Add support for typed array.

array.go

@@ -0,0 +1,169 @@
+package zerolog
+
+import (
+	"sync"
+	"time"
+
+	"github.com/rs/zerolog/internal/json"
+)
+
+var arrayPool = &sync.Pool{
+	New: func() interface{} {
+		return &Array{
+			buf: make([]byte, 0, 500),
+		}
+	},
+}
+
+type Array struct {
+	buf []byte
+}
+
+// Arr creates an array to be added to an Event or Context.
+func Arr() *Array {
+	a := arrayPool.Get().(*Array)
+	a.buf = a.buf[:0]
+	return a
+}
+
+func (*Array) MarshalZerologArray(*Array) {
+}
+
+func (a *Array) write(dst []byte) []byte {
+	if len(a.buf) == 0 {
+		dst = append(dst, `[]`...)
+	} else {
+		a.buf[0] = '['
+		dst = append(append(dst, a.buf...), ']')
+	}
+	arrayPool.Put(a)
+	return dst
+}
+
+// Object marshals an object that implement the LogObjectMarshaler
+// interface and append it to the array.
+func (a *Array) Object(obj LogObjectMarshaler) *Array {
+	a.buf = append(a.buf, ',')
+	e := Dict()
+	obj.MarshalZerologObject(e)
+	e.buf = append(e.buf, '}')
+	a.buf = append(a.buf, e.buf...)
+	return a
+}
+
+// Str append the val as a string to the array.
+func (a *Array) Str(val string) *Array {
+	a.buf = json.AppendString(append(a.buf, ','), val)
+	return a
+}
+
+// Bytes append the val as a string to the array.
+func (a *Array) Bytes(val []byte) *Array {
+	a.buf = json.AppendBytes(append(a.buf, ','), val)
+	return a
+}
+
+// Err append the err as a string to the array.
+func (a *Array) Err(err error) *Array {
+	a.buf = json.AppendError(append(a.buf, ','), err)
+	return a
+}
+
+// Bool append the val as a bool to the array.
+func (a *Array) Bool(b bool) *Array {
+	a.buf = json.AppendBool(append(a.buf, ','), b)
+	return a
+}
+
+// Int append i as a int to the array.
+func (a *Array) Int(i int) *Array {
+	a.buf = json.AppendInt(append(a.buf, ','), i)
+	return a
+}
+
+// Int8 append i as a int8 to the array.
+func (a *Array) Int8(i int8) *Array {
+	a.buf = json.AppendInt8(append(a.buf, ','), i)
+	return a
+}
+
+// Int16 append i as a int16 to the array.
+func (a *Array) Int16(i int16) *Array {
+	a.buf = json.AppendInt16(append(a.buf, ','), i)
+	return a
+}
+
+// Int32 append i as a int32 to the array.
+func (a *Array) Int32(i int32) *Array {
+	a.buf = json.AppendInt32(append(a.buf, ','), i)
+	return a
+}
+
+// Int64 append i as a int64 to the array.
+func (a *Array) Int64(i int64) *Array {
+	a.buf = json.AppendInt64(append(a.buf, ','), i)
+	return a
+}
+
+// Uint append i as a uint to the array.
+func (a *Array) Uint(i uint) *Array {
+	a.buf = json.AppendUint(append(a.buf, ','), i)
+	return a
+}
+
+// Uint8 append i as a uint8 to the array.
+func (a *Array) Uint8(i uint8) *Array {
+	a.buf = json.AppendUint8(append(a.buf, ','), i)
+	return a
+}
+
+// Uint16 append i as a uint16 to the array.
+func (a *Array) Uint16(i uint16) *Array {
+	a.buf = json.AppendUint16(append(a.buf, ','), i)
+	return a
+}
+
+// Uint32 append i as a uint32 to the array.
+func (a *Array) Uint32(i uint32) *Array {
+	a.buf = json.AppendUint32(append(a.buf, ','), i)
+	return a
+}
+
+// Uint64 append i as a uint64 to the array.
+func (a *Array) Uint64(i uint64) *Array {
+	a.buf = json.AppendUint64(append(a.buf, ','), i)
+	return a
+}
+
+// Float32 append f as a float32 to the array.
+func (a *Array) Float32(f float32) *Array {
+	a.buf = json.AppendFloat32(append(a.buf, ','), f)
+	return a
+}
+
+// Float64 append f as a float64 to the array.
+func (a *Array) Float64(f float64) *Array {
+	a.buf = json.AppendFloat64(append(a.buf, ','), f)
+	return a
+}
+
+// Time append t formated as string using zerolog.TimeFieldFormat.
+func (a *Array) Time(t time.Time) *Array {
+	a.buf = json.AppendTime(append(a.buf, ','), t, TimeFieldFormat)
+	return a
+}
+
+// Dur append d to the array.
+func (a *Array) Dur(d time.Duration) *Array {
+	a.buf = json.AppendDuration(append(a.buf, ','), d, DurationFieldUnit, DurationFieldInteger)
+	return a
+}
+
+// Interface append i marshaled using reflection.
+func (a *Array) Interface(i interface{}) *Array {
+	if obj, ok := i.(LogObjectMarshaler); ok {
+		return a.Object(obj)
+	}
+	a.buf = json.AppendInterface(append(a.buf, ','), i)
+	return a
+}

