Re: hpairs?

[Drake Wilson <drake@...>]

Quoth Dirk Laurie <dpl@sun.ac.za>, on 2010-12-28 10:25:22 +0200:
> How does one iterate over all the keys of a table _except_
> the ones that ipairs would reach?

You can't really win that one nicely; that division isn't set up to be
easily used.

I think you could do something like (untested):

  function hpairs(t)
    local f, s, k0 = pairs(t)
    local n = 1
    while t[n+1] ~= nil do n = n+1 end

    local function f2(s, k)
      local v
      repeat k, v = f(s, k) until not(type(k) == 'number' and 1 <= k and k <= n)
      return k, v
    end

    return f2, s, k0
  end

but I wouldn't, unless really needed.  If you have a preceding
ipairs() sitting around you can just save the threshold that way.

   ---> Drake Wilson