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fix: coding style and file format for chapter 11, 12, 13, 14 and 15.

Browse Source
This commit is contained in:
Bo-Yi Wu
2017-02-11 12:32:16 +08:00
parent c5413075c1
commit 4abbfabb52
63 changed files with 2662 additions and 2622 deletions
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6
eBook/exercises/chapter_11/float_sortmain.go
View File

@@ -1,12 +1,12 @@
package main
import (
"fmt"
"./float64"
"./float64"
"fmt"
)
func main() {
f1 := float64.NewFloat64Array()
f1 := float64.NewFloat64Array()
f1.Fill(10)
fmt.Printf("Before sorting %s\n", f1)
float64.Sort(f1)

22
eBook/exercises/chapter_11/interface_nil.go
View File

@@ -3,8 +3,8 @@ package main
import "fmt"
type Any interface {}
type Anything struct {}
type Any interface{}
type Anything struct{}
func main() {
any := getAny()
@@ -13,15 +13,15 @@ func main() {
} else {
fmt.Println("any is not nil")
}
/*
// to get the inner value:
anything := any.(*Anything)
if anything == nil {
fmt.Println("anything is nil")
} else {
fmt.Println("anything is not nil")
}
*/
/*
// to get the inner value:
anything := any.(*Anything)
if anything == nil {
fmt.Println("anything is nil")
} else {
fmt.Println("anything is not nil")
}
*/
}
func getAny() Any {

33
eBook/exercises/chapter_11/interface_poly3.go
View File

@@ -10,7 +10,8 @@ type Shaper interface {
Area() float32
}
type Shape struct {}
type Shape struct{}
func (sh Shape) Area() float32 {
return -1 // the shape is indetermined, so we return something impossible
}
@@ -25,12 +26,12 @@ func (sq *Square) Area() float32 {
}
type Rectangle struct {
length, width float32
Shape
length, width float32
Shape
}
func (r *Rectangle) Area() float32 {
return r.length * r.width
return r.length * r.width
}
type Circle struct {
@@ -39,21 +40,22 @@ type Circle struct {
}
func (c *Circle) Area() float32 {
return math.Pi * c.radius * c.radius
return math.Pi * c.radius * c.radius
}
func main() {
s := Shape{}
r := &Rectangle{5, 3, s} // Area() of Rectangle needs a value
q := &Square{5, s} // Area() of Square needs a pointer
c := &Circle{2.5, s}
shapes := []Shaper{r, q, c, s}
fmt.Println("Looping through shapes for area ...")
for n, _ := range shapes {
fmt.Println("Shape details: ", shapes[n])
fmt.Println("Area of this shape is: ", shapes[n].Area())
}
s := Shape{}
r := &Rectangle{5, 3, s} // Area() of Rectangle needs a value
q := &Square{5, s} // Area() of Square needs a pointer
c := &Circle{2.5, s}
shapes := []Shaper{r, q, c, s}
fmt.Println("Looping through shapes for area ...")
for n := range shapes {
fmt.Println("Shape details: ", shapes[n])
fmt.Println("Area of this shape is: ", shapes[n].Area())
}
}
/* Output:
Looping through shapes for area ...
Shape details: {5 3}
@@ -65,4 +67,3 @@ Area of this shape is: 19.634954
Shape details: {}
Area of this shape is: -1
*/

3
eBook/exercises/chapter_11/interfaces_ext.go
View File

@@ -18,6 +18,7 @@ type AreaInterface interface {
type PeriInterface interface {
Perimeter() float32
}
func main() {
var areaIntf AreaInterface
var periIntf PeriInterface
@@ -47,5 +48,5 @@ func (sq *Square) Perimeter() float32 {
}
func (tr *Triangle) Area() float32 {
return 0.5 * tr.base*tr.height
return 0.5 * tr.base * tr.height
}

