Re: Setting the __mode metatable field

[Mark Hamburg <mhamburg@...>]

I've been considering adding standard global utilities for these to my
project, but they really seem like something worth establishing general
standards for.

Straw man proposal:

    local modemetas = {}

    function table.make( mode )

        local result = {}

        if mode then

            local meta = modemetas[ mode ]

            if not meta then
                meta = { __mode = mode }
                modemetas[ mode ] = meta
            end

            setmetatable( result, meta )

        end

        return result

    end

Usage:

    weakTable = table.make( "kv" )

Mark

on 1/4/05 5:43 AM, Mike Pall at mikelu-0501@mike.de wrote:

> Hi,
> 
> David Jones wrote:
>> t={}
>> setmetatable(t,{})
>> getmetatable(t).__mode='v'
> 
> I think the shortest (and proper) way to do this is:
> 
> local t = setmetatable({}, {__mode='v'})
> 
> If you have many of these tables it is worth sharing the metatable:
> 
> local weakvmeta = {__mode='v'}
> local function weakvtable(t) return setmetatable(t or {}, weakvmeta) end
> 
> local t1 = weakvtable()
> local t2 = weakvtable{foo=a, bar=b}   -- example table initializers
> ...
> 
> Bye,
>    Mike