Lean Vim Script The Hard Way

http://learnvimscriptthehardway.stevelosh.com/

Mappings

:help map :help 40 maping keys syntax :noremap <newkeys> <keynames>

  • list mappings :map. To save them in a file use those 3 commands
    :redir! > ~/Download/vim_keys.txt
    :silent verbose map
    :redir END
    
  • since mappings easilly could be broken, ALWAYS use nore non recursive variant noremap, nnoremap … so it use default meanings of keynames
  • :map <unique> <script> asd asd means that it will not use mappings from other places (only mappings defined in script) and it will fail if it is already defined
  • you can map control CTRL key, for example :map <c-d> dd (<c-d> or <esc> is called angle bracket notation)
  • map (normal visual and operator-pending), nmap normal, vmap visual, omap operator-pending, imap insert, map! insert and command line, cmap command line, xmap ex command mode
  • remove mappings :unmap <key> or nunmap
  • you can map two keys, for example :map -d dd

  • change leader key :let mapleader = "-" so you can write :map <leader>d dd (note that it does not have effect for already defined mappings)
  • :let maplocalleader = "\" can be used for mapings only for local buffer. Mapping can be for specific buffer (file) :nnoremap <buffer> <leader>d dd. You can use both :nnoremap <buffer> <localleader>d dd
  • to check if user has already define a mapping
    :echo !hasmapto('<Plug>TypecorrAdd')
    

Some examples

  • :nnoremap _ f_x~ find next _, remove and uppercase for moving underscore to CamelCase
  • snippet nnoremap ,html :-1read $HOME/.vim/.skeleton.html<CR>3jwf>a my snippets
  • <silent> is good if you are having mappings that launch ex commands.
  • black screen is caused to silent command https://github.com/vim/vim/issues/1253 use :redraw!

Abbreviations

Abbreviations are similar to mappings but for insert, replace and command mode. They are shown while you are typing and are triggered by a non keyword char.

  • :iabbrev adn and this will replace adn<non-keyword-character> with and Difference between map is that map does not count for non-keyword-character. If you have mapping in abbr result you can use :noreabbrev to it skips map
  • :abbreviate list all abbreviations
  • :iabbrev <buffer> --- &mdash; will replace --- with &mdash but only for current buffer. It is <buffer> local abbreviation and is usefull when you want something only for specific type, for example :autocmd FileType javascript :iabbrev <buffer> iff if ()<left> will enable little snippet only for js.
  • cabbrev E e can be used to replace E with e on command line so when you type :E<space> it will end up in :e<space>
  • :abclear to remove all abbrs or :unabberviate adn to remove only one

Commands

  • define custom command :command MyCom 1delete user defined commands must start with a capital letter
  • define number of arguments: one -nargs=1, zero or more -nargs=? and use them with <args> or <q-args> (properly escaped string) for example
    :command -nargs=+ Say :echo <q-args>
    
  • usually command call functions and <f-args> will properly pass the arguments
  • if your command uses range than use -range attribute and use <line1> and <line2> in command.
  • use -bar than command can be followed by |. Also you can use <Bar> inside command definition to join multiple commands
  • to override use bang :command! Say. to remove :delcommand Save

Autocommands

Autocommands are used to run commands on specific events (usually set filetype or call MyFun)

:autocmd BufNewFile * write.

First param is event and can be something of: entering insert mode, not pressing a key for some time. It can can combine, usually BufNewFile,BufRead for all open files, existing or not. Some events :help autocmd-events

  • BufNewFile when you open new files not saved to disk
  • BufReadPost after you open existing file
  • BufWritePre just before write
  • FileType when vim sets filetype
    • :autocmd FileType javascript nnoremap <buffer> <localleader>c I//<esc>

Second param is “pattern” that filter more specific: for example: *.txt is only triggered for txt files

Last part is command that is executed. Note that it is Command-line commands. so to use normal mode commands you need normal (or :normal! which ignore mappings that user could have written). For example jump to the end of file

:autocmd BufReadPost *.log normal G

normal will use all text after it, so if you need to execute two commands than wrap normal G inside execute and use |

:autocmd BufReadPost *.chg execute "normal ONew entry:\<Esc>" |
  \ 1read !date

You can group autocommands (autocmd! is to clear)

augroup filetype_html
    autocmd!
    autocmd FileType html nnoremap <buffer> <localleader>f Vatzf
augroup END

Operator pending mappings

Operator is command waiting for movement command and than executes. For example d, y and c are waiting for movements: dt, (delete till ,), ci( (change inner (), yw (yank word). We can remap movement keys for operator mode :onoremap p i( (inner braces, select parametars), or :onoremap b /end<cr> (block, until end). If you want to select before or some block after current position you can visualy select and it will be executed on that selection. For example, change params while current is on current line before params:

onoremap in( :<c-u>normal! f(vi(<cr>

:normal! means that it simulate pressing in normal mode (and not not use eventual user mappings into consideration). <cr> at the end executes :normal! command. You can indent from command mode: :normal >> <c-u> needs to remove the range that vim may insert.

