Nvim :help pages, generated
from source
using the tree-sitter-vimdoc parser.
{"blue": "#0000ff", "red": "#ff0000"}
#{blue: "#0000ff", red: "#ff0000"}
Blob Binary Large Object. Stores any sequence of bytes. See Blob
for details.
Example: 0zFF00ED015DAF
0z is an empty Blob.:echo "0100" + 0
:if "foo" :" NOT executed"foo" is converted to 0, which means FALSE. If the string starts with a non-zero number it means TRUE:
:if "8foo" :" executedTo test for a non-empty string, use empty():
:if !empty("foo"):let Fn = function("MyFunc")
:echo Fn():function dict.init() dict : let self.val = 0 :endfunctionThe key of the Dictionary can start with a lower case letter. The actual function name is not used here. Also see numbered-function.
:call Fn() :call dict.init()The name of the referenced function can be obtained with string().
:let func = string(Fn)You can use call() to invoke a Funcref and use a list variable for the arguments:
:let r = call(Fn, mylist)
let Cb = function('Callback', ['foo'], myDict)
call Cb('bar')
This will invoke the function as if using:call myDict.Callback('foo', 'bar')
Note that binding a function to a Dictionary also happens when the function is
a member of the Dictionary:let myDict.myFunction = MyFunction call myDict.myFunction()Here MyFunction() will get myDict passed as "self". This happens when the "myFunction" member is accessed. When assigning "myFunction" to otherDict and calling it, it will be bound to otherDict:
let otherDict.myFunction = myDict.myFunction call otherDict.myFunction()Now "self" will be "otherDict". But when the dictionary was bound explicitly this won't happen:
let myDict.myFunction = function(MyFunction, myDict) let otherDict.myFunction = myDict.myFunction call otherDict.myFunction()Here "self" will be "myDict", because it was bound explicitly.
:let mylist = [1, two, 3, "four"] :let emptylist = []An item can be any expression. Using a List for an item creates a List of Lists:
:let nestlist = [[11, 12], [21, 22], [31, 32]]An extra comma after the last item is ignored.
:let item = mylist[0] " get the first item: 1 :let item = mylist[2] " get the third item: 3When the resulting item is a list this can be repeated:
:let item = nestlist[0][1] " get the first list, second item: 12
:let last = mylist[-1] " get the last item: "four"To avoid an error for an invalid index use the get() function. When an item is not available it returns zero or the default value you specify:
:echo get(mylist, idx) :echo get(mylist, idx, "NONE")
:let longlist = mylist + [5, 6] :let longlist = [5, 6] + mylistTo prepend or append an item, turn it into a list by putting [] around it.
:let mylist += [7, 8] :call extend(mylist, [7, 8])
:let shortlist = mylist[2:-1] " get List [3, "four"]Omitting the first index is similar to zero. Omitting the last index is similar to -1.
:let endlist = mylist[2:] " from item 2 to the end: [3, "four"] :let shortlist = mylist[2:2] " List with one item: [3] :let otherlist = mylist[:] " make a copy of the ListNotice that the last index is inclusive. If you prefer using an exclusive index use the slice() method.
:let mylist = [0, 1, 2, 3] :echo mylist[2:8] " result: [2, 3]NOTE: mylist[s:e] means using the variable "s:e" as index. Watch out for using a single letter variable before the ":". Insert a space when needed: mylist[s : e].
:let aa = [1, 2, 3] :let bb = aa :call add(aa, 4) :echo bb
:let aa = [[1, 'a'], 2, 3] :let bb = copy(aa) :call add(aa, 4) :let aa[0][1] = 'aaa' :echo aa
:echo bb
:let alist = [1, 2, 3] :let blist = [1, 2, 3] :echo alist is blist
:echo alist == blist
echo 4 == "4"
echo [4] == ["4"]
:let a = 5 :let b = "5" :echo a == b
:echo [a] == [b]
:let [var1, var2] = mylistWhen the number of variables does not match the number of items in the list this produces an error. To handle any extra items from the list append ";" and a variable name:
:let [var1, var2; rest] = mylistThis works like:
:let var1 = mylist[0] :let var2 = mylist[1] :let rest = mylist[2:]Except that there is no error if there are only two items. "rest" will be an empty list then.
:let list[4] = "four" :let listlist[0][3] = itemTo change part of a list you can specify the first and last item to be modified. The value must at least have the number of items in the range:
:let list[3:5] = [3, 4, 5]To add items to a List in-place, you can use :let+= (list-concatenation):
:let listA = [1, 2] :let listA += [3, 4]
:let listA = [1, 2] :let listB = listA :let listB += [3, 4] :echo listA [1, 2, 3, 4]
:call insert(list, 'a') " prepend item 'a' :call insert(list, 'a', 3) " insert item 'a' before list[3] :call add(list, "new") " append String item :call add(list, [1, 2]) " append a List as one new item :call extend(list, [1, 2]) " extend the list with two more items :let i = remove(list, 3) " remove item 3 :unlet list[3] " idem :let l = remove(list, 3, -1) " remove items 3 to last item :unlet list[3 : ] " idem :call filter(list, 'v:val !~ "x"') " remove items with an 'x'Changing the order of items in a list:
:call sort(list) " sort a list alphabetically :call reverse(list) " reverse the order of items :call uniq(sort(list)) " sort and remove duplicates
:for item in mylist : call Doit(item) :endforThis works like:
:let index = 0 :while index < len(mylist) : let item = mylist[index] : :call Doit(item) : let index = index + 1 :endwhileIf all you want to do is modify each item in the list then the map() function will be a simpler method than a for loop.
