function-names*
You can call and define functions by an evaluated name in a similar way.
Example: >
	:let func_end='whizz'
	:call my_func_{func_end}(parameter)

This would call the function "my_func_whizz(parameter)".

==============================================================================
7. Commands						*expression-commands*

:let {var-name} = {expr1}				*:let* *E18*
			Set internal variable {var-name} to the result of the
			expression {expr1}.  The variable will get the type
			from the {expr}.  If {var-name} didn't exist yet, it
			is created.

:let ${env-name} = {expr1}			*:let-environment* *:let-$*
			Set environment variable {env-name} to the result of
			the expression {expr1}.  The type is always String.

:let @{reg-name} = {expr1}			*:let-register* *:let-@*
			Write the result of the expression {expr1} in register
			{reg-name}.  {reg-name} must be a single letter, and
			must be the name of a writable register (see
			|registers|).  "@@" can be used for the unnamed
			register, "@/" for the search pattern.
			If the result of {expr1} ends in a <CR> or <NL>, the
			register will be linewise, otherwise it will be set to
			characterwise.
			This can be used to clear the last search pattern: >
				:let @/ = ""
<			This is different from searching for an empty string,
			that would match everywhere.

:let &{option-name} = {expr1}			*:let-option* *:let-star*
			Set option {option-name} to the result of the
			expression {expr1}.  The value is always converted to
			the type of the option.
			For an option local to a window or buffer the effect
			is just like using the |:set| command: both the local
			value and the global value is changed.

:let &l:{option-name} = {expr1}
			Like above, but only set the local value of an option
			(if there is one).  Works like |:setlocal|.

:let &g:{option-name} = {expr1}
			Like above, but only set the global value of an option
			(if there is one).  Works like |:setglobal|.

							*E106*
:let {var-name}	..	List the value of variable {var-name}.  Several
			variable names may be given.

:let			List the values of all variables.

							*:unlet* *:unl* *E108*
:unl[et][!] {var-name} ...
			Remove the internal variable {var-name}.  Several
			variable names can be given, they are all removed.
			With [!] no error message is given for non-existing
			variables.

:if {expr1}			*:if* *:endif* *:en* *E171* *E579* *E580*
:en[dif]		Execute the commands until the next matching ":else"
			or ":endif" if {expr1} evaluates to non-zero.

			From Vim version 4.5 until 5.0, every Ex command in
			between the ":if" and ":endif" is ignored.  These two
			commands were just to allow for future expansions in a
			backwards compatible way.  Nesting was allowed.  Note
			that any ":else" or ":elseif" was ignored, the "else"
			part was not executed either.

			You can use this to remain compatible with older
			versions: >
				:if version >= 500
				:  version-5-specific-commands
				:endif
<			The commands still need to be parsed to find the
			"endif".  Sometimes an older Vim has a problem with a
			new command.  For example, ":silent" is recognized as
			a ":substitute" command.  In that case ":execute" can
			avoid problems: >
				:if version >= 600
				:  execute "silent 1,$delete"
				:endif
<
			NOTE: The ":append" and ":insert" commands don't work
			properly in between ":if" and ":endif".

						*:else* *:el* *E581* *E583*
:el[se]			Execute the commands until the next matching ":else"
			or ":endif" if they previously were not being
			executed.

					*:elseif* *:elsei* *E582* *E584*
:elsei[f] {expr1}	Short for ":else" ":if", with the addition that there
			is no extra ":endif".

:wh[ile] {expr1}			*:while* *:endwhile* *:wh* *:endw*
							*E170* *E585* *E588*
:endw[hile]		Repeat the commands between ":while" and ":endwhile",
			as long as {expr1} evaluates to non-zero.
			When an error is detected from a command inside the
			loop, execution continues after the "endwhile".

			NOTE: The ":append" and ":insert" commands don't work
			properly inside a ":while" loop.

						*:continue* *:con* *E586*
:con[tinue]		When used inside a ":while", jumps back to the
			":while".  If it is used after a |:try| inside the
			":while" 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 inside the
			":while".  The outermost ":endtry" then jumps back to
			the ":while".

						*:break* *:brea* *E587*
:brea[k]		When used inside a ":while", skips to the command
			after the matching ":endwhile".  If it is used after
			a |:try| inside the ":while" 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
			inside the ":while".  The outermost ":endtry" then
			jumps to the command after the ":endwhile".

:try				*:try* *:endt* *:endtry* *E600* *E601* *E602*
:endt[ry]		Change the error handling for the commands between
			":try" and ":endtry" including everything being
			executed across ":source" commands, function calls,
			or autocommand invocations.

			When an error or interrupt is detected and there is
			a |:finally| command following, execution continues
			after the ":finally".  Otherwise, or when the
			":endtry" is reached thereafter, the next
			(dynamically) surrounding ":try" is checked for
			a corresponding ":finally" etc.  Then the script
			processing is terminated.  (Whether a function
			definition has an "abort" argument does not matter.)
			Example: >
		:try | edit too much | finally | echo "cleanup" | endtry
		:echo "impossible"	" not reached, script terminated above
<
			Moreover, an error or interrupt (dynamically) inside
			":try" and ":endtry" is converted to an exception.  It
			can be caught as if it were thrown by a |:throw|
			command (see |:catch|).  In this case, the script
			processing is not terminated.

