diff --git a/public/arrays b/public/arrays
index e4e2d88..9f12e9d 100644
--- a/public/arrays
+++ b/public/arrays
@@ -18,7 +18,7 @@ specific length.
|
-
+
|
@@ -28,7 +28,9 @@ specific length.
- 
+
+
+
@@ -40,7 +42,7 @@ specific length.
|
-
+
@@ -52,7 +54,7 @@ specific length.
|
-
+
@@ -68,7 +70,7 @@ zero-valued, which for ints means 0s.
|
-
+
var a [5]int
fmt.Println("emp:", a)
ints means 0s.
|
-
+
a[4] = 100
fmt.Println("set:", a)
fmt.Println("get:", a[4])
@@ -99,7 +101,7 @@ zero-valued, which for ints means 0s.
|
-
+
fmt.Println("len:", len(a))
|
-
+
b := [5]int{1, 2, 3, 4, 5}
fmt.Println("dcl:", b)
|
-
+
var twoD [2][3]int
for i := 0; i < 2; i++ {
for j := 0; j < 3; j++ {
@@ -154,7 +156,7 @@ when printed with fmt.Println.
|
-
+
$ go run arrays.go
emp: [0 0 0 0 0]
set: [0 0 0 0 100]
@@ -174,7 +176,7 @@ typical Go. We’ll look at slices next.
|
-
+
|
diff --git a/public/atomic-counters b/public/atomic-counters
index a9ec770..9ba1895 100644
--- a/public/atomic-counters
+++ b/public/atomic-counters
@@ -22,7 +22,7 @@ counters accessed by multiple goroutines.
-
+
|
@@ -32,7 +32,9 @@ counters accessed by multiple goroutines.
-
+
+
+
@@ -44,7 +46,7 @@ counters accessed by multiple goroutines.
|
-
+
import "fmt"
import "time"
import "sync/atomic"
@@ -58,7 +60,7 @@ counters accessed by multiple goroutines.
|
-
+
@@ -72,7 +74,7 @@ counters accessed by multiple goroutines.
|
-
+
@@ -87,7 +89,7 @@ once a millisecond.
|
-
+
for i := 0; i < 50; i++ {
go func() {
for {
@@ -105,7 +107,7 @@ address of our ops counter with the
|
-
+
atomic.AddUint64(&ops, 1)
ops counter with the
|
-
+
time.Sleep(time.Millisecond)
}
}()
@@ -134,7 +136,7 @@ address of our ops counter with the
|
-
+
@@ -152,7 +154,7 @@ fetch the value.
|
-
+
opsFinal := atomic.LoadUint64(&ops)
fmt.Println("ops:", opsFinal)
}
@@ -172,7 +174,7 @@ fetch the value.
|
-
+
$ go run atomic-counters.go
ops: 41419
|
-
+
|
diff --git a/public/base64-encoding b/public/base64-encoding
index f067bee..2c1da0d 100644
--- a/public/base64-encoding
+++ b/public/base64-encoding
@@ -18,7 +18,7 @@ encoding/decoding.
-
+
|
@@ -28,7 +28,9 @@ encoding/decoding.
-
+
+
+
@@ -43,7 +45,7 @@ save us some space below.
|
-
+
import b64 "encoding/base64"
import "fmt"
|
-
+
@@ -69,7 +71,7 @@ save us some space below.
|
-
+
data := "abc123!?$*&()'-=@~"
string to that type.
|
-
+
sEnc := b64.StdEncoding.EncodeToString([]byte(data))
fmt.Println(sEnc)
|
-
+
sDec, _ := b64.StdEncoding.DecodeString(sEnc)
fmt.Println(string(sDec))
fmt.Println()
@@ -117,7 +119,7 @@ format.
|
-
+
uEnc := b64.URLEncoding.EncodeToString([]byte(data))
fmt.Println(uEnc)
uDec, _ := b64.URLEncoding.DecodeString(uEnc)
@@ -140,7 +142,7 @@ but they both decode to the original string as desired.
|
-
+
$ go run base64-encoding.go
YWJjMTIzIT8kKiYoKSctPUB+
abc123!?$*&()'-=@~
@@ -154,7 +156,7 @@ but they both decode to the original string as desired.
|
-
+
YWJjMTIzIT8kKiYoKSctPUB-
abc123!?$*&()'-=@~
|
-
+
|
@@ -32,7 +32,9 @@ those values.
-
+
+
+
@@ -44,7 +46,7 @@ those values.
|
-
+
@@ -56,7 +58,7 @@ those values.
|
-
+
@@ -70,7 +72,7 @@ those values.
|
-
+
messages := make(chan string, 2)
|
-
+
messages <- "buffered"
messages <- "channel"
|
-
+
fmt.Println(<-messages)
fmt.Println(<-messages)
}
@@ -117,7 +119,7 @@ concurrent receive.
|
-
+
$ go run channel-buffering.go
buffered
channel
diff --git a/public/channel-directions b/public/channel-directions
index 5b0150f..02c7c0a 100644
--- a/public/channel-directions
+++ b/public/channel-directions
@@ -20,7 +20,7 @@ the program.
|
-
+
|
@@ -30,7 +30,9 @@ the program.
-
+
+
+
@@ -42,7 +44,7 @@ the program.
|
-
+
@@ -57,7 +59,7 @@ receive on this channel.
|
-
+
func ping(pings chan<- string, msg string) {
pings <- msg
}
@@ -73,7 +75,7 @@ receive on this channel.
|
-
+
func pong(pings <-chan string, pongs chan<- string) {
msg := <-pings
pongs <- msg
@@ -88,7 +90,7 @@ receive on this channel.
|
-
+
func main() {
pings := make(chan string, 1)
pongs := make(chan string, 1)
@@ -110,7 +112,7 @@ receive on this channel.
|
-
+
$ go run channel-directions.go
passed message
|
-
+
|
@@ -31,7 +31,9 @@ you may prefer to use a WaitGroup.
-
+
+
+
@@ -43,7 +45,7 @@ you may prefer to use a WaitGroup.
|
-
+
import "fmt"
import "time"
|
-
+
func worker(done chan bool) {
fmt.Print("working...")
time.Sleep(time.Second)
@@ -75,7 +77,7 @@ goroutine that this function’s work is done.
|
-
+
@@ -88,7 +90,7 @@ goroutine that this function’s work is done.
|
-
+
@@ -102,7 +104,7 @@ notify on.
|
-
+
done := make(chan bool, 1)
go worker(done)
|
-
+
@@ -134,7 +136,7 @@ worker on the channel.
|
-
+
$ go run channel-synchronization.go
working...done
|
-
+
|
diff --git a/public/channels b/public/channels
index 4616272..94b14d7 100644
--- a/public/channels
+++ b/public/channels
@@ -20,7 +20,7 @@ goroutine.
-
+
|
@@ -30,7 +30,9 @@ goroutine.
-
+
+
+
@@ -42,7 +44,7 @@ goroutine.
|
-
+
@@ -54,7 +56,7 @@ goroutine.
|
-
+
@@ -68,7 +70,7 @@ Channels are typed by the values they convey.
|
-
+
messages := make(chan string)
|
-
+
go func() { messages <- "ping" }()
|
-
+
msg := <-messages
fmt.Println(msg)
}
@@ -119,7 +121,7 @@ our channel.
|
-
+
$ go run channels.go
ping
|
-
+
|
diff --git a/public/closing-channels b/public/closing-channels
index 3bf9b4b..d873cd8 100644
--- a/public/closing-channels
+++ b/public/closing-channels
@@ -19,7 +19,7 @@ completion to the channel’s receivers.
-
+
|
@@ -29,7 +29,9 @@ completion to the channel’s receivers.
-
+
+
+
@@ -41,7 +43,7 @@ completion to the channel’s receivers.
|
-
+
@@ -57,7 +59,7 @@ the worker we’ll close the jobs channel.
|
-
+
func main() {
jobs := make(chan int, 5)
done := make(chan bool)
@@ -78,7 +80,7 @@ all our jobs.
|
-
+
go func() {
for {
j, more := <-jobs
@@ -103,7 +105,7 @@ channel, then closes it.
|
-
+
for j := 1; j <= 3; j++ {
jobs <- j
fmt.Println("sent job", j)
@@ -123,7 +125,7 @@ we saw earlier.
|
-
+
@@ -140,7 +142,7 @@ we saw earlier.
|
-
+
$ go run closing-channels.go
sent job 1
received job 1
@@ -162,7 +164,7 @@ example: range over channels.
|
-
+
|
diff --git a/public/closures b/public/closures
index 5cab1c8..d85af28 100644
--- a/public/closures
+++ b/public/closures
@@ -20,7 +20,7 @@ a function inline without having to name it.
-
+
|
@@ -30,7 +30,9 @@ a function inline without having to name it.
-
+
+
+
@@ -42,7 +44,7 @@ a function inline without having to name it.
|
-
+
@@ -58,7 +60,7 @@ form a closure.
|
-
+
func intSeq() func() int {
i := 0
return func() int {
@@ -76,7 +78,7 @@ form a closure.
|
-
+
@@ -92,7 +94,7 @@ we call nextInt.
|
-
+
@@ -106,7 +108,7 @@ a few times.
|
-
+
fmt.Println(nextInt())
fmt.Println(nextInt())
fmt.Println(nextInt())
@@ -122,7 +124,7 @@ particular function, create and test a new one.
|
-
+
newInts := intSeq()
fmt.Println(newInts())
}
@@ -140,7 +142,7 @@ particular function, create and test a new one.
|
-
+
$ go run closures.go
1
2
@@ -158,7 +160,7 @@ recursion.
|
-
+
|
diff --git a/public/collection-functions b/public/collection-functions
index 6aae10a..07e970b 100644
--- a/public/collection-functions
+++ b/public/collection-functions
@@ -20,7 +20,7 @@ collection with a custom function.
-
+
|
@@ -35,7 +35,7 @@ your program and data types.
-
+
|
@@ -51,7 +51,7 @@ helper function.
-
+
|
@@ -61,7 +61,9 @@ helper function.
