Implement a thin wrapper for encoding/json's Decoder

decoder.go

@@ -0,0 +1,28 @@
+package simplejson
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// Decoder is a simple wrapper of encoding/json's Decoder.
+type Decoder json.Decoder
+
+// Decode reads the next JSON-encoded value from its input and returns it.
+func (dec *Decoder) Decode() (*Json, error) {
+	j := new(Json)
+	err := (*json.Decoder)(dec).Decode(&j.data)
+	return j, err
+}
+
+// Buffered returns a reader of the data remaining in the Decoder's buffer.
+// The reader is valid until the next call to Decode.
+func (dec *Decoder) Buffered() io.Reader {
+	return (*json.Decoder)(dec).Buffered()
+}
+
+// More reports whether there is another element in the
+// current array or object being parsed.
+func (dec *Decoder) More() bool {
+	return (*json.Decoder)(dec).More()
+}

decoder_go10.go

@@ -0,0 +1,13 @@
+// +build !go1.1
+
+package simplejson
+
+import (
+	"encoding/json"
+	"io"
+)
+
+func NewDecoder(r io.Reader) *Decoder {
+	dec := json.NewDecoder(r)
+	return (*Decoder)(dec)
+}

decoder_go11.go

@@ -0,0 +1,15 @@
+// +build go1.1
+
+package simplejson
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// NewDecoder returns a new decoder that reads from r.
+func NewDecoder(r io.Reader) *Decoder {
+	dec := json.NewDecoder(r)
+	dec.UseNumber()
+	return (*Decoder)(dec)
+}

decoder_test.go

@@ -0,0 +1,142 @@
+package simplejson
+
+import (
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// This test case was copied from encoding/json/stream_test.go
+var streamEncoded = `0.1
+"hello"
+null
+true
+false
+["a","b","c"]
+{"ß":"long s","K":"Kelvin"}
+3.14
+`
+
+func TestDecoder(t *testing.T) {
+	r := strings.NewReader(streamEncoded)
+	dec := NewDecoder(r)
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err := dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, err := j.Float64()
+	if err != nil {
+		t.Error(err)
+	} else if f != 0.1 {
+		t.Errorf(`want %v, but got %v`, 0.1, f)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	s, err := j.String()
+	if err != nil {
+		t.Error(err)
+	} else if s != "hello" {
+		t.Errorf(`want %v, but got %v`, "hello", s)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	i := j.Interface()
+	if i != nil {
+		t.Errorf(`want %v, but got %v`, nil, i)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	b, err := j.Bool()
+	if err != nil {
+		t.Error(err)
+	} else if b != true {
+		t.Errorf(`want %v, but got %v`, true, b)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	b, err = j.Bool()
+	if err != nil {
+		t.Error(err)
+	} else if b != false {
+		t.Errorf(`want %v, but got %v`, false, b)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	a, err := j.Array()
+	if err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(a, []interface{}{"a", "b", "c"}) {
+		t.Errorf(`want %v, but got %v`, true, a)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	m, err := j.Map()
+	if err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(m, map[string]interface{}{"ß": "long s", "K": "Kelvin"}) {
+		t.Errorf(`want %v, but got %v`, true, a)
+	}
+
+	if !dec.More() {
+		t.Error("More must returns true")
+	}
+	j, err = dec.Decode()
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, err = j.Float64()
+	if err != nil {
+		t.Error(err)
+	} else if f != 3.14 {
+		t.Errorf(`want %v, but got %v`, 3.14, f)
+	}
+
+	if dec.More() {
+		t.Error("More must returns false")
+	}
+	_, err = dec.Decode()
+	if err != io.EOF {
+		t.Errorf(`want %v, but got %v`, io.EOF, err)
+	}
+}