2015-devnation: final changes

2015/06-devnation-golang-good-bad-ugly/marshal.go

@@ -0,0 +1,39 @@
+// +build OMIT
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"time"
+)
+
+// START1 OMIT
+type MyStruct struct {
+	Name     string    `json:"myname"`
+	DateTime time.Time `json:"mytime"`
+}
+
+// STOP1 OMIT
+
+func main() {
+	var (
+		buf []byte
+		err error
+	)
+	// START2 OMIT
+	m := MyStruct{"vbatts", time.Now()}
+	fmt.Printf("%#v\n", m)
+	if buf, err = json.Marshal(m); err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%s\n", string(buf))
+
+	var m1 MyStruct
+	if err = json.Unmarshal(buf, &m1); err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%#v\n", m1)
+
+	// STOP2 OMIT
+}

2015/06-devnation-golang-good-bad-ugly/marshal_ugly.go

@@ -0,0 +1,12 @@
+// +build OMIT
+package main
+
+// START1 OMIT
+type Namer interface {
+	Name() string
+}
+
+// STOP1 OMIT
+
+func main() {
+}

2015/06-devnation-golang-good-bad-ugly/marshal_xml.go

@@ -0,0 +1,39 @@
+// +build OMIT
+package main
+
+import (
+	"encoding/xml"
+	"fmt"
+	"log"
+	"time"
+)
+
+// START1 OMIT
+type MyStruct struct {
+	Name     string    `json:"myname"`
+	DateTime time.Time `json:"mytime"`
+}
+
+// STOP1 OMIT
+
+func main() {
+	var (
+		buf []byte
+		err error
+	)
+	// START2 OMIT
+	m := MyStruct{"vbatts", time.Now()}
+	fmt.Printf("%#v\n", m)
+	if buf, err = xml.Marshal(m); err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%s\n", string(buf))
+
+	var m1 MyStruct
+	if err = xml.Unmarshal(buf, &m1); err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%#v\n", m1)
+
+	// STOP2 OMIT
+}

2015/06-devnation-golang-good-bad-ugly/talk.slide

@@ -2,7 +2,7 @@ Golang - the good, the bad, the ugly
 25 June 2015 - devnation.org
 
 Vincent Batts
-Developer
+Engineer
 @vbatts
 vbatts@redhat.com
 https://github.com/vbatts/talks
@@ -13,7 +13,7 @@ https://github.com/vbatts/talks
 	Login: vbatts                           Name: Vincent Batts
 	Such mail.
 	Plan:
-	Contribute with right, joyful effort
+	OHMAN
 	$> id -Gn
 	vbatts devel openshift docker
 
@@ -82,14 +82,24 @@ https://github.com/vbatts/talks
 .play ./pingpong.go /STARTMAIN1/,/STOPMAIN1/
 .link http://talks.golang.org/2013/advconc.slide Sameer Ajmani - Advanced Concurrency
 
+* Marshalling
+
+.code ./marshal.go /START1/,/STOP1/
+.play ./marshal.go /START2/,/STOP2/
+
+* Marshalling
+
+.code ./marshal_xml.go /START1/,/STOP1/
+.play ./marshal_xml.go /START2/,/STOP2/
+
 * 
 .image ./kanye_imma_bookmarklet.png 320 _
 
 - easy learning curve
+- fast compiles
 - `go get`
 - cross-compiles
 
-
 * Bad
 
 * 
@@ -103,7 +113,7 @@ Addresses different concern than distributions
 
 * lack of generics?
 # i don't feel strongly about this, though many do
-- interfaces - are enough for most
+- interfaces - good enough for most
 - go1.4 introduced go:generate
 # produce code for Set, Graph etc, for the types needed, but at compile time. No need to reflect.
 
@@ -112,18 +122,22 @@ Addresses different concern than distributions
 - gdb is there, sort of
 - some known debugging tools for ELF are not useful
 - fmt.Printf("%#v\n", ...)
+- go1.5 has much focus on DWARF symbols
 
 * Concurrency and GC
 
-Calls like setns(2) are rough
+- Calls like setns(2) are rough
-
-
 (yes, even with runtime.LockOSThread())
 
+- go1.5 will greatly improve garbage collections
+(performance and pauses)
+
+
 * Fork/Exec
 
 Not Separate, but together
 
+
 * Ugly? (maybe just new)
 
 * 
@@ -139,6 +153,9 @@ or files with *_linux.go like suffix.
 
 More like extern.
 
+* pointer reciever
+
+.play ./ugly2.go /START1/,/STOP1/
 
 * _
 
@@ -176,11 +193,21 @@ channel
 
 .code ./primitive3.go /START2/,/STOP2/
 
+* interfaces and marshalling
+
+.code ./marshal_ugly.go /START1/,/STOP1/
+
+
 * Conclusions?
 
+* Conclusions?
+
+- easy to adopt
+- enjoyable to learn
+
 * use-case
 
-- like all languages, align with you use-case
 - get familiar enough to like and dislike it
+- like all languages, choose the one that aligns with your use-case
 - don't be afraid to try it out
 

2015/06-devnation-golang-good-bad-ugly/ugly2.go

@@ -0,0 +1,27 @@
+// +build OMIT
+package main
+
+import (
+	"io"
+	"os"
+)
+
+// START1 OMIT
+type Message string
+
+func (m Message) WriteTo(w io.Writer) (int, error) {
+	return w.Write([]byte(m))
+}
+
+func (m Message) Reset() {
+	m = ""
+}
+
+func main() {
+	m := Message("Hello World\n")
+	m.WriteTo(os.Stdout)
+	m.Reset()
+	m.WriteTo(os.Stdout)
+}
+
+// STOP1 OMIT