gem/ex6.lua


1
2
3
4
5
6
7
8
9
10
11
12
13
14

function source.chain(src, f)
  return function()
    if not src then
      return nil
    end
    local chunk, err = src()
    if not chunk then
      src = nil
      return f(nil)
    else
      return f(chunk)
    end
  end
end