Tables, All(), and Count()

Mon, 31 Dec 2018 20:22:02 UTC

Hello!

I have just started to dive into Pico 8 and Lua. I've been working on building a simple animator for my game and have run into some strange issues with regard to tables.

I declare a table and later add to it like this:

a = {}
a.p = {x=1, y=2, z=3}

The function count(a) then returns 0. Additionally, all(a) and foreach(a, function) will not iterate overt the table. Strangely, I am still able to access the information. For example,

print(a.p.x)

will correctly print the number 1. If I declare the table explicitly

a = {p={x=1,y=2,z=3}}

I have no issues. I also don't have issues if I use add() to insert new table values. However, I need to utilize the associative array functionality of the table and to add and remove values at runtime, so neither of these solutions is sufficient.

The best fix I have found is to use pairs() instead of all(). For some reason, pairs() works properly regardless of how I add values to the table. This solves my problem, but the fact that I have no idea why leads me to believe that I have some serious misunderstanding of how Lua tables and/or the Pico 8 tables api works. I'm curious as to whether others have encountered this issue and would appreciate some feedback as to where my misunderstanding may lie.

jhol [Lexaloffle Blog Feed]

Tables, All(), and Count()