Merge branch 'json-prettyprint'

Author: warpfork

cmd/refmt/main.go

@@ -103,7 +103,7 @@ func Main(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 			Action: func(c *cli.Context) error {
 				return shared.TokenPump{
 					cbor.NewDecoder(stdin),
-					json.NewEncoder(stdout),
+					json.NewEncoder(stdout, json.EncodeOptions{}),
 				}.Run()
 			},
 		},
@@ -114,7 +114,7 @@ func Main(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 			Action: func(c *cli.Context) error {
 				return shared.TokenPump{
 					cbor.NewDecoder(hexReader(stdin)),
-					json.NewEncoder(stdout),
+					json.NewEncoder(stdout, json.EncodeOptions{}),
 				}.Run()
 			},
 		},
@@ -125,7 +125,7 @@ func Main(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 			Action: func(c *cli.Context) error {
 				return shared.TokenPump{
 					newYamlTokenSource(stdin),
-					json.NewEncoder(stdout),
+					json.NewEncoder(stdout, json.EncodeOptions{}),
 				}.Run()
 			},
 		},

json/jsonEncoder.go

@@ -8,9 +8,10 @@ import (
 	. "github.com/polydawn/refmt/tok"
 )
 
-func NewEncoder(wr io.Writer) *Encoder {
+func NewEncoder(wr io.Writer, cfg EncodeOptions) *Encoder {
 	return &Encoder{
 		wr:    wr,
+		cfg:   cfg,
 		stack: make([]phase, 0, 10),
 	}
 }
@@ -25,7 +26,8 @@ func (d *Encoder) Reset() {
 	A json.Encoder is a TokenSink implementation that emits json bytes.
 */
 type Encoder struct {
-	wr io.Writer
+	wr  io.Writer
+	cfg EncodeOptions
 
 	// Stack, tracking how many array and map opens are outstanding.
 	// (Values are only 'phase_mapExpectKeyOrEnd' and 'phase_arrExpectValueOrEnd'.)
@@ -74,6 +76,10 @@ func (d *Encoder) Step(tok *Token) (done bool, err error) {
 		case TArrOpen:
 			return true, fmt.Errorf("unexpected arrOpen; expected start of key or end of map")
 		case TMapClose:
+			d.wr.Write(d.cfg.Line)
+			for i := 1; i < len(d.stack); i++ {
+				d.wr.Write(d.cfg.Indent)
+			}
 			d.wr.Write(wordMapClose)
 			return d.popPhase()
 		case TArrClose:
@@ -126,6 +132,10 @@ func (d *Encoder) Step(tok *Token) (done bool, err error) {
 		case TMapClose:
 			return true, fmt.Errorf("unexpected mapClose; expected start of value or end of array")
 		case TArrClose:
+			d.wr.Write(d.cfg.Line)
+			for i := 1; i < len(d.stack); i++ {
+				d.wr.Write(d.cfg.Indent)
+			}
 			d.wr.Write(wordArrClose)
 			return d.popPhase()
 		default:
@@ -149,6 +159,7 @@ func (d *Encoder) pushPhase(p phase) {
 func (d *Encoder) popPhase() (bool, error) {
 	n := len(d.stack) - 1
 	if n == 0 {
+		d.wr.Write(d.cfg.Line)
 		return true, nil
 	}
 	if n < 0 { // the state machines are supposed to have already errored better
@@ -167,6 +178,10 @@ func (d *Encoder) entrySep() {
 		d.wr.Write(wordComma)
 	}
 	d.some = true
+	d.wr.Write(d.cfg.Line)
+	for i := 0; i < len(d.stack); i++ {
+		d.wr.Write(d.cfg.Indent)
+	}
 }
 
 func (d *Encoder) flushValue(tok *Token) {

json/jsonEncoder_test.go

@@ -23,7 +23,7 @@ func TestJsonEncoder(t *testing.T) {
 			title = strings.Join([]string{tr.sequence.Title, tr.title}, ", ")
 		}
 		buf := &bytes.Buffer{}
-		tokenSink := NewEncoder(buf)
+		tokenSink := NewEncoder(buf, EncodeOptions{})
 
 		// Run steps.
 		var done bool

json/jsonHelpers.go

@@ -36,7 +36,7 @@ func Marshal(v interface{}) ([]byte, error) {
 
 func MarshalAtlased(v interface{}, atl atlas.Atlas) ([]byte, error) {
 	var buf bytes.Buffer
-	if err := NewMarshallerAtlased(&buf, atl).Marshal(v); err != nil {
+	if err := NewMarshallerAtlased(&buf, EncodeOptions{}, atl).Marshal(v); err != nil {
 		return nil, err
 	}
 	return buf.Bytes(), nil
@@ -55,13 +55,13 @@ func (x *Marshaller) Marshal(v interface{}) error {
 }
 
 func NewMarshaller(wr io.Writer) *Marshaller {
-	return NewMarshallerAtlased(wr, atlas.MustBuild())
+	return NewMarshallerAtlased(wr, EncodeOptions{}, atlas.MustBuild())
 }
 
-func NewMarshallerAtlased(wr io.Writer, atl atlas.Atlas) *Marshaller {
+func NewMarshallerAtlased(wr io.Writer, cfg EncodeOptions, atl atlas.Atlas) *Marshaller {
 	x := &Marshaller{
 		marshaller: obj.NewMarshaller(atl),
-		encoder:    NewEncoder(wr),
+		encoder:    NewEncoder(wr, cfg),
 	}
 	x.pump = shared.TokenPump{
 		x.marshaller,

json/jsonOptions.go

@@ -1,7 +1,13 @@
 package json
 
 type EncodeOptions struct {
-	// future: indentation opts and such
+	// If set, this will be prefixed to every "line" to pretty-print.
+	// (Typically you want to just set this to `[]byte{'\n'}`!)
+	Line []byte
+
+	// If set, this will be prefixed $N$ times before each line's content to pretty-print.
+	// (Likely values are a tab, or a few spaces.)
+	Indent []byte
 }
 
 // marker method -- you may use this type to instruct `refmt.Marshal`

marshalHelpers.go

@@ -50,9 +50,9 @@ func NewMarshaller(opts EncodeOptions, wr io.Writer) Marshaller {
 }
 
 func NewMarshallerAtlased(opts EncodeOptions, wr io.Writer, atl atlas.Atlas) Marshaller {
-	switch opts.(type) {
+	switch o2 := opts.(type) {
 	case json.EncodeOptions:
-		return json.NewMarshallerAtlased(wr, atl)
+		return json.NewMarshallerAtlased(wr, o2, atl)
 	case cbor.EncodeOptions:
 		return cbor.NewMarshallerAtlased(wr, atl)
 	default: