Need Help with Turing Game

[Kyle Biro]

What is it you are trying to achieve?
I am trying to make an inventory system for a text based RPG


What is the problem you are having?
I cannot figure out an easy, efficient way to do it

Turing:

var woodSword : boolean := false var stoneSword : boolean := false var bronzeSword : boolean := false var ironSword : boolean := false put "There are four swords at your feet." put "A wooden, a stone, a bronze, and an iron sword." class Inventory     import ironSword, woodSword, stoneSword, bronzeSword     export displayNames, displayDesc     var itemNames : array 1 .. 10 of string     itemNames (1) := "wooden sword"     itemNames (2) := "stone sword"     itemNames (3) := "bronze sword"     itemNames (4) := "iron sword"     var itemDesc : array 1 .. 10 of string     itemDesc (1) := "a weak sword made of wood."     itemDesc (2) := "a weak sword made of stone."     itemDesc (3) := "a strong sword made of bronze."     itemDesc (4) := "a very strong sword made of iron."     proc displayNames ()         if woodSword = true then             put itemNames (1)         end if         if stoneSword = true then             put itemNames (2)         end if         if bronzeSword = true then             put itemNames (3)         end if         if ironSword = true then             put itemNames (4)         end if     end displayNames     proc displayDesc ()         if woodSword = true then             put itemDesc (1)         end if         if stoneSword = true then             put itemDesc (2)         end if         if bronzeSword = true then             put itemDesc (3)         end if         if ironSword = true then             put itemDesc (4)         end if     end displayDesc end Inventory var commands : array 1 .. 6 of string commands (1) := "take" commands (2) := "go" commands (3) := "attack" commands (4) := "look around" commands (5) := "open" commands (6) := "examine" var items : array 1 .. 5 of string items (1) := "wooden sword" items (2) := "stone sword" items (3) := "bronze sword" items (4) := "iron sword" items (5) := "inventory" var movements : array 1 .. 4 of string movements (1) := "north" movements (2) := "south" movements (3) := "east" movements (4) := "west" var monsters : array 1 .. 3 of string monsters (1) := "giant rat" monsters (2) := "skeleton" monsters (3) := "goblin" var input, input2 : string var Awesome : ^Inventory new Awesome loop     get input     put "" ..     get input2 : *     if input = commands (1) and input2 = items (1) then         woodSword := true         put "You took the ", items (1)         end if     if input = commands (5) then         put "You have:"         Awesome -> displayNames     elsif input = commands (6) and input2 = items (1) then         Awesome -> displayDesc     end if end loop

Please specify what version of Turing you are using
4.1.1

[Tony]

What kind of problems are you having with your current design?

Also

Quote:

itemDesc (4) := "a very strong sword made of iron."

don't you think that the ironSword class should be holding that description about itself, and not have this very tight coupling? In how many places would you have to change your Inventory class to add a 5th type of a sword? Does it make sense to change the way Inventory works that much, when a sword is essentially a tuple of (name, description, damage)?

[Kyle Biro]

So what you are saying is have a class for every sword type?
Also, my problem is that I don't want to have 100 if statements to display the names and descriptions. There must be an easier way.

[Raknarg]

So instead, compile them into an array.

This is how I think most games do it: each weapon would have a kind of weapon ID, so a wood sword ID would inherently be one and iron sword would inherently be four. This way you can just call a number, and have a function or procedure do all this for you.

Description (1), damage (1), name (1) would all refer to item 1. Much simpler than creating a boolean for every item type. Otherwise, there's not really a point to classes.

Turing:

proc displayNames (id : int)         if woodSword = true then             put itemNames (id)     end displayNames     proc displayDesc (id : int)             put itemDesc (id)     end displayDesc

Also, take in to account what Tony said. You want to create objects that are flexible, not tie them to certain things. For instance, you are coupling all the item information and objects together when they should be seperate.

[Kyle Biro]

Turing:

put "There is a wooden sword in this room." var woodSword : boolean := false var input, input2 : string var itemsDesc : array 1 .. 10 of string itemsDesc (1) := "a weak sword made of wood." itemsDesc (2) := "your inventory, this is where your items are stored." var items : array 1 .. 10 of string items (1) := "wooden sword" items (2) := "inventory" var commands : array 1 .. 5 of string commands (1) := "take" commands (2) := "open" commands (3) := "examine" class Inventory     import items, itemsDesc, woodSword     export displayItems, displayDesc     proc displayItems (id : int)         if woodSword = true then             put items (id)         end if     end displayItems     proc displayDesc (id : int)         if woodSword = true then             put itemsDesc (id)         else             put "You do not have a ", items (id)         end if     end displayDesc end Inventory var equipment : ^Inventory new equipment loop     get input     put "" ..     get input2 : *     if input = commands (1) and input2 = items (1) then %take wooden sword         woodSword := true         put "You took the ", items (1)     elsif input = commands (3) and input2 = items (1) then %examine wooden sword         equipment -> displayDesc (1)     elsif input = commands (2) and input2 = items (2) then %open inventory         put "You have:"         equipment -> displayItems (1) %display the inventory     end if end loop

Something like this? I feel like something very obvious is missing and/or wrong.

