How to translate this PAWN example to LUA?

Question

I have a new question for you all.

I am wondering if you're able to do enumerations within Lua (I am not sure if this is the correct name for it).

The best way I can explain this is if I show you an example using PAWN (if you know a C type language it will make sense).

#define MAX_SPIDERS 1000

new spawnedSpiders;

enum _spiderData {
    spiderX,
    spiderY,
    bool:spiderDead
}

new SpiderData[MAX_SPIDERS][_spiderData];

stock SpawnSpider(x, y)
{
    spawnedSpiders++;
    new thisId = spawnedSpiders;
    SpiderData[thisId][spiderX] = x;
    SpiderData[thisId][spiderY] = y;
    SpiderData[thisId][spiderDead] = false;
    return thisId;
}

So that's what it would look like in PAWN, however I don't know how to do this in Lua... This is what I got so far.

local spawnedSpiders = {x, y, dead}
local spawnCount = 0

function spider.spawn(tilex, tiley)
    spawnCount = spawnCount + 1
    local thisId = spawnCount
    spawnedSpiders[thisId].x = tilex
    spawnedSpiders[thisId].y = tiley
    spawnedSpiders[thisId].dead = false
    return thisId
end

But obviously it gives an error, do any of you know the proper way of doing this? Thanks!

This conversation doesn't solve the issue given in title "How to do enumerations in LUA?". Could it be modified to: "How to translate the PAW example to LUA?" — Akhneyzar, Oct 16 '15 at 14:11

score 4 · Answer 1 · answered Sep 24 '13 at 12:23

I don't know about PAWN, but I think this is what you mean:

local spawnedSpiders = {}

function spawn(tilex, tiley)
    local spiderData = {x = tilex, y = tiley, dead = false} 
    spawnedSpiders[#spawnedSpiders + 1] = spiderData
    return #spawnedSpiders
end

Give it a test:

spawn("first", "hello")
spawn("second", "world")

print(spawnedSpiders[1].x, spawnedSpiders[1].y)

Output: first hello

catwell · Accepted Answer · 2013-09-24T12:34:12.567

4

Something like this?

local spawnedSpiders = {}
local spawnCount = 0

function spawn_spider(tilex, tiley)
    spawnCount = spawnCount + 1
    spawnedSpiders[spawnCount] = {
      x = tilex,
      y = tiley,
      dead = false,
    }
    return spawnCount
end

EDIT: Yu Hao was faster than me :)

edited Sep 24 '13 at 12:34

answered Sep 24 '13 at 12:27

catwell

6,770
1
23
21

Aha that's okay! It's what I was looking for anyway :3 – Bicentric Sep 24 '13 at 14:54
1

`spawnCount` can be replace with `#spawnedSpiders` – hjpotter92 Sep 24 '13 at 20:13
1

@hjpotter92 For simplicity, yes, like in Yu Hao's answer. If there is a *lot* of spiders it will be slightly less efficient though because the length operator `#` is `O(log n)`. But the real reason I didn't do it is I wanted to stay close to @Bicentric's code (avoid introducing another concept). – catwell Sep 25 '13 at 08:59

How to translate this PAWN example to LUA?

2 Answers2