Re: Lua match regex

[Rob Kendrick <lua-l@...>]

On Fri, 14 Nov 2008 19:36:23 +0800
"Pete Kay" <petedao@gmail.com> wrote:

> I am struggling with trying to match regex agains string.  Let's say
> I have a reg that looks like 4|44|22|445, basically a bunch of
> arbitrary numbers. Is that any Lua function that can tell me if a
> string match exactly one of those numbers?
> 
> Any suggestion will be great.

You have a number represented as a string, and you want to check if
it's in a list of numbers?  Try this:

valid = { [4] = true, [44] = true, [22] = true, [445] = true }

if valid[tonumber(mystring)] then
	-- number is in the valid list
end

One can of course write a little helper function to make building the
valid table easier.  Perhaps something like this;

function build_valid(...)
	local r = { }
	for _, v in ipairs { ... } do
		r[v] = true
	end
	return r
end

valid = build_valid(4, 44, 22, 445)

B.