Test

local parameters = { ["you "] = { ["please "] = { ["listen"] = {}, ["look "] = { ["up"] = {}, ["down"] = {} },
    ["eat"] = {} }, ["give "] = { ["up"] = {}, ["blood"] = {}, }, ["kindly"] = {} } }

local function tabCompletionFunction(shell, parNumber, curText, lastText)
    -- Check that the parameters entered so far are valid:
    local curParam = parameters
    for i = 2, #lastText do
        if curParam[lastText[i] .. " "] then
            curParam = curParam[lastText[i] .. " "]
        else
            return {}
        end
    end

    -- Check for suitable words for the current parameter:
    local results = {}
    for word, _ in pairs(curParam) do
        if word:sub(1, #curText) == curText then
            results[#results + 1] = word:sub(#curText + 1)
        end
    end
    return results
end

shell.setCompletionFunction("would", tabCompletionFunction)