Typical "Identifier not found" with class variable

BlitzMax Forums/BlitzMax Beginners Area/Typical "Identifier not found" with class variable

Adam Bossy

(Posted 2005) [#1]

Does Blitz support custom types as class variables? I'm getting an error on the "lstTiles = New TList" line in the "Create" function: "Identifier "lstTiles" not found."

Not sure what is wrong. Similar functions with primitive class variables seem to work... not this. I've searched the forum and people have had similar problems, nothing that I can apply here, tho'.

Type Tileset

	Field lstTiles:TList

	Function Create ()
		lstTiles = New TList
		lstTiles = CreateList ()
	End Function
	
	Method addTile (t:Tile)
		lstTiles.AddLast(t)
	End Method

End Type

Dreamora

(Posted 2005) [#2]

fields are specific to type instances not the type itself. Because of that, they can only be accessed by methods which are bound to type instance scope as well.

if you want to have a field accessed by functions, you need to make it global, which makes it unique for the whole type.

if you want to have a list per instance, use the following:

Type Tileset

	Field lstTiles:TList
        
        method new ()
                lstTiles = New TList
        end method

	Function Create:Tileset ()
                return new Tileset
	End Function
	
	Method addTile (t:Tile)
		lstTiles.AddLast(t)
	End Method

End Type

Adam Bossy

(Posted 2005) [#3]

I want exactly what your example posted; a list per instance. Thanks!

Two questions:

1. Is "new" the name for the default constructor? From the examples I've seen, I assumed "create" was.

2. Would a "global" variable inside of a custom type be used like a static variable? Is that what you mean by "make it unique for the whole type?"

Thanks,

Difference

(Posted 2005) [#4]

You can just go:

Type Tileset
	Field lstTiles:TList = New TList	

	Method addTile (t:Tile)
		lstTiles.AddLast(t)
	End Method
End Type

Theres no need for the extra code when doing one type per instance. The extra stuff is only needed for Globals, and Mark is planning on fixing that too.

FlameDuck

(Posted 2005) [#5]

if you want to have a list per instance, use the following:

Or alternatively:

Type Tileset
	Field lstTiles:TList
   
	Function Create:Tileset ()
		Local temp:Tileset = New TIleset
		temp.lstTiles = New TList
		Return temp
	End Function
End Type

Difference

(Posted 2005) [#6]

Like I said, you don't have to write anything in the New() function or make a create() function just go:

Type Tileset
	Field lstTiles:TList = New TList
End Type

If you need the list object handle, it's right there:

local myTileset = new TileSet

myTileset.lstTiles.AddLast(whatever)