27
eBook/exercises/chapter_11/interfaces_poly2.go
View File

@@ -19,11 +19,11 @@ func (sq *Square) Area() float32 {
}
type Rectangle struct {
length, width float32
length, width float32
}
func (r Rectangle) Area() float32 {
return r.length * r.width
return r.length * r.width
}
type Circle struct {
@@ -31,21 +31,22 @@ type Circle struct {
}
func (c *Circle) Area() float32 {
return math.Pi * c.radius * c.radius
return math.Pi * c.radius * c.radius
}
func main() {
r := Rectangle{5, 3} // Area() of Rectangle needs a value
q := &Square{5} // Area() of Square needs a pointer
c := &Circle{2.5}
fmt.Println("Looping through shapes for area ...")
// shapes := []Shaper{Shaper(r), Shaper(q), Shaper(c)}
shapes := []Shaper{r, q, c}
for n, _ := range shapes {
fmt.Println("Shape details: ", shapes[n])
fmt.Println("Area of this shape is: ", shapes[n].Area())
}
r := Rectangle{5, 3} // Area() of Rectangle needs a value
q := &Square{5} // Area() of Square needs a pointer
c := &Circle{2.5}
fmt.Println("Looping through shapes for area ...")
// shapes := []Shaper{Shaper(r), Shaper(q), Shaper(c)}
shapes := []Shaper{r, q, c}
for n := range shapes {
fmt.Println("Shape details: ", shapes[n])
fmt.Println("Area of this shape is: ", shapes[n].Area())
}
}
/* Output:
Looping through shapes for area ...
Shape details: {5 3}

3
eBook/exercises/chapter_11/main_stack.go
View File

@@ -2,8 +2,8 @@
package main
import (
"fmt"
"./stack/stack"
"fmt"
)
var st1 stack.Stack
@@ -21,6 +21,7 @@ func main() {
fmt.Println(item)
}
}
/* Output:
[Java C++ Python C# Ruby]
100

18
eBook/exercises/chapter_11/main_stack_v2.go
View File

@@ -2,16 +2,16 @@
package main
import (
"./stack/collection"
"fmt"
"./stack/collection"
"fmt"
)
func main() {
var s collection.Stack
s.Push("world")
s.Push("hello, ")
for s.Size() > 0 {
fmt.Print(s.Pop())
}
fmt.Println()
var s collection.Stack
s.Push("world")
s.Push("hello, ")
for s.Size() > 0 {
fmt.Print(s.Pop())
}
fmt.Println()
}

17
eBook/exercises/chapter_11/map_function_interface.go
View File

@@ -8,10 +8,10 @@ func main() {
// define a generic lambda function mf:
mf := func(i obj) obj {
switch i.(type) {
case int:
return i.(int) * 2
case string:
return i.(string) + i.(string)
case int:
return i.(int) * 2
case string:
return i.(string) + i.(string)
}
return i
}
@@ -30,7 +30,7 @@ func main() {
}
}
func mapFunc(mf func(obj) obj, list []obj) ([]obj) {
func mapFunc(mf func(obj) obj, list []obj) []obj {
result := make([]obj, len(list))
for ix, v := range list {
@@ -39,12 +39,13 @@ func mapFunc(mf func(obj) obj, list []obj) ([]obj) {
// Equivalent:
/*
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
*/
return result
}
/* Output:
0
2

17
eBook/exercises/chapter_11/map_function_interface_var.go
View File

@@ -8,10 +8,10 @@ func main() {
// define a generic lambda function mf:
mf := func(i obj) obj {
switch i.(type) {
case int:
return i.(int) * 2
case string:
return i.(string) + i.(string)
case int:
return i.(int) * 2
case string:
return i.(string) + i.(string)
}
return i
}
@@ -27,7 +27,7 @@ func main() {
}
}
func mapFunc(mf func(obj) obj, list ...obj) ([]obj) {
func mapFunc(mf func(obj) obj, list ...obj) []obj {
result := make([]obj, len(list))
for ix, v := range list {
@@ -36,12 +36,13 @@ func mapFunc(mf func(obj) obj, list ...obj) ([]obj) {
// Equivalent:
/*
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
*/
return result
}
/* Output:
0
2

