hypermap.vim

let s:maps = {}
function! HyperMap(from, to) abort
  let key = a:from[-1:]
  let prefix = a:from[:-2]

  let map = get(s:maps, key, {})
  let s:maps[key] = map

  let map[prefix] = {'mapto': a:to, 'eval': v:false}
  execute 'inoremap' '<expr>' key 'HyperResolve("' .. key .. '")'
endfunction

function! HyperResolve(key) abort
  let line = getline('.')
  let lastidx = col('.') - 2
  for [map_prev, map] in items(get(s:maps, a:key, {}))
    let prev = line[max([0, lastidx - (len(map_prev) - 1)]):col('.') - 2]
    if prev ==# map_prev
      return repeat("\<BS>", len(map_prev)) .. map.mapto
    endif
  endfor
  return a:key
endfunction

call HyperMap('sf', '(')
call HyperMap('lj', ')')
call HyperMap('wf', '{')
call HyperMap('oj', '}')