On Thu, Dec 4, 2008 at 5:28 PM, Hans Hagen 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

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-- Best Regards Chen ---------------------------------------------------------------- Zhi-chu Chen | Shanghai Synchrotron Radiation Facility No. 2019 | Jialuo Rd. | Jiading | Shanghai | P.R. China tel: 086 21 5955 3405 | zhichu.chen.googlepages.com | www.sinap.ac.cn ----------------------------------------------------------------

On Fri, Dec 5, 2008 at 8:05 AM, Arthur Reutenauer wrote:

...

...

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.

You really should look into the book, it has a whole chapter about object-oriented programming in Lua, and explains useful conventions.

Oh it's a long document. I almost took a day to finish it. I've got the main idea now. Thanks. I'm sorry, I got another question now. How to link two variables? Like if I change one, the other would be changed as well. This may be a piece of cake for you and please forgive my laziness.

Arthur ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________

-- Best Regards Chen ---------------------------------------------------------------- Zhi-chu Chen | Shanghai Synchrotron Radiation Facility No. 2019 | Jialuo Rd. | Jiading | Shanghai | P.R. China tel: 086 21 5955 3405 | zhichu.chen.googlepages.com | www.sinap.ac.cn ----------------------------------------------------------------