Resource reuse

local sprite = require "sprite"

local character = {}

character.spriteSet = setmetatable({},
    {
        __index = function(t, size)
            local new = setmetatable({},
                {
                    __index = function(t, name)
                        local set = sprite.newSpriteSet(
                            sprite.newSpriteSheet("visuals/character_" .. name .. ".png", size, size),
                        1, 12)
                        sprite.add(character.Set, "Stationary", 1, 2, 500)
                        sprite.add(character.Set, "Selected", 3, 2, 500)
                        sprite.add(character.Set, "MoveUp", 5, 2, 500)
                        sprite.add(character.Set, "MoveDown", 7, 2, 500)
                        sprite.add(character.Set, "MoveLeft", 9, 2, 500)
                        sprite.add(character.Set, "MoveRight", 11, 2, 500)
                        t[name] = set
                        return set
                    end
                }
            )
            t[size] = new
            return new
        end
    }
)

function character.Move(self, size, xTile, yTile)
    self.x, self.y = xTile * size, yTile * size + 20
    self.xTile, self.yTile = xTile, yTile
end

function character.Create(spritesheet, size, health, move, attack, defense, xTile, yTile)
    local self = sprite.newSprite(character.spriteSet[size][spritesheet])
        self:setReferencePoint(display.TopLeftReferencePoint)
    function self:Move(...)
            return character.Move(self, size, ...)
        end
        self:Move(xTile, yTile)
        self:prepare("Stationary")
        self:play()
    return self
end

return character