cmd/cue/cmd: move vet to filetypes
Also change package loading. This now allows packages
and files arguments. File arguments must follow the
packages.
Closes #183
Change-Id: Ie88f486f50e10de4ce029c54bc4c6f8c12bae25e
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/5020
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/internal/encoding/encoding.go b/internal/encoding/encoding.go
new file mode 100644
index 0000000..a032bde
--- /dev/null
+++ b/internal/encoding/encoding.go
@@ -0,0 +1,152 @@
+// Copyright 2020 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
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "strings"
+
+ "cuelang.org/go/cue/ast"
+ "cuelang.org/go/cue/build"
+ "cuelang.org/go/encoding/json"
+ "cuelang.org/go/encoding/protobuf"
+ "cuelang.org/go/internal/third_party/yaml"
+)
+
+type Decoder struct {
+ closer io.Closer
+ next func() (ast.Expr, error)
+ expr ast.Expr
+ file *ast.File
+ filename string // may change on iteration for some formats
+ index int
+ err error
+}
+
+func (i *Decoder) Expr() ast.Expr { return i.expr }
+func (i *Decoder) Filename() string { return i.filename }
+func (i *Decoder) Index() int { return i.index }
+func (i *Decoder) Done() bool { return i.err != nil }
+
+func (i *Decoder) Next() {
+ if i.err == nil {
+ i.expr, i.err = i.next()
+ i.index++
+ }
+}
+
+func (i *Decoder) File() *ast.File {
+ if i.file != nil {
+ return i.file
+ }
+ switch x := i.expr.(type) {
+ case nil:
+ return nil
+ case *ast.StructLit:
+ return &ast.File{Decls: x.Elts}
+ default:
+ return &ast.File{
+ Decls: []ast.Decl{&ast.EmbedDecl{Expr: i.expr}},
+ }
+ }
+}
+
+func (i *Decoder) Err() error {
+ if i.err == io.EOF {
+ return nil
+ }
+ return i.err
+}
+
+func (i *Decoder) Close() {
+ i.closer.Close()
+}
+
+type Config struct {
+ Stdin io.Reader
+ Stdout io.Writer
+ ProtoPath []string
+}
+
+// NewDecoder returns a stream of non-rooted data expressions. The encoding
+// type of f must be a data type, but does not have to be an encoding that
+// can stream. stdin is used in case the file is "-".
+func NewDecoder(f *build.File, cfg *Config) *Decoder {
+ r, err := reader(f, cfg.Stdin)
+ i := &Decoder{
+ closer: r,
+ err: err,
+ filename: f.Filename,
+ next: func() (ast.Expr, error) {
+ if err == nil {
+ err = io.EOF
+ }
+ return nil, io.EOF
+ },
+ }
+ if err != nil {
+ return i
+ }
+
+ path := f.Filename
+ switch f.Encoding {
+ case build.JSON, build.JSONL:
+ i.next = json.NewDecoder(nil, path, r).Extract
+ i.Next()
+ case build.YAML:
+ d, err := yaml.NewDecoder(path, r)
+ i.err = err
+ i.next = d.Decode
+ i.Next()
+ case build.Text:
+ b, err := ioutil.ReadAll(r)
+ i.err = err
+ i.expr = ast.NewString(string(b))
+ case build.Protobuf:
+ paths := &protobuf.Config{Paths: cfg.ProtoPath}
+ i.file, i.err = protobuf.Extract(path, r, paths)
+ default:
+ i.err = fmt.Errorf("unsupported stream type %q", f.Encoding)
+ }
+
+ return i
+}
+
+func reader(f *build.File, stdin io.Reader) (io.ReadCloser, error) {
+ switch s := f.Source.(type) {
+ case nil:
+ // Use the file name.
+ case string:
+ return ioutil.NopCloser(strings.NewReader(s)), nil
+ case []byte:
+ return ioutil.NopCloser(bytes.NewReader(s)), nil
+ case *bytes.Buffer:
+ // is io.Reader, but it needs to be readable repeatedly
+ if s != nil {
+ return ioutil.NopCloser(bytes.NewReader(s.Bytes())), nil
+ }
+ default:
+ return nil, fmt.Errorf("invalid source type %T", f.Source)
+ }
+ // TODO: should we allow this?
+ if f.Filename == "-" {
+ return ioutil.NopCloser(stdin), nil
+ }
+ return os.Open(f.Filename)
+}
