prefix handling is incomplete

[pborman]

goyang tends to ignore prefixes. In openconfig we do not expect to see conflicts on names sans prefixes, but for general use, goyang must support prefixes better.

[andaru]

In our present usages, one area we've run into a concern with not having prefixes is for type names - since types are often pulled in from other modules (e.g., common prefix inet), so we describe the type name as inet:as-number in one place, and as-number in another, because we receive only as-number back from goyang.

It thus seems preferable for users who do care about prefixes to get back the fully qualified type name (i.e., that with the source module prefix) from things like (*yang.Entry).Type.Name.

[r-cc-c]

Just FYI. I got this error when parsing openconfig-bgp: "../policy/openconfig-policy-types.yang:123:7: unknown prefix: yang for type hex-string". pyang didn't complain about this.

[pborman]

I believe pull request 60 may resolve this.

[r-cc-c]

Thanks pborman. FYI, I just tried the latest (with #60 and #61). Same error appear.

[pborman]

Can you provide instructions on how to reproduce this, including where all the .yang files have come from and what version? It would be great if you could just say

mkdir foo
cd foo
git clone ....
git clone ....
git cone https://github.com/openconfig/goyang
cd goyang
go build
./goyang ...

So I can reproduce exactly what you are seeing.

[r-cc-c]

Thanks Again! I discovered on my script the policy-types.yang file appear twice. It was my bad.
Thanks for your help!

[rski]

Looks like leafs (and maybe leaft-lists and uses leaf-lists) don't have prefixes set, because ToEntry() doesn't set a prefix in these cases.

Here is a snipper that shows that:

git clone https://github.com/openconfig/public /tmp/public

package main

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/openconfig/goyang/pkg/yang"
)

func main() {
	yangDir := "/tmp/public/release/models"

	ms := yang.NewModules()
	filepath.Walk(yangDir, func(path string, info os.FileInfo, err error) error {
		if !strings.HasSuffix(path, ".yang") {
			return nil
		}
		return ms.Read(path)
	})

	for _, k := range ms.Modules["openconfig-isis"].Grouping {
		if k.Name == "isis-overload-bit-reset-config" {
			e := yang.ToEntry(k)
			fmt.Printf("Prefixes:\n%s:%s\n%#v\n", e.Prefix.Name, e.Name, e.Dir["delay"].Prefix)
		}
	}
}

Results in:

go run *.go
Prefixes:
oc-isis:isis-overload-bit-reset-config
(*yang.Value)(nil)

Maybe adding a

if e.Prefix == nil {
		if m := RootNode(e.Node); m != nil {
			e.Prefix = m.getPrefix()
		}
	}

in these three cases is the right thing to do?

edit by wenovus: #70 resolves this issue.