:for [lnum, col] in [[1, 3], [2, 8], [3, 0]] : call Doit(lnum, col) :endforThis works like a :let command is done for each list item. Again, the types must remain the same to avoid an error.
:for [i, j; rest] in listlist : call Doit(i, j) : if !empty(rest) : echo "remainder: " .. string(rest) : endif :endforFor a Blob one byte at a time is used.
for c in text echo 'This character is ' .. c endfor
:let r = call(funcname, list) " call a function with an argument list
:if empty(list) " check if list is empty
:let l = len(list) " number of items in list
:let big = max(list) " maximum value in list
:let small = min(list) " minimum value in list
:let xs = count(list, 'x') " count nr of times 'x' appears in list
:let i = index(list, 'x') " index of first 'x' in list
:let lines = getline(1, 10) " get ten text lines from buffer
:call append('$', lines) " append text lines in buffer
:let list = split("a b c") " create list from items in a string
:let string = join(list, ', ') " create string from list items
:let s = string(list) " String representation of list
:call map(list, '">> " .. v:val') " prepend ">> " to each item
Don't forget that a combination of features can make things simple. For
example, to add up all the numbers in a list::exe 'let sum = ' .. join(nrlist, '+')
:let mydict = {1: 'one', 2: 'two', 3: 'three'}
:let emptydict = {}:let mydict = #{zero: 0, one_key: 1, two-key: 2, 333: 3}
Note that 333 here is the string "333". Empty keys are not possible with #{}.:let nestdict = {1: {11: 'a', 12: 'b'}, 2: {21: 'c'}}
An extra comma after the last entry is ignored.:let val = mydict["one"] :let mydict["four"] = 4You can add new entries to an existing Dictionary this way, unlike Lists.
:let val = mydict.one :let mydict.four = 4Since an entry can be any type, also a List and a Dictionary, the indexing and key lookup can be repeated:
:echo dict.key[idx].key
:for key in keys(mydict) : echo key .. ': ' .. mydict[key] :endforThe List of keys is unsorted. You may want to sort them first:
:for key in sort(keys(mydict))To loop over the values use the values() function:
:for v in values(mydict) : echo "value: " .. v :endforIf you want both the key and the value use the items() function. It returns a List in which each item is a List with two items, the key and the value:
:for [key, value] in items(mydict) : echo key .. ': ' .. value :endfor
:let onedict = {'a': 1, 'b': 2}
:let adict = onedict
:let adict['a'] = 11
:echo onedict['a']
11
Two Dictionaries compare equal if all the key-value pairs compare equal. For
more info see list-identity.:let dict[4] = "four" :let dict['one'] = itemRemoving an entry from a Dictionary is done with remove() or :unlet. Three ways to remove the entry with key "aaa" from dict:
:let i = remove(dict, 'aaa') :unlet dict.aaa :unlet dict['aaa']Merging a Dictionary with another is done with extend():
:call extend(adict, bdict)This extends adict with all entries from bdict. Duplicate keys cause entries in adict to be overwritten. An optional third argument can change this. Note that the order of entries in a Dictionary is irrelevant, thus don't expect ":echo adict" to show the items from bdict after the older entries in adict.
:call filter(dict, 'v:val =~ "x"')This removes all entries from "dict" with a value not matching 'x'. This can also be used to remove all entries:
call filter(dict, 0)
:function Mylen() dict
: return len(self.data)
:endfunction
:let mydict = {'data': [0, 1, 2, 3], 'len': function("Mylen")}
:echo mydict.len()
This is like a method in object oriented programming. The entry in the
Dictionary is a Funcref. The local variable "self" refers to the dictionary
the function was invoked from.:let mydict = {'data': [0, 1, 2, 3]}
:function mydict.len()
: return len(self.data)
:endfunction
:echo mydict.len()
The function will then get a number and the value of dict.len is a Funcref
that references this function. The function can only be used through a
Funcref. It will automatically be deleted when there is no Funcref
remaining that refers to it.:function g:42
:if has_key(dict, 'foo') " TRUE if dict has entry with key "foo" :if empty(dict) " TRUE if dict is empty :let l = len(dict) " number of items in dict :let big = max(dict) " maximum value in dict :let small = min(dict) " minimum value in dict :let xs = count(dict, 'x') " count nr of times 'x' appears in dict :let s = string(dict) " String representation of dict :call map(dict, '">> " .. v:val') " prepend ">> " to each item
:let b = 0zFF00ED015DAFDots can be inserted between bytes (pair of hex characters) for readability, they don't change the value:
:let b = 0zFF00.ED01.5DAFA blob can be read from a file with readfile() passing the
{type} argument
set to "B", for example::let b = readfile('image.png', 'B')
:let myblob = 0z00112233 :let byte = myblob[0] " get the first byte: 0x00 :let byte = myblob[2] " get the third byte: 0x22A negative index is counted from the end. Index -1 refers to the last byte in the Blob, -2 to the last but one byte, etc.