array_test.go

@@ -0,0 +1,30 @@
+package zerolog
+
+import (
+	"testing"
+	"time"
+)
+
+func TestArray(t *testing.T) {
+	a := Arr().
+		Bool(true).
+		Int(1).
+		Int8(2).
+		Int16(3).
+		Int32(4).
+		Int64(5).
+		Uint(6).
+		Uint8(7).
+		Uint16(8).
+		Uint32(9).
+		Uint64(10).
+		Float32(11).
+		Float64(12).
+		Str("a").
+		Time(time.Time{}).
+		Dur(0)
+	want := `[true,1,2,3,4,5,6,7,8,9,10,11,12,"a","0001-01-01T00:00:00Z",0]`
+	if got := string(a.write([]byte{})); got != want {
+		t.Errorf("Array.write()\ngot:  %s\nwant: %s", got, want)
+	}
+}

context.go

@@ -31,6 +31,26 @@ func (c Context) Dict(key string, dict *Event) Context {
 	return c
 }
 
+// Array adds the field key with an array to the event context.
+// Use zerolog.Arr() to create the array or pass a type that
+// implement the LogArrayMarshaler interface.
+func (c Context) Array(key string, arr LogArrayMarshaler) Context {
+	c.l.context = json.AppendKey(c.l.context, key)
+	if arr, ok := arr.(*Array); ok {
+		c.l.context = arr.write(c.l.context)
+		return c
+	}
+	var a *Array
+	if aa, ok := arr.(*Array); ok {
+		a = aa
+	} else {
+		a = Arr()
+		arr.MarshalZerologArray(a)
+	}
+	c.l.context = a.write(c.l.context)
+	return c
+}
+
 // Object marshals an object that implement the LogObjectMarshaler interface.
 func (c Context) Object(key string, obj LogObjectMarshaler) Context {
 	e := newEvent(levelWriterAdapter{ioutil.Discard}, 0, true)

event.go

@@ -28,10 +28,18 @@ type Event struct {
 	done    func(msg string)
 }
 
+// LogObjectMarshaler provides a strongly-typed and encoding-agnostic interface
+// to be implemented by types used with Event/Context's Object methods.
 type LogObjectMarshaler interface {
 	MarshalZerologObject(e *Event)
 }
 
+// LogArrayMarshaler provides a strongly-typed and encoding-agnostic interface
+// to be implemented by types used with Event/Context's Array methods.
+type LogArrayMarshaler interface {
+	MarshalZerologArray(a *Array)
+}
+
 func newEvent(w LevelWriter, level Level, enabled bool) *Event {
 	if !enabled {
 		return &Event{}
@@ -127,6 +135,25 @@ func Dict() *Event {
 	return newEvent(levelWriterAdapter{ioutil.Discard}, 0, true)
 }
 
