Re: Wrapping a Lua table around a C array

[Jim Pryor <lists+lua@...>]

On Sat, Dec 12, 2009 at 07:08:27PM +0200, Dimitris Papavasiliou wrote:
>    So the question is: apart from the obvious solutions of implementing my
>    own lua_objlen, hacking the internals of Lua etc. can you think of a slick
>    way to create a table or userdata object that will contain a reference to
>    a string with binary data and provide set, get and length access to it so
>    that it can pose as a normal Lua table?

Here's a sketch. You may want to do some of this in C.

local function byte_array_get(self, k)
    ...
end

local function byte_array_set(self, k, val)
    ...
end

local function byte_array_len(self)
    ...
end

local byte_array_prototype=newproxy(true)
local mt = getmetatable(byte_array_prototype)
mt.__index = byte_array_get
mt.__newindex = byte_array_set
mt.__len = byte_array_len

function byte_array()
    return newproxy(byte_array_prototype)
end

local b = byte_array()
b[1]=2
print(b[1]) -- 2
print(#b) -- 1

-- 
Jim Pryor
profjim@jimpryor.net