:let last = myblob[-1] " get the last byte: 0x33To avoid an error for an invalid index use the get() function. When an item is not available it returns -1 or the default value you specify:
:echo get(myblob, idx) :echo get(myblob, idx, 999)
:for byte in 0z112233 : call Doit(byte) :endforThis calls Doit() with 0x11, 0x22 and 0x33.
:let longblob = myblob + 0z4455 :let longblob = 0z4455 + myblob
:let myblob += 0z6677
:let myblob = 0z00112233 :let shortblob = myblob[1:2] " get 0z1122 :let shortblob = myblob[2:-1] " get 0z2233Omitting the first index is similar to zero. Omitting the last index is similar to -1.
:let endblob = myblob[2:] " from item 2 to the end: 0z2233 :let shortblob = myblob[2:2] " Blob with one byte: 0z22 :let otherblob = myblob[:] " make a copy of the BlobIf the first index is beyond the last byte of the Blob or the second index is before the first index, the result is an empty Blob. There is no error message.
:echo myblob[2:8] " result: 0z2233
:let blob[4] = 0x44When the index is just one beyond the end of the Blob, it is appended. Any higher index is an error.
let blob[1:3] = 0z445566The length of the replaced bytes must be exactly the same as the value provided. E972
:let blob[3:5] = 0z334455To add items to a Blob in-place, you can use :let+= (blob-concatenation):
:let blobA = 0z1122 :let blobA += 0z3344
:let blobA = 0z1122 :let blobB = blobA :let blobB += 0z3344 :echo blobA 0z11223344
if blob == 0z001122And for equal identity:
if blob is otherblob
:let blob = 0z112233 :let blob2 = blob :echo blob == blob2
:echo blob is blob2
:let blob3 = blob[:] :echo blob == blob3
:echo blob is blob3
'string' string constant, ' is doubled
[expr1, ...] List
{expr1: expr1, ...} Dictionary
#{key: expr1, ...} Dictionary
&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
{args -> expr1} lambda expression&nu || &list && &shell == "csh"All expressions within one level are parsed from left to right.
:echo lnum == 1 ? "top" : lnumSince 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" : lnumTo keep this readable, using line-continuation is suggested:
:echo lnum == 1 :\ ? "top" :\ : lnum == 1000 :\ ? "last" :\ : lnumYou should always put a space before the ':', otherwise it can be mistaken for use in a variable such as "a:1".
echo theList ?? 'list is empty' echo GetName() ?? 'unknown'These are similar, but not equal:
expr2 ?? expr1 expr2 ? expr2 : expr1In the second line "expr2" is evaluated twice.
&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 || bThis is valid even if there is no variable called "b" because "a" is TRUE, so the result must be TRUE. 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.{cmp} expr5if get(Part1, 'name') == get(Part2, 'name') " Part1 and Part2 refer to the same functionUsing "is" or "isnot" with a List, Dictionary or Blob checks whether the expressions are referring to the same List, Dictionary or Blob instance. A copy of a List is different from the original List. When using "is" without a List, Dictionary or Blob, it is equivalent to using "equal", using "isnot" is equivalent to using "not equal". Except that a different type means the values are different:
echo 4 == '4' 1 echo 4 is '4' 0 echo 0 is [] 0"is#"/"isnot#" and "is?"/"isnot?" can be used to match and ignore case.
echo 0 == 'x' 1because 'x' converted to a Number is zero. However:
echo [0] == ['x'] 0Inside a List or Dictionary this conversion is not used.
1 . 90 + 90.0As:
(1 . 90) + 90.0That works, since the String "190" is automatically converted to the Number 190, which can be added to the Float 90.0. However:
1 . 90 * 90.0Should be read as:
1 . (90 * 90.0)Since '.' has lower precedence than "*". This does NOT work, since this attempts to concatenate a Float and a String.
byteidx() for an alternative, or use
split() to turn the string into a list of characters. Example, to get the
byte under the cursor::let c = getline(".")[col(".") - 1]
Index zero gives the first byte. This is like it works in C. Careful:
text column numbers start with one! Example, to get the byte under the
cursor::let c = getline(".")[col(".") - 1]
Index zero gives the first byte. Careful: text column numbers start with one!:let item = mylist[-1] " get last itemGenerally, if a List index is equal to or higher than the length of the List, or more negative than the length of the List, this results in an error.
:let c = name[-1:] " last byte of a string
:let c = name[0:-1] " the whole string
:let c = name[-2:-2] " last but one byte of a string
:let s = line(".")[4:] " from the fifth byte to the end
:let s = s[:-3] " remove last two bytes:let l = mylist[:3] " first four items :let l = mylist[4:4] " List with one item :let l = mylist[:] " shallow copy of a ListIf expr8 is a Blob this results in a new Blob with the bytes in the indexes expr1a and expr1b, inclusive. Examples:
:let b = 0zDEADBEEF :let bs = b[1:2] " 0zADBE :let bs = b[] " copy of 0zDEADBEEFUsing expr8[expr1] or expr8[expr1a : expr1b] on a Funcref results in an error.
