abstract and reuse parts of a map command in vimrc - vim

I wrote a map command in vim that verges on the line of being too complicated for my taste. I'd like to:
Abstract away parts, or at least spit them into multiple lines and explain each.
Reuse most of it with only 2 things, changing only 2 things in it each time.
The command uses the vim-pandoc plugin to create an Html file out of the current pandoc file and copy it to clipboard.
nnoremap <leader><leader>11 :w<cr>:Pandoc html<cr>:sleep 100m<cr>:e <c-r>=expand('%:r')<cr>.html<cr>ggVG"+y:b#<cr>:bd #<cr>
My first attempt is thus:
nnoremap <expr> <leader><leader>22 MyFunc()
func! MyFunc()
let save = ':w<cr>'
let runPandoc = ':Pandoc html<cr>'
let sleep = ':sleep 100m<cr>'
let viewResult = ':e ' . expand('%:r') . '.html' . '<cr>'
let copyAll = 'ggVG"+y'
let backToPrevBuf = ':b#<cr>'
return save . runPandoc . sleep . viewResult . copyAll . backToPrevBuf
endfunc
However, this does not work because it has <cr> in the returned value instead of actually executing enter.
Using this I can pass an arg to MyFunc that will change the html portions to other filetypes.
My two questions are:
Is there a better, more direct way of abstracting away portions of long maps?
How can I solve the issue with the <cr> appearing in the result instead of actually meaning "Press the enter button".
Thanks for the help!
EDIT:
After getting suggestions I now have the current version, it seems a bit verbose.
While I can wrap the feedkeys to be a shorter name with the 'n' parameter, is there anything else I can do?
func! MyFunc()
call feedkeys(":w\<cr>",'n')
call feedkeys(":Pandoc html\<cr>",'n')
call feedkeys(":sleep 100m\<cr>",'n')
call feedkeys(':e ' . expand('%:r') . '.html' . "\<cr>",'n')
"TODO read about :%y+ understand why it copies the entire file
call feedkeys('ggVG"+y','n')
call feedkeys(":b#\<cr>",'n')
endfunc
EDIT:
Finally, I've understood what it means to get rid of the feedkeys, and now I reached the final destination:
nnoremap <silent> <leader><leader>22 :call MyFunc()<cr><cr>
func! MyFunc()
w
Pandoc html
sleep 100m
execute 'e' (expand('%:r') . '.html')
%y+
b#
endfunc
Thanks for the help!

Is there a better, more direct way of abstracting away portions of
long maps?
Since you have already called a function, and the function just concatenate the rhs mappings, why not just do the actual work in your function, and just map to execute the function like :nnoremap whatever :call yourFunc()<cr>
How can I solve the issue with the <cr> appearing in the result
instead of actually meaning "Press the enter button".
Use "\<cr>"

Related

Selecting a Javascript arrow function in Vim

It's been a challenge for me to select a whole arrow function via Vim without using relative line numbers. Any thoughts on how I can accomplish that?
Here is an example:
const myFunction = () => {
console.log('hello')
}
As always in Vim, there are lots of ways to do that but the right way is very context-dependent. For example, this problem:
const myFunction = () => {
console.log('hello')
}
is different from this problem:
console.log('---')
const myFunction = () => {
console.log('hello')
}
console.log('---')
or this one:
console.log('---')
const myFunction = () => {
console.log('hello')
}
console.log('---')
and the location of the cursor might be important as well.
Assuming your cursor is somewhere on the first or last line of the snippet, the following command should do what you want:
$V% " move cursor to end of line,
" enter visual-line mode,
" extend the selection to the matching pair
If the cursor is somewhere in the body, you could simply do Vip to visually select the current paragraph but that won't work if there are empty lines in the body or if you have other lines above and below. This is why context matters.
With the cursor somewhere in the body, you could do:
[mV% " jump to previous start of method,
" enter visual-line mode,
" extend the selection to the matching pair
But there are various ways in which it might not work, like when you are in a conditional or a switch.
FWIW, I have used (and updated) the following snippet for many years because the built-in ways have always felt limited to me:
" in after/ftplugin/javascript.vim
function! SelectFunction() abort
call search('\(function\|=>\)', "bWc")
call search("{", "Wc")
normal v%V
endfunction
xnoremap <buffer> af :<C-u>call SelectFunction()<CR>
onoremap <buffer> af :normal vaf<CR>
SelectFunction() searches for a typical JS function declaration at or before the cursor, then it searches for the opening brace at or after the cursor, then it visually selects until the matched pair.
The two mappings essentially define a custom pseudo-text object af that uses SelectFunction() under the hood. It is not a real text object in the sense that it doesn't support count or nesting, but it is nevertheless pretty damn useful:
vaf " visually select current function
daf " cut current function
yaf " yank current function
" etc.
vaf with the cursor somewhere in the body, then daf with the cursor on the closing brace:
Note that the function above probably has shortcomings. From previous interactions with the community, it seems that "select the current function" is not exactly a solved problem.

