RyanPattison

local alias_table = {}

function alias_table:new(weights) 
  local total = 0
  for _,v in ipairs(weights) do
      assert(v >= 0, "all weights must be non-negative")
      total = total + v
  end

  assert(total > 0, "total weight must be positive")

RyanPattison

local ordered_table = {}
--[[
This implementation of ordered table does not hold performance above functionality.
It invokes a metamethod `__newindex` for every access, and
while this is not ideal performance wise, the resulting table behaves very closely to
a standard Lua table, with the quirk that the keys are ordered by when they are first seen
(unless deleted and then reinserted.)
--]]

-- private unique keys