More Lua
Well, I'm getting a little further into Lua, and learning some more things unique about it. One of which is asymetric coroutines, but I'm getting ahead of myself here (that's not supposed to be until chapter 9). No, what I've been playing with is return values or rather return lists.

Besides the old a,b=1,2, you can also say a,b=getpair() where getpair() returns more than one value. This is kind of strange, because you would expect that Lua would try and leverage on its built in dictionary type, not the sub-set of lists. But its in there, though it works kind of strange. For instance, if you try to cascade return values (lists) together, it doesn't really work:

function a(x) return x,x*2,x*4 end
function b(x) return x,x*3,x*9 end
=a(10)
   10   20   30
=b(10)
   10   30   90
=a(10),b(10)
   10   10   30   90

So if you're making a list, the only thing that can return a list is the last item in the list. This of course has not yet been mentioned in the documentation (they don't want to show things coming apart at the seems yet), but I did run across somebody discussing this in my original foray looking into Lua.

You can hack things up by making one function take the other function:

function a(x,fn) return x,x*2,x*4,fn(x) end
=a(10,b)
   10   20   40   10   30   90

which will even let you use anonymous functions

=a(10,function(x) return x,x*x,x*x*x end)
   10   20   40   10   100   1000

Of course if you forget the function, its not very happy, so I attempted to make it more robust:

a=function(x,fn) return x,x*2,x*4,fn and fn(x) end
-- you can use asignment interchangably with named definitions
=a(10)
   10   20   40   nil
=a(10,b)
   10   20   40   10

Hmmm, not so good. Making a table didn't work any better because then you get a table reference back, not a set. You get into similar trouble in Perl right around now, but perl has the dereference operator and slice functions, and I don't know what the equivilent is Lua is yet. Oh well, enough fun for one night.  ¶ 9:00 PM