Question

I’m trying to write a few functions that will let me move around easier in JavaScript source files. The first thing that I realize is that I need to be aware of what scope my cursor is in. Looking through Vim’s built in functions, I don’t see anything that that does this for me automatically.

My question is, do I need to attack this problem as if Vim has no concept of scope or block structure? That is, find the first ‘{‘ and it’s matching pair, define everything inbetween as scopeLevel0, find the next ‘{‘ and it’s matching pair and call it scopeLevel1… etc. This seems naive to me and am wondering if Vim can allow me to access and navigate between blocks automatically.

Answer 1

You should explain the kind of navigation you want to achieve.

Vim has the concept of scope which is defined in the syntax file for your language. There are a number of functions displaying the scope of your cursor floating here and elsewhere. The one I have in my .vimrc is:

function! SynStack()
    if !exists("*synstack")
        return
    endif
    echo map(synstack(line('.'), col('.')), 'synIDattr(v:val, "name")')
endfunc
nnoremap <C-p> :call SynStack()<CR>

Navigating inside a document, specifically code, is already a great strength of Vim with text-object motions like ( and ) or [(, [{, ]) and ]} or [m and ]m… See :help navigation. Coupled with other motions like *, #, / and ? or tags you already have a lot of power in your fingers.

Do you want more granularity?

For more specific needs you might want to define your own text-objects. There is a script called textobj-user designed to assist in that task. Many special text-objects have been created with or without this tool and made available on vim.org.