*if_tcl.txt*    For Vim version 8.2.  Last change: 2021 May 27


		  VIM REFERENCE MANUAL    by Ingo Wilken


The Tcl Interface to Vim				*tcl* *Tcl* *TCL*

1. Commands				|tcl-ex-commands|
2. Tcl commands				|tcl-commands|
3. Tcl variables			|tcl-variables|
4. Tcl window commands			|tcl-window-cmds|
5. Tcl buffer commands			|tcl-buffer-cmds|
6. Miscellaneous; Output from Tcl	|tcl-misc| |tcl-output|
7. Known bugs & problems		|tcl-bugs|
8. Examples				|tcl-examples|
9. Dynamic loading			|tcl-dynamic|

*E280*
{only available when Vim was compiled with the |+tcl| feature}

WARNING: There are probably still some bugs.  Please send bug reports,
comments, ideas etc to <Ingo.Wilken@informatik.uni-oldenburg.de>

==============================================================================
1. Commands				*tcl-ex-commands* *E571* *E572*

							*:tcl*
:tcl {cmd}		Execute Tcl command {cmd}.  A simple check if `:tcl`
			is working: >
				:tcl puts "Hello"

:[range]tcl << [trim] [{endmarker}]
{script}
{endmarker}
			Execute Tcl script {script}.
			Note: This command doesn't work when the Tcl feature
			wasn't compiled in.  To avoid errors, see
			|script-here|.

If [endmarker] is omitted from after the "<<", a dot '.' must be used after
{script}, like for the |:append| and |:insert| commands.  Refer to
|:let-heredoc| for more information.

This form of the |:tcl| command is mainly useful for including tcl code in Vim
scripts.

Example: >
	function! DefineDate()
	    tcl << EOF
	    proc date {} {
		return [clock format [clock seconds]]
	    }
	EOF
	endfunction
<
To see what version of Tcl you have: >
	:tcl puts [info patchlevel]
<

							*:tcldo* *:tcld*
:[range]tcld[o] {cmd}	Execute Tcl command {cmd} for each line in [range]
			with the variable "line" being set to the text of each
			line in turn, and "lnum" to the line number.  Setting
			"line" will change the text, but note that it is not
			possible to add or delete lines using this command.
			If {cmd} returns an error, the command is interrupted.
			The default for [range] is the whole file: "1,$".
			See |tcl-var-line| and |tcl-var-lnum|.

							*:tclfile* *:tclf*
:tclf[ile] {file}	Execute the Tcl script in {file}.  This is the same as
			":tcl source {file}", but allows file name completion.


Note that Tcl objects (like variables) persist from one command to the next,
just as in the Tcl shell.

Executing Tcl commands is not possible in the |sandbox|.

==============================================================================
2. Tcl commands						*tcl-commands*

Tcl code gets all of its access to vim via commands in the "::vim" namespace.
The following commands are implemented: >

	::vim::beep			# Guess.
	::vim::buffer {n}		# Create Tcl command for one buffer.
	::vim::buffer list		# Create Tcl commands for all buffers.
	::vim::command [-quiet] {cmd}	# Execute an Ex command.
	::vim::expr {expr}		# Use Vim's expression evaluator.
	::vim::option {opt}		# Get vim option.
	::vim::option {opt} {val}	# Set vim option.
	::vim::window list		# Create Tcl commands for all windows.

Commands:
	::vim::beep					*tcl-beep*
	Honk.  Does not return a result.

	::vim::buffer {n}				*tcl-buffer*
	::vim::buffer exists {n}
	::vim::buffer list
	Provides access to vim buffers.  With an integer argument, creates a
	buffer command (see |tcl-buffer-cmds|) for the buffer with that
	number, and returns its name as the result.  Invalid buffer numbers
	result in a standard Tcl error.  To test for valid buffer numbers,
	vim's internal functions can be used: >
		set nbufs [::vim::expr bufnr("$")]
		set isvalid [::vim::expr "bufexists($n)"]
<	The "list" option creates a buffer command for each valid buffer, and
	returns a list of the command names as the result.
	Example: >
		set bufs [::vim::buffer list]
		foreach b $bufs { $b append end "The End!" }
<	The "exists" option checks if a buffer with the given number exists.
	Example: >
		if { [::vim::buffer exists $n] } { ::vim::command ":e #$n" }
<	This command might be replaced by a variable in future versions.
	See also |tcl-var-current| for the current buffer.

