Unable to create Linked struct in go repl

[ihgann]

If I create a code block for Go that simulates a type of Linked object, I receive an error:

type Node struct {
    Next *Node
}

Response:

repl.go:2:11: undefined identifier: Node

Unfortunately this limits quite a few data structures from being able to be presented.

[SpencerPark]

I just tried that example while on #105 and things seemed to work fine so I think this is a problem in the old interpreter which will be updated when #105 is merged. There are a lot of new goodies that @cosmos72 has added to gomacro since the vendored copy currently in gophernotes .

[cosmos72]

Confirmed, recent versions of the interpreter support recursive types as the example above.

I re-opened a pull request to update the vendored copy of gomacro interpreter, hopefully it will be merged soon (see issue #112)

[cosmos72]

Merged, see commit 2ad243b.

gophernotes now supports recursive type declarations.

Alas, that's not the end of the story and I am working further on it (not yet merged). The reason is: recursive type declarations are currently emulated.

Unluckily there is no way to implement them exactly with the current approach: reflect.StructOf() cannot create recursive types. As a consequence, the interpreter needs a lot of tricks at runtime because of the emulation, and I am not convinced I caught all the cases.

If you want, you could help by getting gomacro with go get github.com/cosmos72/gomacro, running it (it's a text-mode Go interpreter, no fancy graphics as in gophernotes), use recursive types as your example type Node struct { Next *Node }, and report what you find - both successes and failures.

[cosmos72]

In alternative, if I do not find problems with the (not yet merged) gomacro patch, I will merge it into gophernotes sometimes next week

[cosmos72]

Fix applied in commit 48b1ccc

Please report if it works or you still get errors.