[DemonWasp]

The first thing that's wrong is that you no longer need the woodSword boolean. Your code doesn't need to know whether the player has woodSword through a boolean: you can look at all the items the player has, and if any of them is a "Wooden Sword" then they have the wooden sword. Your Inventory->displayItems() and Inventory->displayDesc() procedures should have exactly one line in them (for the moment).

The big idea that you're missing is that you can use a class to describe items:

Turing:

class Item     var name, description : string     % other variables to describe that object here... end Item

This lets you add new objects whenever: just make another instance of Item and set its properties:

Turing:

var woodenSword : ^Item new woodenSword woodenSword->name := "Wooden Sword" woodenSword->description := "A weak sword made of wood. Who makes a sword out of wood, seriously?" var steelSword : ^Item new steelSword steelSword->name := "Sword" steelSword->description := "Now that's more like it!"

Once you have items, you can even put them into arrays:

Turing:

var inventorySlots : array 1..MAX_INVENTORY of ^Item inventorySlots(0) := woodenSword % puts the woodenSword in the player inventory (at slot 0, potentially replacing something) inventorySlots(1) := steelSword % now the player inventory has a woodenSword and a steelSword and nothing else (every other slot is nil)

From there, you can probably imagine an Inventory class, with a "slots" variable with type "array 1..max of ^Item". You could have methods like addItem(item:^Item) that puts a new item in the first open inventory space, dropItem(^Item) that drops an item if present, or even a function like findItem(name:string):^Item, which looks for an item matching that name in the player's inventory and returns a pointer to it.

[Raknarg]

This still seems like a kind of inefficient solution... You shouldn't have to hard code every single item

[DemonWasp]

Well, obviously the solution is to put all your data in a file and then just read it in. But, as a starting point, create a couple of objects in Turing code then figure out how to read them from a file.

[Kyle Biro]

Turing:

class Item     export name, description, damage     var name, description : string     var damage : int     %other variables end Item var woodSword : ^Item new woodSword woodSword -> name := "wooden sword" woodSword -> description := "A weak sword made of wood. Seriously, who makes a sword of wood?" woodSword -> damage := 5 var steelSword : ^Item new steelSword steelSword -> name := "steel sword" steelSword -> description := "Now this is a real sword!" steelSword -> damage := 10 put steelSword -> name put steelSword -> description

This gives me a warning saying: "'name' is read-only and cannot be assigned to" and it says this for "description" and "damage".
It still puts the name and description.

Just to add: classes and arrays are new to me.

[Dreadnought]

I suggest you read the documentation for export. Variable members of a class are exported as "read-only" by default.

[Kyle Biro]

Okay, I'll make sure I read that.

[Kyle Biro]

I'm still a little confused how to add the items on to the array, then display them if the user types something like "inventory".
From other languages I've programming in I know that they have "push" and "pop", but it seems that Turing doesn't have this function.

Some help would be appreciated.
Thanks!

[Tony]

Kyle Biro @ Wed Mar 06, 2013 1:24 am wrote:

From other languages I've programming in I know that they have "push" and "pop", but it seems that Turing doesn't have this function.

push and pop are conceptual operations on a stack, not an array. Though since a stack can be backed by an array, some libraries implement those methods as well. E.g. Ruby

Quote:

ruby-1.9.3-p0 :001 > stack = []
=> []
ruby-1.9.3-p0 :002 > stack.push(1)
=> [1]
ruby-1.9.3-p0 :003 > stack.push(2)
=> [1, 2]
ruby-1.9.3-p0 :004 > stack.pop
=> 2

but that doesn't give you random access to any element directly (how many times do you have to pop to get the 3rd element?)

array's index gives you that functionality

Quote:

Python 2.6.1 (r261:67515, Aug 2 2010, 20:10:18)
>>> array = ["one","two","three","four"]
>>> array[2]
'three'
>>> array[0]
'one'

Turing's arrays at the latter -- you can access any specific element directly. There's an additional constraint that you must declare the size of the array. If you run out of space, you'd need to create a new array and copy data over, much like one would do in C.

Someone will probably also mention flexible arrays

[Kyle Biro]

When I compile the items into an array called "inventorySlots" the program runs with no errors, which is what I expected. When I try to do "put inventorySlots(1)" it throws an error at me saying "illegal put item".

Is there something I'm doing wrong, or is there another way to display items stored in an array?

[Tony]

put can display strings, numbers, some other basic types. It doesn't know how to display an instance of type ^Item

you might have seen methods like to_string in other languages -- you'd need to implement and use such to get to a string representation of the object.