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- Subject: Re: Operator override and RE: Metatables for primitives performance?
- From: Chris Marrin <chris@...>
- Date: Sat, 25 Mar 2006 20:44:01 -0800
Jerome Vuarand wrote:
I was porting an old C++/Java school project to Lua, and it contains a
vector3 class representing a position/vector in 3d space. Since I'm using
Lua 5.1 since the day it's out, I thought it would have been nice to use
the # operator to get the length of the vector. My vector is a table with
x, y and z fields, and I don't care about the length of the table itself.
My problem is that I then figured out that the # operator is not
for tables, since it already exists. I thought it was a bug of some
the Lua source seems to be explicit about that:
I have implemented a similar object. But I implemented it as a userdata
with space for 3 floats. Then I override the __index and __newindex
metamethods to access the components. The nice thing about this is that
I can use a.y and a styles of component access and get to the same
components. I've also overridden arithmetic operations so I can add and
subtract vectors. This method also allows the use of the '#' operator
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