mylist[n:] " uses variable n mylist[s:] " uses namespace s:, error!expr8.name entry in a Dictionary expr-entry
:let dict = {"one": 1, 2: "two"}
:echo dict.one " shows "1"
:echo dict.2 " shows "two"
:echo dict .2 " error because of space before the dot
Note that the dot is also used for String concatenation. To avoid confusion
always put spaces around the dot for String concatenation.name(expr8 [, args])There can also be methods specifically for the type of "expr8".
mylist->filter(filterexpr)->map(mapexpr)->sort()->join()
GetPercentage()->{x -> x * 100}()->printf('%d%%')-1.234->string()Is equivalent to:
(-1.234)->string()And NOT:
-(1.234->string())
mylist \ ->filter(filterexpr) \ ->map(mapexpr) \ ->sort() \ ->join()When using the lambda form there must be no white space between the } and the
{N} and {M} are numbers. Both {N} and {M} must be present and can only
contain digits.
[-+] means there is an optional plus or minus sign.
{exp} is the exponent, power of 10.
Only a decimal point is accepted, not a comma. No matter what the current
locale is.{M}
1e40 missing .{M}:let pi = 3.14159265359 :let e = 2.71828182846Or, if you don't want to write them in as floating-point literals, you can also use functions, like the following:
:let pi = acos(-1.0) :let e = exp(1.0)
:echo printf('%.15e', atan(1))<BS>
\e escape <Esc>
\f formfeed 0x0C
\n newline <NL>
\r return <CR>
\t tab <Tab>
\\ backslash
\" double quote
\<xxx> Special key named "xxx". e.g. "\<C-W>" for CTRL-W. This is for use
in mappings, the 0x80 byte is escaped.
To use the double quote character it must be escaped: "<M-\">".
Don't use <Char-xxxx> to get a UTF-8 character, use \uxxxx as
mentioned above.
\<*xxx> Like \<xxx> but prepends a modifier instead of including it in the
character. E.g. "\<C-w>" is one character 0x17 while "\<*C-w>" is four
bytes: 3 for the CTRL modifier and then character "W".:let b = 0zFF00ED015DAF
if a =~ "\\s*" if a =~ '\s*'
let your_name = input("What's your name? ")echo
echo $"Hello, {your_name}!"echo $"The square root of {{9}} is {sqrt(9)}"{9} is 3.0echo "tabstop is " .. &tabstop if &expandtabAny 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.
getenv() and setenv() can also be used and work for
environment variables with non-alphanumeric names.
The function environ() can be used to get a Dict with all environment
variables.:echo $shell
:echo expand("$shell")
The first one probably doesn't echo anything, the second echoes the $shell
variable (if your shell supports it).:let F = {arg1, arg2 -> arg1 - arg2}
:echo F(5, 2):let F = {-> 'error function'}
:echo F('ignored'):function Foo(arg)
: let i = 3
: return {x -> x + i - a:arg}
:endfunction
:let Bar = Foo(4)
:echo Bar(6)if has('lambda')
Examples for using a lambda expression with sort(), map() and filter()::echo map([1, 2, 3], {idx, val -> val + 1}):echo sort([3,7,2,1,4], {a, b -> a - b}):let timer = timer_start(500,
\ {-> execute("echo 'Handler called'", "")},
\ {'repeat': 3})function Function()
let x = 0
let F = {-> x}
endfunction
The closure uses "x" from the function scope, and "F" in that same scope
refers to the closure. This cycle results in the memory not being freed.
Recommendation: don't do this.<lambda>42'. If you get an error
for a lambda expression, you can find what it is with the following command::function <lambda>42See also: numbered-function
:for k in keys(s:) : unlet s:[k] :endfor
:if my_changedtick != b:changedtick : let my_changedtick = b:changedtick : call My_Update() :endif
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.
let s:counter = 0 command Tick let s:counter = s:counter + 1 | echo s:counterWhen 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.
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().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.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".echo my_{&background}_message
would output the contents of "my_dark_message" or "my_light_message" depending
on the current value of 'background'.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".:let foo='a + b'
:echo c{foo}d
.. since the result of expansion is "ca + bd", which is not a variable name.:let func_end='whizz'
:call my_func_{func_end}(parameter)
This would call the function "my_func_whizz(parameter)".:let i = 3
:let @{i} = '' " error
:echo @{i} " error
{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.{var-name}[{idx}] = {expr1} E689 {expr1}. {var-name} must refer to a list and {idx}
must be a valid index in that list. For nested list
the index can be repeated.
This cannot be used to add an item to a List.
This cannot be used to set a byte in a String. You
can do that like this::let var = var[0:2] .. 'X' .. var[4:]
{var-name} is a Blob then {idx} can be the
length of the blob, in which case one byte is
appended.{var-name}[{idx1}:{idx2}] = {expr1} E708 E709 E710
Set a sequence of items in a List to the result of
the expression {expr1}, which must be a list with the
correct number of items.
{idx1} can be omitted, zero is used instead.
{idx2} can be omitted, meaning the end of the list.
When the selected range of items is partly past the
end of the list, items will be added.{var} += {expr1} Like ":let {var} = {var} + {expr1}".
:let {var} -= {expr1} Like ":let {var} = {var} - {expr1}".
:let {var} *= {expr1} Like ":let {var} = {var} * {expr1}".