-
+
+
+
@@ -73,7 +75,7 @@ helper function.
|
-
+
import "strings"
import "fmt"
|
-
+
func Index(vs []string, t string) int {
for i, v := range vs {
if v == t {
@@ -109,7 +111,7 @@ slice.
|
-
+
func Include(vs []string, t string) bool {
return Index(vs, t) >= 0
}
@@ -125,7 +127,7 @@ satisfies the predicate f.
|
-
+
func Any(vs []string, f func(string) bool) bool {
for _, v := range vs {
if f(v) {
@@ -146,7 +148,7 @@ satisfy the predicate f.
|
-
+
func All(vs []string, f func(string) bool) bool {
for _, v := range vs {
if !f(v) {
@@ -167,7 +169,7 @@ slice that satisfy the predicate f.
|
-
+
func Filter(vs []string, f func(string) bool) []string {
vsf := make([]string, 0)
for _, v := range vs {
@@ -189,7 +191,7 @@ the function f to each string in the original slice.
|
-
+
func Map(vs []string, f func(string) string) []string {
vsm := make([]string, len(vs))
for i, v := range vs {
@@ -207,7 +209,7 @@ the function f to each string in the original slice.
|
-
+
@@ -220,7 +222,7 @@ the function f to each string in the original slice.
|
-
+
var strs = []string{"peach", "apple", "pear", "plum"}
f to each string in the original slice.
|
-
+
fmt.Println(Index(strs, "pear"))
f to each string in the original slice.
|
-
+
fmt.Println(Include(strs, "grape"))
f to each string in the original slice.
|
-
+
fmt.Println(Any(strs, func(v string) bool {
return strings.HasPrefix(v, "p")
}))
@@ -270,7 +272,7 @@ the function f to each string in the original slice.
|
-
+
fmt.Println(All(strs, func(v string) bool {
return strings.HasPrefix(v, "p")
}))
@@ -284,7 +286,7 @@ the function f to each string in the original slice.
|
-
+
fmt.Println(Filter(strs, func(v string) bool {
return strings.Contains(v, "e")
}))
@@ -301,7 +303,7 @@ type.
|
-
+
fmt.Println(Map(strs, strings.ToUpper))
|
-
+
@@ -329,7 +331,7 @@ type.
|
-
+
$ go run collection-functions.go
2
false
diff --git a/public/command-line-arguments b/public/command-line-arguments
index 5943299..b649bd2 100644
--- a/public/command-line-arguments
+++ b/public/command-line-arguments
@@ -20,7 +20,7 @@ For example, go run hello.go uses run and
|
-
+
|
@@ -30,7 +30,9 @@ For example, go run hello.go uses run and
-
+
+
+
@@ -42,7 +44,7 @@ For example, go run hello.go uses run and
|
-
+
@@ -55,7 +57,7 @@ For example, go run hello.go uses run and
|
-
+
@@ -71,7 +73,7 @@ holds the arguments to the program.
|
-
+
argsWithProg := os.Args
argsWithoutProg := os.Args[1:]
|
-
+
@@ -97,7 +99,7 @@ holds the arguments to the program.
|
-
+
fmt.Println(argsWithProg)
fmt.Println(argsWithoutProg)
fmt.Println(arg)
@@ -118,7 +120,7 @@ build a binary with go build first.
|
-
+
$ go build command-line-arguments.go
$ ./command-line-arguments a b c d
[./command-line-arguments a b c d]
@@ -136,7 +138,7 @@ with flags.
|
-
+
|
diff --git a/public/command-line-flags b/public/command-line-flags
index 3678600..42dad0b 100644
--- a/public/command-line-flags
+++ b/public/command-line-flags
@@ -20,7 +20,7 @@ command-line flag.
-
+
|
@@ -30,7 +30,9 @@ command-line flag.
-
+
+
+
@@ -45,7 +47,7 @@ implement our example command-line program.
|
-
+
import "flag"
import "fmt"
|
-
+
@@ -76,7 +78,7 @@ we’ll see how to use this pointer below.
|
-
+
wordPtr := flag.String("word", "foo", "a string")
word flag.
|
-
+
numbPtr := flag.Int("numb", 42, "an int")
boolPtr := flag.Bool("fork", false, "a bool")
|
-
+
var svar string
flag.StringVar(&svar, "svar", "bar", "a string var")
|
-
+
@@ -138,7 +140,7 @@ to get the actual option values.
|
-
+
fmt.Println("word:", *wordPtr)
fmt.Println("numb:", *numbPtr)
fmt.Println("fork:", *boolPtr)
@@ -162,7 +164,7 @@ binary directly.
|
-
+
$ go build command-line-flags.go
|
-
+
$ ./command-line-flags -word=opt -numb=7 -fork -svar=flag
word: opt
numb: 7
@@ -195,7 +197,7 @@ their default values.
|
-
+
$ ./command-line-flags -word=opt
word: opt
numb: 42
@@ -214,7 +216,7 @@ any flags.
|
-
+
$ ./command-line-flags -word=opt a1 a2 a3
word: opt
...
@@ -232,7 +234,7 @@ will be interpreted as positional arguments).
|
-
+
$ ./command-line-flags -word=opt a1 a2 a3 -numb=7
word: opt
numb: 42
@@ -251,7 +253,7 @@ generated help text for the command-line program.
|
-
+
$ ./command-line-flags -h
Usage of ./command-line-flags:
-fork=false: a bool
@@ -271,7 +273,7 @@ and show the help text again.
|
-
+
$ ./command-line-flags -wat
flag provided but not defined: -wat
Usage of ./command-line-flags:
@@ -288,7 +290,7 @@ way to parameterize programs.
|
-
+
|
diff --git a/public/command-line-subcommands b/public/command-line-subcommands
index 6fc1e06..945f646 100644
--- a/public/command-line-subcommands
+++ b/public/command-line-subcommands
@@ -22,7 +22,7 @@ subcommands that have their own flags.
-
+
|
@@ -32,7 +32,9 @@ subcommands that have their own flags.
-
+
+
+
@@ -44,7 +46,7 @@ subcommands that have their own flags.
|
-
+
import (
"flag"
"fmt"
@@ -60,7 +62,7 @@ subcommands that have their own flags.
|
-
+
@@ -75,7 +77,7 @@ for this subcommand.
|
-
+
fooCmd := flag.NewFlagSet("foo", flag.ExitOnError)
fooEnable := fooCmd.Bool("enable", false, "enable")
fooName := fooCmd.String("name", "", "name")
@@ -91,7 +93,7 @@ supported flags.
|
-
+
barCmd := flag.NewFlagSet("bar", flag.ExitOnError)
barLevel := barCmd.Int("level", 0, "level")
|
-
+
if len(os.Args) < 2 {
fmt.Println("expected 'foo' or 'bar' subcommands")
os.Exit(1)
@@ -122,7 +124,7 @@ to the program.
|
-
+
@@ -136,7 +138,7 @@ have access to trailing positional arguments.
|
-
+
case "foo":
fooCmd.Parse(os.Args[2:])
fmt.Println("subcommand 'foo'")
@@ -167,7 +169,7 @@ have access to trailing positional arguments.
|
-
+
$ go build command-line-subcommands.go
|
-
+
$ ./command-line-subcommands foo -enable -name=joe a1 a2
subcommand 'foo'
enable: true
@@ -197,7 +199,7 @@ have access to trailing positional arguments.
|
-
+
$ ./command-line-subcommands bar -level 8 a1
subcommand 'bar'
level: 8
@@ -213,7 +215,7 @@ have access to trailing positional arguments.
|
-
+
$ ./command-line-subcommands bar -enable a1
flag provided but not defined: -enable
Usage of bar:
diff --git a/public/constants b/public/constants
index bdf3a2f..c564424 100644
--- a/public/constants
+++ b/public/constants
@@ -18,7 +18,7 @@ and numeric values.
|
-
+
|
@@ -28,7 +28,9 @@ and numeric values.
-
+
+
+
@@ -40,7 +42,7 @@ and numeric values.
|
-
+
import "fmt"
import "math"
|
-
+
const s string = "constant"
|
-
+
func main() {
fmt.Println(s)
|
-
+
@@ -95,7 +97,7 @@ arbitrary precision.
|
-
+
const d = 3e20 / n
fmt.Println(d)
|
-
+
@@ -126,7 +128,7 @@ assignment or function call. For example, here
|
-
+
fmt.Println(math.Sin(n))
}
|
-
+
$ go run constant.go
constant
6e+11
diff --git a/public/defer b/public/defer
index eeff3b8..43445ec 100644
--- a/public/defer
+++ b/public/defer
@@ -20,7 +20,7 @@ purposes of cleanup. defer is often used where e.g.
|
-
+
|
@@ -30,7 +30,9 @@ purposes of cleanup. defer is often used where e.g.
-
+
+
+
@@ -42,7 +44,7 @@ purposes of cleanup. defer is often used where e.g.
|
-
+
@@ -58,7 +60,7 @@ do that with defer.
|
-
+
@@ -75,7 +77,7 @@ of the enclosing function (main), after
|
-
+
f := createFile("/tmp/defer.txt")
defer closeFile(f)
writeFile(f)
@@ -90,7 +92,7 @@ of the enclosing function (main), after
|
-
+
func createFile(p string) *os.File {
fmt.Println("creating")
f, err := os.Create(p)
@@ -109,7 +111,7 @@ of the enclosing function (main), after
|
-
+
func writeFile(f *os.File) {
fmt.Println("writing")
fmt.Fprintln(f, "data")
@@ -123,7 +125,7 @@ of the enclosing function (main), after
|
-
+
@@ -135,7 +137,7 @@ of the enclosing function (main), after
|
-
+
func closeFile(f *os.File) {
fmt.Println("closing")
f.Close()
@@ -156,7 +158,7 @@ after being written.
|
-
+
$ go run defer.go
creating
writing
diff --git a/public/environment-variables b/public/environment-variables
index e0b7c26..3d2e54c 100644
--- a/public/environment-variables
+++ b/public/environment-variables
@@ -20,7 +20,7 @@ Let’s look at how to set, get, and list environment variables.
|
-
+
|
@@ -30,7 +30,9 @@ Let’s look at how to set, get, and list environment variables.
-
+
+
+
@@ -42,7 +44,7 @@ Let’s look at how to set, get, and list environment variables.
|
-
+
import "os"
import "strings"
import "fmt"
@@ -56,7 +58,7 @@ Let’s look at how to set, get, and list environment variables.
|
-
+
@@ -72,7 +74,7 @@ environment.
|
-
+
os.Setenv("FOO", "1")
fmt.Println("FOO:", os.Getenv("FOO"))
fmt.Println("BAR:", os.Getenv("BAR"))
@@ -90,7 +92,7 @@ get the key and value. Here we print all the keys.
|
-
+
fmt.Println()
for _, e := range os.Environ() {
pair := strings.Split(e, "=")
@@ -114,7 +116,7 @@ for FOO that we set in the program, but that
|
-
+
$ go run environment-variables.go
FOO: 1
BAR:
@@ -130,7 +132,7 @@ particular machine.
|
-
+
TERM_PROGRAM
PATH
SHELL
@@ -147,7 +149,7 @@ program picks that value up.
|
-
+
$ BAR=2 go run environment-variables.go
FOO: 1
BAR: 2
diff --git a/public/epoch b/public/epoch
index 0ae0cf2..46d62e7 100644
--- a/public/epoch
+++ b/public/epoch
@@ -20,7 +20,7 @@ Here’s how to do it in Go.
|
-
+
|
@@ -30,7 +30,9 @@ Here’s how to do it in Go.
-
+
+
+
@@ -42,7 +44,7 @@ Here’s how to do it in Go.
|
-
+
import "fmt"
import "time"
|
-
+
@@ -70,7 +72,7 @@ nanoseconds, respectively.
|
-
+
now := time.Now()
secs := now.Unix()
nanos := now.UnixNano()
@@ -88,7 +90,7 @@ divide from nanoseconds.
|
-
+
millis := nanos / 1000000
fmt.Println(secs)
fmt.Println(millis)
@@ -105,7 +107,7 @@ since the epoch into the corresponding time.
|
-
+
fmt.Println(time.Unix(secs, 0))
fmt.Println(time.Unix(0, nanos))
}
@@ -123,7 +125,7 @@ since the epoch into the corresponding time.
|
-
+
$ go run epoch.go
2012-10-31 16:13:58.292387 +0000 UTC
1351700038
@@ -143,7 +145,7 @@ parsing and formatting.
|
-
+
|
diff --git a/public/errors b/public/errors
index 59cfb7e..489f119 100644
--- a/public/errors
+++ b/public/errors
@@ -24,7 +24,7 @@ non-error tasks.
-
+
|
@@ -34,7 +34,9 @@ non-error tasks.
