Better way to code an iterator function?

["Lawrence E. Bakst" <ml@...>]

1. Is there a better, shorter, cuter, or cooler way to code the example below?

2. I guess something I didn't try was to "deep copy" paths, use that as the state, and then remove one element at a time from the state.

3. This is probably FAQ, but I couldn't find much with a quick search on Google.

I miss C's pre/post inc/dec operators and I can't be the only one. Is there any way to make inc and dec functions that increment or decrement the number passed in and return the previous value? Seems difficult in a language that only has pass by value for numbers and strings.

Thanks in advance for all help and suggestions.

function it_paths(paths)
    local function next(state, var)
        if (state.idx > #paths) then return nil end;
        state.idx = state.idx + 1;
        return paths[state.idx - 1];
    end
    local state = {idx = 1};
    return next, state, "";
end;

function process_random_files(paths)
    for path in it_paths(paths) do
        print(path);
    end
end

process_random_files{"foo", "bar", "baz", "quuz"};

-- 
leb@iridescent.org