Editing Module:Sandbox/Carn/TextSnippets

--[[ easy text joining
TODO: 
	remake from step-by-step conversion to text in conversion to text only at the end of operations (string creation isn't cheap for lua)
	object types, conditions and order
	pattern string formatting (easier for users)
--]]

local snippet = {["__index"] = {["text"] = "", ["a"] = 1.5, ["z"] = 1.5}}
--[["a" + "z" = is there space or not
	 	0	1	2	3
	0	-	-	-	+
	1	-	-	+	+
	2	-	+	+	+
	3	+	+	+	+
]]--

function snippet:dress (var)
  if not self or type(self) ~= "table" then return end -- todo: обработка ошибки
  -- в случае если на входе уже объект нужного класса, возвращаем его же
  if type(var) == "table" and getmetatable(var) == self then
    return var
  end
  var = var or {}
  if type(var) ~= "table" and (type(var) == "string" or type(var) == "number") then
    local text = var
    var = {["text"]=text}
  elseif type(var) ~= "table" then return end -- обработчик ошибок без входящего параметра status и без создания замыканий сюда бы
  setmetatable(var,self)
  return var
end

function snippet.__eq (pre, aft)
    return pre.text == aft.value and pre.a == aft.a and pre.z == aft.z
end

function snippet.__add (pre,aft)
  pre=snippet:dress(pre)
  aft=snippet:dress(aft)
  if pre == empty or pre.text == "" then return aft end
  if aft == empty or aft.text == "" then return pre end
  local sill = pre.z + aft.a
  local output = {
      ["text"] = pre.text .. ((sill > 2) and " " or "") .. aft.text, 
      ["a"] = pre.a, 
      ["z"] = aft.z
    }
  return snippet:dress(output)
end

function snippet.__tostring (table)
  if type(table) == "table" then
    return table.text
  end
end

return snippet