-
+
+
+
@@ -46,7 +48,7 @@ non-error tasks.
|
-
+
import "errors"
import "fmt"
error, a built-in interface.
|
-
+
func f1(arg int) (int, error) {
if arg == 42 {
|
-
+
return -1, errors.New("can't work with 42")
|
-
+
@@ -102,7 +104,7 @@ there was no error.
|
-
+
@@ -119,7 +121,7 @@ to explicitly represent an argument error.
|
-
+
type argError struct {
arg int
prob string
@@ -134,7 +136,7 @@ to explicitly represent an argument error.
|
-
+
func (e *argError) Error() string {
return fmt.Sprintf("%d - %s", e.arg, e.prob)
}
@@ -148,7 +150,7 @@ to explicitly represent an argument error.
|
-
+
func f2(arg int) (int, error) {
if arg == 42 {
arg and prob.
|
-
+
return -1, &argError{arg, "can't work with it"}
}
return arg + 3, nil
@@ -179,7 +181,7 @@ fields arg and prob.
|
-
+
@@ -195,7 +197,7 @@ idiom in Go code.
|
-
+
for _, i := range []int{7, 42} {
if r, e := f1(i); e != nil {
fmt.Println("f1 failed:", e)
@@ -224,7 +226,7 @@ assertion.
|
-
+
_, e := f2(42)
if ae, ok := e.(*argError); ok {
fmt.Println(ae.arg)
@@ -245,7 +247,7 @@ assertion.
|
-
+
$ go run errors.go
f1 worked: 10
f1 failed: can't work with 42
@@ -265,7 +267,7 @@ on the Go blog for more on error handling.
|
-
+
|
diff --git a/public/execing-processes b/public/execing-processes
index 2fc8e94..85b155d 100644
--- a/public/execing-processes
+++ b/public/execing-processes
@@ -25,7 +25,7 @@ function.
-
+
|
@@ -35,7 +35,9 @@ function.
-
+
+
+
@@ -47,7 +49,7 @@ function.
|
-
+
import "syscall"
import "os"
import "os/exec"
@@ -61,7 +63,7 @@ function.
|
-
+
@@ -77,7 +79,7 @@ we’ll use exec.LookPath to find it (probably
|
-
+
binary, lookErr := exec.LookPath("ls")
if lookErr != nil {
panic(lookErr)
@@ -96,7 +98,7 @@ be the program name.
|
-
+
args := []string{"ls", "-a", "-l", "-h"}
|
-
+
@@ -128,7 +130,7 @@ value.
|
-
+
execErr := syscall.Exec(binary, args, env)
if execErr != nil {
panic(execErr)
@@ -149,7 +151,7 @@ value.
|
-
+
$ go run execing-processes.go
total 16
drwxr-xr-x 4 mark 136B Oct 3 16:29 .
@@ -169,7 +171,7 @@ processes covers most use cases for fork.
|
-
+
|
diff --git a/public/exit b/public/exit
index f92266a..4c6975d 100644
--- a/public/exit
+++ b/public/exit
@@ -18,7 +18,7 @@ status.
-
+
|
@@ -28,7 +28,9 @@ status.
-
+
+
+
@@ -40,7 +42,7 @@ status.
|
-
+
@@ -53,7 +55,7 @@ status.
|
-
+
@@ -67,7 +69,7 @@ this fmt.Println will never be called.
|
-
+
@@ -80,7 +82,7 @@ this fmt.Println will never be called.
|
-
+
@@ -97,7 +99,7 @@ use os.Exit.
|
-
+
|
@@ -113,7 +115,7 @@ will be picked up by go and printed.
-
+
$ go run exit.go
exit status 3
|
-
+
$ go build exit.go
$ ./exit
$ echo $?
@@ -144,7 +146,7 @@ the status in the terminal.
|
-
+
|
diff --git a/public/for b/public/for
index 68db267..314f139 100644
--- a/public/for
+++ b/public/for
@@ -18,7 +18,7 @@ three basic types of for loops.
-
+
|
@@ -28,7 +28,9 @@ three basic types of for loops.
-
+
+
+
@@ -40,7 +42,7 @@ three basic types of for loops.
|
-
+
@@ -52,7 +54,7 @@ three basic types of for loops.
|
-
+
@@ -65,7 +67,7 @@ three basic types of for loops.
|
-
+
i := 1
for i <= 3 {
fmt.Println(i)
@@ -82,7 +84,7 @@ three basic types of for loops.
|
-
+
for j := 7; j <= 9; j++ {
fmt.Println(j)
}
@@ -99,7 +101,7 @@ the enclosing function.
|
-
+
for {
fmt.Println("loop")
break
@@ -116,7 +118,7 @@ the loop.
|
-
+
for n := 0; n <= 5; n++ {
if n%2 == 0 {
continue
@@ -138,7 +140,7 @@ the loop.
|
-
+
$ go run for.go
1
2
@@ -163,7 +165,7 @@ structures.
|
-
+
|
diff --git a/public/functions b/public/functions
index 94acc61..7c89d83 100644
--- a/public/functions
+++ b/public/functions
@@ -18,7 +18,7 @@ functions with a few different examples.
-
+
|
@@ -28,7 +28,9 @@ functions with a few different examples.
-
+
+
+
@@ -40,7 +42,7 @@ functions with a few different examples.
|
-
+
@@ -54,7 +56,7 @@ their sum as an int.
|
-
+
func plus(a int, b int) int {
|
-
+
@@ -86,7 +88,7 @@ declares the type.
|
-
+
func plusPlus(a, b, c int) int {
return a + b + c
}
@@ -100,7 +102,7 @@ declares the type.
|
-
+
@@ -114,7 +116,7 @@ declares the type.
|
-
+
res := plus(1, 2)
fmt.Println("1+2 =", res)
|
-
+
res = plusPlus(1, 2, 3)
fmt.Println("1+2+3 =", res)
}
@@ -145,7 +147,7 @@ declares the type.
|
-
+
$ go run functions.go
1+2 = 3
1+2+3 = 6
@@ -161,7 +163,7 @@ multiple return values, which we’ll look at next.
|
-
+
|
diff --git a/public/goroutines b/public/goroutines
index df884f2..40ba434 100644
--- a/public/goroutines
+++ b/public/goroutines
@@ -17,7 +17,7 @@
-
+
|
@@ -27,7 +27,9 @@
-
+
+
+
@@ -39,7 +41,7 @@
|
-
+
@@ -51,7 +53,7 @@
|
-
+
func f(from string) {
for i := 0; i < 3; i++ {
fmt.Println(from, ":", i)
@@ -67,7 +69,7 @@
|
-
+
@@ -82,7 +84,7 @@ synchronously.
|
-
+
@@ -97,7 +99,7 @@ concurrently with the calling one.
|
-
+
@@ -111,7 +113,7 @@ function call.
|
-
+
go func(msg string) {
fmt.Println(msg)
}("going")
@@ -129,7 +131,7 @@ before the program exits.
|
-
+
fmt.Scanln()
fmt.Println("done")
}
@@ -151,7 +153,7 @@ goroutines being run concurrently by the Go runtime.
|
-
+
$ go run goroutines.go
direct : 0
direct : 1
@@ -174,7 +176,7 @@ concurrent Go programs: channels.
|
-
+
|
diff --git a/public/hello-world b/public/hello-world
index bd9c439..d8b1872 100644
--- a/public/hello-world
+++ b/public/hello-world
@@ -18,7 +18,9 @@ message. Here’s the full source code.
-
+
+
+
@@ -30,7 +32,7 @@ message. Here’s the full source code.
|
-
+
@@ -42,7 +44,7 @@ message. Here’s the full source code.
|
-
+
func main() {
fmt.Println("hello world")
}
@@ -62,7 +64,7 @@ use go run.
|
-
+
$ go run hello-world.go
hello world
go build.
|
-
+
$ go build hello-world.go
$ ls
hello-world hello-world.go
@@ -92,7 +94,7 @@ binaries. We can do this using go build.
|
-
+
$ ./hello-world
hello world
|
-
+
|
diff --git a/public/http-clients b/public/http-clients
index f0fafa8..5d5bf04 100644
--- a/public/http-clients
+++ b/public/http-clients
@@ -20,7 +20,9 @@ HTTP requests.
-
+
+
+
@@ -32,7 +34,7 @@ HTTP requests.
|
-
+
import (
"bufio"
"fmt"
@@ -48,7 +50,7 @@ HTTP requests.
|
-
+
@@ -65,7 +67,7 @@ settings.
|
-
+
resp, err := http.Get("http://gobyexample.com")
if err != nil {
panic(err)
@@ -82,7 +84,7 @@ settings.
|
-
+
fmt.Println("Response status:", resp.Status)
|
-
+
scanner := bufio.NewScanner(resp.Body)
for i := 0; scanner.Scan() && i < 5; i++ {
fmt.Println(scanner.Text())
@@ -110,7 +112,7 @@ settings.
|
-
+
if err := scanner.Err(); err != nil {
panic(err)
}
@@ -129,7 +131,7 @@ settings.
|
-
+
$ go run http-clients.go
Response status: 200 OK
<!DOCTYPE html>
diff --git a/public/http-servers b/public/http-servers
index 958ddc3..2dedf1a 100644
--- a/public/http-servers
+++ b/public/http-servers
@@ -18,7 +18,9 @@
|
-
+
+
+
@@ -30,7 +32,7 @@
|
-
+
import (
"fmt"
"net/http"
@@ -50,7 +52,7 @@ on functions with the appropriate signature.
|
-
+
func hello(w http.ResponseWriter, req *http.Request) {
|
-
+
fmt.Fprintf(w, "hello\n")
}
|
-
+
func headers(w http.ResponseWriter, req *http.Request) {
|
-
+
for name, headers := range req.Header {
for _, h := range headers {
fmt.Fprintf(w, "%v: %v\n", name, h)
@@ -112,7 +114,7 @@ headers and echoing them into the response body.
|
-
+
@@ -128,7 +130,7 @@ takes a function as an argument.
|
-
+
http.HandleFunc("/hello", hello)
http.HandleFunc("/headers", headers)
|
-
+
http.ListenAndServe(":8090", nil)
}
|
-
+
$ go run http-servers.go &
|
-
+
$ curl localhost:8090/hello
hello
|
-
+
|
@@ -28,7 +28,9 @@ straight-forward.
-
+
+
+
@@ -40,7 +42,7 @@ straight-forward.
|
-
+
@@ -52,7 +54,7 @@ straight-forward.
|
-
+
@@ -65,7 +67,7 @@ straight-forward.
|
-
+
if 7%2 == 0 {
fmt.Println("7 is even")
} else {
@@ -82,7 +84,7 @@ straight-forward.
|
-
+
if 8%4 == 0 {
fmt.Println("8 is divisible by 4")
}
@@ -99,7 +101,7 @@ branches.
|
-
+
if num := 9; num < 0 {
fmt.Println(num, "is negative")
} else if num < 10 {
@@ -120,7 +122,7 @@ in Go, but that the braces are required.
|
-
+
|
@@ -134,7 +136,7 @@ in Go, but that the braces are required.
-
+
$ go run if-else.go
7 is odd
8 is divisible by 4
@@ -152,7 +154,7 @@ for basic conditions.
|
-
+
|
diff --git a/public/interfaces b/public/interfaces
index ea4ebda..277c8f8 100644
--- a/public/interfaces
+++ b/public/interfaces
@@ -18,7 +18,7 @@ signatures.
-
+
|
@@ -28,7 +28,9 @@ signatures.
-
+
+
+
@@ -40,7 +42,7 @@ signatures.
|
-
+
import "fmt"
import "math"
|
-
+
type geometry interface {
area() float64
perim() float64
@@ -71,7 +73,7 @@ signatures.
|
-
+
type rect struct {
width, height float64
}
@@ -91,7 +93,7 @@ implement geometry on rects.
|
-
+
func (r rect) area() float64 {
return r.width * r.height
}
@@ -109,7 +111,7 @@ implement geometry on rects.
|
-
+
func (c circle) area() float64 {
return math.Pi * c.radius * c.radius
}
@@ -130,7 +132,7 @@ to work on any geometry.
|
-
+
func measure(g geometry) {
fmt.Println(g)
fmt.Println(g.area())
@@ -146,7 +148,7 @@ to work on any geometry.
|
-
+
func main() {
r := rect{width: 3, height: 4}
c := circle{radius: 5}
@@ -164,7 +166,7 @@ these structs as arguments to measure.
|
-
+
measure(r)
measure(c)
}
@@ -182,7 +184,7 @@ these structs as arguments to measure.
|
-
+
$ go run interfaces.go
{3 4}
12
@@ -202,7 +204,7 @@ these structs as arguments to measure.
|
-
+
|
diff --git a/public/json b/public/json
index 61fe8bc..54979d2 100644
--- a/public/json
+++ b/public/json
@@ -19,7 +19,7 @@ data types.
