diff --git a/cue/encoding/encoding.go b/cue/encoding/encoding.go
deleted file mode 100644
index 6c7e3f0..0000000
--- a/cue/encoding/encoding.go
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2018 The CUE Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package encoding provides support for managing data format files supported
-// by CUE.
-package encoding // import "cuelang.org/go/cue/encoding"
-
-import "strings"
-
-// Encoding represents a data encoding.
-type Encoding struct {
-	name string
-}
-
-// Name returns a lowercase name of an encoding. This is conventionally the most
-// common file extension in lower case.
-func (e *Encoding) Name() string {
-	return e.name
-}
-
-// All returns all known encodings.
-func All() []*Encoding {
-	return []*Encoding{jsonEnc, yamlEnc, protodefEnc}
-}
-
-// MapExtension returns the likely encoding for a given file extension.
-func MapExtension(ext string) *Encoding {
-	return extensions[strings.ToLower(ext)]
-}
-
-var (
-	cueEnc      = &Encoding{name: "cue"}
-	jsonEnc     = &Encoding{name: "json"}
-	yamlEnc     = &Encoding{name: "yaml"}
-	protodefEnc = &Encoding{name: "protobuf"}
-)
-
-// extensions maps a file extension to a Kind.
-var extensions = map[string]*Encoding{
-	".cue":    cueEnc,
-	".json":   jsonEnc,
-	".jsonl":  jsonEnc,
-	".ndjson": jsonEnc,
-	".yaml":   yamlEnc,
-	".yml":    yamlEnc,
-	".proto":  protodefEnc,
-}