How to detect a function in Vim?

Question

If the cursor is in somewhere within a very long function, is there a way to let Vim tell the user in which function he/she is editing?

By the way, I use taglist but seems that taglist does not auto update where you are even if you have moved the cursor to a different function.

Answer 1

The taglist plugin provides this feature. The function in which the cursor is currently positioned is highlighted automatically in the list of functions of taglist.

Make sure that Tlist_Auto_Highlight_Tag is not equal 0 to enable this feature.

'updatetime' defines the time of no activity which must elapse before taglist highlights the current function. Default is 4 seconds.

:help taglist.txt See section "Highlighting the current tag"

As a quick test: Type :TlistHighlightTag to force taglist to highlight the current function. If this works I suppose that you have disabled the automatic highlighting in any way (see Tlist_Auto_Highlight_Tag).

Answer 2

As an addition to Habi's answer, if you want to do it without using taglist, you can quite easily define a function that will work it out. It depends what language you're programming in, but for C-like languages, you can do this:

nmap ,f call ShowFuncName()
" Show the name of the current function (designed for C/C++, Perl, Java etc)
fun! ShowFuncName() 
    let lnum = line(".")
    let col = col(".") 
    echohl ModeMsg 
    echo getline(search("^[^ \t#/]\\{2}.*[^:]\s*$", 'bW')) 
    echohl None 
    call search("\\%" . lnum . "l" . "\\%" . col . "c") 
endfun 

Put that it in your vimrc and then press ,f to see the current function.

Taken from here.