Viml functions
Basics
All vim Functions must start with a captial letter (an underscore is also valid)
function ResizeTabs(size, num, ...) " (...) indicates accepts *args let size = a:size " args must be saved to variable in order to be used let num = a:num let num_extra = a:0 " number of ... args let extraA = a:1 " (...) *args accessed by number let extraB = a:2 return "success" endfuncviml functions are cannot be called directly from the vim's command-mode, you must call them using the keyword
call
:call ResizeTabs("four", 4, "abc", "efg")You may also define a
command
for your function, allowing it to be used withoutcall
command ResizeTabs call ResizeTabs() " make function into vim-command :ResizeTabsSee Also viml commands .
Public/Private
vim's version of private-functions are script-local scoped functions. They have a prefix of
s:
.function Public() " ... endfunc function s:Private() " ... endfunc
Parameters
function! PrintArgs(text) echo a:text " arguments are scoped with 'a:...' endfunc call PrintArgs("mytext")You may define a variable number of args (like python's
*args
using...
.function! VarArgs(name, ...) echo a:name echo a:0 " number of spread-arguments echo a:1 " 1st spread-argument echo a:2 " 2nd spread-argument echo a:000 " list of all spread-arguments (max 20) " ... endfunc" pass all spread-args to another function function! Foo(...) echo a:0 endfunc function! Bar(...) call('Foo', a:000) " <-- expand spread arguments when calling function 'Foo' endfuncYou can call a function with an array of variable parameters
function! Foo(...) echo a:0 endfunction call Foo("a", "b", "c") ">> '3' call call("Foo", ["a", "b", "c"]) ">> '3' -- parameters from array
Visual Selection Range
Both the function and the command need special syntax to properly handle a visual selection range.
function! OrgToMarkdown() range echo "firstline num " . a:firstline echo "lastline num" . a:lastline endfunc command -range OrgToMarkdown <line1>,<line2>:call OrgToMarkdown()
Async
You can schedule background tasks within vim now.
They can be recurring, or scheduled after a period of seconds.function SayHi(timer) echom "hi" endfunc let timer = timer_start(2000, 'SayHi') " in 2s, run 'call SayHi(timer)'
Anonymous Functions
Viml supports lambda expressions.
" define lambda expression let my_fn = {params -> some_other_function(params)} " call lambda expression call my_fn("abc")