chain-op-test.vim

function! HasKey(dict, key)
  return has_key(a:dict, a:key)
endfunction
function! s:has_key(dict, key)
  return has_key(a:dict, a:key)
endfunction

function! Fold(list, init, f)
  let l:V = a:init
  for l:Elem in a:list
    let l:V = a:f(l:V, l:Elem)
  endfor
  return l:V
endfunction
function! s:fold(list, init, f)
  return Fold(a:list, a:init, a:f)
endfunction

function! s:main()
  echo {'foo': 42}->HasKey('foo')
  echo range(1,10)->Fold(0, {acc,n -> acc + n})

  echo {'foo': 42}->s:has_key('foo')
  echo range(1,10)->s:fold(0, {acc,n -> acc + n})

  let l:Percent = {x -> x * 100}
  echo (10.0 / 100.0)->l:Percent()

  echo 2->{n -> n * 2}
  echo 'hello'->{s -> execute('echon s')}

  echo HasKey({'foo': 42}, 'foo')
  echo Fold(range(1,10), 0, {acc,n -> acc + n})
endfunction

call s:main()