I want to create a {} completion myself, and I did:
inoremap <CR> if_open_curly_on_left()? <CR>}<ESC>O : <CR> function! s:if_open_curly_on_left() abort let col = col('.') - 1 return !col || getline('.')[col - 1] =~# '{' endfunction which is modified by other's code, since I don't really understand the meaning inside the function.
When I typed enter I got:
How to fix this?
The logic is wrong here:
getline('.')[col - 1] =~# '{' This is saying anywhere before my cursor do I have a { character.
Probably want something that says does the end have a { character
getline('.')[col - 1] =~# '{$' getline('.')[col - 1] == '{' Although in theory that could still be weird if you put your insert cursor between {} characters and hit <cr>. So I imagine this needs to be adjusted a bit to become more robust
Maybe you the logic and be something like:
col('.') == (col('$') - 1) && strpart(getline('.'), -1) == '{' This will check that your in the final column and it ends with {
Aside:
Why
col('.')-2to get the previous character?
TL;DR: column position is 1-indexed and strings/arrays are 0-indexed
col('.') give you the current cursor position with the first column being 1
getline('.') will return a string or an array of characters with the first index being 0
Assume the following line and you cursor on the r:
bar So if we do a getline('.') and split it e.g. split(getline('.'), '\zs') we get:
['b', 'a', 'r'] Since we are on the r character then col('.') gives us 3 which is outside the bounds of our array by one. We compensate for the column starting on position one by subtracting one, col('.') - 1, to give the current position. To give the "previous character" then subtract by 2
return line[col] != '}' && line[col-1] == '}'. Regarding the original one, why it's col-1 in getline('.')[col-1] when I already did let col = col('.')-1? After some search this work(, but might be simplified further):
" My try inoremap <silent><expr> <CR> \ <SID>if_open_curly_on_left()? "\<CR>}\<ESC>O": \ "\<CR>" function! s:if_open_curly_on_left() abort let col = col('.') - 1 return getline('.')[col - 1] == '{' endfunction