	::vim::command {cmd}				*tcl-command*
	::vim::command -quiet {cmd}
	Execute the vim (ex-mode) command {cmd}.  Any Ex command that affects
	a buffer or window uses the current buffer/current window.  Does not
	return a result other than a standard Tcl error code.  After this
	command is completed, the "::vim::current" variable is updated.
	The "-quiet" flag suppresses any error messages from vim.
	Examples: >
		::vim::command "set ts=8"
		::vim::command "%s/foo/bar/g"
<	To execute normal-mode commands, use "normal" (see |:normal|): >
		set cmd "jj"
		::vim::command "normal $cmd"
<	See also |tcl-window-command| and |tcl-buffer-command|.

	::vim::expr {expr}				*tcl-expr*
	Evaluates the expression {expr} using vim's internal expression
	evaluator (see |expression|).   Any expression that queries a buffer
	or window property uses the current buffer/current window.  Returns
	the result as a string.  A |List| is turned into a string by joining
	the items and inserting line breaks.
	Examples: >
		set perl_available [::vim::expr has("perl")]
<	See also |tcl-window-expr| and |tcl-buffer-expr|.

	::vim::option {opt}				*tcl-option*
	::vim::option {opt} {value}
	Without second argument, queries the value of a vim option.  With this
	argument, sets the vim option to {value}, and returns the previous
	value as the result.  Any options that are marked as 'local to buffer'
	or 'local to window' affect the current buffer/current window.  The
	global value is not changed, use the ":set" command for that.  For
	boolean options, {value} should be "0" or "1", or any of the keywords
	"on", "off" or "toggle".  See |option-summary| for a list of options.
	Example: >
		::vim::option ts 8
<	See also |tcl-window-option| and |tcl-buffer-option|.

	::vim::window {option}				*tcl-window*
	Provides access to vim windows.  Currently only the "list" option is
	implemented.  This creates a window command (see |tcl-window-cmds|) for
	each window, and returns a list of the command names as the result.
	Example: >
		set wins [::vim::window list]
		foreach w $wins { $w height 4 }
<	This command might be replaced by a variable in future versions.
	See also |tcl-var-current| for the current window.

==============================================================================
3. Tcl variables					*tcl-variables*

The ::vim namespace contains a few variables.  These are created when the Tcl
interpreter is called from vim and set to current values. >

	::vim::current		# array containing "current" objects
	::vim::lbase		# number of first line
	::vim::range		# array containing current range numbers
	line			# current line as a string (:tcldo only)
	lnum			# current line number (:tcldo only)

Variables:
	::vim::current					*tcl-var-current*
	This is an array providing access to various "current" objects
	available in vim.  The contents of this array are updated after
	"::vim::command" is called, as this might change vim's current
	settings (e.g., by deleting the current buffer).
	The "buffer" element contains the name of the buffer command for the
	current buffer.  This can be used directly to invoke buffer commands
	(see |tcl-buffer-cmds|).  This element is read-only.
	Example: >
		$::vim::current(buffer) insert begin "Hello world"
<	The "window" element contains the name of the window command for the
	current window.  This can be used directly to invoke window commands
	(see |tcl-window-cmds|).  This element is read-only.
	Example: >
		$::vim::current(window) height 10
<
	::vim::lbase					*tcl-var-lbase*
	This variable controls how Tcl treats line numbers.  If it is set to
	'1', then lines and columns start at 1.  This way, line numbers from
	Tcl commands and vim expressions are compatible.  If this variable is
	set to '0', then line numbers and columns start at 0 in Tcl.  This is
	useful if you want to treat a buffer as a Tcl list or a line as a Tcl
	string and use standard Tcl commands that return an index ("lsort" or
	"string first", for example).  The default value is '1'.  Currently,
	any non-zero values is treated as '1', but your scripts should not
	rely on this.  See also |tcl-linenumbers|.

	::vim::range					*tcl-var-range*
	This is an array with three elements, "start", "begin" and "end".  It
	contains the line numbers of the start and end row of the current
	range.  "begin" is the same as "start".  This variable is read-only.
	See |tcl-examples|.

	line						*tcl-var-line*
	lnum						*tcl-var-lnum*
	These global variables are only available if the ":tcldo" Ex command
	is being executed.  They contain the text and line number of the
	current line.  When the Tcl command invoked by ":tcldo" is completed,
	the current line is set to the contents of the "line" variable, unless
	the variable was unset by the Tcl command.  The "lnum" variable is
	read-only.  These variables are not in the "::vim" namespace so they
	can be used in ":tcldo" without much typing (this might be changed in
	future versions).  See also |tcl-linenumbers|.