How to access script-variable in mapping?

I want to do following behaviour
let s:cmd = “echo ‘here is a long command’”
map aa :execute s:cmd<cr>
“ error, mapping cannot access script variable
map bb :execute <SID>cmd<cr>
“ error no variable named <SNR>…cmd
How to access the script variable in mapping?
You can provide a script local function and then access to the variable through that function.
let s:var = 'foo'
function! s:get(key) abort
return get(s:, a:key)
endfunction
nnoremap <silent> µ :<c-u>echo <sid>get('var')<cr>

Vim - Overwrite Plugin Scoped Function

I've a plugin in Vim and I don't like the behavior of a single function within it. But it isn't rly a case to open a pull request, but more an extension for it.
I know that overwriting a function ist possible by using a bang as postfix, as soon as the new definition comes after the previous one. But how can I do such thing, if this method is scoped to a script within a plugin?
I wasn't able to find a hint in _Vim_s help, nor by request a search engine. Anybody aware of this topic, at least if he can say that it is simply not possible.
A short example:
plugin/autoload/plugin.vim
...
function! s:foo() {
// behavior I would like to adjust
}
...
~/.vimrc
function! foo() {
// the "correct" behavior
}
Thanks for any help!
Actually it is possible. But as #romainl said, you'd better suggest your patch to the plugin maintainer or ask for a variation point.
Regarding the how.
First, you'll need to identify the script number of this autoload plugin. Let's say that :scriptname says it's 210. In order to do that automatically I have a lh#askvim#scriptid() function in my library plugin that does the job -- see the current definition at the end of the answer.
Then, to override the s:foo() function, you'll need to provide a new definition for
function! <SNR>210_Foo()
new definition
endfunction
(I've just tested it with vim 8.0-1157)
IOW, we can override a script-local function. However, I haven't found how to override a script-local variable directly without a reference to its s: dictionary. We could inject setter/getter functions to a specific variable or a function that returns the local s: dictionary.
lh#askvim#scriptid() current definition is the following
" Function: lh#askvim#execute(command) {{{3
" #since Version 4.0.0
if exists('*execute')
function! lh#askvim#execute(command) abort
return split(execute(a:command), "\n")
endfunction
else
function! lh#askvim#execute(command) abort
return s:beware_running_through_client_server ? [] : split(lh#askvim#exe(a:command), "\n")
endfunction
endif
" Function: lh#askvim#scriptnames() {{{3
function! lh#askvim#scriptnames() abort
let scripts = lh#askvim#execute('scriptnames')
let s:scripts = map(copy(scripts), 'split(v:val, "\\v:=\\s+")')
call lh#list#map_on(s:scripts, 1, 'fnamemodify(v:val, ":p")')
return s:scripts
endfunction
" Function: lh#askvim#scriptid(name) {{{3
function! lh#askvim#scriptid(name, ...) abort
let last_change = get(a:, 1, 0)
if last_change || !exists('s:scripts')
call lh#askvim#scriptnames()
endif
let matches = filter(copy(s:scripts), 'v:val[1] =~ a:name')
if len(matches) > 1
throw "Too many scripts match `".a:name."`: ".string(matches)
elseif empty(matches)
if last_change
throw "No script match `".a:name."`"
else
return lh#askvim#scriptid(a:name, 1)
endif
endif
return matches[0][0]
endfunction
That is not possible.
s:foo() is scoped to the script it belongs to (see :help s:) so it can't be accessed from anywhere else.
Fork it.
Make the desired changes to your fork.
Use your fork instead of the original.
Consider submitting a pull request.

