Extra Lua Table Functions

setfenv(1,{print=print,setmetatable=setmetatable,type=type,getmetatable=getmetatable})
local table={
    sub=function(tab,a,b)
        local g={}
        for i=a,b do
            if tab[a] and tab[b] then
                table.insert(g,i)
            end
        end
        return g
    end,
    concat=function(tab)
        local new=""
        for i=1,#tab do
            new=new..tab[i]
        end
        return new
    end,
    meta=function(tab,tab2)
        if tab and tab2 then
            setmetatable(tab,tab2)
        end
    end,
    insert=function(tab,val)
        tab[#tab+1]=val
    end,
    remove=function(tab,val)
        if type(val)~="number" then
            for _,v in next,tab do
                if v==val then
                    tab[_]=nil
                end
            end
        else
            tab[val]=nil
        end
    end,
    find=function(tab,val)
        if tab then
            for _,v in next,tab do
                if v==val then
                    return true
                else
                    return false
                end
            end
        end
    end,
    removeStrings=function(tab)
        for i=1,#tab do
            if type(tab[i])=="string" then
                tab[i]=nil
            end
        end
    end,
    removeNums=function(tab)
        for i=1,#tab do
            if type(tab[i])=="number" then
                tab[i]=nil
            end
        end
    end,
    wipe=function(tab)
        for i=1,#tab do
            tab[i]=nil
        end
    end
}
table.link=function(tab1,tab2)
    local g={}
    for i=1,#tab1 do
        table.insert(g,tab1[i])
    end
    for i=1,#tab2 do
        table.insert(g,tab2[i])
    end
    return g
end
table.copy=function(tab)
    local g={}
    for i=1,#tab do
        table.insert(g,tab[i])
    end
    return g
end
table.cut=function(tab)
    local g={}
    for i=1,#tab do
        table.insert(g,tab[i])
        table.remove(tab,i)
    end
    return g
end
table.display=function(tab)
    for i=1,#tab do
        print(tab[i])
    end
end