==============================================================================
4. Tcl window commands					*tcl-window-cmds*

Window commands represent vim windows.  They are created by several commands:
	::vim::window list			|tcl-window|
	"windows" option of a buffer command	|tcl-buffer-windows|
The ::vim::current(window) variable contains the name of the window command
for the current window.  A window command is automatically deleted when the
corresponding vim window is closed.

Let's assume the name of the window command is stored in the Tcl variable "win",
i.e. "$win" calls the command.  The following options are available: >

	$win buffer		# Create Tcl command for window's buffer.
	$win command {cmd}	# Execute Ex command in windows context.
	$win cursor		# Get current cursor position.
	$win cursor {var}	# Set cursor position from array variable.
	$win cursor {row} {col}	# Set cursor position.
	$win delcmd {cmd}	# Call Tcl command when window is closed.
	$win expr {expr}	# Evaluate vim expression in windows context.
	$win height		# Report the window's height.
	$win height {n}		# Set the window's height.
	$win option {opt} [val]	# Get/Set vim option in windows context.

Options:
	$win buffer					*tcl-window-buffer*
	Creates a Tcl command for the window's buffer, and returns its name as
	the result.  The name should be stored in a variable: >
		set buf [$win buffer]
<	$buf is now a valid Tcl command.  See |tcl-buffer-cmds| for the
	available options.

	$win cursor					*tcl-window-cursor*
	$win cursor {var}
	$win cursor {row} {col}
	Without argument, reports the current cursor position as a string.
	This can be converted to a Tcl array variable: >
		array set here [$win cursor]
<	"here(row)" and "here(column)" now contain the cursor position.
	With a single argument, the argument is interpreted as the name of a
	Tcl array variable, which must contain two elements "row" and "column".
	These are used to set the cursor to the new position: >
		$win cursor here	;# not $here !
<	With two arguments, sets the cursor to the specified row and column: >
		$win cursor $here(row) $here(column)
<	Invalid positions result in a standard Tcl error, which can be caught
	with "catch".  The row and column values depend on the "::vim::lbase"
	variable.  See |tcl-var-lbase|.

	$win delcmd {cmd}				*tcl-window-delcmd*
	Registers the Tcl command {cmd} as a deletion callback for the window.
	This command is executed (in the global scope) just before the window
	is closed.  Complex commands should be built with "list": >
		$win delcmd [list puts vimerr "window deleted"]
<	See also |tcl-buffer-delcmd|.

	$win height					*tcl-window-height*
	$win height {n}
	Without argument, reports the window's current height.  With an
	argument, tries to set the window's height to {n}, then reports the
	new height (which might be different from {n}).

	$win command [-quiet] {cmd}			*tcl-window-command*
	$win expr {expr}				*tcl-window-expr*
	$win option {opt} [val]				*tcl-window-option*
	These are similar to "::vim::command" etc., except that everything is
	done in the context of the window represented by $win, instead of the
	current window.  For example, setting an option that is marked 'local
	to window' affects the window $win.  Anything that affects or queries
	a buffer uses the buffer displayed in this window (i.e. the buffer
	that is represented by "$win buffer").  See |tcl-command|, |tcl-expr|
	and |tcl-option| for more information.
	Example: >
		$win option number on

==============================================================================
5. Tcl buffer commands					*tcl-buffer-cmds*

Buffer commands represent vim buffers.  They are created by several commands:
	::vim::buffer {N}			|tcl-buffer|
	::vim::buffer list			|tcl-buffer|
	"buffer" option of a window command	|tcl-window-buffer|
The ::vim::current(buffer) variable contains the name of the buffer command
for the current buffer.  A buffer command is automatically deleted when the
corresponding vim buffer is destroyed.  Whenever the buffer's contents are
changed, all marks in the buffer are automatically adjusted.  Any changes to
the buffer's contents made by Tcl commands can be undone with the "undo" vim
command (see |undo|).