			The value "Vim:Interrupt" is used for an interrupt
			exception.  An error in a Vim command is converted
			to a value of the form "Vim({command}):{errmsg}",
			other errors are converted to a value of the form
			"Vim:{errmsg}".  {command} is the full command name,
			and {errmsg} is the message that is displayed if the
			error exception is not caught, always beginning with
			the error number.
			Examples: >
		:try | sleep 100 | catch /^Vim:Interrupt$/ | endtry
		:try | edit | catch /^Vim(edit):E\d\+/ | echo "error" | endtry
<
					*:cat* *:catch* *E603* *E604* *E605*
:cat[ch] /{pattern}/	The following commands until the next ":catch",
			|:finally|, or |:endtry| that belongs to the same
			|:try| as the ":catch" are executed when an exception
			matching {pattern} is being thrown and has not yet
			been caught by a previous ":catch".  Otherwise, these
			commands are skipped.
			When {pattern} is omitted all errors are caught.
			Examples: >
		:catch /^Vim:Interrupt$/	" catch interrupts (CTRL-C)
		:catch /^Vim\%((\a\+)\)\=:E/	" catch all Vim errors
		:catch /^Vim\%((\a\+)\)\=:/	" catch errors and interrupts
		:catch /^Vim(write):/		" catch all errors in :write
		:catch /^Vim\%((\a\+)\)\=:E123/	" catch error E123
		:catch /my-exception/		" catch user exception
		:catch /.*/			" catch everything
		:catch				" same as /.*/
<
			Another character can be used instead of / around the
			{pattern}, so long as it does not have a special
			meaning (e.g., '|' or '"') and doesn't occur inside
			{pattern}.
			NOTE: It is not reliable to ":catch" the TEXT of
			an error message because it may vary in different
			locales.

					*:fina* *:finally* *E606* *E607*
:fina[lly]		The following commands until the matching |:endtry|
			are executed whenever the part between the matching
			|:try| and the ":finally" is left:  either by falling
			through to the ":finally" or by a |:continue|,
			|:break|, |:finish|, or |:return|, or by an error or
			interrupt or exception (see |:throw|).

							*:th* *:throw* *E608*
:th[row] {expr1}	The {expr1} is evaluated and thrown as an exception.
			If the ":throw" is used after a |:try| but before the
			first corresponding |:catch|, commands are skipped
			until the first ":catch" matching {expr1} is reached.
			If there is no such ":catch" or if the ":throw" is
			used after a ":catch" but before the |:finally|, the
			commands following the ":finally" (if present) up to
			the matching |:endtry| are executed.  If the ":throw"
			is after the ":finally", commands up to the ":endtry"
			are skipped.  At the ":endtry", this process applies
			again for the next dynamically surrounding ":try"
			(which may be found in a calling function or sourcing
			script), until a matching ":catch" has been found.
			If the exception is not caught, the command processing
			is terminated.
			Example: >
		:try | throw "oops" | catch /^oo/ | echo "caught" | endtry
<

							*:ec* *:echo*
:ec[ho] {expr1} ..	Echoes each {expr1}, with a space in between.  The
			first {expr1} starts on a new line.
			Also see |:comment|.
			Use "\n" to start a new line.  Use "\r" to move the
			cursor to the first column.
			Uses the highlighting set by the |:echohl| command.
			Cannot be followed by a comment.
			Example: >
		:echo "the value of 'shell' is" &shell
<			A later redraw may make the message disappear again.
			To avoid that a command from before the ":echo" causes
			a redraw afterwards (redraws are often postponed until
			you type something), force a redraw with the |:redraw|
			command.  Example: >
		:new | redraw | echo "there is a new window"
<
							*:echon*
:echon {expr1} ..	Echoes each {expr1}, without anything added.  Also see
			|:comment|.
			Uses the highlighting set by the |:echohl| command.
			Cannot be followed by a comment.
			Example: >
				:echon "the value of 'shell' is " &shell
<
			Note the difference between using ":echo", which is a
			Vim command, and ":!echo", which is an external shell
			command: >
		:!echo %		--> filename
<			The arguments of ":!" are expanded, see |:_%|. >
		:!echo "%"		--> filename or "filename"
<			Like the previous example.  Whether you see the double
			quotes or not depends on your 'shell'. >
		:echo %			--> nothing
<			The '%' is an illegal character in an expression. >
		:echo "%"		--> %
<			This just echoes the '%' character. >
		:echo expand("%")	--> filename
<			This calls the expand() function to expand the '%'.

							*:echoh* *:echohl*
:echoh[l] {name}	Use the highlight group {name} for the following
			|:echo|, |:echon| and |:echomsg| commands.  Also used
			for the |input()| prompt.  Example: >
		:echohl WarningMsg | echo "Don't panic!" | echohl None
<			Don't forget to set the group back to "None",
			otherwise all following echo's will be highlighted.

							*:echom* *:echomsg*
:echom[sg] {expr1} ..	Echo the expression(s) as a true message, saving the
			message in the |message-history|.
			Spaces are placed between the arguments as with the
			|:echo| command.  But unprintable characters are
			displayed, not interpreted.
			Uses the highlighting set by the |:echohl| command.
			Example: >
		:echomsg "It's a Zizzer Zazzer Zuzz, as you can plainly see."
<
							*:echoe* *:echoerr*
:echoe[rr] {expr1} ..	Echo the expression(s) as an error message, saving the
			message in the |message-history|.  When used in a
			script or function the line number will be added.
			Spaces are placed between the arguments as with the
			:echo command.  When used inside a try conditional,
			the message is raised as an error exception instead
			(see |try-echoerr|).
			Example: >
		:echoerr "This script just failed!"
<			If you just want a highlighted message use |:echohl|.
			And to get a beep: >
		:exe "normal \<Esc>"
<
							*:exe* *:execute*
:exe[cute] {expr1} ..	Executes the string that results from the evaluation
			of {expr1} as an Ex command.  Multiple arguments are
			concatenated, with a space in between.  {expr1} is
			used as the processed command, command line editing
			keys are not recognized.
			Cannot be followed by a comment.
			Examples: >
		:execute "buffer " nextbuf
		:execute "normal " count . "w"
<
			":execute" can be used to append a command to commands
			that don't accept a '|'.  Example: >
		:execute '!ls' | echo "theend"

<			":execute" is also a nice way to avoid having to type
			control characters in a Vim script for a ":normal"
			command: >
		:execute "normal ixxx\<Esc>"
<			This has an <Esc> character, see |expr-string|.

			Note: The executed string may be any command-line, but
			you cannot start or end a "while" or "if" command.
			Thus this is illegal: >
		:execute 'while i > 5'
		:execute 'echo "test" | break'
<
			It is allowed to have a "while" or "if" command
			completely in the executed string: >
		:execute 'while i < 5 | echo i | let i = i + 1 | endwhile'
<

							*:comment*
			":execute", ":echo" and ":echon" cannot be followed by
			a comment directly, because they see the '"' as the
			start of a string.  But, you can use '|' followed by a
			comment.  Example: >
		:echo "foo" | "this is a comment

==============================================================================
8. Exception handling					*exception-handling*

The Vim script language comprises an exception handling feature.  This section
explains how it can be used in a Vim script.