:execute takes vimscript string and performs as command :execute "write". It is used since :normal can not recognize special characters like <cr> (if you try to use quotes :normal "' will just print/show them, so normal without execute interpolation is just for commands without <cr> like operators and moves). Another usage is when you need to run normal commands from string (interpolate). execute will substitute any special charactes before running string, special chars are :help expr-quote. You can insert those special characters without escaping if you use ctrl-v (:help i_ctrl-v) it will insert terminal code

  • \r return <CR> (if you are using ctrl-v than it is ` `)
  • \n new line <NL>
  • \<_key_> ( \<Esc> with ctrl-v )
  • \\ is backslash \. You can use single as quote normal '/,\+' if you have many backslashes and you do not want to escape them, or those parts inside execute
    :executue "normal /foo.\\+\<cr>"
    :executue 'normal /foo.\+' . "\<cr>"
    

If you need to get value of option which name is in variable you can use eval

:let optname = "path"
:let optval = eval('&' . optname)

" The same thing can be done with:
:exe 'let optval = &' . optname

Example using execute to change current title header (=======\n Header) in markdown text with keys cih:

:onoremap ih :<c-u>execute "normal! ?^==\\+$\r:nohlsearch\rkvg_"<cr>

Map keys to execute Operator function

https://learnvimscriptthehardway.stevelosh.com/chapters/32.html Here we will create usual mapping but execute our function, we will call it grep oprator. [email protected] will call operatorfunc as operator (so it can accept motion as any other operator like w word or i{ inner braces)

nnoremap <leader>g :set operatorfunc=GrepOperator<cr>[email protected]

function! GrepOperator(type)
  echom "test"
endfunction

Options and Variables

:help 41 For example

:let i = 1
:while i < 5
:  echo "count is " i
:  let i += 1
:endwhile

Yank those lines and execute with :@" command.

  • .vimrc script file execute any colon command (ex command, command-line command) and you can omit colon in scripts
  • to set a variable use let {variable} = {expression}. Local scope variables are with prefix like :let b:a=2 (b: buffer, w: window, t: tab, g: global, l: local to function, a: argument, s: script). :echo v:version v: are vim variables Note that variables still exists when script finish. Check with:
    :if !exists("s:call_count")
    :  let s:call_count = 0
    :endif
    :let s:call_count = s:call_count + 1
    :echo "called" s:call_count "times"
    

    To clear variable use :unlet s:call_count (:unlet! to skipp error if not exists).

  • :setlocal nowrap is only for current buffer (file), when you open another file (inside same window) it will not have nowrap. If you have same mappings than local will be chosen since it is more specific.
  • Numbers can be: decimal 123, hexadecimal 0x7f, octal 012 (starts with zero), and binary 0b101 (starts with 0b). :echo 0xf always print decimal
  • Strings inside double quote can include special chars "\tHi \"you\"" and single quote 'Hi ''you''' can’t use special chars. Concatenate with dot. Special characters are excaped with \ like "\t \<Esc>"
  • use $NAME for environment variable, &name for option and @r for register
  • to set option you can use :set xxx or :set xxx=value or :let &xxx=value To unset :set noxxx or :set xxx!. To check if it is set :set xxx? or :echo &xxx. To set to default value use ampersand & like :set iskeyword& For boolean options 1 is true and 0 is false. :let is more powerfull than :set since it can use math and other operations. Escape space with backslash like :set tags=my\ nice\ file
  • to set variable use :let foo = "bar" and print :echo 'foo=' foo arguments will be separated with space. You can add or remove item from list, you can do with :set k+=v or -=. If you have space inside value than you need to escape :set xxx+=my\ value
  • to set registers run let @a = "hello" so you can paste "ap. To read register run :echo @a (:echo @" is unnamed yank register, :echo @\ is search register … :help registers).
  • to get current value of variable you can use = and <TAB> for example :set xxx= and press tab so vim autocomplete the value so you can edit it. Or you can press enter after the name (skip equal sign), for example :se ft<cr>
  • print env variables on command line: :echo $MYVIMRC or :echo filetype?. :echom $PATH will save output into :messages so you can view later (it will differently show special characters :echom "a\nb" will not be shown as new line)