Let's assume the name of the buffer command is stored in the Tcl variable "buf",
i.e. "$buf" calls the command.  The following options are available: >

	$buf append {n} {str}	# Append a line to buffer, after line {n}.
	$buf command {cmd}	# Execute Ex command in buffers context.
	$buf count		# Report number of lines in buffer.
	$buf delcmd {cmd}	# Call Tcl command when buffer is deleted.
	$buf delete {n}		# Delete a single line.
	$buf delete {n} {m}	# Delete several lines.
	$buf expr {expr}	# Evaluate vim expression in buffers context.
	$buf get {n}		# Get a single line as a string.
	$buf get {n} {m}	# Get several lines as a list.
	$buf insert {n} {str}	# Insert a line in buffer, as line {n}.
	$buf last		# Report line number of last line in buffer.
	$buf mark {mark}	# Report position of buffer mark.
	$buf name		# Report name of file in buffer.
	$buf number		# Report number of this buffer.
	$buf option {opt} [val]	# Get/Set vim option in buffers context.
	$buf set {n} {text}	# Replace a single line.
	$buf set {n} {m} {list}	# Replace several lines.
	$buf windows		# Create Tcl commands for buffer's windows.
<
							*tcl-linenumbers*
Most buffer commands take line numbers as arguments.  How Tcl treats these
numbers depends on the "::vim::lbase" variable (see |tcl-var-lbase|).  Instead
of line numbers, several keywords can be also used: "top", "start", "begin",
"first", "bottom", "end" and "last".

Options:
	$buf append {n} {str}				*tcl-buffer-append*
	$buf insert {n} {str}				*tcl-buffer-insert*
	Add a line to the buffer.  With the "insert" option, the string
	becomes the new line {n}, with "append" it is inserted after line {n}.
	Example: >
		$buf insert top "This is the beginning."
		$buf append end "This is the end."
<	To add a list of lines to the buffer, use a loop: >
		foreach line $list { $buf append $num $line ; incr num }
<
	$buf count					*tcl-buffer-count*
	Reports the total number of lines in the buffer.

	$buf delcmd {cmd}				*tcl-buffer-delcmd*
	Registers the Tcl command {cmd} as a deletion callback for the buffer.
	This command is executed (in the global scope) just before the buffer
	is deleted.  Complex commands should be built with "list": >
		$buf delcmd [list puts vimerr "buffer [$buf number] gone"]
<	See also |tcl-window-delcmd|.

	$buf delete {n}					*tcl-buffer-delete*
	$buf delete {n} {m}
	Deletes line {n} or lines {n} through {m} from the buffer.
	This example deletes everything except the last line: >
		$buf delete first [expr [$buf last] - 1]
<
	$buf get {n}					*tcl-buffer-get*
	$buf get {n} {m}
	Gets one or more lines from the buffer.  For a single line, the result
	is a string; for several lines, a list of strings.
	Example: >
		set topline [$buf get top]
<
	$buf last					*tcl-buffer-last*
	Reports the line number of the last line.  This value depends on the
	"::vim::lbase" variable.  See |tcl-var-lbase|.

	$buf mark {mark}				*tcl-buffer-mark*
	Reports the position of the named mark as a string, similar to the
	cursor position of the "cursor" option of a window command (see
	|tcl-window-cursor|).  This can be converted to a Tcl array variable: >
		array set mpos [$buf mark "a"]
<	"mpos(column)" and "mpos(row)" now contain the position of the mark.
	If the mark is not set, a standard Tcl error results.

	$buf name
	Reports the name of the file in the buffer.  For a buffer without a
	file, this is an empty string.

	$buf number
	Reports the number of this buffer.  See |:buffers|.
	This example deletes a buffer from vim: >
		::vim::command "bdelete [$buf number]"
<
	$buf set {n} {string}				*tcl-buffer-set*
	$buf set {n} {m} {list}
	Replace one or several lines in the buffer.  If the list contains more
	elements than there are lines to replace, they are inserted into the
	buffer.  If the list contains fewer elements, any unreplaced line is
	deleted from the buffer.

	$buf windows					*tcl-buffer-windows*
	Creates a window command for each window that displays this buffer, and
	returns a list of the command names as the result.
	Example: >
		set winlist [$buf windows]
		foreach win $winlist { $win height 4 }
<	See |tcl-window-cmds| for the available options.

	$buf command [-quiet] {cmd}			*tcl-buffer-command*
	$buf expr {expr}				*tcl-buffer-expr*
	$buf option {opt} [val]				*tcl-buffer-option*
	These are similar to "::vim::command" etc., except that everything is
	done in the context of the buffer represented by $buf, instead of the
	current buffer.  For example, setting an option that is marked 'local
	to buffer' affects the buffer $buf.  Anything that affects or queries
	a window uses the first window in vim's window list that displays this
	buffer (i.e. the first entry in the list returned by "$buf windows").
	See |tcl-command|, |tcl-expr| and |tcl-option| for more information.
	Example: >
		if { [$buf option modified] } { $buf command "w" }

==============================================================================
6. Miscellaneous; Output from Tcl		*tcl-misc* *tcl-output*

The standard Tcl commands "exit" and "catch" are replaced by custom versions.
"exit" terminates the current Tcl script and returns to vim, which deletes the
Tcl interpreter.  Another call to ":tcl" then creates a new Tcl interpreter.
"exit" does NOT terminate vim!  "catch" works as before, except that it does
not prevent script termination from "exit".  An exit code != 0 causes the ex
command that invoked the Tcl script to return an error.

