Type conversion

#1

I’m using: SWI-Prolog version 8.0.2

I want the code to: convert the type of position from Node?position to position as a a pair of integers (X,Y)

But what I’m getting is: @2349857/position

My code looks like this:
show_position(Node) :->
“show position of a node”::
point(X,Y)=Node?position, %this type conversion does not work

#2

This does nothing more or less that Prolog unification. Prolog knows nothing about xpce and just sees two different terms and thus fails. Ty this:

    get(Node, position, point(X,Y))

P.s. Please enclose code blocks in ``` ... ```, so we can read it :slight_smile: