On 12/02/2021 02:39, Andras Tantos wrote: > 1. Ports, which are the connection points on the various netlist > entities. These would be the inputs and outputs of an AND gate for example > > 2. NetTypes, which describe the type of data that can travel through a > net (and thus through a Port). One such type would be an 8-bit signed > integer, or a simple logic signal.
> 2. A (derived) Port instance has a member of a (derived) NetType instance Sounds like the right solution. > Now, when a Port gets assigned a NetType, it needs to gain all sorts of > new features. It for example should have a 'length' attribute that tells > how many bits are needed to represent its possible values. The list of > these new features (attributes, methods, properties) are known to the > NetType and should be injected into the Port when the NetType is > assigned to the Port. So aren't these operations of the type rather than the port. If you expose the type the users can message it directly. n = myport.type.length() Keep the responsibility with the object that owns them. Creating a facade over another object is sometimes useful but a dynamic facade sounds like trouble. Client code is going to have to know which methods exist and when. Can you ever change the type? What happens to the injected methods, do you need to remove them and replace them with others? -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos -- https://mail.python.org/mailman/listinfo/python-list
