Merge pull request #4 from moul/dev/moul/with

example_test.go

@@ -77,12 +77,13 @@ func Example_composite() {
 	}()
 	composite.Info("hello composite 2!")
 	cli.Info("hello cli 2!")
+	composite.With(zap.String("foo", "bar")).Warn("warn composite!")
 	scanner := bufio.NewScanner(r)
 	lines := 0
 	for scanner.Scan() {
 		fmt.Println("-> ", scanner.Text())
 		lines++
-		if lines == 2 {
+		if lines == 3 {
 			break
 		}
 	}
@@ -92,8 +93,10 @@ func Example_composite() {
 	// {"level":"info","msg":"hello composite!"}
 	// {"level":"info","msg":"hello composite 2!"}
 	// {"level":"info","msg":"hello cli 2!"}
+	// {"level":"warn","msg":"warn composite!","foo":"bar"}
 	// ->  {"L":"INFO","M":"hello composite!"}
 	// ->  {"L":"INFO","M":"hello composite 2!"}
+	// ->  {"L":"WARN","M":"warn composite!","foo":"bar"}
 }
 
 func Example_simple() {

zapring.go

@@ -59,6 +59,23 @@ func (c *Core) Enabled(level zapcore.Level) bool {
 	return c.Core.Enabled(level)
 }
 
+func (c *Core) clone() *Core {
+	return &Core{
+		buffer: c.buffer,
+		enc:    c.enc.Clone(),
+		Core:   c.Core,
+	}
+}
+
+// With implements zapcore.Core.
+func (c *Core) With(fields []zapcore.Field) zapcore.Core {
+	clone := c.clone()
+	for _, field := range fields {
+		field.AddTo(clone.enc)
+	}
+	return clone
+}
+
 // Check implements zapcore.Core.
 func (c *Core) Check(entry zapcore.Entry, checked *zapcore.CheckedEntry) *zapcore.CheckedEntry {
 	c.setup()