Lean Vim Script The Hard Way

http://learnvimscriptthehardway.stevelosh.com/

Mappings

maping keys :noremap <newkeys> <keynames>

  • since mappings easilly could be broken, ALWAYS use nore non recursive variant noremap, nnoremap … so it use default meanings of keynames
  • you can map control CTRL key, for example :map <c-d> dd
  • do not use comments " in mapping
  • nmap normal, vmap visual, imap insert, omap operator, cmap command, xmap (do not know) mode. Dor example in insert mode :imap <esc>ddi
  • 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

Abbreviations

Abbreviations are similar to mappings but for insert, replace and command mode

: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

: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.

Autocommands

Autocommands are used to run commands on specific events

: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
  • BufRead 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.

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. <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>. execute will substitute any special charactes before running string, special chars are :help expr-quote

  • \r return <CR>
  • \n new line <NL> For example change current title header in markdown text with cih:
:onoremap ih :<c-u>execute "normal! ?^==\\+$\r:nohlsearch\rkvg_"<cr>`

Status Line

:set statusline=%f\ -\ FileType:\ %y will change status line to show

  • %f path to the file
  • %F full path to the file
  • %y filetype of the file
  • %L total lines

Variables

  • print env variables on command line: :echo $MYVIMRC or :echo filetype?. :echom $PATH will save output into :messages so you can view later
  • to set variable use :let foo = "bar" and pring :echo foo
  • 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. For boolean options 1 is true and 0 is false. :let is more powerfull than :set since it can use math and other operations. 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 you can use = and <TAB> for example :set xxx= and press tab so vim autocomplete the value so you can edit it

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)

: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.

Multiline commands can be written as:

:echom "foo" | echom "bar"

" or

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

Conditional

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

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") " when there is no return. default return is 0
:echom MyFunction("Duke")

Variable types can be:

  • numbers 100, 0xff (hex representation), 010 (octal representation)
  • float 100.1, 1.001e+2 (e notation, decimal is required). For division to work in float you need to use float as one of params (type cast, coercion of second param is automatic) echo 3/2.0
  • string "asd", Concatenation is with dot . (+ is only for numbers). Special characters: \\, \", \n

    26

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