basic menu function

--[[
call newmenu with a table as the first parameter, the table is a list of all options in the menu, if you like you can specify a table as one/more of the options, it will then show the first value in that table as the choice and will call the second value as a function if you select that option, it will call the function with the option as a parameter and the newmenu function will return whatever your choice returns. if the choice is not a table then it will simply return the string that is the choice. example:

newmenu({1,2,3,4},2,2)

would generate a menu where you can choose 1; 2; 3 or 4 and if you choose 2 it will return 2. the menu will start at CDS 2,2

newmenu({1,{2,function(param) return print('you selected '..param) end},3,4},2,2)

would generate an identical looking menu but this time if you select 2 it will call the function there with param=2 and the newmenu function will return whatever the function returns
]]

local function newmenu(tList,x,y)
    x=x or 1
    y=y or 1
    y=y-1
    local selected=1
    local function render()
        for num,item in ipairs(tList) do
            term.setCursorPos(x,y+num)
            write((num==selected and '[' or ' ')..(type(item)=='table' and item[1] or item)..(num==selected and ']' or ' '))
        end
    end
    while true do
        render()
        local evts={os.pullEvent('key')}
        if evts[1]=="key" and evts[2]==200 and selected>1 then
            selected=selected-1
        elseif evts[1]=="key" and evts[2]==208 and selected<#tList then
            selected=selected+1
        elseif evts[1]=="key" and evts[2]==28 or evts[2]==156 then
            return (type(tList[selected])=='table' and tList[selected][2](tList[selected][1]) or tList[selected])
        end
    end
end