Multiline commands can be written as:

:echom "foo" | echom "bar"

" or

:augroup testgroup
:   autocmd BufWrite * :echom "Baz"
:autgroup END

To loop instead of :while you can use :for i in range(1,4). Function range(n) will create a list [0, 1, ... n-1]. Usefull in buffers

:for line in getline(1,20)

Inside loop you can use :continue (just to start and keep looping) and :break (break the loop) sleep 40m to sleep for 40 miliseconds

For conditional use :if {condition} :else :elseif and :endif. You can use a > 1 ? 'big' : 'small'. String what does not start with number, when converted to number is always 0 which means false

: if 0
:   echom "not possible"
: elsif "also_zero0"
:  echom "also 0"
: elsif "1one" - 1
:   echom "also zero value"
: elsif "zero1" + "1one"
:   echom "finally"
: else
: end

Vim is by default ignorecase but it can be changed. There are case insensitive (append ?) and case sensitive (append #) equal operator regardless of ignorecase setting (so you use that in your scripts :help expr4):

:if "Asd" == "asd" | echo "case insensitive equal" | end
:set noignorecase
:if "Asd" != "asd" | echo "case sensitive different" | end

:if "Asd" ==? "asd" | echo "case insensitive equal" | end
:if "Asd" !=# "asd" | echo "case sensitive different" | end

String match a =~ b and not match a !~ '\.$' (does not end with full stop). Also supports case insensitive !~? and case sensitive !~#.

Function

Functions must start with capital if they are unscoped. Parameters are always pefixed with a: (argument scope).

:function MyFuction(name)
: let result = "hi " . a:name
: return result
:endfunction

:call MyFunction("Duke")
:echom MyFunction("Duke")

There are many functions :help functions Working with text in current buffer:

  • getline('.') get the line under the cursor, setline('.', new_line) set

String manipulation

  • substitute({expr}, {pattern}, {sub}, {flags})
  • strlen("foo")
  • split("one,two,three", ",") and join(["one","two"], "...")

List manipulation

  • map({list}, {expression}) change each list item with expression which should be a string or function. If it is a string than v:val is containing item :call map(mylist, '"> " . v:val . " <"') When it is a function than you can define function
    :func KeyValue(key, val)
    :  return a:key . '-' . a:val
    :endfunc
    :call map(myDict, function('KeyValue'))
    

    It is shorter when using a |lambda|: :call map(myDict, {key, val -> key . '-' . val})

Define function that is called with a range with range keyword

:function Count_lines() range
:  return a:lastline - a:firstline
:endfunction

" call with
:10,30call Count_lines()

Define function on dictionary so you can use it with self variable. get(self, v:val, '???') return item if exists, otherwise '???'.

:let uk2nl = {'one': 'een', 'two': 'twee', 'three': 'drie'}
:function uk2nl.translate(line) dict
:   return join(map(split(a:line), 'get(self, v:val, "???")'))
:endfunction

:echo uk2nl.translate('three two five one')
dire twee ??? een

You can define arbitrary number of arguments with function Show(start, ...) so inside it a:0 is count of those arguments a:1, a:2

To list all functions

:function

To show function defition

:function Min

Debug :help debug-scripts Delete function :delfunction Min. Store function in variable let Afunc = function('Min') and call using call function :echo call(Afunc, []) In script you can use global variable to know if functions are loaded so you can undefine them (or you can simply call finish to exit)

" This is the XXX package

if exists("XXX_loaded")
  delfun XXX_one
  delfun XXX_two
endif

function XXX_one(a)
... body of function ...
endfun

function XXX_two(b)
... body of function ...
endfun

let XXX_loaded = 1

Lists and dictionaries

List is ordered sequence of things

:let alist = ['a', 1]

add one item using add() function, add multiple items with extend(), concatenate with +

:call add(alist, 'foo')

Dictionary store key-value

:let dict = {'one': 1. 'two': 2}

use them like index dict['one'] or dict.one. Assign new key

:let dict['three'] = 3

Retrieve keys with :let keys = keys(dict)

Exceptions

:try
:  read pascal.tmpl
:catch /E484:/
:  echo 'Sorry, pascal.tmpl can not be found'
:finally
:  echo 'This is always executed
:endtry

Comments

Commane is after double quote till the end of line

  • There can be no comment after :map, :abbreviate, :execute and ! You can add | so there are two commands

Command line ex special characters

:help cmdline-special In command line you can get work under cursor with <cword> inside :grep which is quickfix command along with :make.

