forward reference to structure

[peterverkaik]

Hi,

I am using 2 structures, and each structure has a field that holds a pointer
to the other structure.

Code: Select all

structure A_
  dim _next as ^B 'error
end structure
typedef A as A_

structure B_
  dim info as ^A
end structure
typedef B as B_

The compiler complains at the marked line that B is undefined.
Since _next contains a pointer the size of A is known, even with B undefined at that time.

How can I make this work?

regards peter

[peterverkaik]

Hi,

I found the keyword 'forward' so I tried

structure B_ forward
and
typedef B forward

but neither works.

I am actually converting a C program to Basic and
there are numerous circular references with pointers in structures
so I really need a way to do this or a workaround.

Anyone?

regards peter

[janko.kaljevic]

Hello,

At the moment there is no way to do this in mikroBasic.
We are aware of this and we will provide solution as soon as possible.

Forward declaration will help you to declare procedures without following implementation.

Currently you can do this but it will require some modifications to your code.

Thanks for reporting this.

Best regards.

[peterverkaik]

Hi,

I found a workaround by defining
dim _next as word 'dim _next as ^B

and using a helper variable
dim _next as ^B

in subroutines where I access B.

If you make 'forward' apply to types, we can use
typedef B forward

Also, type union would be useful besides structure.

regards peter

[janko.kaljevic]

Hello,

type union is on our wishlist and we will implement it in some of the next releases.

Best regards.