:let {var} /= {expr1} Like ":let {var} = {var} / {expr1}".
:let {var} %= {expr1} Like ":let {var} = {var} % {expr1}".
:let {var} .= {expr1} Like ":let {var} = {var} . {expr1}".
:let {var} ..= {expr1} Like ":let {var} = {var} .. {expr1}".
These fail if {var} was not set yet and when the type
of {var} and {expr1} don't fit the operator.
+= modifies a List or a Blob in-place instead of
creating a new one.{expr1} :let-environment :let-$
Set environment variable {env-name} to the result of
the expression {expr1}. The type is always String.
:let ${env-name} .= {expr1}
Append {expr1} to the environment variable {env-name}.
If the environment variable didn't exist yet this
works like "=".{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
charwise.
This can be used to clear the last search pattern::let @/ = ""
{expr1}
Append {expr1} to register {reg-name}. If the
register was empty it's like setting it to {expr1}.{expr1} :let-option :let-&
Set option {option-name} to the result of the
expression {expr1}. A String or Number 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 are changed.
Example::let &path = &path .. ',/usr/local/include':let &{option-name} .=
{expr1}
For a string option: Append {expr1} to the value.
Does not insert a comma like :set+=.{expr1}
:let &{option-name} -= {expr1}
For a number or boolean option: Add or subtract
{expr1}.{expr1}
:let &l:{option-name} .= {expr1}
:let &l:{option-name} += {expr1}
:let &l:{option-name} -= {expr1}
Like above, but only set the local value of an option
(if there is one). Works like :setlocal.{expr1}
:let &g:{option-name} .= {expr1}
:let &g:{option-name} += {expr1}
:let &g:{option-name} -= {expr1}
Like above, but only set the global value of an option
(if there is one). Works like :setglobal.{name1}, {name2}, ...] = {expr1} :let-unpack E687 E688
{expr1} must evaluate to a List. The first item in
the list is assigned to {name1}, the second item to
{name2}, etc.
The number of names must match the number of items in
the List.
Each name can be one of the items of the ":let"
command as mentioned above.
Example::let [s, item] = GetItem(s)
{expr1} is evaluated first, then the
assignments are done in sequence. This matters if
{name2} depends on {name1}. Example::let x = [0, 1] :let i = 0 :let [i, x[i]] = [1, 2] :echo x
{name1}, {name2}, ...] .= {expr1}
:let [{name1}, {name2}, ...] += {expr1}
:let [{name1}, {name2}, ...] -= {expr1}
Like above, but append/add/subtract the value for each
List item.{name}, ..., ; {lastname}] = {expr1} E452 {lastname}. If there are no
remaining items {lastname} is set to an empty list.
Example::let [a, b; rest] = ["aval", "bval", 3, 4]
{name}, ..., ; {lastname}] .= {expr1}
:let [{name}, ..., ; {lastname}] += {expr1}
:let [{name}, ..., ; {lastname}] -= {expr1}
Like above, but append/add/subtract the value for each
List item.{var-name} =<< [trim] [eval] {endmarker}
text...
text...
{endmarker}
Set internal variable {var-name} to a List
containing the lines of text bounded by the string
{endmarker}.{expr} is evaluated and the result replaces the
expression, like with interpolated-string.
Example where $HOME is expanded:let lines =<< trim eval END
some text
See the file {$HOME}/.vimrc
more text
END{endmarker} must not contain white space.
{endmarker} cannot start with a lower case character.
The last line should end only with the {endmarker}
string without any other character. Watch out for
white space after {endmarker}!{endmarker}, then indentation is stripped so you can
do:let text =<< trim END
if ok
echo 'done'
endif
END["if ok", " echo 'done'", "endif"]
The marker must line up with "let" and the indentation
of the first line is removed from all the text lines.
Specifically: all the leading indentation exactly
matching the leading indentation of the first
non-empty text line is stripped from the input lines.
All leading indentation exactly matching the leading
indentation before let is stripped from the line
containing {endmarker}. Note that the difference
between space and tab matters here.{var-name} didn't exist yet, it is created.
Cannot be followed by another command, but can be
followed by a comment.set cpo+=C let var =<< END \ leading backslash END set cpo-=C
let var1 =<< END
Sample text 1
Sample text 2
Sample text 3
END
let data =<< trim DATA
1 2 3 4
5 6 7 8
DATA
let code =<< trim eval CODE
let v = {10 + 20}
let h = "{$HOME}"
let s = "{Str1()} abc {Str2()}"
let n = {MyFunc(3, 4)}
CODE{var-name} .. List the value of variable {var-name}. Multiple
variable names may be given. Special names recognized
here: E738 <nothing> String
# Number
* Funcref{name} ... :unlet :unl E108 E795
Remove the internal variable {name}. Several variable
names can be given, they are all removed. The name
may also be a List or Dictionary item.
With [!] no error message is given for non-existing
variables.
One or more items from a List can be removed::unlet list[3] " remove fourth item :unlet list[3:] " remove fourth item to last
:unlet dict['two'] :unlet dict.two
{env-name}.
Can mix {name} and ${env-name} in one :unlet command.
No error message is given for a non-existing
variable, also without !.