For :echo we need to expand() string to see the value. Echo is different from :grep in terms that it works with strings and we can use functions (similar to :execute)

:nnoremap <leader>g :grep -R '<cWORD>' .<cr>
:echo expand('<cWORD>')
:execute ':echo 2 ' shellescape(expand('<cWORD>'))
:nnoremap <leader>g :silent execute "grep! -R " . shellescape(expand("<cWORD>")) . " ."<cr>:copen<cr>

Plugins

If you need to export function so user can use mappings than you need to use <SID>MyFunc() (instead of s:MyFunc()) so vim know which script to use. For other place is it ok to use s:MyFunc() in autocommands, user commands… Example of plugin in ~/.vim/plugin/typecorr.vim

" Vim global plugin for correcting typing mistakes
" Last Change:	2000 Oct 15
" Maintainer:	Bram Moolenaar <[email protected]>
" License:	This file is placed in the public domain.

if exists("g:loaded_typecorr")
  finish
endif
let g:loaded_typecorr = 1
let s:save_cpo = &cpo
set cpo&vim
iabbrev teh the
iabbrev otehr other
iabbrev wnat want
iabbrev synchronisation
	\ synchronization
let s:count = 4

let s:count = 4
if !hasmapto('<Plug>TypecorrAdd')
  map <unique> <Leader>a  <Plug>TypecorrAdd
endif
noremap <unique> <script> <Plug>TypecorrAdd  <SID>Add

noremenu <script> Plugin.Add\ Correction      <SID>Add
noremap <SID>Add  :call <SID>Add(expand("<cword>"), 1)<CR>

function s:Add(from, correct)
  let to = input("type the correction for " . a:from . ": ")
  exe ":iabbrev " . a:from . " " . to
  if a:correct | exe "normal viws\<C-R>\" \b\e" | endif
  let s:count = s:count + 1
  echo s:count . " corrections now"
endfunction
if !exists(":Correct")
  command -nargs=1  Correct  :call s:Add(<q-args>, 0)
endif
let &cpo = s:save_cpo
unlet s:save_cpo

33

TODO https://github.com/mhinz/vim-galore

TODO read and merge to the text

  • functions can be used to wrap some commands and give it a name. Use function! so you can overwrite it without error. Undo will undo whole function at once.

    function! MyFuction()
      normal! mmu`m
    endfunction
    nnoremap <leader>sp :call MyFuction()<cr>
    
  • source current file while editing with :source % or using sop `nnoremap sop :source %` so you do not need to exit and start vim again. You can reload any `.vim` file, for example `:source ~/config/vim/syntastic.vim`
  • conditionals

    function! MF(level)
      if a:level == 1
        normal! yy
      elseif a:level == 2
        " ....
      endif
    endfunction
    

Shell script

Calling external shell script is with bang :!pwd. When you visually select it operates on lines and use it as argument, for example select multuple lines and run :'<,'>!sort to sort them. If nothing is selected, last selected visual line (whole line) is used. You can use cat to pass argument. For example run :'<,'>!echo 1cat2, and it will replace whole line by inserting 1…line…2. Another way to pass is using system("echo ", @") unnamed register.

To work on part of a line, you can use visual match replacement :'<,'>s/\%V.*\%V/\=system('echo -n "the result"'). To use visual selected text as inputs, you can do it manually by pasting with <C-R> + " (“ is a standard register for yanking). Or you can use helper function that will yank to register and get register https://stackoverflow.com/questions/12805922/vim-vmap-send-selected-text-as-parameter-to-function

func! GetSelectedText()
  normal gv"xy
  let result = getreg("x")
  normal gv
  return result
endfunc

vnoremap <F6> :call MyFunc(GetSelectedText())<cr>

https://stackoverflow.com/questions/9637921/vim-filter-only-visual-selection-not-the-entire-line

Translate

Run scripts on visual selection and change with output. I use translate.rb and sudo ln -s /home/orlovic/config/ruby/translate.rb /usr/local/bin/ and chmod +x ~/config/ruby/translate.rb https://github.com/duleorlovic/config/blob/master/ruby/translate.rb In vim there is a ProgramFilter function

There is an issue with ending space (at the end of a line) when pasting. Same problem is when selecting word and super + p