Question

I created a lot of functions in menu.vim.

I noted that in many functions the same code is used that’s why I decided to clean up my file with the use of
subfunctions.

p.e this is code what often returns in my functions:

let zoek = @/    
if a:type == "'<,'>"    
 let r = substitute(zoek, '\\%V', '', 'g')    
elseif a:type == "%"    
 let r = zoek    
endif    

let a = substitute(r, '\', '', 'g')      

if matchstr(d, '>') == '>' || matchstr(d, '<') == '<'     
 let e = substitute(d, '\zs>\(\d\+\)%<\ze', '\1-', 'g')     
endif

How can I create a subfunction from it? How can I invoke it?
Does Vim have subfunctions?

Answer 1

You can have «local» functions by defining them in the dictionary: in the following code

function MyFunc()
    let d={}
    function d.function()
        echo "Foo"
    endfunction
    call d.function()
endfunction

function d.function is accessible only inside s:MyFunc and is destroyed after s:MyFunc exits. I put «local» in quotes because d.function is really global function named 42 (or another number, it does not matter). It cannot be called without a reference to it and the only way to create a reference is to use function dict.key() (references may be copied after creation, but you can’t create a reference using call to function(), though it is possible for MyFunc: function("MyFunc")). Note that number (in this case 42) is incremented each time you create a function and I know neither what is the maximum number nor what will happen when it will be reached. I personally use dictionary functions because they have two other advantages:

1. Dictionary function defined inside a script-local dictionary cannot be reached without a debugger or explicit passing the function reference (possibly as a part of its container) somewhere.
2. If more then one function is defined inside a dictionary in order to purge them all you need is to unlet this dictionary. Useful for reloading plugins.