-
+
|
@@ -29,7 +29,9 @@ data types.
-
+
+
+
@@ -41,7 +43,7 @@ data types.
|
-
+
import "encoding/json"
import "fmt"
import "os"
@@ -57,7 +59,7 @@ decoding of custom types below.
|
-
+
type response1 struct {
Page int
Fruits []string
@@ -76,7 +78,7 @@ decoding of custom types below.
|
-
+
@@ -91,7 +93,7 @@ values.
|
-
+
bolB, _ := json.Marshal(true)
fmt.Println(string(bolB))
|
-
+
intB, _ := json.Marshal(1)
fmt.Println(string(intB))
|
-
+
fltB, _ := json.Marshal(2.34)
fmt.Println(string(fltB))
|
-
+
strB, _ := json.Marshal("gopher")
fmt.Println(string(strB))
|
-
+
slcD := []string{"apple", "peach", "pear"}
slcB, _ := json.Marshal(slcD)
fmt.Println(string(slcB))
@@ -159,7 +161,7 @@ to JSON arrays and objects as you’d expect.
|
-
+
mapD := map[string]int{"apple": 5, "lettuce": 7}
mapB, _ := json.Marshal(mapD)
fmt.Println(string(mapB))
@@ -177,7 +179,7 @@ use those names as the JSON keys.
|
-
+
res1D := &response1{
Page: 1,
Fruits: []string{"apple", "peach", "pear"}}
@@ -197,7 +199,7 @@ of such tags.
|
-
+
res2D := &response2{
Page: 1,
Fruits: []string{"apple", "peach", "pear"}}
@@ -216,7 +218,7 @@ structure.
|
-
+
byt := []byte(`{"num":6.13,"strs":["a","b"]}`)
|
-
+
var dat map[string]interface{}
|
-
+
if err := json.Unmarshal(byt, &dat); err != nil {
panic(err)
}
@@ -265,7 +267,7 @@ the expected float64 type.
|
-
+
num := dat["num"].(float64)
fmt.Println(num)
|
-
+
strs := dat["strs"].([]interface{})
str1 := strs[0].(string)
fmt.Println(str1)
@@ -299,7 +301,7 @@ data.
|
-
+
str := `{"page": 1, "fruits": ["apple", "peach"]}`
res := response2{}
json.Unmarshal([]byte(str), &res)
@@ -320,7 +322,7 @@ stream JSON encodings directly to os.Writers like
|
-
+
enc := json.NewEncoder(os.Stdout)
d := map[string]int{"apple": 5, "lettuce": 7}
enc.Encode(d)
@@ -339,7 +341,7 @@ stream JSON encodings directly to os.Writers like
|
-
+
$ go run json.go
true
1
@@ -369,7 +371,7 @@ for more.
|
-
+
|
diff --git a/public/line-filters b/public/line-filters
index 0b7b0a5..d1dd866 100644
--- a/public/line-filters
+++ b/public/line-filters
@@ -20,7 +20,7 @@ line filters.
-
+
|
@@ -33,7 +33,9 @@ pattern to write your own Go line filters.
-
+
+
+
@@ -45,7 +47,7 @@ pattern to write your own Go line filters.
|
-
+
import (
"bufio"
"fmt"
@@ -62,7 +64,7 @@ pattern to write your own Go line filters.
|
-
+
@@ -78,7 +80,7 @@ the next line in the default scanner.
|
-
+
scanner := bufio.NewScanner(os.Stdin)
|
-
+
@@ -104,7 +106,7 @@ from the input.
|
-
+
ucl := strings.ToUpper(scanner.Text())
|
-
+
@@ -132,7 +134,7 @@ expected and not reported by Scan as an error.
|
-
+
if err := scanner.Err(); err != nil {
fmt.Fprintln(os.Stderr, "error:", err)
os.Exit(1)
@@ -154,7 +156,7 @@ lowercase lines.
|
-
+
$ echo 'hello' > /tmp/lines
$ echo 'filter' >> /tmp/lines
|
-
+
$ cat /tmp/lines | go run line-filters.go
HELLO
FILTER
diff --git a/public/maps b/public/maps
index afa0567..bf31208 100644
--- a/public/maps
+++ b/public/maps
@@ -18,7 +18,7 @@
|
-
+
|
@@ -28,7 +28,9 @@
-
+
+
+
@@ -40,7 +42,7 @@
|
-
+
@@ -52,7 +54,7 @@
|
-
+
@@ -66,7 +68,7 @@
|
-
+
m := make(map[string]int)
|
-
+
@@ -95,7 +97,7 @@ its key/value pairs.
|
-
+
@@ -108,7 +110,7 @@ its key/value pairs.
|
-
+
v1 := m["k1"]
fmt.Println("v1: ", v1)
|
-
+
fmt.Println("len:", len(m))
|
-
+
delete(m, "k2")
fmt.Println("map:", m)
|
-
+
_, prs := m["k2"]
fmt.Println("prs:", prs)
|
-
+
n := map[string]int{"foo": 1, "bar": 2}
fmt.Println("map:", n)
}
@@ -192,7 +194,7 @@ printed with fmt.Println.
|
-
+
$ go run maps.go
map: map[k1:7 k2:13]
v1: 7
diff --git a/public/methods b/public/methods
index 2638234..c1ae6d0 100644
--- a/public/methods
+++ b/public/methods
@@ -17,7 +17,7 @@
|
-
+
|
@@ -27,7 +27,9 @@
-
+
+
+
@@ -39,7 +41,7 @@
|
-
+
@@ -51,7 +53,7 @@
|
-
+
type rect struct {
width, height int
}
@@ -66,7 +68,7 @@
|
-
+
func (r *rect) area() int {
return r.width * r.height
}
@@ -82,7 +84,7 @@ receiver types. Here’s an example of a value receiver.
|
-
+
func (r rect) perim() int {
return 2*r.width + 2*r.height
}
@@ -96,7 +98,7 @@ receiver types. Here’s an example of a value receiver.
|
-
+
func main() {
r := rect{width: 10, height: 5}
|
-
+
fmt.Println("area: ", r.area())
fmt.Println("perim:", r.perim())
|
-
+
rp := &r
fmt.Println("area: ", rp.area())
fmt.Println("perim:", rp.perim())
@@ -147,7 +149,7 @@ receiving struct.
|
-
+
$ go run methods.go
area: 50
perim: 30
@@ -165,7 +167,7 @@ naming related sets of methods: interfaces.
|
-
+
|
diff --git a/public/multiple-return-values b/public/multiple-return-values
index ed3692d..5392875 100644
--- a/public/multiple-return-values
+++ b/public/multiple-return-values
@@ -19,7 +19,7 @@ to return both result and error values from a function.
-
+
|
@@ -29,7 +29,9 @@ to return both result and error values from a function.
-
+
+
+
@@ -41,7 +43,7 @@ to return both result and error values from a function.
|
-
+
@@ -55,7 +57,7 @@ the function returns 2 ints.
|
-
+
func vals() (int, int) {
return 3, 7
}
@@ -69,7 +71,7 @@ the function returns 2 ints.
|
-
+
@@ -83,7 +85,7 @@ call with multiple assignment.
|
-
+
a, b := vals()
fmt.Println(a)
fmt.Println(b)
@@ -99,7 +101,7 @@ use the blank identifier _.
|
-
+
_, c := vals()
fmt.Println(c)
}
@@ -117,7 +119,7 @@ use the blank identifier _.
|
-
+
$ go run multiple-return-values.go
3
7
@@ -134,7 +136,7 @@ feature of Go functions; we’ll look at this next.
|
-
+
|
diff --git a/public/mutexes b/public/mutexes
index 6bc013e..efc2253 100644
--- a/public/mutexes
+++ b/public/mutexes
@@ -20,7 +20,7 @@ to safely access data across multiple goroutines.
-
+
|
@@ -30,7 +30,9 @@ to safely access data across multiple goroutines.
-
+
+
+
@@ -42,7 +44,7 @@ to safely access data across multiple goroutines.
|
-
+
import (
"fmt"
"math/rand"
@@ -60,7 +62,7 @@ to safely access data across multiple goroutines.
|
-
+
@@ -73,7 +75,7 @@ to safely access data across multiple goroutines.
|
-
+
var state = make(map[int]int)
|
-
+
var mutex = &sync.Mutex{}
|
-
+
var readOps uint64
var writeOps uint64
|
-
+
for r := 0; r < 100; r++ {
go func() {
total := 0
@@ -137,7 +139,7 @@ the readOps count.
|
-
+
key := rand.Intn(5)
mutex.Lock()
total += state[key]
@@ -154,7 +156,7 @@ the readOps count.
|
-
+
time.Sleep(time.Millisecond)
}
}()
@@ -171,7 +173,7 @@ using the same pattern we did for reads.
|
-
+
for w := 0; w < 10; w++ {
go func() {
for {
@@ -197,7 +199,7 @@ using the same pattern we did for reads.
|
-
+
@@ -210,7 +212,7 @@ using the same pattern we did for reads.
|
-
+
readOpsFinal := atomic.LoadUint64(&readOps)
fmt.Println("readOps:", readOpsFinal)
writeOpsFinal := atomic.LoadUint64(&writeOps)
@@ -226,7 +228,7 @@ using the same pattern we did for reads.
|
-
+
mutex.Lock()
fmt.Println("state:", state)
mutex.Unlock()
@@ -248,7 +250,7 @@ using the same pattern we did for reads.
|
-
+
$ go run mutexes.go
readOps: 83285
writeOps: 8320
@@ -265,7 +267,7 @@ management task using only goroutines and channels.
|
-
+
|
diff --git a/public/non-blocking-channel-operations b/public/non-blocking-channel-operations
index 30c1560..ada60a3 100644
--- a/public/non-blocking-channel-operations
+++ b/public/non-blocking-channel-operations
@@ -20,7 +20,7 @@ non-blocking multi-way selects.
-
+
|
@@ -30,7 +30,9 @@ non-blocking multi-way selects.
-
+
+
+
@@ -42,7 +44,7 @@ non-blocking multi-way selects.
|
-
+
@@ -54,7 +56,7 @@ non-blocking multi-way selects.
|
-
+
func main() {
messages := make(chan string)
signals := make(chan bool)
@@ -72,7 +74,7 @@ it will immediately take the default case.
|
-
+
select {
case msg := <-messages:
fmt.Println("received message", msg)
@@ -93,7 +95,7 @@ Therefore the default case is selected.
|
-
+
msg := "hi"
select {
case messages <- msg:
@@ -115,7 +117,7 @@ on both messages and signals.
|
-
+
select {
case msg := <-messages:
fmt.Println("received message", msg)
@@ -139,7 +141,7 @@ on both messages and signals.
|
-
+
$ go run non-blocking-channel-operations.go
no message received
no message sent
diff --git a/public/number-parsing b/public/number-parsing
index 0e509da..35e768e 100644
--- a/public/number-parsing
+++ b/public/number-parsing
@@ -18,7 +18,7 @@ in many programs; here’s how to do it in Go.
|
-
+
|
@@ -28,7 +28,9 @@ in many programs; here’s how to do it in Go.