If the system does not support deleting an environment
variable, it is made empty.{var-name} = {expr1}
:cons[t] [{name1}, {name2}, ...] = {expr1}
:cons[t] [{name}, ..., ; {lastname}] = {expr1}
:cons[t] {var-name} =<< [trim] [eval] {marker}
text...
text...
{marker}
Similar to :let, but additionally lock the variable
after setting the value. This is the same as locking
the variable with :lockvar just after :let, thus::const x = 1
:let x = 1 :lockvar! x
const ll = [1, 2, 3] let ll[1] = 5 " Error!
let lvar = ['a'] const lconst = [0, lvar] let lconst[0] = 2 " Error! let lconst[1][0] = 'b' " OK
{var-name}
If no argument is given or only {var-name} is given,
the behavior is the same as :let.{name} ... :lockvar :lockv
Lock the internal variable {name}. Locking means that
it can no longer be changed (until it is unlocked).
A locked variable can be deleted::lockvar v :let v = 'asdf' " fails! :unlet v " works
{name}".
If you try to lock or unlock a built-in variable you
will get an error message "E940: Cannot lock or unlock
variable {name}".{name} but not its
value.
1 Lock the List or Dictionary itself,
cannot add or remove items, but can
still change their values.
2 Also lock the values, cannot change
the items. If an item is a List or
Dictionary, cannot add or remove
items, but can still change the
values.
3 Like 2 but for the List /
Dictionary in the List /
Dictionary, one level deeper.
The default [depth] is 2, thus when {name} is a List
or Dictionary the values cannot be changed.let mylist = [1, 2, 3] lockvar 0 mylist let mylist[0] = 77 " OK call add(mylist, 4) " OK let mylist = [7, 8, 9] " Error!
:let l = [0, 1, 2, 3] :let cl = l :lockvar l :let cl[1] = 99 " won't work!
{name} ... :unlockvar :unlo
Unlock the internal variable {name}. Does the
opposite of :lockvar.{name} does not exist.{expr1} :if :end :endif :en E171 E579 E580
:en[dif] Execute the commands until the next matching :else
or :endif if {expr1} evaluates to non-zero.
Although the short forms work, it is recommended to
always use :endif to avoid confusion and to make
auto-indenting work properly.:if and :endif is ignored. These two
commands were just to allow for future expansions in a
backward compatible way. Nesting was allowed. Note
that any :else or :elseif was ignored, the else
part was not executed either.:if version >= 500 : version-5-specific-commands :endif
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
:append and :insert commands don't work
properly in between :if and :endif.:else
or :endif if they previously were not being
executed.{expr1} Short for :else :if, with the addition that there
is no extra :endif.{expr1} :while :endwhile :wh :endw
E170 E585 E588 E733
: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.
Example::let lnum = 1
:while lnum <= line("$")
:call FixLine(lnum)
:let lnum = lnum + 1
:endwhile:append and :insert commands don't work
properly inside a :while and :for loop.{var} in {object} :for E690 E732
:endfo[r] :endfo :endfor
Repeat the commands between :for and :endfor for
each item in {object}. {object} can be a List,
a Blob or a String.{var} is set to the value of each item.endfor.
Changing {object} inside the loop affects what items
are used. Make a copy if this is unwanted::for item in copy(mylist)
{object} is a List and not making a copy, Vim
stores a reference to the next item in the List
before executing the commands with the current item.
Thus the current item can be removed without effect.
Removing any later item means it will not be found.
Thus the following example works (an inefficient way
to make a List empty):for item in mylist call remove(mylist, 0) endfor
{object} is a Blob, Vim always makes a copy to
iterate over. Unlike with List, modifying the
Blob does not affect the iteration.{object} is a String each item is a string with
one character, plus any combining characters.{var1}, {var2}, ...] in {listlist}
:endfo[r]
Like :for above, but each item in {listlist} must be
a list, of which each item is assigned to {var1},
{var2}, etc. Example::for [lnum, col] in [[1, 3], [2, 5], [3, 8]] :echo getline(lnum)[col] :endfor
:while or :for loop, jumps back
to the start of the loop.:try inside the loop 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 :trys inside the loop. The outermost
:endtry then jumps back to the start of the loop.:while or :for loop, skips to
the command after the matching :endwhile or
:endfor.
If it is used after a :try inside the loop 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 :trys inside the loop. The outermost
:endtry then jumps to the command after the loop.:try and :endtry including everything being
executed across :source commands, function calls,
or autocommand invocations.: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 | call Unknown() | finally | echomsg "cleanup" | endtry echomsg "not reached"
: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.{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
: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 /.*/
{pattern}, so long as it does not have a special
meaning (e.g., '|' or '"') and doesn't occur inside
{pattern}.
Information about the exception is available in
v:exception. Also see throw-variables.
NOTE: It is not reliable to ":catch" the TEXT of
an error message because it may vary in different
locales.: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).{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
{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
: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"
:let l = [] :call add(l, l) :let l2 = [] :call add(l2, [l2]) :echo l l2
{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
:echo, which is a
Vim command, and :!echo, which is an external shell
command::!echo % --> filename
:!echo "%" --> filename or "filename"
:echo % --> nothing
:echo "%" --> %
:echo expand("%") --> filename{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
{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.
