On 09/02/2025 20:03, Waldek Hebisch wrote: >> Well I often get thrown by the differences between SPAD categories and >> say Java interfaces so the code may well be sub optimal. > I have no deep knowledge of Java, but I do not think there are big > conceptual differences between Spad categories and Java interfaces. > Spad category lists signatures (functions) that should be available > in all domains declared to belong to given category. Implementation > part of category gives default implementation. IIUC the same thing > holds in Java: interface specifies functions and may give default > implementation.
There was some difference that always used to cause me problems because categories are more statically defined than interfaces but I have forgotten the details now. That's the problem when concepts are so similar but important details are different. For example, in Java you might have an interface called 'shape' and this interface has functions such as 'draw' so classes that implement shape such as 'square' and 'circle' all have there own implementations of 'draw'. Some other part of the code may have a List of 'shape' and if you call 'draw' on each of the elements it would call the appropriate version of draw depending on whether it is a 'square' or a 'circle'. I don't think you can do that with categories because they are more statically defined so you cant have 'List shape' and this makes a big difference to how you would go about constructing such a programming task. I mention this just as a reminder of the sort of problems new users may have when coming to SPAD from other languages. I think it would be good if there was something on fricas.github.io listing potential issues like this for new users (and me). Martin -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/fricas-devel/4405940b-077a-4fd6-82d5-0cde52680454%40martinb.com.