Exceptions may be raised by Vim on an error or on interrupt, see
|catch-errors| and |catch-interrupt|.  You can also explicitly throw an
exception by using the ":throw" command, see |throw-catch|.


TRY CONDITIONALS					*try-conditionals*

Exceptions can be caught or can cause cleanup code to be executed.  You can
use a try conditional to specify catch clauses (that catch exceptions) and/or
a finally clause (to be executed for cleanup).
   A try conditional begins with a |:try| command and ends at the matching
|:endtry| command.  In between, you can use a |:catch| command to start
a catch clause, or a |:finally| command to start a finally clause.  There may
be none or multiple catch clauses, but there is at most one finally clause,
which must not be followed by any catch clauses.  The lines before the catch
clauses and the finally clause is called a try block. >

     :try
     :  ...
     :  ...				TRY BLOCK
     :  ...
     :catch /{pattern}/
     :  ...
     :  ...				CATCH CLAUSE
     :  ...
     :catch /{pattern}/
     :  ...
     :  ...				CATCH CLAUSE
     :  ...
     :finally
     :  ...
     :  ...				FINALLY CLAUSE
     :  ...
     :endtry

The try conditional allows to watch code for exceptions and to take the
appropriate actions.  Exceptions from the try block may be caught.  Exceptions
from the try block and also the catch clauses may cause cleanup actions.
   When no exception is thrown during execution of the try block, the control
is transferred to the finally clause, if present.  After its execution, the
script continues with the line following the ":endtry".
   When an exception occurs during execution of the try block, the remaining
lines in the try block are skipped.  The exception is matched against the
patterns specified as arguments to the ":catch" commands.  The catch clause
after the first matching ":catch" is taken, other catch clauses are not
executed.  The catch clause ends when the next ":catch", ":finally", or
":endtry" command is reached - whatever is first.  Then, the finally clause
(if present) is executed.  When the ":endtry" is reached, the script execution
continues in the following line as usual.
   When an exception that does not match any of the patterns specified by the
":catch" commands is thrown in the try block, the exception is not caught by
that try conditional and none of the catch clauses is executed.  Only the
finally clause, if present, is taken.  The exception pends during execution of
the finally clause.  It is resumed at the ":endtry", so that commands after
the ":endtry" are not executed and the exception might be caught elsewhere,
see |try-nesting|.
   When during execution of a catch clause another exception is thrown, the
remaining lines in that catch clause are not executed.  The new exception is
not matched against the patterns in any of the ":catch" commands of the same
try conditional and none of its catch clauses is taken.  If there is, however,
a finally clause, it is executed, and the exception pends during its
execution.  The commands following the ":endtry" are not executed.  The new
exception might, however, be caught elsewhere, see |try-nesting|.
   When during execution of the finally clause (if present) an exception is
thrown, the remaining lines in the finally clause are skipped.  If the finally
clause has been taken because of an exception from the try block or one of the
catch clauses, the original (pending) exception is discarded.  The commands
following the ":endtry" are not executed, and the exception from the finally
clause is propagated and can be caught elsewhere, see |try-nesting|.

The finally clause is also executed, when a ":break" or ":continue" for
a ":while" loop enclosing the complete try conditional is executed from the
try block or a catch clause.  Or when a ":return" or ":finish" is executed
from the try block or a catch clause of a try conditional in a function or
sourced script, respectively.  The ":break", ":continue", ":return", or
":finish" pends during execution of the finally clause and is resumed when the
":endtry" is reached.  It is, however, discarded when an exception is thrown
from the finally clause.
   When a ":break" or ":continue" for a ":while" loop enclosing the complete
try conditional or when a ":return" or ":finish" is encountered in the finally
clause, the rest of the finally clause is skipped, and the ":break",
":continue", ":return" or ":finish" is executed as usual.  If the finally
clause has been taken because of an exception or an earlier ":break",
":continue", ":return", or ":finish" from the try block or a catch clause,
this pending exception or command is discarded.

For examples see |throw-catch| and |try-finally|.


NESTING	OF TRY CONDITIONALS				*try-nesting*

Try conditionals can be nested arbitrarily.  That is, a complete try
conditional can be put into the try block, a catch clause, or the finally
clause of another try conditional.  If the inner try conditional does not
catch an exception thrown in its try block or throws a new exception from one
of its catch clauses or its finally clause, the outer try conditional is
checked according to the rules above.  If the inner try conditional is in the
try block of the outer try conditional, its catch clauses are checked, but
otherwise only the finally clause is executed.  It does not matter for
nesting, whether the inner try conditional is directly contained in the outer
one, or whether the outer one sources a script or calls a function containing
the inner try conditional.

When none of the active try conditionals catches an exception, just their
finally clauses are executed.  Thereafter, the script processing terminates.
An error message is displayed in case of an uncaught exception explicitly
thrown by a ":throw" command.  For uncaught error and interrupt exceptions
implicitly raised by Vim, the error message(s) or interrupt message are shown
as usual.

For examples see |throw-catch|.


EXAMINING EXCEPTION HANDLING CODE			*except-examine*

Exception handling code can get tricky.  If you are in doubt what happens, set
'verbose' to 13 or use the ":13verbose" command modifier when sourcing your
script file.  Then you see when an exception is thrown, discarded, caught, or
finished.  When using a verbosity level of at least 14, things pending in
a finally clause are also shown.  This information is also given in debug mode
(see |debug-scripts|).