20
eBook/exercises/chapter_11/min_interface.go
View File

@@ -7,22 +7,24 @@ type Miner interface {
Less(i, j int) bool
}
func Min(data Miner) interface{} {
func Min(data Miner) interface{} {
min := data.ElemIx(0)
for i:=1; i < data.Len(); i++ {
for i := 1; i < data.Len(); i++ {
if data.Less(i, i-1) {
min = data.ElemIx(i)
min = data.ElemIx(i)
}
}
return min
}
type IntArray []int
func (p IntArray) Len() int { return len(p) }
func (p IntArray) ElemIx(ix int) interface{} { return p[ix] }
func (p IntArray) Less(i, j int) bool { return p[i] < p[j] }
func (p IntArray) Len() int { return len(p) }
func (p IntArray) ElemIx(ix int) interface{} { return p[ix] }
func (p IntArray) Less(i, j int) bool { return p[i] < p[j] }
type StringArray []string
func (p StringArray) Len() int { return len(p) }
func (p StringArray) ElemIx(ix int) interface{} { return p[ix] }
func (p StringArray) Less(i, j int) bool { return p[i] < p[j] }
func (p StringArray) Len() int { return len(p) }
func (p StringArray) ElemIx(ix int) interface{} { return p[ix] }
func (p StringArray) Less(i, j int) bool { return p[i] < p[j] }

24
eBook/exercises/chapter_11/minmain.go
View File

@@ -2,27 +2,27 @@
package main
import (
"fmt"
"./min"
"./min"
"fmt"
)
func ints() {
data := []int{74, 59, 238, -784, 9845, 959, 905, 0, 0, 42, 7586, -5467984, 7586}
a := min.IntArray(data) //conversion to type IntArray
m := min.Min(a)
fmt.Printf("The minimum of the array is: %v\n", m)
data := []int{74, 59, 238, -784, 9845, 959, 905, 0, 0, 42, 7586, -5467984, 7586}
a := min.IntArray(data) //conversion to type IntArray
m := min.Min(a)
fmt.Printf("The minimum of the array is: %v\n", m)
}
func strings() {
data := []string{"ddd", "eee", "bbb", "ccc", "aaa"}
a := min.StringArray(data)
m := min.Min(a)
fmt.Printf("The minimum of the array is: %v\n", m)
data := []string{"ddd", "eee", "bbb", "ccc", "aaa"}
a := min.StringArray(data)
m := min.Min(a)
fmt.Printf("The minimum of the array is: %v\n", m)
}
func main() {
ints()
strings()
ints()
strings()
}
/* Output:

9
eBook/exercises/chapter_11/point_interfaces.go
View File

@@ -46,13 +46,13 @@ func main() {
m = p1 // p1 is type *Point, has method Abs()
fmt.Printf("The length of the vector p1 is: %f\n", m.Abs())
p2:= &Point{4, 5}
p2 := &Point{4, 5}
m = p2
fmt.Printf("The length of the vector p2 is: %f\n", m.Abs() )
fmt.Printf("The length of the vector p2 is: %f\n", m.Abs())
p1.Scale(5)
m = p1
fmt.Printf("The length of the vector p1 after scaling is: %f\n", m.Abs() )
fmt.Printf("The length of the vector p1 after scaling is: %f\n", m.Abs())
fmt.Printf("Point p1 after scaling has the following coordinates: X %f - Y %f\n", p1.X, p1.Y)
mag := m.Abs()
@@ -60,8 +60,9 @@ func main() {
mag += m.Abs()
m = Polar{2.0, math.Pi / 2}
mag += m.Abs()
fmt.Printf("The float64 mag is now: %f", mag )
fmt.Printf("The float64 mag is now: %f", mag)
}
/* Output:
The length of the vector p1 is: 5.000000
The length of the vector p2 is: 6.403124

