Toast Driven

← Back to November 26, 2008

Knee Jerk Reactions To Lua

So I've been playing with Lua for what amounts to 2 cumulative hours now. More specifically, I've been working my way through Programming In Lua and thought I'd post some of my more immediate reactions to it.

What I Like

  • Compiled from source, a piece of cake and tiny too.
  • Compact syntax
  • Yay, no curlies everywhere!
  • Man, this is pretty fast.
  • Knowing Python and Ruby, this is pretty easy to get into. It seems to strike a balance between the two syntaxes.
  • Holy crap, this is really fast!
  • Yay, first class functions!
  • Tables everywhere. Interesting...
  • do ... end looks like an anonymous block to me. Where can I all use that syntax?
  • Yay! elseif, not elif or elsif! Thank you for a touch of sanity.

What I Don't Like

  • I understand that packages can be created with tables and simulate OO, but I really kinda want a slight more traditional OO implementation. Maybe it will grow on me.
  • The PIL could really use a better quick start, or a companion book targeted toward developers already familiar with similar languages.
  • Not sure I like the assumed global variable names unless specified local. I'd rather it were the other way (everything is local unless you say global).
  • I kinda want to sink my teeth into something that actually does something, as opposed to itty-bitty toy programs that demonstrate a single feature. This is great for someone new to this but I feel like I'm ready for more.
  • The comment syntax, especially the block comment, makes me want to gag.
  • Lua's builtin math.random sucks. Absolutely terrible.

Overall, my experience is favorable enough that I'll try to write a couple more programs in Lua to get a better feel for it. I love how fast it is, even on trivial stuff. Maybe I'm just imagining but it feels palpable to me.

Anyway, I'm posting my first real Lua snippet. Nothing impressive ("Guess My Number" is my "Hello World") but tests a bunch of aspects of the language in practice.

#!/usr/bin/env lua

minimum_number = 1
maximum_number = 100
total_guesses = 10

-- Throwaway to start producing random numbers.
math.random(minimum_number, maximum_number)

function check_guess(correct_number, guessed_number)
    if guessed_number > correct_number then
        return "Too high!"
    elseif guessed_number < correct_number then
        return "Too low!"
        return "Correct!"

function main()
    local correct_number = math.random(minimum_number, maximum_number)
    local guess_count = 1
    local guessed_correctly = false
    print("Guess My Number (" .. minimum_number .. " to " .. maximum_number .. ").")
    while guess_count <= total_guesses do
        print("Enter a guess:")
        local guess_number ="*number")
        local response = check_guess(correct_number, guess_number)
        if response == "Correct!" then
            guessed_correctly = true
        guess_count = guess_count + 1
    if guessed_correctly == true then
        print("You guessed right! The correct number was " .. correct_number .. ".")
        print("You took " .. guess_count .. " guesses.")
        print("Sorry! The correct number was " .. correct_number .. ".")

-- Run!
Toast Driven