diff --git a/vendor/golang.org/x/text/internal/language/compact/compact.go b/vendor/golang.org/x/text/internal/language/compact/compact.go
new file mode 100644
index 0000000..1b36935
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/language/compact/compact.go
@@ -0,0 +1,61 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package compact defines a compact representation of language tags.
+//
+// Common language tags (at least all for which locale information is defined
+// in CLDR) are assigned a unique index. Each Tag is associated with such an
+// ID for selecting language-related resources (such as translations) as well
+// as one for selecting regional defaults (currency, number formatting, etc.)
+//
+// It may want to export this functionality at some point, but at this point
+// this is only available for use within x/text.
+package compact // import "golang.org/x/text/internal/language/compact"
+
+import (
+	"sort"
+	"strings"
+
+	"golang.org/x/text/internal/language"
+)
+
+// ID is an integer identifying a single tag.
+type ID uint16
+
+func getCoreIndex(t language.Tag) (id ID, ok bool) {
+	cci, ok := language.GetCompactCore(t)
+	if !ok {
+		return 0, false
+	}
+	i := sort.Search(len(coreTags), func(i int) bool {
+		return cci <= coreTags[i]
+	})
+	if i == len(coreTags) || coreTags[i] != cci {
+		return 0, false
+	}
+	return ID(i), true
+}
+
+// Parent returns the ID of the parent or the root ID if id is already the root.
+func (id ID) Parent() ID {
+	return parents[id]
+}
+
+// Tag converts id to an internal language Tag.
+func (id ID) Tag() language.Tag {
+	if int(id) >= len(coreTags) {
+		return specialTags[int(id)-len(coreTags)]
+	}
+	return coreTags[id].Tag()
+}
+
+var specialTags []language.Tag
+
+func init() {
+	tags := strings.Split(specialTagsStr, " ")
+	specialTags = make([]language.Tag, len(tags))
+	for i, t := range tags {
+		specialTags[i] = language.MustParse(t)
+	}
+}