The parsing works slightly different from :echo,
more like :execute. All the expressions are first
evaluated and concatenated before echoing anything.
If expressions does not evaluate to a Number or
String, string() is used to turn it into a string.
Uses the highlighting set by the :echohl command.
Example::echomsg "It's a Zizzer Zazzer Zuzz, as you can plainly see."
{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
:echomsg 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!"
:echohl.
And to get a beep::exe "normal \<Esc>"
{expr} Evaluate {expr} and discard the result. Example::eval Getlist()->Filter()->append('$')append() call appends the List with text to the
buffer. This is similar to :call but works with any
expression.:ev or :eva, but
these are hard to recognize and therefore not to be
used.{expr1} .. Executes the string that results from the evaluation
of {expr1} as an Ex command.
Multiple arguments are concatenated, with a space in
between. To avoid the extra space use the ".."
operator to concatenate strings into one argument.
{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 '!ls' | echo "theend"
:execute "normal ixxx\<Esc>"
<Esc> character, see expr-string.:execute "e " .. fnameescape(filename) :execute "!ls " .. shellescape(filename, 1)
:if 0 : execute 'while i > 5' : echo "test" : endwhile :endif
:execute 'while i < 5 | echo i | let i = i + 1 | endwhile'
:echo "foo" | "this is a comment
: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.:throw 4711 :throw "string"
: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.:if Foo("arrgh")
: echo "then"
:else
: echo "else"
:endif
Here neither of "then" or "else" is displayed.: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\+$/ : echo "Number thrown"The first ":catch" here matches always, so that the second catch clause is never taken.
: catch /^\d\+$/ : echo "Number thrown. Value is" v:exceptionYou 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 caughtA 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 : try : throw "foo" : catch /foobar/ : echo "foobar" : finally : echo "inner finally" : endtry :catch /foo/ : echo "foo" :endtryThe 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".
: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 :endtryThis displays "Caught foo, throw bar" and then "Caught bar".
:function! Bar() : try : call Foo() : catch /.*/ : echo "Rethrow" v:exception : throw v:exception : endtry :endfunction
:try : try : asdf : catch /.*/ : echoerr v:exception : endtry :catch /.*/ : echo v:exception :endtryThis code displays
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 :endtryThis 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.
: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.)
:try : try : echo "Press CTRL-C for interrupt" : while 1 : endwhile : finally : unlet novar : endtry :catch /novar/ :endtry :echo "Script still running" :sleep 1If 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.
Vim({cmdname}):{errmsg}
orVim:{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.:unlet novarnormally 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
:dwimnormally produces the error message
E492: Not an editor command: dwimwhich is converted inside try conditionals to an exception
Vim:E492: Not an editor command: dwimYou 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 nofuncand
:delfunction nofuncboth produce the error message
E128: Function name must start with a capital: nofuncwhich is converted inside try conditionals to an exception
Vim(function):E128: Function name must start with a capital: nofuncor
Vim(delfunction):E128: Function name must start with a capital: nofuncrespectively. 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 = novarproduce multiple error messages, here:
E121: Undefined variable: novar E15: Invalid expression: novarOnly 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 /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
:try : write :catch :endtryBut 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 novarThere 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):/ :endtrywhich only catches real write errors. So catch only what you'd like to ignore intentionally.
:silent! nunmap kThis works also when a try conditional is active.
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$/
: echo "\nCommand interrupted"
: " Caught the interrupt. Continue with next prompt.
: endtry
:endwhile
You can interrupt a task here by pressing CTRL-C; the script then asks for
a new command. If you press CTRL-C at the prompt, the script is terminated.CTRL-C would be pressed on a specific line in
your script, use the debug mode and execute the >quit or >interrupt
command on that line. See debug-scripts.:catch /.*/ :catch // :catchcatch everything, error exceptions, interrupt exceptions and exceptions explicitly thrown by the :throw command. This is useful at the top level of a script in order to catch unexpected things. Example:
:try
:
: " do the hard work here
:
:catch /MyException/
:
: " handle known problem
:
:catch /^Vim:Interrupt$/
: 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
: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 :endtryThis displays "Oops!" and "Arrgh!".
:autocmd BufWritePre * throw "FAIL" :autocmd BufWritePre * echo "Should not be displayed" : :try : write :catch : echo "Caught:" v:exception "from" v:throwpoint :endtryHere, 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 "*"
:autocmd BufWritePost * echo "File successfully written!" : :try : write /i/m/p/o/s/s/i/b/l/e :catch : echo v:exception :endtryThis 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
: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 xThis displays "after fail".
:autocmd BufWritePost * throw ":-("
:autocmd BufWritePost * echo "Should not be displayed"
:
:try
: write
:catch
: echo v:exception
:endtry: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
firstFile successfully written!then
Error on writing (file contents not changed)then
Error after writingetc.
