Re: metatable - tostring,tonumber
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- Subject: Re: metatable - tostring,tonumber
- From: Tom Wrensch <twrensch@...>
- Date: 2002年3月19日 14:51:50 -0800 (PST)
On 2002年3月19日, nikdo79 wrote:
> Hi there,
>
> there's no entry in the Metatable for tostring/tonumber?
> I can't make a Object-Table to say it's class when being tostring'ed?
> so that e.g.:
You can add this fairly easily: (untested code)
_tostring = tostring
function tostring(obj)
local tsf = _tostring
local mt = metatable(obj)
if mt~=nil then
tsf = mt.tostring or tsf
end
return tsf(obj)
end
The version for tonumber is similar: (again, untested)
_tonumber = tonumber
function tonumber(obj)
local tnf = _tonumber
local mt = metatable(obj)
if mt ~= nil then
tnf = mt.tonumber or tnf
end
return tnf(obj)
end
Of course you can also implement these in 'C' if you need to.
- Tom
> myobject=Car.New{TopSpeed=160,Brand='Opel',Type='Corsa'}
>
> write(tostring(myobject))
>
> would result in:
> Car Object: Opel Corsa, 160 km/h max
>
> That's right, isn't it?
>
> Dom
>
>