I'm currently experimenting with OOP J. Creating objects and playing with
them.This is my code:
NB. My class def
coclass 'GameObject' px =: 0 py =: 0 pz =: 0 movex =: 3 : 'px =:
y' destroy =: codestroy
NB. lets make instances and play.
cocurrent 'base' go =: conew 'GameObject'
px__go
0 NB. returned 0, that is what I expected!
NB. move the px value...
movex__go 5
5 px__go
5 NB. again this is what I expect.
NB. create a list of GameObjects...
list =: 5 $ conew 'GameObject' NB. I don't understand the output here. list
┌─┬─┬─┬─┬─┐│2│2│2│2│2│└─┴─┴─┴─┴─┘
NB. anyway let's at least try to get a hold of one of the objects.
go =. 0{list px__go
0 NB. Wow, it worked!
movex__go 5
5 px__go
5 go2 =: 1{list px__go2
5
The very end, "px__go2" is troubling, because this object's px value is 5! The
only way this can be is if(a) 1{list and 0{list somehow point to the same
object,(b) px is a static variable.
I'm going to guess (a), but I would like to know what is going on here.
Secondly, in my object definition, I would like to have a "create" verb which
does the following:
create_go 1 4 5
this will set px to 1, py to 4 and pz to 5. I'm not sure how to do multiple
assignments in J with on function.
I think if it wasn't a class function I could do (for three arbitrary variables)
'px py pz' =: 3 NB. sets all vars to 3, not really what I want, but it's a
start.
or something like that, but for class functions I don't know how to do this.
Any help appreciated.
Regards.
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