:autocmd BufWritePre * try : :autocmd BufWritePost * catch :autocmd BufWritePost * echo v:exception :autocmd BufWritePost * endtry : :write
: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" fnameescape(a:file)
: catch /^Vim(write):/
: throw "EXCEPT:IO(" .. getcwd() .. ", " .. a:file .. "):WRITEERR"
: endtry
:endfunction
:
:try
:
: " something with arithmetic 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.: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" :endtryThis 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.:try | unlet! foo # | catch | endtryraises 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.
echo novarcauses
E121: Undefined variable: novar E15: Invalid expression: novarThe value of the error exception inside try conditionals is:
Vim(echo):E121: Undefined variable: novar
unlet novar #causes
E108: No such variable: "novar" E488: Trailing charactersThe value of the error exception inside try conditionals is:
Vim(unlet):E488: Trailing charactersThis 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.:" The function Nr2Bin() returns the binary string representation of a number. :func Nr2Bin(nr) : let n = a:nr : let r = "" : while n : let r = '01'[n % 2] .. r : let n = n / 2 : endwhile : return r :endfunc :" The function String2Bin() converts each character in a string to a :" binary string, separated with dashes. :func String2Bin(str) : let out = '' : for ix in range(strlen(a:str)) : let out = out .. '-' .. Nr2Bin(char2nr(a:str[ix])) : endfor : return out[1:] :endfuncExample of its use:
:echo Nr2Bin(32)result: "100000"
:echo String2Bin("32")
result: "110011-110010":func SortBuffer()
: let lines = getline(1, '$')
: call sort(lines, function("Strcmp"))
: call setline(1, lines)
:endfunction
As a one-liner::call setline(1, sort(getline(1, '$'), function("Strcmp"))):" 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)
:scriptnames command can be used to get a list of all script files that
have been sourced. There is also the getscriptinfo() function, but the
information returned is not exactly the same. In case you need to manipulate
the output of scriptnames this code can be used:" Get the output of ":scriptnames" in the scriptnames_output variable.
let scriptnames_output = ''
redir => scriptnames_output
silent scriptnames
redir END
" Split the output into lines and parse each line. Add an entry to the
" "scripts" dictionary.
let scripts = {}
for line in split(scriptnames_output, "\n")
" Only do non-blank lines.
if line =~ '\S'
" Get the first number in the line.
let nr = matchstr(line, '\d\+')
" Get the file name, remove the script number " 123: ".
let name = substitute(line, '.\+:\s*', '', '')
" Add an item to the Dictionary
let scripts[nr] = name
endif
endfor
unlet scriptnames_output
CTRL-R = in the command line.
The sandbox is also used for the :sandbox command.{cmd} Execute {cmd} in the sandbox. Useful to evaluate an
option that may have been set from a modeline, e.g.
'foldexpr'.Error is used
and some other intermediate groups are present.= in :let
hl-NvimAugmentedAssignment NvimAssignment Generic, +=/`-=`/`.=`
hl-NvimAssignmentWithAddition NvimAugmentedAssignment += in :let+=
hl-NvimAssignmentWithSubtraction NvimAugmentedAssignment -= in :let-=
hl-NvimAssignmentWithConcatenation NvimAugmentedAssignment .= in :let.=#/`?` near expr4 op
hl-NvimBinaryPlus NvimBinaryOperator expr-+
hl-NvimBinaryMinus NvimBinaryOperator expr--
hl-NvimConcat NvimBinaryOperator expr-.
hl-NvimConcatOrSubscript NvimConcat expr-. or expr-entry
hl-NvimOr NvimBinaryOperator expr-barbar
hl-NvimAnd NvimBinaryOperator expr-&&
hl-NvimMultiplication NvimBinaryOperator expr-star
hl-NvimDivision NvimBinaryOperator expr-/
hl-NvimMod NvimBinaryOperator expr-%{/`}` in lambda
hl-NvimNestingParenthesis NvimParenthesis (/`)` in expr-nesting
hl-NvimCallingParenthesis NvimParenthesis (/`)` in expr-function[/`]` in expr-[]
hl-NvimSubscriptColon NvimSubscript : in expr-[:]
hl-NvimCurly NvimSubscript {/`}` in
curly-braces-names{/`}` in dict literal
hl-NvimList NvimContainer [/`]` in list literal: in
internal-variables
hl-NvimIdentifierScopeDelimiter NvimIdentifier : after namespace
letter
hl-NvimIdentifierName NvimIdentifier Rest of the ident
hl-NvimIdentifierKey NvimIdentifier Identifier after
expr-entry: in dict literal
hl-NvimComma Delimiter , in dict or list
literal or
expr-function
hl-NvimArrow Delimiter -> in lambda0 for octal-number
0x for hex-number
0b for binary-number
hl-NvimFloat NvimNumber Floating-point
number& in expr-option
hl-NvimOptionScope NvimIdentifierScope Option scope if any
hl-NvimOptionScopeDelimiter NvimIdentifierScopeDelimiter
: after option scope
hl-NvimOptionName NvimIdentifier Option name$ in expr-env
hl-NvimEnvironmentName NvimIdentifier Env variable name' in expr-'
hl-NvimSingleQuotedBody NvimStringBody Literal part of
expr-' string body
hl-NvimSingleQuotedQuote NvimStringSpecial '' inside expr-'
string body" in expr-quote
hl-NvimDoubleQuotedBody NvimStringBody Literal part of
expr-quote body
hl-NvimDoubleQuotedEscape NvimStringSpecial Valid expr-quote
escape sequence
hl-NvimDoubleQuotedUnknownEscape NvimInvalidValue Unrecognized
expr-quote escape
sequence