Re: Dereferencing a pointer (accessing a structure member)

[Hated Moron]

On 13/08/2023 22:47, Alex Farlie via groups.io wrote (cross-posted from the Discussion Group):

How would something like a line:

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Graph^.GraphNode^.NodeWeight 

(which is Pascal/Modula2 style code) be written in BBC Basic for SDL?

I'm not familiar with the Pascal/Modula-2 syntax but I presume the code is equivalent to this in C:

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Graph->GraphNode->NodeWeight 

BBC BASIC doesn't have an exact equivalent to the C -> operator so you have to do it in multiple steps, something like this (where pGraph is a pointer to a Graph{} structure and pGraphNode a pointer to a GraphNode{} structure):

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PTR(Graph{}) = pGraph
PTR(GraphNode{}) = Graph.pGraphNode
PRINT GraphNode.NodeWeight

Since this is a BBC BASIC language question, it makes no difference whether it is BBC BASIC for Windows or BBC BASIC for SDL 2.0, they implement the same language syntax.

[Hated Moron]

On 13/08/2023 22:47, Alex Farlie via groups.io wrote (cross-posted from the Discussion Group):
How would something like [this] be written in BBC Basic for SDL?

BBC BASIC doesn't have an exact equivalent to the C -> operator so you have to do it in multiple steps...

Did this answer your question?

[alex_farlie]

On 13/08/2023 22:47, Alex Farlie via groups.io wrote (cross-posted from the Discussion Group):
How would something like [this] be written in BBC Basic for SDL?

BBC BASIC doesn't have an exact equivalent to the C -> operator so you have to do it in multiple steps...

Did this answer your question?

(With apologies for a duplicate posting).
Yes . And you were correct about the C style synatx. I used the Modula2/Pascal version because it was what I was familar with .

I'd been keeping a low profile, and did not seem to have "notifications" enabled.