Return the def object rather than the filetype string

ftdetect.go

@@ -2,17 +2,19 @@ package highlight
 
 import "bytes"
 
-func DetectFiletype(defs []*Def, filename string, fileSrc []byte) string {
+func DetectFiletype(defs []*Def, filename string, fileSrc []byte) *Def {
 	firstLine := bytes.Split(fileSrc, []byte("\n"))[0]
 
 	for _, d := range defs {
 		if d.ftdetect[0].Match([]byte(filename)) {
-			return d.ft
+			return d
 		}
-		if d.ftdetect[1].Match(firstLine) {
+		if len(d.ftdetect) > 1 {
-			return d.ft
+			if d.ftdetect[1].Match(firstLine) {
+				return d
+			}
 		}
 	}
 
-	return "Unknown"
+	return nil
 }