Re: advice needed: OO style
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- Subject: Re: advice needed: OO style
- From: Tony Finch <dot@...>
- Date: 2011年4月28日 11:33:19 +0100
Emmanuel Oga <emmanueloga@gmail.com> wrote:
>
> IMO there is just too much overhead in using a proxy "just in case the
> user modifies the values".
Yes, I think something simpler is the right approach. For instance, here's
a "class" keyword-alike:
local class = (function()
local metaclass = {
__call =
function (class, ...)
local object = {}
setmetatable(object,class)
if class.init then object:init(...) end
return object
end
}
return function (class)
class = class or {}
setmetatable(class,metaclass)
class.__index = class
return class
end
)()
which allows you to just call the class name to construct an instance of
the class. For example,
local stack = class {
init = function (self)
self.n = 0
end
push = function (self, item)
self.n = self.n + 1
self[self.n] = item
end
pop = function (self)
if self.n < 1 then return nil end
local item = self[self.n]
self[self.n] = nil
self.n = self.n - 1
return item
end
}
local lifo = stack()
lifo:push(1)
lifo:push(2)
print(lifo:pop()) -- 2
Tony.
--
f.anthony.n.finch <dot@dotat.at> http://dotat.at/
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