THROWING AND CATCHING EXCEPTIONS			*throw-catch*

You can throw any number or string as an exception.  Use the |:throw| command
and pass the value to be thrown as argument: >
	:throw 4711
	:throw "string"
<							*throw-expression*
You can also specify an expression argument.  The expression is then evaluated
first, and the result is thrown: >
	:throw 4705 + strlen("string")
	:throw strpart("strings", 0, 6)

An exception might be thrown during evaluation of the argument of the ":throw"
command.  Unless it is caught there, the expression evaluation is abandoned.
The ":throw" command then does not throw a new exception.
   Example: >

	:function! Foo(arg)
	:  try
	:    throw a:arg
	:  catch /foo/
	:  endtry
	:  return 1
	:endfunction
	:
	:function! Bar()
	:  echo "in Bar"
	:  return 4710
	:endfunction
	:
	:throw Foo("arrgh") + Bar()

This throws "arrgh", and "in Bar" is not displayed since Bar() is not
executed. >
	:throw Foo("foo") + Bar()
however displays "in Bar" and throws 4711.

Any other command that takes an expression as argument might also be
abandoned by an (uncaught) exception during the expression evaluation.  The
exception is then propagated to the caller of the command.
   Example: >

	:if Foo("arrgh")
	:  echo "then"
	:else
	:  echo "else"
	:endif

Here neither of "then" or "else" is displayed.

							*catch-order*
Exceptions can be caught by a try conditional with one or more |:catch|
commands, see |try-conditionals|.   The values to be caught by each ":catch"
command can be specified as a pattern argument.  The subsequent catch clause
gets executed when a matching exception is caught.
   Example: >

	:function! Foo(value)
	:  try
	:    throw a:value
	:  catch /^\d\+$/
	:    echo "Number thrown"
	:  catch /.*/
	:    echo "String thrown"
	:  endtry
	:endfunction
	:
	:call Foo(0x1267)
	:call Foo('string')

The first call to Foo() displays "Number thrown", the second "String thrown".
An exception is matched against the ":catch" commands in the order they are
specified.  Only the first match counts.  So you should place the more
specific ":catch" first.  The following order does not make sense: >

	:  catch /.*/
	:    echo "String thrown"
	:  catch /^\d\+$/
	:    echo "Number thrown"

The first ":catch" here matches always, so that the second catch clause is
never taken.

							*throw-variables*
If you catch an exception by a general pattern, you may access the exact value
in the variable |v:exception|: >

	:  catch /^\d\+$/
	:    echo "Number thrown.  Value is" v:exception

You may also be interested where an exception was thrown.  This is stored in
|v:throwpoint|.  Note that "v:exception" and "v:throwpoint" are valid for the
exception most recently caught as long it is not finished.
   Example: >

	:function! Caught()
	:  if v:exception != ""
	:    echo 'Caught "' . v:exception . '" in ' . v:throwpoint
	:  else
	:    echo 'Nothing caught'
	:  endif
	:endfunction
	:
	:function! Foo()
	:  try
	:    try
	:      try
	:	 throw 4711
	:      finally
	:	 call Caught()
	:      endtry
	:    catch /.*/
	:      call Caught()
	:      throw "oops"
	:    endtry
	:  catch /.*/
	:    call Caught()
	:  finally
	:    call Caught()
	:  endtry
	:endfunction
	:
	:call Foo()

This displays >

	Nothing caught
	Caught "4711" in function Foo, line 4
	Caught "oops" in function Foo, line 10
	Nothing caught

A practical example:  The following command ":LineNumber" displays the line
number in the script or function where it has been used: >

	:function! LineNumber()
	:    return substitute(v:throwpoint, '.*\D\(\d\+\).*', '\1', "")
	:endfunction
	:command! LineNumber try | throw "" | catch | echo LineNumber() | endtry
<
							*try-nested*
An exception that is not caught by a try conditional can be caught by
a surrounding try conditional: >

	:try
	:  try
	:    throw "foo"
	:  catch /foobar/
	:    echo "foobar"
	:  finally
	:    echo "inner finally"
	:  endtry
	:catch /foo/
	:  echo "foo"
	:endtry

The inner try conditional does not catch the exception, just its finally
clause is executed.  The exception is then caught by the outer try
conditional.  The example displays "inner finally" and then "foo".

							*throw-from-catch*
You can catch an exception and throw a new one to be caught elsewhere from the
catch clause: >

	:function! Foo()
	:  throw "foo"
	:endfunction
	:
	:function! Bar()
	:  try
	:    call Foo()
	:  catch /foo/
	:    echo "Caught foo, throw bar"
	:    throw "bar"
	:  endtry
	:endfunction
	:
	:try
	:  call Bar()
	:catch /.*/
	:  echo "Caught" v:exception
	:endtry

This displays "Caught foo, throw bar" and then "Caught bar".

							*rethrow*
There is no real rethrow in the Vim script language, but you may throw
"v:exception" instead: >

	:function! Bar()
	:  try
	:    call Foo()
	:  catch /.*/
	:    echo "Rethrow" v:exception
	:    throw v:exception
	:  endtry
	:endfunction
<							*try-echoerr*
Note that this method cannot be used to "rethrow" Vim error or interrupt
exceptions, because it is not possible to fake Vim internal exceptions.
Trying so causes an error exception.  You should throw your own exception
denoting the situation.  If you want to cause a Vim error exception containing
the original error exception value, you can use the |:echoerr| command: >

	:try
	:  try
	:    asdf
	:  catch /.*/
	:    echoerr v:exception
	:  endtry
	:catch /.*/
	:  echo v:exception
	:endtry

This code displays

	Vim(echoerr):Vim:E492: Not an editor command:   asdf ~


CLEANUP CODE						*try-finally*

Scripts often change global settings and restore them at their end.  If the
user however interrupts the script by pressing CTRL-C, the settings remain in
an inconsistent state.  The same may happen to you in the development phase of
a script when an error occurs or you explicitly throw an exception without
catching it.  You can solve these problems by using a try conditional with
a finally clause for restoring the settings.  Its execution is guaranteed on
normal control flow, on error, on an explicit ":throw", and on interrupt.
(Note that errors and interrupts from inside the try conditional are converted
to exceptions.  When not caught, they terminate the script after the finally
clause has been executed.)
Example: >

	:try
	:  let s:saved_ts = &ts
	:  set ts=17
	:
	:  " Do the hard work here.
	:
	:finally
	:  let &ts = s:saved_ts
	:  unlet s:saved_ts
	:endtry

This method should be used locally whenever a function or part of a script
changes global settings which need to be restored on failure or normal exit of
that function or script part.

