simplify fixed field extractor

1 files changed, 4 insertions, 31 deletions

diff --git a/skate/map.go b/skate/map.go
index 5584371..9d3c98d 100644
--- a/skate/map.go
+++ b/skate/map.go
@@ -5,10 +5,10 @@ import (
 	"errors"
 	"reflect"
 	"runtime"
-	"strconv"
 	"strings"
 
 	json "github.com/segmentio/encoding/json"
+	"github.com/tidwall/gjson"
 )
 
 var (
@@ -47,7 +47,7 @@ func (f Mapper) AsTSV(p []byte) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	return append(bytes.Join(fields, bTab), bNewline...), nil
+	return bytes.Join(fields, bTab), nil
 }
 
 // WithPrefix adds a given prefix to the first element.
@@ -84,36 +84,9 @@ func Identity(p []byte) ([][]byte, error) {
 // CreateFixedMapper extract the value from a given fixed top level json key.
 // Returns a function that maps doc to (v, doc).
 func CreateFixedMapper(field string) Mapper {
-	if field == "" {
-		return func(p []byte) ([][]byte, error) {
-			return nil, ErrMissingFieldName
-		}
-	}
 	f := func(p []byte) ([][]byte, error) {
-		var (
-			doc map[string]interface{}
-			v   interface{}
-			ok  bool
-			key []byte
-		)
-		if err := json.Unmarshal(p, &doc); err != nil {
-			return nil, err
-		}
-		if v, ok = doc[field]; !ok {
-			return nil, nil
-		}
-		switch w := v.(type) {
-		case string:
-			key = []byte(w)
-		case int:
-			key = []byte(strconv.Itoa(w))
-		case int64:
-			key = []byte(strconv.Itoa(int(w)))
-		case float64:
-			key = []byte(strconv.FormatFloat(w, 'f', 52, 64))
-		default:
-			return nil, nil
-		}
+		result := gjson.GetBytes(p, field)
+		key := []byte(result.String())
 		return [][]byte{key, p}, nil
 	}
 	return f