23
eBook/exercises/chapter_11/print.go
View File

@@ -13,7 +13,7 @@ type Stringer interface {
type Celsius float64
func (c Celsius) String() string {
return strconv.FormatFloat(float64(c),'f', 1, 64) + " °C"
return strconv.FormatFloat(float64(c), 'f', 1, 64) + " °C"
}
type Day int
@@ -26,18 +26,25 @@ func (day Day) String() string {
func print(args ...interface{}) {
for i, arg := range args {
if i > 0 {os.Stdout.WriteString(" ")}
if i > 0 {
os.Stdout.WriteString(" ")
}
switch a := arg.(type) { // type switch
case Stringer: os.Stdout.WriteString(a.String())
case int: os.Stdout.WriteString(strconv.Itoa(a))
case string: os.Stdout.WriteString(a)
// more types
default: os.Stdout.WriteString("???")
case Stringer:
os.Stdout.WriteString(a.String())
case int:
os.Stdout.WriteString(strconv.Itoa(a))
case string:
os.Stdout.WriteString(a)
// more types
default:
os.Stdout.WriteString("???")
}
}
}
func main() {
print(Day(1), "was", Celsius(18.36)) // Tuesday was 18.4 °C
print(Day(1), "was", Celsius(18.36)) // Tuesday was 18.4 °C
}
// Tuesday was 18.4 °C

3
eBook/exercises/chapter_11/simple_interface.go
View File

@@ -29,6 +29,7 @@ func fI(it Simpler) int {
func main() {
var s Simple
fmt.Println(fI(&s)) // &s is required because Get() is defined with a receiver type pointer
fmt.Println(fI(&s)) // &s is required because Get() is defined with a receiver type pointer
}
// Output: 5

13
eBook/exercises/chapter_11/simple_interface2.go
View File

@@ -38,23 +38,24 @@ func (p *RSimple) Set(u int) {
func fI(it Simpler) int {
switch it.(type) {
case *Simple:
it.Set(5)
return it.Get()
it.Set(5)
return it.Get()
case *RSimple:
it.Set(50)
return it.Get()
it.Set(50)
return it.Get()
default:
return 99
return 99
}
return 0
}
func main() {
var s Simple
fmt.Println(fI(&s)) // &s is required because Get() is defined with a receiver type pointer
fmt.Println(fI(&s)) // &s is required because Get() is defined with a receiver type pointer
var r RSimple
fmt.Println(fI(&r))
}
/* Output:
5
50

19
eBook/exercises/chapter_11/simple_interface3.go
View File

@@ -38,25 +38,25 @@ func (p *RSimple) Set(u int) {
func fI(it Simpler) int {
switch it.(type) {
case *Simple:
it.Set(5)
return it.Get()
it.Set(5)
return it.Get()
case *RSimple:
it.Set(50)
return it.Get()
it.Set(50)
return it.Get()
default:
return 99
return 99
}
return 0
}
func gI(any interface{}) int {
// return any.(Simpler).Get() // unsafe, runtime panic possible
if v, ok := any.(Simpler); ok {
return v.Get()
}
return 0 // default value
return 0 // default value
}
/* Output:
6
60
@@ -64,10 +64,11 @@ func gI(any interface{}) int {
func main() {
var s Simple = Simple{6}
fmt.Println(gI(&s)) // &s is required because Get() is defined with a receiver type pointer
var r RSimple = RSimple{60,60}
fmt.Println(gI(&s)) // &s is required because Get() is defined with a receiver type pointer
var r RSimple = RSimple{60, 60}
fmt.Println(gI(&r))
}
/* Output:
6
60

12
eBook/exercises/chapter_11/sort/sort.go
View File

@@ -20,8 +20,8 @@ func Sort(Sorter Interface) {
*/
func Sort(data Sorter) {
for pass:=1; pass < data.Len(); pass++ {
for i:=0; i < data.Len() - pass; i++ {
for pass := 1; pass < data.Len(); pass++ {
for i := 0; i < data.Len()-pass; i++ {
if data.Less(i+1, i) {
data.Swap(i, i+1)
}
@@ -53,8 +53,8 @@ func (p StringArray) Less(i, j int) bool { return p[i] < p[j] }
func (p StringArray) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
// Convenience wrappers for common cases
func SortInts(a []int) { Sort(IntArray(a)) }
func SortStrings(a []string) { Sort(StringArray(a)) }
func SortInts(a []int) { Sort(IntArray(a)) }
func SortStrings(a []string) { Sort(StringArray(a)) }
func IntsAreSorted(a []int) bool { return IsSorted(IntArray(a)) }
func StringsAreSorted(a []string) bool { return IsSorted(StringArray(a)) }
func IntsAreSorted(a []int) bool { return IsSorted(IntArray(a)) }
func StringsAreSorted(a []string) bool { return IsSorted(StringArray(a)) }