+// Array adds the field key with an array to the event context.
+// Use zerolog.Arr() to create the array or pass a type that
+// implement the LogArrayMarshaler interface.
+func (e *Event) Array(key string, arr LogArrayMarshaler) *Event {
+	if !e.enabled {
+		return e
+	}
+	e.buf = json.AppendKey(e.buf, key)
+	var a *Array
+	if aa, ok := arr.(*Array); ok {
+		a = aa
+	} else {
+		a = Arr()
+		arr.MarshalZerologArray(a)
+	}
+	e.buf = a.write(e.buf)
+	return e
+}
+
 func (e *Event) appendObject(obj LogObjectMarshaler) {
 	pos := len(e.buf)
 	obj.MarshalZerologObject(e)
@@ -143,6 +170,9 @@ func (e *Event) appendObject(obj LogObjectMarshaler) {
 
 // Object marshals an object that implement the LogObjectMarshaler interface.
 func (e *Event) Object(key string, obj LogObjectMarshaler) *Event {
+	if !e.enabled {
+		return e
+	}
 	e.buf = json.AppendKey(e.buf, key)
 	e.appendObject(obj)
 	return e
@@ -166,7 +196,7 @@ func (e *Event) Strs(key string, vals []string) *Event {
 	return e
 }
 
-// Bytes adds the field key with val as a []byte to the *Event context.
+// Bytes adds the field key with val as a string to the *Event context.
 func (e *Event) Bytes(key string, val []byte) *Event {
 	if !e.enabled {
 		return e

log_example_test.go

@@ -150,9 +150,49 @@ func (u User) MarshalZerologObject(e *zerolog.Event) {
 		Time("created", u.Created)
 }
 
+type Users []User
+
+func (uu Users) MarshalZerologArray(a *zerolog.Array) {
+	for _, u := range uu {
+		a.Object(u)
+	}
+}
+
+func ExampleEvent_Array() {
+	log := zerolog.New(os.Stdout)
+
+	log.Log().
+		Str("foo", "bar").
+		Array("array", zerolog.Arr().
+			Str("baz").
+			Int(1),
+		).
+		Msg("hello world")
+
+	// Output: {"foo":"bar","array":["baz",1],"message":"hello world"}
+}
+
+func ExampleEvent_Array_object() {
+	log := zerolog.New(os.Stdout)
+
+	// Users implements zerolog.LogArrayMarshaler
+	u := Users{
+		User{"John", 35, time.Time{}},
+		User{"Bob", 55, time.Time{}},
+	}
+
+	log.Log().
+		Str("foo", "bar").
+		Array("users", u).
+		Msg("hello world")
+
+	// Output: {"foo":"bar","users":[{"name":"John","age":35,"created":"0001-01-01T00:00:00Z"},{"name":"Bob","age":55,"created":"0001-01-01T00:00:00Z"}],"message":"hello world"}
+}
+
 func ExampleEvent_Object() {
 	log := zerolog.New(os.Stdout)
 
+	// User implements zerolog.LogObjectMarshaler
 	u := User{"John", 35, time.Time{}}
 
 	log.Log().
@@ -222,7 +262,38 @@ func ExampleContext_Dict() {
 	// Output: {"foo":"bar","dict":{"bar":"baz","n":1},"message":"hello world"}
 }
 
+func ExampleContext_Array() {
+	log := zerolog.New(os.Stdout).With().
+		Str("foo", "bar").
+		Array("array", zerolog.Arr().
+			Str("baz").
+			Int(1),
+		).Logger()
+
+	log.Log().Msg("hello world")
+
+	// Output: {"foo":"bar","array":["baz",1],"message":"hello world"}
+}
+
+func ExampleContext_Array_object() {
+	// Users implements zerolog.LogArrayMarshaler
+	u := Users{
+		User{"John", 35, time.Time{}},
+		User{"Bob", 55, time.Time{}},
+	}
+
+	log := zerolog.New(os.Stdout).With().
+		Str("foo", "bar").
+		Array("users", u).
+		Logger()
+
+	log.Log().Msg("hello world")
+
+	// Output: {"foo":"bar","users":[{"name":"John","age":35,"created":"0001-01-01T00:00:00Z"},{"name":"Bob","age":55,"created":"0001-01-01T00:00:00Z"}],"message":"hello world"}
+}
+
 func ExampleContext_Object() {
+	// User implements zerolog.LogObjectMarshaler
 	u := User{"John", 35, time.Time{}}
 
 	log := zerolog.New(os.Stdout).With().