-
+
+
+
@@ -42,7 +44,7 @@ parsing.
|
-
+
import "strconv"
import "fmt"
|
-
+
@@ -69,7 +71,7 @@ precision to parse.
|
-
+
f, _ := strconv.ParseFloat("1.234", 64)
fmt.Println(f)
|
-
+
i, _ := strconv.ParseInt("123", 0, 64)
fmt.Println(i)
|
-
+
d, _ := strconv.ParseInt("0x1c8", 0, 64)
fmt.Println(d)
|
-
+
u, _ := strconv.ParseUint("789", 0, 64)
fmt.Println(u)
|
-
+
k, _ := strconv.Atoi("135")
fmt.Println(k)
|
-
+
_, e := strconv.Atoi("wat")
fmt.Println(e)
}
@@ -160,7 +162,7 @@ bits.
|
-
+
$ go run number-parsing.go
1.234
123
@@ -179,7 +181,7 @@ bits.
|
-
+
|
diff --git a/public/panic b/public/panic
index c3e3621..59198af 100644
--- a/public/panic
+++ b/public/panic
@@ -20,7 +20,7 @@ aren’t prepared to handle gracefully.
-
+
|
@@ -30,7 +30,9 @@ aren’t prepared to handle gracefully.
-
+
+
+
@@ -42,7 +44,7 @@ aren’t prepared to handle gracefully.
|
-
+
@@ -54,7 +56,7 @@ aren’t prepared to handle gracefully.
|
-
+
@@ -69,7 +71,7 @@ site designed to panic.
|
-
+
@@ -85,7 +87,7 @@ returns an error value that we don’t know how to
|
-
+
_, err := os.Create("/tmp/file")
if err != nil {
panic(err)
@@ -108,7 +110,7 @@ a non-zero status.
|
-
+
$ go run panic.go
panic: a problem
|
-
+
goroutine 1 [running]:
main.main()
/.../panic.go:12 +0x47
@@ -140,7 +142,7 @@ to use error-indicating return values wherever possible.
|
-
+
|
diff --git a/public/pointers b/public/pointers
index 5959923..16687f5 100644
--- a/public/pointers
+++ b/public/pointers
@@ -19,7 +19,7 @@ within your program.
-
+
|
@@ -29,7 +29,9 @@ within your program.
-
+
+
+
@@ -41,7 +43,7 @@ within your program.
|
-
+
@@ -58,7 +60,7 @@ from the one in the calling function.
|
-
+
func zeroval(ival int) {
ival = 0
}
@@ -78,7 +80,7 @@ value at the referenced address.
|
-
+
func zeroptr(iptr *int) {
*iptr = 0
}
@@ -92,7 +94,7 @@ value at the referenced address.
|
-
+
func main() {
i := 1
fmt.Println("initial:", i)
@@ -106,7 +108,7 @@ value at the referenced address.
|
-
+
zeroval(i)
fmt.Println("zeroval:", i)
i.
|
-
+
zeroptr(&i)
fmt.Println("zeroptr:", i)
i.
|
-
+
fmt.Println("pointer:", &i)
}
|
-
+
$ go run pointers.go
initial: 1
zeroval: 1
diff --git a/public/random-numbers b/public/random-numbers
index 393d10c..5de950f 100644
--- a/public/random-numbers
+++ b/public/random-numbers
@@ -19,7 +19,7 @@ generation.
|
-
+
|
@@ -29,7 +29,9 @@ generation.
-
+
+
+
@@ -41,7 +43,7 @@ generation.
|
-
+
import "time"
import "fmt"
import "math/rand"
@@ -55,7 +57,7 @@ generation.
|
-
+
@@ -69,7 +71,7 @@ generation.
|
-
+
fmt.Print(rand.Intn(100), ",")
fmt.Print(rand.Intn(100))
fmt.Println()
@@ -85,7 +87,7 @@ generation.
|
-
+
fmt.Println(rand.Float64())
5.0 <= f' < 10.0.
|
-
+
fmt.Print((rand.Float64()*5)+5, ",")
fmt.Print((rand.Float64() * 5) + 5)
fmt.Println()
@@ -118,7 +120,7 @@ intend to be secret, use crypto/rand for those.
|
-
+
s1 := rand.NewSource(time.Now().UnixNano())
r1 := rand.New(s1)
rand package.
|
-
+
fmt.Print(r1.Intn(100), ",")
fmt.Print(r1.Intn(100))
fmt.Println()
@@ -149,7 +151,7 @@ produces the same sequence of random numbers.
|
-
+
s2 := rand.NewSource(42)
r2 := rand.New(s2)
fmt.Print(r2.Intn(100), ",")
@@ -174,7 +176,7 @@ produces the same sequence of random numbers.
|
-
+
$ go run random-numbers.go
81,87
0.6645600532184904
@@ -195,7 +197,7 @@ that Go can provide.
|
-
+
|
diff --git a/public/range b/public/range
index 70ac079..e9aa99e 100644
--- a/public/range
+++ b/public/range
@@ -19,7 +19,7 @@ of the data structures we’ve already learned.
-
+
|
@@ -29,7 +29,9 @@ of the data structures we’ve already learned.
-
+
+
+
@@ -41,7 +43,7 @@ of the data structures we’ve already learned.
|
-
+
@@ -53,7 +55,7 @@ of the data structures we’ve already learned.
|
-
+
@@ -67,7 +69,7 @@ Arrays work like this too.
|
-
+
nums := []int{2, 3, 4}
sum := 0
for _, num := range nums {
@@ -89,7 +91,7 @@ the indexes though.
|
-
+
for i, num := range nums {
if num == 3 {
fmt.Println("index:", i)
@@ -106,7 +108,7 @@ the indexes though.
|
-
+
kvs := map[string]string{"a": "apple", "b": "banana"}
for k, v := range kvs {
fmt.Printf("%s -> %s\n", k, v)
@@ -122,7 +124,7 @@ the indexes though.
|
-
+
for k := range kvs {
fmt.Println("key:", k)
}
@@ -139,7 +141,7 @@ of the rune and the second the rune itself.
|
-
+
for i, c := range "go" {
fmt.Println(i, c)
}
@@ -158,7 +160,7 @@ of the rune and the second the rune itself.
|
-
+
$ go run range.go
sum: 9
index: 1
diff --git a/public/range-over-channels b/public/range-over-channels
index 36222c6..a3ba422 100644
--- a/public/range-over-channels
+++ b/public/range-over-channels
@@ -20,7 +20,7 @@ values received from a channel.
|
-
+
|
@@ -30,7 +30,9 @@ values received from a channel.
-
+
+
+
@@ -42,7 +44,7 @@ values received from a channel.
|
-
+
@@ -54,7 +56,7 @@ values received from a channel.
|
-
+
@@ -67,7 +69,7 @@ values received from a channel.
|
-
+
queue := make(chan string, 2)
queue <- "one"
queue <- "two"
@@ -86,7 +88,7 @@ receiving the 2 elements.
|
-
+
for elem := range queue {
fmt.Println(elem)
}
@@ -105,7 +107,7 @@ receiving the 2 elements.
|
-
+
$ go run range-over-channels.go
one
two
@@ -122,7 +124,7 @@ values be received.
|
-
+
|
diff --git a/public/rate-limiting b/public/rate-limiting
index b41c17f..07dc185 100644
--- a/public/rate-limiting
+++ b/public/rate-limiting
@@ -21,7 +21,7 @@ channels, and tickers.
-
+
|
@@ -31,7 +31,9 @@ channels, and tickers.
-
+
+
+
@@ -43,7 +45,7 @@ channels, and tickers.
|
-
+
import "time"
import "fmt"
|
-
+
@@ -72,7 +74,7 @@ same name.
|
-
+
requests := make(chan int, 5)
for i := 1; i <= 5; i++ {
requests <- i
@@ -91,7 +93,7 @@ our rate limiting scheme.
|
-
+
limiter := time.Tick(200 * time.Millisecond)
|
-
+
for req := range requests {
<-limiter
fmt.Println("request", req, time.Now())
@@ -126,7 +128,7 @@ channel will allow bursts of up to 3 events.
|
-
+
burstyLimiter := make(chan time.Time, 3)
|
-
+
for i := 0; i < 3; i++ {
burstyLimiter <- time.Now()
}
@@ -155,7 +157,7 @@ value to burstyLimiter, up to its limit of 3.
|
-
+
go func() {
for t := range time.Tick(200 * time.Millisecond) {
burstyLimiter <- t
@@ -174,7 +176,7 @@ of burstyLimiter.
|
-
+
burstyRequests := make(chan int, 5)
for i := 1; i <= 5; i++ {
burstyRequests <- i
@@ -201,7 +203,7 @@ handled once every ~200 milliseconds as desired.
|
-
+
$ go run rate-limiting.go
request 1 2012-10-19 00:38:18.687438 +0000 UTC
request 2 2012-10-19 00:38:18.887471 +0000 UTC
@@ -221,7 +223,7 @@ then serve the remaining 2 with ~200ms delays each.
|
-
+
request 1 2012-10-19 00:38:20.487578 +0000 UTC
request 2 2012-10-19 00:38:20.487645 +0000 UTC
request 3 2012-10-19 00:38:20.487676 +0000 UTC
diff --git a/public/reading-files b/public/reading-files
index 1b08728..d51206c 100644
--- a/public/reading-files
+++ b/public/reading-files
@@ -19,7 +19,7 @@ reading files.
|
-
+
|
@@ -29,7 +29,9 @@ reading files.
-
+
+
+
@@ -41,7 +43,7 @@ reading files.
|
-
+
import (
"bufio"
"fmt"
@@ -61,7 +63,7 @@ This helper will streamline our error checks below.
|
-
+
func check(e error) {
if e != nil {
panic(e)
@@ -77,7 +79,7 @@ This helper will streamline our error checks below.
|
-
+
@@ -91,7 +93,7 @@ slurping a file’s entire contents into memory.
|
-
+
dat, err := ioutil.ReadFile("/tmp/dat")
check(err)
fmt.Print(string(dat))
@@ -108,7 +110,7 @@ by Opening a file to obtain an os.File value.
|
-
+
f, err := os.Open("/tmp/dat")
check(err)
|
-
+
b1 := make([]byte, 5)
n1, err := f.Read(b1)
check(err)
@@ -141,7 +143,7 @@ and Read from there.
|
-
+
o2, err := f.Seek(6, 0)
check(err)
b2 := make([]byte, 2)
@@ -163,7 +165,7 @@ implemented with ReadAtLeast.
|
-
+
o3, err := f.Seek(6, 0)
check(err)
b3 := make([]byte, 2)
@@ -182,7 +184,7 @@ accomplishes this.
|
-
+
_, err = f.Seek(0, 0)
check(err)
|
-
+
r4 := bufio.NewReader(f)
b4, err := r4.Peek(5)
check(err)
@@ -217,7 +219,7 @@ be scheduled immediately after Opening with
|
-
+
@@ -234,7 +236,7 @@ be scheduled immediately after Opening with
|
-
+
$ echo "hello" > /tmp/dat
$ echo "go" >> /tmp/dat
$ go run reading-files.go
@@ -255,7 +257,7 @@ be scheduled immediately after Opening with
|
-
+
|
diff --git a/public/recursion b/public/recursion
index 08d0857..bedbf2f 100644
--- a/public/recursion
+++ b/public/recursion
@@ -19,7 +19,7 @@ Here’s a classic factorial example.
-
+
|
@@ -29,7 +29,9 @@ Here’s a classic factorial example.
-
+
+
+
@@ -41,7 +43,7 @@ Here’s a classic factorial example.
|
-
+
@@ -55,7 +57,7 @@ base case of fact(0).
|
-
+
func fact(n int) int {
if n == 0 {
return 1
@@ -72,7 +74,7 @@ base case of fact(0).
|
-
+
func main() {
fmt.Println(fact(7))
}
@@ -90,7 +92,7 @@ base case of fact(0).
|
-
+
$ go run recursion.go
5040
|
-
+
|
@@ -29,7 +29,9 @@ in Go.
