On Thu, Dec 4, 2008 at 5:28 PM, Hans Hagen <[EMAIL PROTECTED]> wrote:
> Zhichu Chen wrote:
>> Hi,
>>
>> I'm learning to use luatex these days, one day actually. It's very
>> interesting. Although reference manuals are available, I still don't
>> know how to implement my designation.
>>
>> The thing is, I know there's a "self" variable for object-oriented
>> programming, like
>> ==================================================================
>> \startluacode
>> testdata = { a = 0,
>> b = 0,
>> c = 0,
>> plus = function (self)
>> self.c = self.a + self.b
>> end
>> }
>> mytest = testdata
>> mytest.a=10
>> mytest.b=100
>> mytest:plus()
>> tex.print(mytest.c)
>> \stopluacode
>> ==================================================================
>> OK, but what if I wanna do something more, like substract? I would
>> like to use another object, like
>> ==================================================================
>> \startluacode
>> testdata = { a = 0,
>> b = 0,
>> c = 0,
>> calc = Calc
>> }
>> Calc = { plus = function (self)
>> self.c = self.a + self.b
>> end,
>> substract = function (self)
>> self.c = self.a - self.b
>> end
>> }
>> mytest = testdata
>> mytest.a=10
>> mytest.b=100
>> mytest.calc:plus()
>> tex.print(mytest.c)
>> \stopluacode
>> ==================================================================
>> Of course this won't work, for the "self" in Calc refers to mytest.calc
>> rather than mytest. How to implement things like that?
>
> Calc = { add = function (self)
> self.c = self.a + self.b
> end,
> substract = function (self)
> self.c = self.a - self.b
> end
> }
>
> testdata = { a = 0,
> b = 0,
> c = 0,
> calc = function(self,f) return Calc[f](self) end
> }
>
> mytest = testdata
> mytest.a=10
> mytest.b=100
> Calc.add(testdata)
> print(mytest.c)
> testdata:calc("substract")
> print(mytest.c)
Thanks
>
> but it might make more sense to look into metatables (i assume that you
> own the programming in lua book which explains that)
I don't have one :(, I'll take a good at it later.
>
> Hans
>
>
> -----------------------------------------------------------------
> Hans Hagen | PRAGMA ADE
> Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
> tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
> | www.pragma-pod.nl
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--
Best Regards
Chen
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Zhi-chu Chen | Shanghai Synchrotron Radiation Facility
No. 2019 | Jialuo Rd. | Jiading | Shanghai | P.R. China
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