Re: A proposal for the confusing pseudo table ≈ array concept

[Dirk Laurie <dirk.laurie@...>]

2018-01-19 19:46 GMT+02:00 Dirk Laurie <dirk.laurie@gmail.com>:

> I append the module 'list' and the module 'dclass' on which it depends.

-- dclass.lua   © Dirk Laurie 2018   MIT License like Lua's.
--[=[    Very simple support for classes. 
  MyClass = class("my class",_methods)   
--   Name of class must be given. If `_methods` is not nil, it must be 
--     a table, whose contents will be copied into 'MyClass'.
  MyClass.method = function(object,...) --[[function body]] end
   obj = MyClass(...)
--   If `MyClass.init` is `false`, `...` is ignored.
--   If `MyClass.init` is a function, `obj:init(...)` is called by MyClass. 
--   Otherwise, the first argument in `...` must be nil or a table, 
--     whose contents will be copied into `obj`. 
--]=]
local class -- semi-global forward declaration
    do  
local new  -- forward declaration
class = function(name,_methods)   -- class creator
  if type(name)~='string' then error(
    "Bad argument #1 to 'class' (expected string, got "..type(name)..")")
  end
  if type(_methods)~='table' and type(_methods)~='nil' then error(
    "Bad argument #2 to 'class' (expected table, got "..type(_methods)..")")
  end
  local methods = {init="No initializer for class '"..name..
    "' has been defined yet."}
  if _methods then
    for k,v in pairs(_methods) do methods[k]=v end
  end
  methods.__name = name
  methods.__index = methods
  local meta = {__call=new,__name="constructor-metatable for class '"..name.."'"}
  local Class = setmetatable(methods,meta)
  return Class
end
new = function(Class,...)  -- generic constructor
  object = setmetatable({},Class)
  if type(Class.init)=='function' then 
    object:init(...) 
  elseif Class.init~=false then
    if type(...)=='table' then
      for k,v in pairs((...)) do object[k]=v end
    elseif type(...) ~= 'nil' then error("Bad initializer to class '"..
      Class.__name.."' (expected table, got "..type(...)..")")
    end
  end
  return object
end
    end 
 return class   -- comment out this line if dclass.lua is copied into code
-- end of file dclass.lua

-- list.lua   © Dirk Laurie 2018   MIT License like Lua's.

local class = require "dclass"
local list = class("list",table)

local none = '⎕'

function list:__len() return self._len end

function list:init(...)
  local t = table.pack(...)
  self._len = t.n
  for k=1,t.n do
    local v = t[k]
    if v==nil then v = none end
    self[k] = v
  end
end

return list