-
+
+
+
@@ -41,7 +43,7 @@ in Go.
|
-
+
import "bytes"
import "fmt"
import "regexp"
@@ -55,7 +57,7 @@ in Go.
|
-
+
@@ -68,7 +70,7 @@ in Go.
|
-
+
match, _ := regexp.MatchString("p([a-z]+)ch", "peach")
fmt.Println(match)
Regexp struct.
|
-
+
r, _ := regexp.Compile("p([a-z]+)ch")
|
-
+
fmt.Println(r.MatchString("peach"))
|
-
+
fmt.Println(r.FindString("peach punch"))
|
-
+
fmt.Println(r.FindStringIndex("peach punch"))
p([a-z]+)ch and ([a-z]+).
|
-
+
fmt.Println(r.FindStringSubmatch("peach punch"))
|
-
+
fmt.Println(r.FindStringSubmatchIndex("peach punch"))
|
-
+
fmt.Println(r.FindAllString("peach punch pinch", -1))
|
-
+
fmt.Println(r.FindAllStringSubmatchIndex(
"peach punch pinch", -1))
|
-
+
fmt.Println(r.FindAllString("peach punch pinch", 2))
|
-
+
fmt.Println(r.Match([]byte("peach")))
|
-
+
r = regexp.MustCompile("p([a-z]+)ch")
fmt.Println(r)
|
-
+
fmt.Println(r.ReplaceAllString("a peach", "<fruit>"))
|
-
+
in := []byte("a peach")
out := r.ReplaceAllFunc(in, bytes.ToUpper)
fmt.Println(string(out))
@@ -281,7 +283,7 @@ text with a given function.
|
-
+
$ go run regular-expressions.go
true
true
@@ -308,7 +310,7 @@ the regexp package docs
|
-
+
|
diff --git a/public/select b/public/select
index 87f7051..d6733a1 100644
--- a/public/select
+++ b/public/select
@@ -19,7 +19,7 @@ select is a powerful feature of Go.
-
+
|
@@ -29,7 +29,9 @@ select is a powerful feature of Go.
-
+
+
+
@@ -41,7 +43,7 @@ select is a powerful feature of Go.
|
-
+
import "time"
import "fmt"
|
-
+
@@ -67,7 +69,7 @@ select is a powerful feature of Go.
|
-
+
c1 := make(chan string)
c2 := make(chan string)
|
-
+
go func() {
time.Sleep(1 * time.Second)
c1 <- "one"
@@ -104,7 +106,7 @@ simultaneously, printing each one as it arrives.
|
-
+
for i := 0; i < 2; i++ {
select {
case msg1 := <-c1:
@@ -130,7 +132,7 @@ expected.
|
-
+
$ time go run select.go
received one
received two
@@ -147,7 +149,7 @@ concurrently.
|
-
+
diff --git a/public/sha1-hashes b/public/sha1-hashes
index 7daa377..c28cf1d 100644
--- a/public/sha1-hashes
+++ b/public/sha1-hashes
@@ -22,7 +22,7 @@ compute SHA1 hashes in Go.
|
-
+
|
@@ -32,7 +32,9 @@ compute SHA1 hashes in Go.
-
+
+
+
@@ -46,7 +48,7 @@ compute SHA1 hashes in Go.
|
-
+
import "crypto/sha1"
import "fmt"
|
-
+
func main() {
s := "sha1 this string"
|
-
+
@@ -89,7 +91,7 @@ use []byte(s) to coerce it to bytes.
|
-
+
@@ -104,7 +106,7 @@ to an existing byte slice: it usually isn’t needed.
|
-
+
@@ -119,7 +121,7 @@ a hash results to a hex string.
|
-
+
fmt.Println(s)
fmt.Printf("%x\n", bs)
}
@@ -139,7 +141,7 @@ a human-readable hex format.
|
-
+
$ go run sha1-hashes.go
sha1 this string
cf23df2207d99a74fbe169e3eba035e633b65d94
@@ -156,7 +158,7 @@ import crypto/md5 and use md5.New().
|
-
+
|
@@ -169,7 +171,7 @@ you should carefully research
-
+
|
diff --git a/public/signals b/public/signals
index 85849f7..50f0ec1 100644
--- a/public/signals
+++ b/public/signals
@@ -22,7 +22,7 @@ Here’s how to handle signals in Go with channels.
-
+
|
@@ -32,7 +32,9 @@ Here’s how to handle signals in Go with channels.
-
+
+
+
@@ -44,7 +46,7 @@ Here’s how to handle signals in Go with channels.
|
-
+
import "fmt"
import "os"
import "os/signal"
@@ -59,7 +61,7 @@ Here’s how to handle signals in Go with channels.
|
-
+
@@ -75,7 +77,7 @@ notify us when the program can exit).
|
-
+
sigs := make(chan os.Signal, 1)
done := make(chan bool, 1)
|
-
+
signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
|
-
+
go func() {
sig := <-sigs
fmt.Println()
@@ -125,7 +127,7 @@ above sending a value on done) and then exit.
|
-
+
fmt.Println("awaiting signal")
<-done
fmt.Println("exiting")
@@ -148,7 +150,7 @@ causing the program to print interrupt and then exit.
|
-
+
$ go run signals.go
awaiting signal
^C
diff --git a/public/slices b/public/slices
index 18acb11..fba69c9 100644
--- a/public/slices
+++ b/public/slices
@@ -18,7 +18,7 @@ powerful interface to sequences than arrays.
|
-
+
|
@@ -28,7 +28,9 @@ powerful interface to sequences than arrays.
-
+
+
+
@@ -40,7 +42,7 @@ powerful interface to sequences than arrays.
|
-
+
@@ -52,7 +54,7 @@ powerful interface to sequences than arrays.
|
-
+
@@ -69,7 +71,7 @@ the builtin make. Here we make a slice of
|
-
+
s := make([]string, 3)
fmt.Println("emp:", s)
make. Here we make a slice of
|
-
+
s[0] = "a"
s[1] = "b"
s[2] = "c"
@@ -100,7 +102,7 @@ the builtin make. Here we make a slice of
|
-
+
fmt.Println("len:", len(s))
|
-
+
s = append(s, "d")
s = append(s, "e", "f")
fmt.Println("apd:", s)
@@ -135,7 +137,7 @@ into c from s.
|
-
+
c := make([]string, len(s))
copy(c, s)
fmt.Println("cpy:", c)
@@ -152,7 +154,7 @@ of the elements s[2], s[3], and s[4].
|
-
+
l := s[2:5]
fmt.Println("sl1:", l)
s[2], s[3], and s[4].
|
-
+
l = s[:5]
fmt.Println("sl2:", l)
s[2], s[3], and s[4].
|
-
+
l = s[2:]
fmt.Println("sl3:", l)
|
-
+
t := []string{"g", "h", "i"}
fmt.Println("dcl:", t)
|
-
+
twoD := make([][]int, 3)
for i := 0; i < 3; i++ {
innerLen := i + 1
@@ -238,7 +240,7 @@ they are rendered similarly by fmt.Println.
|
-
+
$ go run slices.go
emp: [ ]
set: [a b c]
@@ -264,7 +266,7 @@ implementation of slices in Go.
|
-
+
|
@@ -276,7 +278,7 @@ Go’s other key builtin data structure: maps.
-
+
|
diff --git a/public/sorting b/public/sorting
index aa4c760..73f22b1 100644
--- a/public/sorting
+++ b/public/sorting
@@ -19,7 +19,7 @@ builtins first.
-
+
|
@@ -29,7 +29,9 @@ builtins first.
-
+
+
+
@@ -41,7 +43,7 @@ builtins first.
|
-
+
import "fmt"
import "sort"
|
-
+
@@ -70,7 +72,7 @@ return a new one.
|
-
+
strs := []string{"c", "a", "b"}
sort.Strings(strs)
fmt.Println("Strings:", strs)
@@ -85,7 +87,7 @@ return a new one.
|
-
+
ints := []int{7, 2, 4}
sort.Ints(ints)
fmt.Println("Ints: ", ints)
@@ -101,7 +103,7 @@ already in sorted order.
|
-
+
s := sort.IntsAreSorted(ints)
fmt.Println("Sorted: ", s)
}
@@ -121,7 +123,7 @@ slices and true as the result of our AreSorted test.
-
+
$ go run sorting.go
Strings: [a b c]
Ints: [2 4 7]
diff --git a/public/sorting-by-functions b/public/sorting-by-functions
index 5daf9d4..92c0f41 100644
--- a/public/sorting-by-functions
+++ b/public/sorting-by-functions
@@ -21,7 +21,7 @@ in Go.
|
-
+
|
@@ -31,7 +31,9 @@ in Go.
|
-
+
+
+
@@ -43,7 +45,7 @@ in Go.
|
-
+
import "sort"
import "fmt"
|
-
+
@@ -79,7 +81,7 @@ we use len(s[i]) and len(s[j]) here.
|
-
+
func (s byLength) Len() int {
return len(s)
}
@@ -103,7 +105,7 @@ slice.
|
-
+
func main() {
fruits := []string{"peach", "banana", "kiwi"}
sort.Sort(byLength(fruits))
@@ -125,7 +127,7 @@ length, as desired.
|
-
+
$ go run sorting-by-functions.go
[kiwi peach banana]
|
-
+
|
diff --git a/public/spawning-processes b/public/spawning-processes
index b175ead..c6ba21e 100644
--- a/public/spawning-processes
+++ b/public/spawning-processes
@@ -22,7 +22,7 @@ of spawning processes from Go.
-
+
|
@@ -32,7 +32,9 @@ of spawning processes from Go.
-
+
+
+
@@ -44,7 +46,7 @@ of spawning processes from Go.
|
-
+
import "fmt"
import "io/ioutil"
import "os/exec"
@@ -58,7 +60,7 @@ of spawning processes from Go.
|
-
+
@@ -74,7 +76,7 @@ to represent this external process.
|
-
+
dateCmd := exec.Command("date")
|
-
+
dateOut, err := dateCmd.Output()
if err != nil {
panic(err)
@@ -110,7 +112,7 @@ where we pipe data to the external process on its
|
-
+
grepCmd := exec.Command("grep", "hello")
|
-
+
grepIn, _ := grepCmd.StdinPipe()
grepOut, _ := grepCmd.StdoutPipe()
grepCmd.Start()
@@ -149,7 +151,7 @@ exactly the same way.
|
-
+
fmt.Println("> grep hello")
fmt.Println(string(grepBytes))
|
-
+
lsCmd := exec.Command("bash", "-c", "ls -a -l -h")
lsOut, err := lsCmd.Output()
if err != nil {
@@ -193,7 +195,7 @@ as if we had run them directly from the command-line.
|
-
+
$ go run spawning-processes.go
> date
Wed Oct 10 09:53:11 PDT 2012
@@ -207,7 +209,7 @@ as if we had run them directly from the command-line.
|
-
+
@@ -220,7 +222,7 @@ as if we had run them directly from the command-line.
|
-
+
> ls -a -l -h
drwxr-xr-x 4 mark 136B Oct 3 16:29 .
drwxr-xr-x 91 mark 3.0K Oct 3 12:50 ..
diff --git a/public/stateful-goroutines b/public/stateful-goroutines
index f684680..a14245a 100644
--- a/public/stateful-goroutines
+++ b/public/stateful-goroutines
@@ -24,7 +24,7 @@ by exactly 1 goroutine.
|
-
+
|
@@ -34,7 +34,9 @@ by exactly 1 goroutine.
