move index mapping to const variables

pkg/index/index.go

@@ -15,8 +15,10 @@ import (
 
 const (
 	maxSearchResult = 101
-
-	docType = "page"
+	docType         = "page"
+	titleField      = "title"
+	storeTitleField = "store_title"
+	searchField     = "search"
 )
 
 type indexPage struct {
@@ -110,7 +112,7 @@ func (i *Index) Search(search string) (results []core.Result, err error) {
 			continue
 		}
 		for fragField, frags := range hit.Fragments {
-			if fragField == "title" || fragField == "search" {
+			if fragField == titleField || fragField == searchField {
 				for _, f := range frags {
 					r.HTML += template.HTML(f)
 				}