Best way to create substitution macros in vim

I'd like to set up some custom auto-complete macros in vim. I'm thinking something like this (| represents the cursor position):
it<TAB>|
immediately becomes:
it("|", function () {
});
Is this possible using straight vim, or would I need a plugin? If so, is there a preferred plugin out there?
Using an abbreviation you could write something like this:
inorea it it("", function () {<cr>});<c-o>k<c-o>f"
The purpose of <c-o>k<c-o>f" at the end is to reposition your cursor inside the double quotes, but it may not work all the time.
Using a mapping, you could try this:
ino <expr> <tab> <sid>expand_last_word()
let s:your_expansions = {
\ 'it': '\<c-w>it(\"\", function () {\<cr>});\<c-o>k\<right>',
\ }
fu! s:expand_last_word() abort
let last_word = matchstr(getline('.'), '\v<\k+%'.col('.').'c')
return has_key(s:your_expansions, last_word)
\ ? eval('"'.s:your_expansions[last_word].'"')
\ : "\<tab>"
endfu
You would have to add your abbreviations and their expansions inside the dictionary s:your_expansions.
Using the :read command, you could define larger snippets of code, and split them across several files:
ino <expr> <tab> <sid>expand_last_word()
fu! s:expand_last_word() abort
let last_word = matchstr(getline('.'), '\v<\k+%'.col('.').'c')
if last_word ==# 'it'
return "\<c-w>\<c-o>:r /path/to/some_file\<cr>\<c-o>f\"\<right>"
endif
return "\<tab>"
endfu
Here /path/to/some_file should contain your snippet:
it("", function () {
});
They are very simple solutions, if you want something more robust, you probably need a snippets plugin. One of them is UltiSnips, which requires that your Vim version has been compiled with Python support (:echo has('python') or :echo has('python3') returns 1).
With UltiSnips, you would write your snippet like this:
snippet it "your description" b
it("$0", function () {
});
endsnippet
Here the definition is included between the keywords snippet and endsnippet. On the 1st line, you can describe the purpose of your snippet, inside the string in double quotes. It will be displayed by UltiSnips inside a list, if you've defined several snippets with the same tab trigger, and there's an ambiguity.
The ending b is an option to prevent the tab trigger it from being expanded anywhere else than the beginning of a line.
$0 is a tabstop, it stands for the position in which you want the cursor to be, once the snippet has been fully expanded.
The readme page on github gives a quick start, and some links to videos.
If you want to have a look at the snippets written by other people, you can install vim-snippets.
There are other snippet managers but I don't know them well enough to describe the syntax of their snippets. If you want a comparison, here's one, and here are links for some of them:
snipmate
mu-template
neosnippet
xptemplate
Here is a abbreviation that you can use for your particular example
:inoreabbrev it it("", function () {<cr>});<esc>kf"a
Typing it followed by ctrl + ] in insert mode will render
it("|", function () {
});
and keep you in insert mode.
But I would definitely go for ultisnips and there is a screencast for creating snippets on the same page. That's why I am omitting the snippet here as you can do it yourself.

Testing vim plugin private functions

I'm creating a vim plugin which has a couple of private functions and I'm trying to add unitary testing to it using vim-vspec.
What is the best way to invoke these private functions in the test file?
For now, I created a public function that invokes the private one, but I don't think that's a good approach because I'm loosing the point of having a private function. Here's some of the code
" File foo.vim (the plugin)
" Private function
fu! s:foo(arg)
...
endfu
" Public function
fu! InvokeFoo(arg)
call <SID>foo(a:arg)
endfu
" File foo-unittest.vim (the test file)
runtime! plugin/foo.vim
describe 'foo function'
it 'should have some behavior'
call InvokeFoo(...)
" Some expectations ...
end
end
I tried creating maps to the private functions but when I call exe map_combination it doesn't have any effect on the testing buffer.
I found a solution to my question here, and it gives one approach for variables and another for functions.
Variables
For the variables, I used vim's scopes. Calling :help internal-variables:
The scope name by itself can be used as a Dictionary. For example, to
delete all script-local variables:
:for k in keys(s:)
: unlet s:[k]
:endfor
So I access the :s scope by making a getter function to its dictionary:
fun! SScope()
return s:
endfu
And finally an variable s:variable will be accessed by:
let l:scope = SScope()
echom l:scope['variable']
Functions
The functions are a bit more complicated due the <SID> string. If you read the manual you'll get
When executing the map command, Vim will replace <SID> with the
special key code , followed
by a number that's unique for the script, and an underscore. Example:
:map <SID>Add could define a mapping "23_Add".
So, we need to access this unique number and one way to do it is to define a map that will serve as an accesor using maparg inside a function:
fu! SID()
return maparg('<SID>', 'n')
endfu
nnoremap <SID> <SID>
Then, to call the function we will make a little hack:
call call(substitute('s:my_function', '^s:', SID(), ''), [arg1, arg2, ...])

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