							*break-finally*
Cleanup code works also when the try block or a catch clause is left by
a ":continue", ":break", ":return", or ":finish".
   Example: >

	:let first = 1
	:while 1
	:  try
	:    if first
	:      echo "first"
	:      let first = 0
	:      continue
	:    else
	:      throw "second"
	:    endif
	:  catch /.*/
	:    echo v:exception
	:    break
	:  finally
	:    echo "cleanup"
	:  endtry
	:  echo "still in while"
	:endwhile
	:echo "end"

This displays "first", "cleanup", "second", "cleanup", and "end". >

	:function! Foo()
	:  try
	:    return 4711
	:  finally
	:    echo "cleanup\n"
	:  endtry
	:  echo "Foo still active"
	:endfunction
	:
	:echo Foo() "returned by Foo"

This displays "cleanup" and "4711 returned by Foo".  You don't need to add an
extra ":return" in the finally clause.  (Above all, this would override the
return value.)

							*except-from-finally*
Using either of ":continue", ":break", ":return", ":finish", or ":throw" in
a finally clause is possible, but not recommended since it abandons the
cleanup actions for the try conditional.  But, of course, interrupt and error
exceptions might get raised from a finally clause.
   Example where an error in the finally clause stops an interrupt from
working correctly: >

	:try
	:  try
	:    echo "Press CTRL-C for interrupt"
	:    while 1
	:    endwhile
	:  finally
	:    unlet novar
	:  endtry
	:catch /novar/
	:endtry
	:echo "Script still running"
	:sleep 1

If you need to put commands that could fail into a finally clause, you should
think about catching or ignoring the errors in these commands, see
|catch-errors| and |ignore-errors|.


CATCHING ERRORS						*catch-errors*

If you want to catch specific errors, you just have to put the code to be
watched in a try block and add a catch clause for the error message.  The
presence of the try conditional causes all errors to be converted to an
exception.  No message is displayed and |v:errmsg| is not set then.  To find
the right pattern for the ":catch" command, you have to know how the format of
the error exception is.
   Error exceptions have the following format: >

	Vim({cmdname}):{errmsg}
or >
	Vim:{errmsg}

{cmdname} is the name of the command that failed; the second form is used when
the command name is not known.  {errmsg} is the error message usually produced
when the error occurs outside try conditionals.  It always begins with
a capital "E", followed by a two or three-digit error number, a colon, and
a space.

Examples:

The command >
	:unlet novar
normally produces the error message >
	E108: No such variable: "novar"
which is converted inside try conditionals to an exception >
	Vim(unlet):E108: No such variable: "novar"

The command >
	:dwim
normally produces the error message >
	E492: Not an editor command: dwim
which is converted inside try conditionals to an exception >
	Vim:E492: Not an editor command: dwim

You can catch all ":unlet" errors by a >
	:catch /^Vim(unlet):/
or all errors for misspelled command names by a >
	:catch /^Vim:E492:/

Some error messages may be produced by different commands: >
	:function nofunc
and >
	:delfunction nofunc
both produce the error message >
	E128: Function name must start with a capital: nofunc
which is converted inside try conditionals to an exception >
	Vim(function):E128: Function name must start with a capital: nofunc
or >
	Vim(delfunction):E128: Function name must start with a capital: nofunc
respectively.  You can catch the error by its number independently on the
command that caused it if you use the following pattern: >
	:catch /^Vim(\a\+):E128:/

Some commands like >
	:let x = novar
produce multiple error messages, here: >
	E121: Undefined variable: novar
	E15: Invalid expression:  novar
Only the first is used for the exception value, since it is the most specific
one (see |except-several-errors|).  So you can catch it by >
	:catch /^Vim(\a\+):E121:/

You can catch all errors related to the name "nofunc" by >
	:catch /\<nofunc\>/

You can catch all Vim errors in the ":write" and ":read" commands by >
	:catch /^Vim(\(write\|read\)):E\d\+:/

You can catch all Vim errors by the pattern >
	:catch /^Vim\((\a\+)\)\=:E\d\+:/
<
							*catch-text*
NOTE: You should never catch the error message text itself: >
	:catch /No such variable/
only works in the english locale, but not when the user has selected
a different language by the |:language| command.  It is however helpful to
cite the message text in a comment: >
	:catch /^Vim(\a\+):E108:/   " No such variable


IGNORING ERRORS						*ignore-errors*

You can ignore errors in a specific Vim command by catching them locally: >

	:try
	:  write
	:catch
	:endtry

But you are strongly recommended NOT to use this simple form, since it could
catch more than you want.  With the ":write" command, some autocommands could
be executed and cause errors not related to writing, for instance: >

	:au BufWritePre * unlet novar

There could even be such errors you are not responsible for as a script
writer: a user of your script might have defined such autocommands.  You would
then hide the error from the user.
   It is much better to use >

	:try
	:  write
	:catch /^Vim(write):/
	:endtry

which only catches real write errors.  So catch only what you'd like to ignore
intentionally.

For a single command that does not cause execution of autocommands, you could
even suppress the conversion of errors to exceptions by the ":silent!"
command: >
	:silent! nunmap k
This works also when a try conditional is active.


CATCHING INTERRUPTS					*catch-interrupt*

When there are active try conditionals, an interrupt (CTRL-C) is converted to
the exception "Vim:Interrupt".  You can catch it like every exception.  The
script is not terminated, then.
   Example: >

	:function! TASK1()
	:  sleep 10
	:endfunction

	:function! TASK2()
	:  sleep 20
	:endfunction

	:while 1
	:  let command = input("Type a command: ")
	:  try
	:    if command == ""
	:      continue
	:    elseif command == "END"
	:      break
	:    elseif command == "TASK1"
	:      call TASK1()
	:    elseif command == "TASK2"
	:      call TASK2()
	:    else
	:      echo "\nIllegal command:" command
	:      continue
	:    endif
	:  catch /^Vim:Interrupt$/
	:    echo "\nCommand interrupted"
	:    " Caught the interrupt.  Continue with next prompt.
	:  endtry
	:endwhile

You can interrupt a task here by pressing CTRL-C; the script then asks for
a new command.  If you press CTRL-C at the prompt, the script is terminated.

