operators.pluto

-- lparser.cpp's builtinoperators

local Pluto_operator_new <const> = function(mt, ...)
  if not mt then
    error("attempt to construct a nil value")
  end
  if mt.new then
    return mt.new(...)
  end
  local t = {}
  setmetatable(t, mt)
  if not rawget(mt, "__index") then
    mt.__index = mt
  end
  if mt.__construct then
    mt.__construct(t, ...)
  end
  return t
end

local Pluto_operator_extends <const> = function(c, p)
  if (p_type := type(p)) != "table" then
    error("expected a class or class-like table to extend, got " .. p_type)
  end
  for {
    -- luaT_eventname
    "__index", "__mindex", "__newindex",
    "__gc", "__mode", "__len", "__eq",
    "__add", "__sub", "__mul", "__mod", "__pow",
    "__div", "__idiv",
    "__band", "__bor", "__bxor", "__shl", "__shr",
    "__unm", "__bnot", "__lt", "__le",
    "__concat", "__call", "__close",
    -- misc
    "__tostring", "__pairs"
  } as mm do
    if p[mm] and not c[mm] then
      c[mm] = p[mm]
    end
  end

  setmetatable(c, { __index = p })
  c.__parent = p
end

local Pluto_operator_instanceof <const> = function(t, mt)
  t = getmetatable(t)
  while t do
    if t == mt then
      return true
    end
    t = t.__parent
  end
  return false
end

local Pluto_operator_spaceship <const> = function(a, b)
  return a ~= b ? a < b ? -1 : +1 : 0
end

local Pluto_operator_ipow <const> = function(x, p)
  local res = 1
  while p > 0 do
    if p & 1 ~= 0 then
      res *= x
    end
    p >>= 1
    x *= x
  end
  return res
end