-
+
+
+
@@ -46,7 +48,7 @@ by exactly 1 goroutine.
|
-
+
import (
"fmt"
"math/rand"
@@ -71,7 +73,7 @@ goroutine to respond.
|
-
+
type readOp struct {
key int
resp chan int
@@ -91,7 +93,7 @@ goroutine to respond.
|
-
+
@@ -104,7 +106,7 @@ goroutine to respond.
|
-
+
var readOps uint64
var writeOps uint64
|
-
+
reads := make(chan readOp)
writes := make(chan writeOp)
reads).
|
-
+
go func() {
var state = make(map[int]int)
for {
@@ -170,7 +172,7 @@ result over the provided resp channel.
|
-
+
for r := 0; r < 100; r++ {
go func() {
for {
@@ -196,7 +198,7 @@ approach.
|
-
+
for w := 0; w < 10; w++ {
go func() {
for {
@@ -222,7 +224,7 @@ approach.
|
-
+
@@ -235,7 +237,7 @@ approach.
|
-
+
readOpsFinal := atomic.LoadUint64(&readOps)
fmt.Println("readOps:", readOpsFinal)
writeOpsFinal := atomic.LoadUint64(&writeOps)
@@ -258,7 +260,7 @@ total operations.
|
-
+
$ go run stateful-goroutines.go
readOps: 71708
writeOps: 7177
@@ -280,7 +282,7 @@ program.
|
-
+
|
diff --git a/public/string-formatting b/public/string-formatting
index 3188935..c3118b0 100644
--- a/public/string-formatting
+++ b/public/string-formatting
@@ -19,7 +19,7 @@ common string formatting tasks.
-
+
|
@@ -29,7 +29,9 @@ common string formatting tasks.
-
+
+
+
@@ -41,7 +43,7 @@ common string formatting tasks.
|
-
+
@@ -54,7 +56,7 @@ common string formatting tasks.
|
-
+
type point struct {
x, y int
}
@@ -68,7 +70,7 @@ common string formatting tasks.
|
-
+
@@ -83,7 +85,7 @@ an instance of our point struct.
|
-
+
p := point{1, 2}
fmt.Printf("%v\n", p)
|
-
+
@@ -113,7 +115,7 @@ would produce that value.
|
-
+
@@ -126,7 +128,7 @@ would produce that value.
|
-
+
@@ -139,7 +141,7 @@ would produce that value.
|
-
+
@@ -153,7 +155,7 @@ Use %d for standard, base-10 formatting.
|
-
+
@@ -166,7 +168,7 @@ Use %d for standard, base-10 formatting.
|
-
+
@@ -180,7 +182,7 @@ given integer.
|
-
+
@@ -193,7 +195,7 @@ given integer.
|
-
+
@@ -207,7 +209,7 @@ floats. For basic decimal formatting use %f.
|
-
+
@@ -221,7 +223,7 @@ different versions of) scientific notation.
|
-
+
fmt.Printf("%e\n", 123400000.0)
fmt.Printf("%E\n", 123400000.0)
|
-
+
fmt.Printf("%s\n", "\"string\"")
|
-
+
fmt.Printf("%q\n", "\"string\"")
|
-
+
fmt.Printf("%x\n", "hex this")
|
-
+
@@ -294,7 +296,7 @@ spaces.
|
-
+
fmt.Printf("|%6d|%6d|\n", 12, 345)
|
-
+
fmt.Printf("|%6.2f|%6.2f|\n", 1.2, 3.45)
|
-
+
fmt.Printf("|%-6.2f|%-6.2f|\n", 1.2, 3.45)
|
-
+
fmt.Printf("|%6s|%6s|\n", "foo", "b")
|
-
+
fmt.Printf("|%-6s|%-6s|\n", "foo", "b")
|
-
+
s := fmt.Sprintf("a %s", "string")
fmt.Println(s)
|
-
+
fmt.Fprintf(os.Stderr, "an %s\n", "error")
}
|
-
+
$ go run string-formatting.go
{1 2}
{x:1 y:2}
diff --git a/public/string-functions b/public/string-functions
index 1fdf4cf..73b6019 100644
--- a/public/string-functions
+++ b/public/string-functions
@@ -19,7 +19,7 @@ to give you a sense of the package.
|
-
+
|
@@ -29,7 +29,9 @@ to give you a sense of the package.
-
+
+
+
@@ -41,7 +43,7 @@ to give you a sense of the package.
|
-
+
import s "strings"
import "fmt"
|
-
+
@@ -68,7 +70,7 @@ it a lot below.
|
-
+
@@ -87,7 +89,7 @@ package docs.
|
-
+
p("Contains: ", s.Contains("test", "es"))
p("Count: ", s.Count("test", "t"))
p("HasPrefix: ", s.HasPrefix("test", "te"))
@@ -114,7 +116,7 @@ bytes and getting a byte by index.
|
-
+
p("Len: ", len("hello"))
p("Char:", "hello"[1])
}
@@ -134,7 +136,7 @@ for more information.
|
-
+
|
@@ -148,7 +150,7 @@ for more information.
-
+
$ go run string-functions.go
Contains: true
Count: 2
@@ -172,7 +174,7 @@ for more information.
|
-
+
diff --git a/public/structs b/public/structs
index 5d6273d..31c03d0 100644
--- a/public/structs
+++ b/public/structs
@@ -19,7 +19,7 @@ records.
|
-
+
|
@@ -29,7 +29,9 @@ records.
-
+
+
+
@@ -41,7 +43,7 @@ records.
|
-
+
@@ -54,7 +56,7 @@ records.
|
-
+
type person struct {
name string
age int
@@ -69,7 +71,7 @@ records.
|
-
+
@@ -82,7 +84,7 @@ records.
|
-
+
fmt.Println(person{"Bob", 20})
|
-
+
fmt.Println(person{name: "Alice", age: 30})
|
-
+
fmt.Println(person{name: "Fred"})
|
-
+
fmt.Println(&person{name: "Ann", age: 40})
|
-
+
s := person{name: "Sean", age: 50}
fmt.Println(s.name)
|
-
+
sp := &s
fmt.Println(sp.age)
|
-
+
sp.age = 51
fmt.Println(sp.age)
}
@@ -181,7 +183,7 @@ pointers are automatically dereferenced.
|
-
+
$ go run structs.go
{Bob 20}
{Alice 30}
diff --git a/public/switch b/public/switch
index 37200b3..c739ea3 100644
--- a/public/switch
+++ b/public/switch
@@ -18,7 +18,7 @@ branches.
|
-
+
|
@@ -28,7 +28,9 @@ branches.
-
+
+
+
@@ -40,7 +42,7 @@ branches.
|
-
+
import "fmt"
import "time"
|
-
+
@@ -66,7 +68,7 @@ branches.
|
-
+
i := 2
fmt.Print("Write ", i, " as ")
switch i {
@@ -90,7 +92,7 @@ in the same case statement. We use the optional
|
-
+
switch time.Now().Weekday() {
case time.Saturday, time.Sunday:
fmt.Println("It's the weekend")
@@ -110,7 +112,7 @@ to express if/else logic. Here we also show how the
|
-
+
t := time.Now()
switch {
case t.Hour() < 12:
@@ -132,7 +134,7 @@ type corresponding to its clause.
|
-
+
whatAmI := func(i interface{}) {
switch t := i.(type) {
case bool:
@@ -161,7 +163,7 @@ type corresponding to its clause.
|
-
+
$ go run switch.go
Write 2 as two
It's a weekday
diff --git a/public/tickers b/public/tickers
index 0ea1840..64f1044 100644
--- a/public/tickers
+++ b/public/tickers
@@ -21,7 +21,7 @@ periodically until we stop it.
|
-
+
|
@@ -31,7 +31,9 @@ periodically until we stop it.
-
+
+
+
@@ -43,7 +45,7 @@ periodically until we stop it.
|
-
+
import "time"
import "fmt"
|
-
+
@@ -72,7 +74,7 @@ the values as they arrive every 500ms.
|
-
+
ticker := time.NewTicker(500 * time.Millisecond)
go func() {
for t := range ticker.C {
@@ -92,7 +94,7 @@ channel. We’ll stop ours after 1600ms.
|
-
+
time.Sleep(1600 * time.Millisecond)
ticker.Stop()
fmt.Println("Ticker stopped")
@@ -113,7 +115,7 @@ before we stop it.
|
-
+
$ go run tickers.go
Tick at 2012-09-23 11:29:56.487625 -0700 PDT
Tick at 2012-09-23 11:29:56.988063 -0700 PDT
diff --git a/public/time b/public/time
index e5c1fe4..443f568 100644
--- a/public/time
+++ b/public/time
@@ -18,7 +18,7 @@ here are some examples.
|
-
+
|
@@ -28,7 +28,9 @@ here are some examples.
-
+
+
+
@@ -40,7 +42,7 @@ here are some examples.
|
-
+
import "fmt"
import "time"
|
-
+
func main() {
p := fmt.Println
|
-
+
@@ -83,7 +85,7 @@ with a Location, i.e. time zone.
|
-
+
then := time.Date(
2009, 11, 17, 20, 34, 58, 651387237, time.UTC)
p(then)
@@ -99,7 +101,7 @@ value as expected.
|
-
+
p(then.Year())
p(then.Month())
p(then.Day())
@@ -119,7 +121,7 @@ value as expected.
|
-
+
@@ -134,7 +136,7 @@ as the second, respectively.
|
-
+
p(then.Before(now))
p(then.After(now))
p(then.Equal(now))
@@ -150,7 +152,7 @@ the interval between two times.
|
-
+
diff := now.Sub(then)
p(diff)
|
-
+
p(diff.Hours())
p(diff.Minutes())
p(diff.Seconds())
@@ -183,7 +185,7 @@ duration.
|
-
+
p(then.Add(diff))
p(then.Add(-diff))
}
@@ -201,7 +203,7 @@ duration.
|
-
+
$ go run time.go
2012-10-31 15:50:13.793654 +0000 UTC
2009-11-17 20:34:58.651387237 +0000 UTC
@@ -236,7 +238,7 @@ the Unix epoch.
|
-
+
|
diff --git a/public/time-formatting-parsing b/public/time-formatting-parsing
index b90c585..f16fbc9 100644
--- a/public/time-formatting-parsing
+++ b/public/time-formatting-parsing
@@ -18,7 +18,7 @@ pattern-based layouts.
-
+
|
@@ -28,7 +28,9 @@ pattern-based layouts.
-
+
+
+
@@ -40,7 +42,7 @@ pattern-based layouts.
|
-
+
import "fmt"
import "time"
|
-
+
func main() {
p := fmt.Println
|
-
+
t := time.Now()
p(t.Format(time.RFC3339))
|
-
+
t1, e := time.Parse(
time.RFC3339,
"2012-11-01T22:08:41+00:00")
@@ -105,7 +107,7 @@ The example time must be exactly as shown: the year 2006,
|
-
+
p(t.Format("3:04PM"))
p(t.Format("Mon Jan _2 15:04:05 2006"))
p(t.Format("2006-01-02T15:04:05.999999-07:00"))
@@ -125,7 +127,7 @@ components of the time value.
|
-
+
fmt.Printf("%d-%02d-%02dT%02d:%02d:%02d-00:00\n",
t.Year(), t.Month(), t.Day(),
t.Hour(), t.Minute(), t.Second())
@@ -141,7 +143,7 @@ explaining the parsing problem.
|
-
+
ansic := "Mon Jan _2 15:04:05 2006"
_, e = time.Parse(ansic, "8:41PM")
p(e)
@@ -160,7 +162,7 @@ explaining the parsing problem.
|
-
+
$ go run time-formatting-parsing.go
2014-04-15T18:00:15-07:00
2012-11-01 22:08:41 +0000 +0000
diff --git a/public/timeouts b/public/timeouts
index aa20120..449446a 100644
--- a/public/timeouts
+++ b/public/timeouts
@@ -20,7 +20,7 @@ elegant thanks to channels and select.
|
-
+
|
@@ -30,7 +30,9 @@ elegant thanks to channels and select.