For testing what happens when CTRL-C would be pressed on a specific line in
your script, use the debug mode and execute the |>quit| or |>interrupt|
command on that line.  See |debug-scripts|.


CATCHING ALL						*catch-all*

The commands >

	:catch /.*/
	:catch //
	:catch

catch everything, error exceptions, interrupt exceptions and exceptions
explicitly thrown by the |:throw| command.  This is useful at the top level of
a script in order to catch unexpected things.
   Example: >

	:try
	:
	:  " do the hard work here
	:
	:catch /MyException/
	:
	:  " handle known problem
	:
	:catch /^Vim:Interrupt$/
	:    echo "Script interrupted"
	:catch /.*/
	:  echo "Internal error (" . v:exception . ")"
	:  echo " - occurred at " . v:throwpoint
	:endtry
	:" end of script

Note: Catching all might catch more things than you want.  Thus, you are
strongly encouraged to catch only for problems that you can really handle by
specifying a pattern argument to the ":catch".
   Example: Catching all could make it nearly impossible to interrupt a script
by pressing CTRL-C: >

	:while 1
	:  try
	:    sleep 1
	:  catch
	:  endtry
	:endwhile


EXCEPTIONS AND AUTOCOMMANDS				*except-autocmd*

Exceptions may be used during execution of autocommands.  Example: >

	:autocmd User x try
	:autocmd User x   throw "Oops!"
	:autocmd User x catch
	:autocmd User x   echo v:exception
	:autocmd User x endtry
	:autocmd User x throw "Arrgh!"
	:autocmd User x echo "Should not be displayed"
	:
	:try
	:  doautocmd User x
	:catch
	:  echo v:exception
	:endtry

This displays "Oops!" and "Arrgh!".

							*except-autocmd-Pre*
For some commands, autocommands get executed before the main action of the
command takes place.  If an exception is thrown and not caught in the sequence
of autocommands, the sequence and the command that caused its execution are
abandoned and the exception is propagated to the caller of the command.
   Example: >

	:autocmd BufWritePre * throw "FAIL"
	:autocmd BufWritePre * echo "Should not be displayed"
	:
	:try
	:  write
	:catch
	:  echo "Caught:" v:exception "from" v:throwpoint
	:endtry

Here, the ":write" command does not write the file currently being edited (as
you can see by checking 'modified'), since the exception from the BufWritePre
autocommand abandons the ":write".  The exception is then caught and the
script displays: >

	Caught: FAIL from BufWrite Auto commands for "*"
<
							*except-autocmd-Post*
For some commands, autocommands get executed after the main action of the
command has taken place.  If this main action fails and the command is inside
an active try conditional, the autocommands are skipped and an error exception
is thrown that can be caught by the caller of the command.
   Example: >

	:autocmd BufWritePost * echo "File successfully written!"
	:
	:try
	:  write /i/m/p/o/s/s/i/b/l/e
	:catch
	:  echo v:exception
	:endtry

This just displays: >

	Vim(write):E212: Can't open file for writing (/i/m/p/o/s/s/i/b/l/e)

If you really need to execute the autocommands even when the main action
fails, trigger the event from the catch clause.
   Example: >

	:autocmd BufWritePre  * set noreadonly
	:autocmd BufWritePost * set readonly
	:
	:try
	:  write /i/m/p/o/s/s/i/b/l/e
	:catch
	:  doautocmd BufWritePost /i/m/p/o/s/s/i/b/l/e
	:endtry
<
You can also use ":silent!": >

	:let x = "ok"
	:let v:errmsg = ""
	:autocmd BufWritePost * if v:errmsg != ""
	:autocmd BufWritePost *   let x = "after fail"
	:autocmd BufWritePost * endif
	:try
	:  silent! write /i/m/p/o/s/s/i/b/l/e
	:catch
	:endtry
	:echo x

This displays "after fail".

If the main action of the command does not fail, exceptions from the
autocommands will be catchable by the caller of the command:  >

	:autocmd BufWritePost * throw ":-("
	:autocmd BufWritePost * echo "Should not be displayed"
	:
	:try
	:  write
	:catch
	:  echo v:exception
	:endtry
<
							*except-autocmd-Cmd*
For some commands, the normal action can be replaced by a sequence of
autocommands.  Exceptions from that sequence will be catchable by the caller
of the command.
   Example:  For the ":write" command, the caller cannot know whether the file
had actually been written when the exception occurred.  You need to tell it in
some way. >

	:if !exists("cnt")
	:  let cnt = 0
	:
	:  autocmd BufWriteCmd * if &modified
	:  autocmd BufWriteCmd *   let cnt = cnt + 1
	:  autocmd BufWriteCmd *   if cnt % 3 == 2
	:  autocmd BufWriteCmd *     throw "BufWriteCmdError"
	:  autocmd BufWriteCmd *   endif
	:  autocmd BufWriteCmd *   write | set nomodified
	:  autocmd BufWriteCmd *   if cnt % 3 == 0
	:  autocmd BufWriteCmd *     throw "BufWriteCmdError"
	:  autocmd BufWriteCmd *   endif
	:  autocmd BufWriteCmd *   echo "File successfully written!"
	:  autocmd BufWriteCmd * endif
	:endif
	:
	:try
	:	write
	:catch /^BufWriteCmdError$/
	:  if &modified
	:    echo "Error on writing (file contents not changed)"
	:  else
	:    echo "Error after writing"
	:  endif
	:catch /^Vim(write):/
	:    echo "Error on writing"
	:endtry

When this script is sourced several times after making changes, it displays
first >
	File successfully written!
then >
	Error on writing (file contents not changed)
then >
	Error after writing
etc.

