return util.cathash({ spec = spec }, props)

  local spec_table = type(spec) == "table" and spec or { spec = spec }
  return util.cathash(spec_table, props)
end
local function spec_fn(specfn)
  return { specfn = specfn }

  return { spec = spec, cond = fn }

  local spec_table = type(spec) == "table" and spec or { spec = spec }
  return util.cathash(spec_table, { cond = fn })

      return util.cathash(monster_creator_fn(arg.spec), arg)

      local spec = arg.spec or arg.specfn()
      return util.cathash(monster_creator_fn(spec), arg)

-- spec_fn can be used to wrap a function that returns a monster spec.
-- This is useful if you want to adjust monster weights in the spec
-- wrt to depth in the ziggurat. At level-generation time, the spec
-- returned by this function will also be used to init the monster
-- population (with dgn.set_random_mon_list). As an example:
mset(spec_fn(function ()
               local depth = zig().depth
               return "place:Vault:$ w:" .. (50 - depth) ..
                 " / ancient lich w:" .. math.max(0, depth - 12)
             end))

    local weightkey = weightfn

                 return table[weightfn]

                 return table[weightkey]