skate: move out helper function

1 files changed, 2 insertions, 20 deletions

diff --git a/skate/cmd/skate-derive-key/main.go b/skate/cmd/skate-derive-key/main.go
index 61c79e1..05e1261 100644
--- a/skate/cmd/skate-derive-key/main.go
+++ b/skate/cmd/skate-derive-key/main.go
@@ -29,7 +29,6 @@ import (
 
 	"git.archive.org/martin/cgraph/skate"
 	"git.archive.org/martin/cgraph/skate/parallel"
-	json "github.com/segmentio/encoding/json"
 )
 
 var (
@@ -40,7 +39,7 @@ var (
 	verbose       = flag.Bool("verbose", false, "show progress")
 	bestEffort    = flag.Bool("B", false, "best effort")
 	logFile       = flag.String("log", "", "log filename")
-	skipEmptyKeys = flag.Bool("skip-empty-keys", false, "omit docs without keys")
+	skipEmptyKeys = flag.Bool("skip-empty-keys", false, "omit docs with empty keys")
 
 	wsReplacer = strings.NewReplacer("\t", "", "\n", "")
 	keyOpts    = map[string]skate.IdentifierKeyFunc{
@@ -58,24 +57,7 @@ func main() {
 	if *fixedField != "" {
 		// We want this, because from biblioref we wanted source_release_ident,
 		// from refs release_ident, etc.
-		keyFunc = func(p []byte) (id string, key string, err error) {
-			var doc map[string]interface{}
-			if err = json.Unmarshal(p, &doc); err != nil {
-				return
-			}
-			v, ok := doc[*fixedField]
-			if !ok {
-				return "", "", nil
-			}
-			switch t := v.(type) {
-			case string:
-				return "", t, nil
-			case int, int64, float32, float64:
-				return "", fmt.Sprintf("%v", t), nil
-			default:
-				return "", "", nil
-			}
-		}
+		keyFunc = skate.CreateFixedFieldFunc(*fixedField)
 	} else {
 		if keyFunc, ok = keyOpts[*keyFuncName]; !ok {
 			log.Fatal("invalid key func")