							*except-autocmd-ill*
You cannot spread a try conditional over autocommands for different events.
The following code is ill-formed: >

	:autocmd BufWritePre  * try
	:
	:autocmd BufWritePost * catch
	:autocmd BufWritePost *   echo v:exception
	:autocmd BufWritePost * endtry
	:
	:write


EXCEPTION HIERARCHIES AND PARAMETERIZED EXCEPTIONS	*except-hier-param*

Some programming languages allow to use hierarchies of exception classes or to
pass additional information with the object of an exception class.  You can do
similar things in Vim.
   In order to throw an exception from a hierarchy, just throw the complete
class name with the components separated by a colon, for instance throw the
string "EXCEPT:MATHERR:OVERFLOW" for an overflow in a mathematical library.
   When you want to pass additional information with your exception class, add
it in parentheses, for instance throw the string "EXCEPT:IO:WRITEERR(myfile)"
for an error when writing "myfile".
   With the appropriate patterns in the ":catch" command, you can catch for
base classes or derived classes of your hierarchy.  Additional information in
parentheses can be cut out from |v:exception| with the ":substitute" command.
   Example: >

	:function! CheckRange(a, func)
	:  if a:a < 0
	:    throw "EXCEPT:MATHERR:RANGE(" . a:func . ")"
	:  endif
	:endfunction
	:
	:function! Add(a, b)
	:  call CheckRange(a:a, "Add")
	:  call CheckRange(a:b, "Add")
	:  let c = a:a + a:b
	:  if c < 0
	:    throw "EXCEPT:MATHERR:OVERFLOW"
	:  endif
	:  return c
	:endfunction
	:
	:function! Div(a, b)
	:  call CheckRange(a:a, "Div")
	:  call CheckRange(a:b, "Div")
	:  if (a:b == 0)
	:    throw "EXCEPT:MATHERR:ZERODIV"
	:  endif
	:  return a:a / a:b
	:endfunction
	:
	:function! Write(file)
	:  try
	:    execute "write" a:file
	:  catch /^Vim(write):/
	:    throw "EXCEPT:IO(" . getcwd() . ", " . a:file . "):WRITEERR"
	:  endtry
	:endfunction
	:
	:try
	:
	:  " something with arithmetics and I/O
	:
	:catch /^EXCEPT:MATHERR:RANGE/
	:  let function = substitute(v:exception, '.*(\(\a\+\)).*', '\1', "")
	:  echo "Range error in" function
	:
	:catch /^EXCEPT:MATHERR/	" catches OVERFLOW and ZERODIV
	:  echo "Math error"
	:
	:catch /^EXCEPT:IO/
	:  let dir = substitute(v:exception, '.*(\(.\+\),\s*.\+).*', '\1', "")
	:  let file = substitute(v:exception, '.*(.\+,\s*\(.\+\)).*', '\1', "")
	:  if file !~ '^/'
	:    let file = dir . "/" . file
	:  endif
	:  echo 'I/O error for "' . file . '"'
	:
	:catch /^EXCEPT/
	:  echo "Unspecified error"
	:
	:endtry

The exceptions raised by Vim itself (on error or when pressing CTRL-C) use
a flat hierarchy:  they are all in the "Vim" class.  You cannot throw yourself
exceptions with the "Vim" prefix; they are reserved for Vim.
   Vim error exceptions are parameterized with the name of the command that
failed, if known.  See |catch-errors|.


PECULIARITIES
							*except-compat*
The exception handling concept requires that the command sequence causing the
exception is aborted immediately and control is transferred to finally clauses
and/or a catch clause.

In the Vim script language there are cases where scripts and functions
continue after an error: in functions without the "abort" flag or in a command
after ":silent!", control flow goes to the following line, and outside
functions, control flow goes to the line following the outermost ":endwhile"
or ":endif".  On the other hand, errors should be catchable as exceptions
(thus, requiring the immediate abortion).

This problem has been solved by converting errors to exceptions and using
immediate abortion (if not suppressed by ":silent!") only when a try
conditional is active.  This is no restriction since an (error) exception can
be caught only from an active try conditional.  If you want an immediate
termination without catching the error, just use a try conditional without
catch clause.  (You can cause cleanup code being executed before termination
by specifying a finally clause.)

When no try conditional is active, the usual abortion and continuation
behavior is used instead of immediate abortion.  This ensures compatibility of
scripts written for Vim 6.1 and earlier.

However, when sourcing an existing script that does not use exception handling
commands (or when calling one of its functions) from inside an active try
conditional of a new script, you might change the control flow of the existing
script on error.  You get the immediate abortion on error and can catch the
error in the new script.  If however the sourced script suppresses error
messages by using the ":silent!" command (checking for errors by testing
|v:errmsg| if appropriate), its execution path is not changed.  The error is
not converted to an exception.  (See |:silent|.)  So the only remaining cause
where this happens is for scripts that don't care about errors and produce
error messages.  You probably won't want to use such code from your new
scripts.

							*except-syntax-err*
Syntax errors in the exception handling commands are never caught by any of
the ":catch" commands of the try conditional they belong to.  Its finally
clauses, however, is executed.
   Example: >

	:try
	:  try
	:    throw 4711
	:  catch /\(/
	:    echo "in catch with syntax error"
	:  catch
	:    echo "inner catch-all"
	:  finally
	:    echo "inner finally"
	:  endtry
	:catch
	:  echo 'outer catch-all caught "' . v:exception . '"'
	:  finally
	:    echo "outer finally"
	:endtry

This displays: >
    inner finally
    outer catch-all caught "Vim(catch):E54: Unmatched \("
    outer finally
The original exception is discarded and an error exception is raised, instead.

							*except-single-line*
The ":try", ":catch", ":finally", and ":endtry" commands can be put on
a single line, but then syntax errors may make it difficult to recognize the
"catch" line, thus you better avoid this.
   Example: >
	:try | unlet! foo # | catch | endtry
raises an error exception for the trailing characters after the ":unlet!"
argument, but does not see the ":catch" and ":endtry" commands, so that the
error exception is discarded and the "E488: Trailing characters" message gets
displayed.