Two new I/O streams are available in Tcl, "vimout" and "vimerr".  All output
directed to them is displayed in the vim message area, as information messages
and error messages, respectively.  The standard Tcl output streams stdout and
stderr are mapped to vimout and vimerr, so that a normal "puts" command can be
used to display messages in vim.

==============================================================================
7. Known bugs & problems				*tcl-bugs*

Calling one of the Tcl Ex commands from inside Tcl (via "::vim::command") may
have unexpected side effects.  The command creates a new interpreter, which
has the same abilities as the standard interpreter - making "::vim::command"
available in a safe child interpreter therefore makes the child unsafe.  (It
would be trivial to block nested :tcl* calls or ensure that such calls from a
safe interpreter create only new safe interpreters, but quite pointless -
depending on vim's configuration, "::vim::command" may execute arbitrary code
in any number of other scripting languages.)  A call to "exit" within this new
interpreter does not affect the old interpreter; it only terminates the new
interpreter, then script processing continues normally in the old interpreter.

Input from stdin is currently not supported.

==============================================================================
8. Examples:						*tcl-examples*

Here are a few small (and maybe useful) Tcl scripts.

This script sorts the lines of the entire buffer (assume it contains a list
of names or something similar):
	set buf $::vim::current(buffer)
	set lines [$buf get top bottom]
	set lines [lsort -dictionary $lines]
	$buf set top bottom $lines

This script reverses the lines in the buffer.  Note the use of "::vim::lbase"
and "$buf last" to work with any line number setting.
	set buf $::vim::current(buffer)
	set t $::vim::lbase
	set b [$buf last]
	while { $t < $b } {
		set tl [$buf get $t]
		set bl [$buf get $b]
		$buf set $t $bl
		$buf set $b $tl
		incr t
		incr b -1
	}

This script adds a consecutive number to each line in the current range:
	set buf $::vim::current(buffer)
	set i $::vim::range(start)
	set n 1
	while { $i <= $::vim::range(end) } {
		set line [$buf get $i]
		$buf set $i "$n\t$line"
		incr i ; incr n
	}

The same can also be done quickly with two Ex commands, using ":tcldo":
	:tcl set n 1
	:[range]tcldo set line "$n\t$line" ; incr n

This procedure runs an Ex command on each buffer (idea stolen from Ron Aaron):
	proc eachbuf { cmd } {
		foreach b [::vim::buffer list] {
			$b command $cmd
		}
	}
Use it like this:
	:tcl eachbuf %s/foo/bar/g
Be careful with Tcl's string and backslash substitution, tough.  If in doubt,
surround the Ex command with curly braces.


If you want to add some Tcl procedures permanently to vim, just place them in
a file (e.g. "~/.vimrc.tcl" on Unix machines), and add these lines to your
startup file (usually "~/.vimrc" on Unix):
	if has("tcl")
		tclfile ~/.vimrc.tcl
	endif

==============================================================================
9. Dynamic loading					*tcl-dynamic*

On MS-Windows and Unix the Tcl library can be loaded dynamically.  The
|:version| output then includes |+tcl/dyn|.

This means that Vim will search for the Tcl DLL or shared library file only
when needed.  When you don't use the Tcl interface you don't need it, thus you
can use Vim without this file.


MS-Windows ~

To use the Tcl interface the Tcl DLL must be in your search path.  In a
console window type "path" to see what directories are used.  The 'tcldll'
option can be also used to specify the Tcl DLL.

The name of the DLL must match the Tcl version Vim was compiled with.
Currently the name is "tcl86.dll".  That is for Tcl 8.6.  To know for sure
edit "gvim.exe" and search for "tcl\d*.dll\c".


Unix ~

The 'tcldll' option can be used to specify the Tcl shared library file instead
of DYNAMIC_TCL_DLL file what was specified at compile time.  The version of
the shared library must match the Tcl version Vim was compiled with.

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