Re: lua function arguments

[lhf (Luiz Henrique de Figueiredo)]

>From jeske@home.chat.net Mon May 18 14:11:34 1998
lhf> The information about the number of parameters a function expects is preserved
lhf> for run time, because it's needed for adjustment.

>Did not know that. However, at the very least it does throw away the
>_names_ of the arguments, correct?

not if $debug is on.
arguments are like local variables and these names are preserved when
$debugging information is requested.

>> Like I said, I don't see any need for a "define function" fallback,
>> given the existence of the "setglobal" tag method.
>
>functions arn't always setup as globals. However, I was more specifically
>referring to a way to get enough information to recreate the function
>"prototype" including the argument names.

again, if $debug is on, then everything is available.
luac uses this info for creating a listing:

20  function T(x,y,z)
21          local a,b
22  end

function defined at "t":20 (9 bytes at 100054f8); used at main+40
locals: x y z (a (b))
     0  05        STACK         5
     1  03        ARGS          3
     2  7B14      SETLINE       20      ; "t":20
     4  7B15      SETLINE       21      ; "t":21
     6  0101      PUSHNIL       1
     8  00        ENDCODE      

but of course, luac does use inside information not available in lua.h.

>I don't think I'd use it any, but it seems like it would be useful in
>Steve's Lua graphical programming environment. (as I understand it) Right
>now he has to exert facist control over entry of functions into Lua in
>order to get this information. 

For this kind of application, I think that inside information is ok.
--lhf