							*except-several-errors*
When several errors appear in a single command, the first error message is
usually the most specific one and therefor converted to the error exception.
   Example: >
	echo novar
causes >
	E121: Undefined variable: novar
	E15: Invalid expression: novar
The value of the error exception inside try conditionals is: >
	Vim(echo):E121: Undefined variable: novar
<							*except-syntax-error*
But when a syntax error is detected after a normal error in the same command,
the syntax error is used for the exception being thrown.
   Example: >
	unlet novar #
causes >
	E108: No such variable: "novar"
	E488: Trailing characters
The value of the error exception inside try conditionals is: >
	Vim(unlet):E488: Trailing characters
This is done because the syntax error might change the execution path in a way
not intended by the user.  Example: >
	try
	    try | unlet novar # | catch | echo v:exception | endtry
	catch /.*/
	    echo "outer catch:" v:exception
	endtry
This displays "outer catch: Vim(unlet):E488: Trailing characters", and then
a "E600: Missing :endtry" error message is given, see |except-single-line|.

==============================================================================
9. Examples						*eval-examples*

Printing in Hex ~
>
  :" The function Nr2Hex() returns the Hex string of a number.
  :func Nr2Hex(nr)
  :  let n = a:nr
  :  let r = ""
  :  while n
  :    let r = '0123456789ABCDEF'[n % 16] . r
  :    let n = n / 16
  :  endwhile
  :  return r
  :endfunc

  :" The function String2Hex() converts each character in a string to a two
  :" character Hex string.
  :func String2Hex(str)
  :  let out = ''
  :  let ix = 0
  :  while ix < strlen(a:str)
  :    let out = out . Nr2Hex(char2nr(a:str[ix]))
  :    let ix = ix + 1
  :  endwhile
  :  return out
  :endfunc

Example of its use: >
  :echo Nr2Hex(32)
result: "20" >
  :echo String2Hex("32")
result: "3332"


Sorting lines (by Robert Webb) ~

Here is a Vim script to sort lines.  Highlight the lines in Vim and type
":Sort".  This doesn't call any external programs so it'll work on any
platform.  The function Sort() actually takes the name of a comparison
function as its argument, like qsort() does in C.  So you could supply it
with different comparison functions in order to sort according to date etc.
>
  :" Function for use with Sort(), to compare two strings.
  :func! Strcmp(str1, str2)
  :  if (a:str1 < a:str2)
  :	return -1
  :  elseif (a:str1 > a:str2)
  :	return 1
  :  else
  :	return 0
  :  endif
  :endfunction

  :" Sort lines.  SortR() is called recursively.
  :func! SortR(start, end, cmp)
  :  if (a:start >= a:end)
  :	return
  :  endif
  :  let partition = a:start - 1
  :  let middle = partition
  :  let partStr = getline((a:start + a:end) / 2)
  :  let i = a:start
  :  while (i <= a:end)
  :	let str = getline(i)
  :	exec "let result = " . a:cmp . "(str, partStr)"
  :	if (result <= 0)
  :	    " Need to put it before the partition.  Swap lines i and partition.
  :	    let partition = partition + 1
  :	    if (result == 0)
  :		let middle = partition
  :	    endif
  :	    if (i != partition)
  :		let str2 = getline(partition)
  :		call setline(i, str2)
  :		call setline(partition, str)
  :	    endif
  :	endif
  :	let i = i + 1
  :  endwhile

  :  " Now we have a pointer to the "middle" element, as far as partitioning
  :  " goes, which could be anywhere before the partition.  Make sure it is at
  :  " the end of the partition.
  :  if (middle != partition)
  :	let str = getline(middle)
  :	let str2 = getline(partition)
  :	call setline(middle, str2)
  :	call setline(partition, str)
  :  endif
  :  call SortR(a:start, partition - 1, a:cmp)
  :  call SortR(partition + 1, a:end, a:cmp)
  :endfunc

  :" To Sort a range of lines, pass the range to Sort() along with the name of a
  :" function that will compare two lines.
  :func! Sort(cmp) range
  :  call SortR(a:firstline, a:lastline, a:cmp)
  :endfunc

  :" :Sort takes a range of lines and sorts them.
  :command! -nargs=0 -range Sort <line1>,<line2>call Sort("Strcmp")
<
							*sscanf*
There is no sscanf() function in Vim.  If you need to extract parts from a
line, you can use matchstr() and substitute() to do it.  This example shows
how to get the file name, line number and column number out of a line like
"foobar.txt, 123, 45". >
   :" Set up the match bit
   :let mx='\(\f\+\),\s*\(\d\+\),\s*\(\d\+\)'
   :"get the part matching the whole expression
   :let l = matchstr(line, mx)
   :"get each item out of the match
   :let file = substitute(l, mx, '\1', '')
   :let lnum = substitute(l, mx, '\2', '')
   :let col = substitute(l, mx, '\3', '')

The input is in the variable "line", the results in the variables "file",
"lnum" and "col". (idea from Michael Geddes)

==============================================================================
10. No +eval feature				*no-eval-feature*

When the |+eval| feature was disabled at compile time, none of the expression
evaluation commands are available.  To prevent this from causing Vim scripts
to generate all kinds of errors, the ":if" and ":endif" commands are still
recognized, though the argument of the ":if" and everything between the ":if"
and the matching ":endif" is ignored.  Nesting of ":if" blocks is allowed, but
only if the commands are at the start of the line.  The ":else" command is not
recognized.

Example of how to avoid executing commands when the |+eval| feature is
missing: >

	:if 1
	:  echo "Expression evaluation is compiled in"
	:else
	:  echo "You will _never_ see this message"
	:endif

==============================================================================
11. The sandbox					*eval-sandbox* *sandbox* *E48*

The 'foldexpr', 'includeexpr', 'indentexpr', 'statusline' and 'foldtext'
options are evaluated in a sandbox.  This means that you are protected from
these expressions having nasty side effects.  This gives some safety for when
these options are set from a modeline.  It is also used when the command from
a tags file is executed.
This is not guaranteed 100% secure, but it should block most attacks.

These items are not allowed in the sandbox:
	- changing the buffer text
	- defining or changing mapping, autocommands, functions, user commands
	- setting certain options (see |option-summary|)
	- executing a shell command
	- reading or writing a file
	- jumping to another buffer or editing a file

 vim:tw=78:ts=8:ft=help:norl: