[Eventing Question] Givining a random item

mgriffin said:

Something along these lines maybe?

Code:

pool = [:POTION,:POKEBALL,:ANTIDOTE,:PARALYZEHEAL]
index = ??? # generate random number from 0 to pool.length-1
item = pool[index]
# give item to player

This assumes that all items should be equally likely.

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items=[
:SITRUSBERRY,:ORANBERRY,:LEAFSTONE,
:MIRACLESEED,:SUNSTONE,:CHESTOBERRY,]
random2=0
loop do
random2=rand(items.length)
break if hasConst?(PBItems,items[
random2])
end
Kernel.pbReceiveItem(getConst(
PBItems,items[random2]))

NewAgeSteel said:

Code:

loop do
  random2=rand(items.length)
  break if hasConst?(PBItems,items[random2])
end

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random2=rand(items.length)

throw "error" unless items.all? { |i| hasConst?(PBItems,i) }
random2=rand(items.length)

mgriffin said:

Awesome, it looks to me like it will work fine.

I have a small comment about this bit from the perspective of a software developer:



This generates a random element from the list until it finds one that actually exists in PBItems. You could argue that this is appropriate for a script intended for other people to install, but my view is that it's a great way to hide typo-related errors (and trap your script in an infinite loop if you somehow make 100% typos/delete all the items from the game).

Personally I'd prefer to write that particular part as simply:

Code:

random2=rand(items.length)

And get an error if an invalid item happens to be picked. Or possibly even something like this:

Code:

throw "error" unless items.all? { |i| hasConst?(PBItems,i) }
random2=rand(items.length)

Not exactly sure how throw works in Ruby, but the intention here is to double-check the whole list of items and ensure that they all exist so that you don't have the possibility of you never encountering an error for a non-existent item but a player does (because by chance the particular buggy numbers never came up).

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NewAgeSteel said:

yeah I took out the part with the loop and it still works fine. although its still in the pokemon follower script lol.
but I dont think that could happen as long as the names are written into the code properly right?

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Ego13 said:

The way you do it is perfectly fine. Just want to add my solution to this question, which only is one line shorter but also more readable in my opinion.

Code:

Kernel.pbReceiveItem(item.random)

item.random returns a random element of your item pool and the way you set this up actually allows to directly you it in pbReceiveItem

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Ego13 said:

@mggriffin : There is no need for a throw exception in Pokemon Essentials. If you ever get an error it will always tell you in what script section and in which line the error occured and what kind of error it is. I think this true for Ruby in general.

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mgriffin said:

It's not important, but as-written I did need to throw something because hasConst? only returns a bool not throws an error. Perhaps getConst throws? Or maybe it returns nil? Anyway, I digress :)

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Ego13 said:

I'm notsure what you mean by that

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throw "error" unless items.all? { |i| hasConst?(PBItems,i) }

items = [PBItems::POTION, PBItems::ANTIDOTE]

mgriffin said:

So the intention of this code:

Code:

throw "error" unless items.all? { |i| hasConst?(PBItems,i) }

Is to check that all the items in the list are valid items before we randomly choose one to give to the player. The idea is that this will catch 100% of typos, whereas without this check you'll only know that you made a typo if the random number generator chooses that item.

Of course maybe the really sensible thing to do is write the list more like this:

Code:

items = [PBItems::POTION, PBItems::ANTIDOTE]

Because by being explicit about the module here you'll get an error if the constant doesn't exist, and you don't have to litter your code with defensive checks.

The behavior is now slightly different, PBItems::POTION is equivalent to getConst(PBItems, :POTION), but that wouldn't be an issue in this example.

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Ego13 said:

Ah I see so it is a way to check the spelling. I feel like this should be more a debug thingy and then it would be easier to check them by hand or by simply testing it out by giving each item once.

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Ego13 said:

Also I feel like "[PBItems::POTION" gives room for more misspelling, besides I don't think this works with the item giving method (I might be wrong though)

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mgriffin said:

That's reasonable. In my day job I've broken code by having typos that weren't covered in testing so my preference is that the game doesn't even start if there's an error in it (so that I know immediately after making a change if something is broken), but if you have different experiences who am I to judge? And besides, fan games aren't quite as high-stakes as business software :D

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