Start hacking
let name = "John"
echo "Hello, " . name
You can either put this in a script (script.vim
) and run it (:source script.vim
), or you can type the commands individually in normal mode as :let
and :echo
.
Learn by example
function! SuperTab()
let l:part = strpart(getline('.'),col('.')-2,1)
if (l:part=~'^\W\?$')
return "\<Tab>"
else
return "\<C-n>"
endif
endfunction
imap <Tab> <C-R>=SuperTab()<CR>
Here’s another example with functions, variables and mapping.
Variables
Defining
let var = "hello"
Variable prefixes
let g:ack_options = '-s -H' " g: global
let s:ack_program = 'ack' " s: local (to script)
let l:foo = 'bar' " l: local (to function)
The s:
prefix is also available in function names. See :help local-variables
Other prefixes
let w:foo = 'bar' " w: window
let b:state = 'on' " b: buffer
let t:state = 'off' " t: tab
echo v:var " v: vim special
let @/ = '' " @ register (this clears last search pattern)
echo $PATH " $ env
Vim options
echo 'tabstop is ' . &tabstop
if &insertmode
echo &g:option
echo &l:option
Prefix Vim options with &
Operators
a + b " numbers only!
'hello ' . name " concat
let var -= 2
let var += 5
let var .= 'string' " concat
Strings
Strings
let str = "String"
let str = "String with \n newline"
let literal = 'literal, no \ escaping'
let literal = 'that''s enough' " double '' => '
echo "result = " . re " concatenation
Also see :help literal-string
and :help expr-quote
.
See: Strings
String functions
strlen(str) " length
len(str) " same
strchars(str) " character length
split("one two three") "=> ['one', 'two', 'three']
split("one.two.three", '.') "=> ['one', 'two', 'three']
join(['a', 'b'], ',') "=> 'a,b'
tolower('Hello')
toupper('Hello')
Also see :help functions
See: String functions
Functions
Functions
" prefix with s: for local script-only functions
function! s:Initialize(cmd, args)
" a: prefix for arguments
echo "Command: " . a:cmd
return true
endfunction
See: Functions
Namespacing
function! myplugin#hello()
Calling functions
call s:Initialize()
call s:Initialize("hello")
Consuming return values
echo "Result: " . s:Initialize()
Abortable
function! myfunction() abort
endfunction
Aborts when an error occurs.
Var arguments
function! infect(...)
echo a:0 "=> 2
echo a:1 "=> jake
echo a:2 "=> bella
for s in a:000 " a list
echon ' ' . s
endfor
endfunction
infect('jake', 'bella')
See :help function-argument
. See: Var arguments
Loops
for s in list
echo s
continue " jump to start of loop
break " breaks out of a loop
endfor
while x < 5
endwhile
Custom commands
Custom commands
command! Save :set fo=want tw=80 nowrap
Custom commands start with uppercase letters. The !
redefines a command if it already exists.
Commands calling functions
command! Save call <SID>foo()
function! s:foo()
...
endfunction
Commands with arguments
command! -nargs=? Save call script#foo(<args>)
What | What |
---|---|
-nargs=0 |
0 arguments, default |
-nargs=1 |
1 argument, includes spaces |
-nargs=? |
0 or 1 argument |
-nargs=* |
0+ arguments, space separated |
-nargs=+ |
1+ arguments, space reparated |
Flow
Conditionals
let char = getchar()
if char == "\<LeftMouse>"
" ...
elseif char == "\<RightMouse>"
" ...
else
" ...
endif
Truthiness
if 1 | echo "true" | endif
if 0 | echo "false" | endif
if 1 "=> 1 (true)
if 0 "=> 0 (false)
if "1" "=> 1 (true)
if "456" "=> 1 (true)
if "xfz" "=> 0 (false)
No booleans. 0
is false, 1
is true.
See: Truthiness
Operators
if 3 > 2
if a && b
if (a && b) || (c && d)
if !c
See :help expression-syntax
.
See: Operators
Strings
if name ==# 'John' " case-sensitive
if name ==? 'John' " case-insensitive
if name == 'John' " depends on :set ignorecase
" also: is#, is?, >=#, >=?, and so on
Identity operators
a is b
a isnot b
Checks if it’s the same instance object.
Regexp matches
"hello" =~ '/x/'
"hello" !~ '/x/'
Single line
if empty(a:path) | return [] | endif
a ? b : c
Use |
to join lines together.
