Re: How to implement this with LuaMacro?
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- Subject: Re: How to implement this with LuaMacro?
- From: steve donovan <steve.j.donovan@...>
- Date: 2010年1月25日 10:28:17 +0200
On Mon, Jan 25, 2010 at 10:04 AM, Pavel Shevaev <pacha.shevaev@gmail.com> wrote:
> Guys, now I'm trying to implement this and it looks like I need
> variable arguments list within a macro. Is it possible at all?
Very much so. Consider this macro:
macro.define ('sum',{handle_parms = macro.parameter_grabber(')',',','(')},
function(ls,...)
local args = {...}
local subst,put = macro.subst_putter()
local n = #args
for i = 1,n do
put(args[i])
if i < n then put '+' end
end
return subst
end
)
sum(10,20,30) will expand to 10+20+30
Here handle_parms is a function which explicitly expects an arguments
list: start with '(', use ',' as the delimiter, and end with ')'.
This gives you an array of arguments.
The substitution is here a function, which receives an arbitrary
number of arguments and explicitly creates an output token list.
It's more low-level, but one can create anything this way.
steve d.