spacevim/bundle/vim-cursorword/autoload/cursorword.vim

" =============================================================================
" Filename: autoload/cursorword.vim
" Author: itchyny
" License: MIT License
" Last Change: 2020/06/20 14:12:12.
" =============================================================================

let s:save_cpo = &cpo
set cpo&vim

function! cursorword#highlight() abort
  if !get(g:, 'cursorword_highlight', 1) | return | endif
  highlight CursorWord0 term=underline cterm=underline gui=underline
  redir => out
    silent! highlight CursorLine
  redir END
  let highlight = 'highlight CursorWord1 term=underline cterm=underline gui=underline'
  execute highlight matchstr(out, 'ctermbg=#\?\w\+') matchstr(out, 'guibg=#\?\w\+')
endfunction

let s:alphabets = '^[\x00-\x7f\xb5\xc0-\xd6\xd8-\xf6\xf8-\u01bf\u01c4-\u02af\u0370-\u0373\u0376\u0377\u0386-\u0481\u048a-\u052f]\+$'

function! cursorword#matchadd(...) abort
  let enable = get(b:, 'cursorword', get(g:, 'cursorword', 1)) && !has('vim_starting')
  if !enable && !get(w:, 'cursorword_match') | return | endif
  let i = (a:0 ? a:1 : mode() ==# 'i' || mode() ==# 'R') && col('.') > 1
  let line = getline('.')
  let linenr = line('.')
  let word = matchstr(line[:(col('.')-i-1)], '\k*$') . matchstr(line[(col('.')-i-1):], '^\k*')[1:]
  if get(w:, 'cursorword_state', []) ==# [ linenr, word, enable ] | return | endif
  let w:cursorword_state = [ linenr, word, enable ]
  if get(w:, 'cursorword_match')
    silent! call matchdelete(w:cursorword_id0)
    silent! call matchdelete(w:cursorword_id1)
  endif
  let w:cursorword_match = 0
  if !enable || word ==# '' || len(word) !=# strchars(word) && word !~# s:alphabets || len(word) > 1000 | return | endif
  let pattern = '\<' . escape(word, '~"\.^$[]*') . '\>'
  let w:cursorword_id0 = matchadd('CursorWord0', pattern, -100)
  let w:cursorword_id1 = matchadd('CursorWord' . &l:cursorline, '\%' . linenr . 'l' . pattern, -100)
  let w:cursorword_match = 1
endfunction

let s:delay = get(g:, 'cursorword_delay', 50)
if has('timers') && s:delay > 0
  let s:timer = 0
  function! cursorword#cursormoved() abort
    if get(w:, 'cursorword_match')
      silent! call matchdelete(w:cursorword_id0)
      silent! call matchdelete(w:cursorword_id1)
      let w:cursorword_match = 0
      let w:cursorword_state = []
    endif
    call timer_stop(s:timer)
    let s:timer = timer_start(s:delay, 'cursorword#timer_callback')
  endfunction
  function! cursorword#timer_callback(...) abort
    call cursorword#matchadd()
  endfunction
else
  function! cursorword#cursormoved() abort
    call cursorword#matchadd()
  endfunction
endif

let &cpo = s:save_cpo
unlet s:save_cpo