Make available traversal code reusable

available.go

@@ -2,6 +2,7 @@ package pm
 
 import (
 	"net/url"
+	"sort"
 
 	"github.com/pkg/errors"
 )
@@ -62,3 +63,27 @@ func (a Available) SetRemote(u url.URL) {
 		}
 	}
 }
+
+func (a Available) Traverse() <-chan Meta {
+	r := make(chan Meta)
+	go func() {
+		names := Names{}
+		nvs := map[Name]Versions{}
+		for n, vers := range a {
+			names = append(names, n)
+			for v := range vers {
+				nvs[n] = append(nvs[n], v)
+			}
+			sort.Sort(nvs[n])
+		}
+		sort.Sort(names)
+
+		for _, n := range names {
+			for _, v := range nvs[n] {
+				r <- a[n][v]
+			}
+		}
+		close(r)
+	}()
+	return r
+}

db/available.go

@@ -7,7 +7,6 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
-	"sort"
 
 	"github.com/pkg/errors"
 	"mcquay.me/fs"
@@ -56,22 +55,8 @@ func ListAvailable(root string, w io.Writer) error {
 	if err != nil {
 		return errors.Wrap(err, "loading")
 	}
-	names := pm.Names{}
-	nvs := map[pm.Name]pm.Versions{}
-	for n, vers := range db {
-		names = append(names, n)
-		for v := range vers {
-			nvs[n] = append(nvs[n], v)
-		}
-		sort.Sort(nvs[n])
-	}
-	sort.Sort(names)
-
-	for _, n := range names {
-		for _, v := range nvs[n] {
-			m := db[n][v]
-			fmt.Fprintf(w, "%v\t%v\t%v\n", m.Name, m.Version, m.Remote.String())
-		}
+	for m := range db.Traverse() {
+		fmt.Fprintf(w, "%v\t%v\t%v\n", m.Name, m.Version, m.Remote.String())
 	}
 	return nil
 }