Boolean logic
if g:use_dispatch && s:has_dispatch
···
endif
Lists
Lists
let mylist = [1, two, 3, "four"]
let first = mylist[0]
let last = mylist[-1]
" Supresses errors
let second = get(mylist, 1)
let second = get(mylist, 1, "NONE")
Functions
len(mylist)
empty(mylist)
sort(list)
let sortedlist = sort(copy(list))
split('hello there world', ' ')
Concatenation
let longlist = mylist + [5, 6]
let mylist += [7, 8]
Sublists
let shortlist = mylist[2:-1]
let shortlist = mylist[2:] " same
let shortlist = mylist[2:2] " one item
Push
let alist = [1, 2, 3]
let alist = add(alist, 4)
Map
call map(files, "bufname(v:val)") " use v:val for value
call filter(files, 'v:val != ""')
Dictionaries
Dictionaries
let colors = {
\ "apple": "red",
\ "banana": "yellow"
}
echo colors["a"]
echo get(colors, "apple") " supress error
See :help dict
Using dictionaries
remove(colors, "apple")
" :help E715
if has_key(dict, 'foo')
if empty(dict)
keys(dict)
len(dict)
max(dict)
min(dict)
count(dict, 'x')
string(dict)
map(dict, '<>> " . v:val')
Iteration
for key in keys(mydict)
echo key . ': ' . mydict(key)
endfor
Prefixes
keys(s:)
Prefixes (s:
, g:
, l:
, etc) are actually dictionaries.
Extending
" Extending with more
let extend(s:fruits, { ... })
Casting
str2float("2.3")
str2nr("3")
float2nr("3.14")
Numbers
Numbers
let int = 1000
let int = 0xff
let int = 0755 " octal
See :help Number
.
See: Numbers
Floats
let fl = 100.1
let fl = 5.4e4
See :help Float
Arithmetic
3 / 2 "=> 1, integer division
3 / 2.0 "=> 1.5
3 * 2.0 "=> 6.0
Math functions
sqrt(100)
floor(3.5)
ceil(3.3)
abs(-3.4)
sin() cos() tan()
sinh() cosh() tanh()
asin() acos() atan()
Vim-isms
Execute a command
execute "vsplit"
execute "e " . fnameescape(filename)
Runs an ex command you typically run with :
. Also see :help execute
.
See: Execute a command
Running keystrokes
normal G
normal! G " skips key mappings
execute "normal! gg/foo\<cr>dd"
Use :normal
to execute keystrokes as if you’re typing them in normal mode. Combine with :execute
for special keystrokes.
See: Running keystrokes
Getting filenames
echo expand("%") " path/file.txt
echo expand("%:t") " file.txt
echo expand("%:p:h") " /home/you/path/file.txt
echo expand("%:r") " path/file
echo expand("%:e") " txt
See :help expand
Silencing
silent g/Aap/p
Supresses output. See :help silent
Echo
echoerr 'oh it failed'
echomsg 'hello there'
echo 'hello'
echohl WarningMsg | echomsg "=> " . a:msg | echohl None
Settings
set number
set nonumber
set number! " toggle
set numberwidth=5
set guioptions+=e
Prompts
let result = confirm("Sure?")
execute "confirm q"
Built-ins
has("feature") " :h feature-list
executable("python")
globpath(&rtp, "syntax/c.vim")
exists("$ENV")
exists(":command")
exists("variable")
exists("+option")
exists("g:...")
Mapping
Mapping commands
nmap
vmap
imap
xmap
nnoremap
vnoremap
inoremap
xnoremap
...
Explanation
[nvixso](nore)map
│ └ don't recurse
│
└ normal, visual, insert,
eX mode, select, operator-pending
Arguments
<buffer> |
only in current buffer |
<silent> |
no echo |
<nowait> |
Syntax
Highlights
hi Comment
term=bold,underline
gui=bold
ctermfg=4
guifg=#80a0ff
Filetype detection
augroup filetypedetect
au! BufNewFile,BufRead *.json setf javascript
augroup END
au Filetype markdown setlocal spell
Conceal
set conceallevel=2
syn match newLine "<br>" conceal cchar=}
hi newLine guifg=green
Region conceal
syn region inBold concealends matchgroup=bTag start="<b>" end="</b>"
hi inBold gui=bold
hi bTag guifg=blue
Syntax
syn match :name ":regex" :flags
syn region Comment start="/\*" end="\*/"
syn region String start=+"+ end=+"+ skip=+\\"+
syn cluster :name contains=:n1,:n2,:n3...
flags:
keepend
oneline
nextgroup=
contains=
contained
hi def link markdownH1 htmlH1
Include guards
if exists('g:loaded_myplugin')
finish
endif
" ...
let g:loaded_myplugin = 1