On May 5, 2018, at 8:38 AM, matthewju...@gmail.com wrote:
> In a generic container I would expect to see items typed as interface{} and
> the behavior defined on a slice of interface{} or struct with private slice
> of interface{} field.
>
> From the godoc it looks like type Node implements type Ki, and there’s no
> other type that implements Ki. I don’t understand why this is necessary, why
> not just define the methods on type Node?
>
> * But a diversity of functionality at each node (i.e., many different
> possible node types)
>
> My thought is this calls for a type Node interface, then there would be more
> types that implement Node. This line of thinking may lead to similar code to
> what you have already, I’m not sure.
Here’s some explanation relative to those points:
* Ki is basically a “Node” interface, but you can’t name a struct and an
interface the same thing, so we have Ki and Node as two sides of the same
thing..
* The Ki interface allows specific nodes to override any of the functions, and,
critically, ONLY an interface type knows what the actual underlying type of a
struct is, so we need that to be able to access the fields etc of the actual
struct at each node. In general, having an interface in Go opens up lots of
extra powers — could not have done many other things without it..
* There is no point in supporting a fully generic interface{} in a Tree
container because the tree structure and logic requires each node to implement
the same basic parent / child structure etc.. So Ki is the “minimal” interface
for all tree nodes, and the Ki tree is a container of nodes that support that
interface.
* The Node struct provides the default impl of the Ki interface, and typically
you don’t need to impl it again in a different way, so almost always new Node
types will just put Node as an anonymous embedded type, and perhaps modify some
part of the Ki api as needed.
Cheers,
- Randy
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