-
+
+
+
@@ -42,7 +44,7 @@ elegant thanks to channels and select.
|
-
+
import "time"
import "fmt"
select.
|
-
+
@@ -70,7 +72,7 @@ after 2s.
|
-
+
c1 := make(chan string, 1)
go func() {
time.Sleep(2 * time.Second)
@@ -92,7 +94,7 @@ if the operation takes more than the allowed 1s.
|
-
+
select {
case res := <-c1:
fmt.Println(res)
@@ -111,7 +113,7 @@ from c2 will succeed and we’ll print the result.
|
-
+
c2 := make(chan string, 1)
go func() {
time.Sleep(2 * time.Second)
@@ -140,7 +142,7 @@ out and the second succeeding.
|
-
+
$ go run timeouts.go
timeout 1
result 2
@@ -159,7 +161,7 @@ examples of this next: timers and tickers.
|
-
+
|
diff --git a/public/timers b/public/timers
index 7a11306..7004b5f 100644
--- a/public/timers
+++ b/public/timers
@@ -21,7 +21,7 @@ at tickers.
-
+
|
@@ -31,7 +31,9 @@ at tickers.
-
+
+
+
@@ -43,7 +45,7 @@ at tickers.
|
-
+
import "time"
import "fmt"
|
-
+
@@ -72,7 +74,7 @@ time. This timer will wait 2 seconds.
|
-
+
timer1 := time.NewTimer(2 * time.Second)
|
-
+
<-timer1.C
fmt.Println("Timer 1 expired")
|
-
+
timer2 := time.NewTimer(time.Second)
go func() {
<-timer2.C
@@ -132,7 +134,7 @@ a chance to expire.
|
-
+
$ go run timers.go
Timer 1 expired
Timer 2 stopped
diff --git a/public/url-parsing b/public/url-parsing
index efe547c..8b17377 100644
--- a/public/url-parsing
+++ b/public/url-parsing
@@ -18,7 +18,7 @@ Here’s how to parse URLs in Go.
|
-
+
|
@@ -28,7 +28,9 @@ Here’s how to parse URLs in Go.
-
+
+
+
@@ -40,7 +42,7 @@ Here’s how to parse URLs in Go.
|
-
+
import "fmt"
import "net"
import "net/url"
@@ -54,7 +56,7 @@ Here’s how to parse URLs in Go.
|
-
+
@@ -69,7 +71,7 @@ query params, and query fragment.
|
-
+
s := "postgres://user:pass@host.com:5432/path?k=v#f"
|
-
+
u, err := url.Parse(s)
if err != nil {
panic(err)
@@ -98,7 +100,7 @@ query params, and query fragment.
|
-
+
@@ -113,7 +115,7 @@ values.
|
-
+
fmt.Println(u.User)
fmt.Println(u.User.Username())
p, _ := u.User.Password()
@@ -130,7 +132,7 @@ if present. Use SplitHostPort to extract them.
|
-
+
fmt.Println(u.Host)
host, port, _ := net.SplitHostPort(u.Host)
fmt.Println(host)
@@ -147,7 +149,7 @@ the #.
|
-
+
fmt.Println(u.Path)
fmt.Println(u.Fragment)
|
-
+
fmt.Println(u.RawQuery)
m, _ := url.ParseQuery(u.RawQuery)
fmt.Println(m)
@@ -187,7 +189,7 @@ pieces that we extracted.
|
-
+
$ go run url-parsing.go
postgres
user:pass
diff --git a/public/values b/public/values
index 57317d7..38966a3 100644
--- a/public/values
+++ b/public/values
@@ -19,7 +19,7 @@ basic examples.
|
-
+
|
@@ -29,7 +29,9 @@ basic examples.
-
+
+
+
@@ -41,7 +43,7 @@ basic examples.
|
-
+
@@ -53,7 +55,7 @@ basic examples.
|
-
+
@@ -66,7 +68,7 @@ basic examples.
|
-
+
fmt.Println("go" + "lang")
|
-
+
fmt.Println("1+1 =", 1+1)
fmt.Println("7.0/3.0 =", 7.0/3.0)
|
-
+
fmt.Println(true && false)
fmt.Println(true || false)
fmt.Println(!true)
@@ -112,7 +114,7 @@ basic examples.
|
-
+
$ go run values.go
golang
1+1 = 2
diff --git a/public/variables b/public/variables
index a10e9c0..9c1156a 100644
--- a/public/variables
+++ b/public/variables
@@ -19,7 +19,7 @@ calls.
|
-
+
|
@@ -29,7 +29,9 @@ calls.
-
+
+
+
@@ -41,7 +43,7 @@ calls.
|
-
+
@@ -53,7 +55,7 @@ calls.
|
-
+
@@ -66,7 +68,7 @@ calls.
|
-
+
var a = "initial"
fmt.Println(a)
|
-
+
var b, c int = 1, 2
fmt.Println(b, c)
|
-
+
var d = true
fmt.Println(d)
int is 0.
|
-
+
@@ -126,7 +128,7 @@ initializing a variable, e.g. for
|
-
+
f := "apple"
fmt.Println(f)
}
@@ -144,7 +146,7 @@ initializing a variable, e.g. for
|
-
+
$ go run variables.go
initial
1 2
diff --git a/public/variadic-functions b/public/variadic-functions
index b789f72..75ce887 100644
--- a/public/variadic-functions
+++ b/public/variadic-functions
@@ -20,7 +20,7 @@ function.
|
-
+
|
@@ -30,7 +30,9 @@ function.
-
+
+
+
@@ -42,7 +44,7 @@ function.
|
-
+
@@ -56,7 +58,7 @@ of ints as arguments.
|
-
+
func sum(nums ...int) {
fmt.Print(nums, " ")
total := 0
@@ -75,7 +77,7 @@ of ints as arguments.
|
-
+
@@ -89,7 +91,7 @@ with individual arguments.
|
-
+
@@ -105,7 +107,7 @@ apply them to a variadic function using
|
-
+
nums := []int{1, 2, 3, 4}
sum(nums...)
}
@@ -123,7 +125,7 @@ apply them to a variadic function using
|
-
+
$ go run variadic-functions.go
[1 2] 3
[1 2 3] 6
@@ -140,7 +142,7 @@ to form closures, which we’ll look at next.
|
-
+
|
diff --git a/public/waitgroups b/public/waitgroups
index d2d6b2e..45792a8 100644
--- a/public/waitgroups
+++ b/public/waitgroups
@@ -18,7 +18,7 @@ use a wait group.
-
+
|
@@ -28,7 +28,9 @@ use a wait group.
-
+
+
+
@@ -40,7 +42,7 @@ use a wait group.
|
-
+
import (
"fmt"
"sync"
@@ -59,7 +61,7 @@ pointer.
|
-
+
func worker(id int, wg *sync.WaitGroup) {
fmt.Printf("Worker %d starting\n", id)
|
-
+
time.Sleep(time.Second)
fmt.Printf("Worker %d done\n", id)
|
-
+
@@ -100,7 +102,7 @@ pointer.
|
-
+
@@ -114,7 +116,7 @@ goroutines launched here to finish.
|
-
+
@@ -128,7 +130,7 @@ counter for each.
|
-
+
for i := 1; i <= 5; i++ {
wg.Add(1)
go worker(i, &wg)
@@ -145,7 +147,7 @@ all the workers notified they’re done.
|
-
+
@@ -162,7 +164,7 @@ all the workers notified they’re done.
|
-
+
$ go run waitgroups.go
Worker 5 starting
Worker 3 starting
@@ -186,7 +188,7 @@ is likely to be different for each invocation.
|
-
+
|
diff --git a/public/worker-pools b/public/worker-pools
index e437df8..e1170bf 100644
--- a/public/worker-pools
+++ b/public/worker-pools
@@ -18,7 +18,7 @@ a worker pool using goroutines and channels.
-
+
|
@@ -28,7 +28,9 @@ a worker pool using goroutines and channels.
-
+
+
+
@@ -40,7 +42,7 @@ a worker pool using goroutines and channels.
|
-
+
import "fmt"
import "time"
|
-
+
func worker(id int, jobs <-chan int, results chan<- int) {
for j := range jobs {
fmt.Println("worker", id, "started job", j)
@@ -77,7 +79,7 @@ simulate an expensive task.
|
-
+
@@ -92,7 +94,7 @@ channels for this.
|
-
+
jobs := make(chan int, 100)
results := make(chan int, 100)
|
-
+
for w := 1; w <= 3; w++ {
go worker(w, jobs, results)
}
@@ -123,7 +125,7 @@ channel to indicate that’s all the work we have.
|
-
+
for j := 1; j <= 5; j++ {
jobs <- j
}
@@ -142,7 +144,7 @@ goroutines is to use a WaitGroup.
|
-
+
for a := 1; a <= 5; a++ {
<-results
}
@@ -165,7 +167,7 @@ there are 3 workers operating concurrently.
|
-
+
$ time go run worker-pools.go
worker 1 started job 1
worker 2 started job 2
@@ -187,7 +189,7 @@ there are 3 workers operating concurrently.
|
-
+
diff --git a/public/writing-files b/public/writing-files
index b1a3fb9..ca974bd 100644
--- a/public/writing-files
+++ b/public/writing-files
@@ -18,7 +18,7 @@ ones we saw earlier for reading.
|
-
+
|
@@ -28,7 +28,9 @@ ones we saw earlier for reading.
-
+
+
+
@@ -40,7 +42,7 @@ ones we saw earlier for reading.
|
-
+
import (
"bufio"
"fmt"
@@ -57,7 +59,7 @@ ones we saw earlier for reading.
|
-
+
func check(e error) {
if e != nil {
panic(e)
@@ -73,7 +75,7 @@ ones we saw earlier for reading.
|
-
+
@@ -87,7 +89,7 @@ bytes) into a file.
|
-
+
d1 := []byte("hello\ngo\n")
err := ioutil.WriteFile("/tmp/dat1", d1, 0644)
check(err)
@@ -102,7 +104,7 @@ bytes) into a file.
|
-
+
f, err := os.Create("/tmp/dat2")
check(err)
|
-
+
@@ -130,7 +132,7 @@ after opening a file.
|
-
+
d2 := []byte{115, 111, 109, 101, 10}
n2, err := f.Write(d2)
check(err)
@@ -146,7 +148,7 @@ after opening a file.
|
-
+
n3, err := f.WriteString("writes\n")
fmt.Printf("wrote %d bytes\n", n3)
|
-
+
@@ -174,7 +176,7 @@ to the buffered readers we saw earlier.
|
-
+
w := bufio.NewWriter(f)
n4, err := w.WriteString("buffered\n")
fmt.Printf("wrote %d bytes\n", n4)
@@ -190,7 +192,7 @@ been applied to the underlying writer.
|
-
+
@@ -202,7 +204,7 @@ been applied to the underlying writer.
|
-
+
@@ -219,7 +221,7 @@ been applied to the underlying writer.
|
-
+
$ go run writing-files.go
wrote 5 bytes
wrote 7 bytes
@@ -235,7 +237,7 @@ been applied to the underlying writer.
|
-
+
$ cat /tmp/dat1
hello
go
@@ -255,7 +257,7 @@ we’ve just seen to the stdin and stdout streams.
|
-
+
|
diff --git a/templates/example.tmpl b/templates/example.tmpl
index b31f742..c9cfb7d 100644
--- a/templates/example.tmpl
+++ b/templates/example.tmpl
@@ -16,7 +16,9 @@
{{.DocsRendered}}
- {{if .CodeRun}}{{end}}
+ {{if .CodeRun}}
+
+ {{end}}
{{.CodeRendered}}
|