14
eBook/exercises/chapter_11/sort_persons.go
View File

@@ -2,8 +2,8 @@
package main
import (
"fmt"
"./sort"
"fmt"
)
type Person struct {
@@ -21,15 +21,15 @@ func (p Persons) Less(i, j int) bool {
return in < jn
}
func (p Persons) Swap(i, j int) {
p[i], p[j] = p[j], p[i]
func (p Persons) Swap(i, j int) {
p[i], p[j] = p[j], p[i]
}
func main() {
p1 := Person{"Xavier","Papadopoulos"}
p2 := Person{"Chris","Naegels"}
p3 := Person{"John","Doe"}
arrP := Persons{p1,p2,p3}
p1 := Person{"Xavier", "Papadopoulos"}
p2 := Person{"Chris", "Naegels"}
p3 := Person{"John", "Doe"}
arrP := Persons{p1, p2, p3}
fmt.Printf("Before sorting: %v\n", arrP)
sort.Sort(arrP)
fmt.Printf("After sorting: %v\n", arrP)

2
eBook/exercises/chapter_11/stack/stack_general.go
View File

@@ -29,7 +29,7 @@ func (stack Stack) Top() (interface{}, error) {
}
func (stack *Stack) Pop() (interface{}, error) {
stk := *stack // dereference to a local variable stk
stk := *stack // dereference to a local variable stk
if len(stk) == 0 {
return nil, errors.New("stack is empty")
}

16
eBook/exercises/chapter_11/stack/stack_general_v2.go
View File

@@ -4,25 +4,25 @@ package collection
// The zero value for Stack is an empty stack ready to use.
type Stack struct {
data []interface{}
data []interface{}
}
// Push adds x to the top of the stack.
func (s *Stack) Push(x interface{}) {
s.data = append(s.data, x)
s.data = append(s.data, x)
}
// Pop removes and returns the top element of the stack.
// It's a run-time error to call Pop on an empty stack.
func (s *Stack) Pop() interface{} {
i := len(s.data) - 1
res := s.data[i]
s.data[i] = nil // to avoid memory leak
s.data = s.data[:i]
return res
i := len(s.data) - 1
res := s.data[i]
s.data[i] = nil // to avoid memory leak
s.data = s.data[:i]
return res
}
// Size returns the number of elements in the stack.
func (s *Stack) Size() int {
return len(s.data)
return len(s.data)
}

60
eBook/exercises/chapter_12/calculator.go
View File

@@ -4,11 +4,11 @@
package main
import (
"fmt"
"strconv"
"bufio"
"os"
"./stack/stack"
"bufio"
"fmt"
"os"
"strconv"
)
func main() {
@@ -21,35 +21,35 @@ func main() {
fmt.Println("Input error !")
os.Exit(1)
}
token = token[0:len(token)-2] // remove "\r\n"
token = token[0 : len(token)-2] // remove "\r\n"
// fmt.Printf("--%s--\n",token) // debug statement
switch {
case token == "q": // stop als invoer = "q"
fmt.Println("Calculator stopped")
return
case token >= "0" && token <= "999999":
i, _ := strconv.Atoi(token)
calc1.Push(i)
case token == "+":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int) + q.(int))
case token == "-":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int) - q.(int))
switch {
case token == "q": // stop als invoer = "q"
fmt.Println("Calculator stopped")
return
case token >= "0" && token <= "999999":
i, _ := strconv.Atoi(token)
calc1.Push(i)
case token == "+":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int)+q.(int))
case token == "-":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int)-q.(int))
case token == "*":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int) * q.(int))
case token == "*":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int)*q.(int))
case token == "/":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int) / q.(int))
default:
fmt.Println("No valid input")
case token == "/":
q, _ := calc1.Pop()
p, _ := calc1.Pop()
fmt.Printf("The result of %d %s %d = %d\n", p, token, q, p.(int)/q.(int))
default:
fmt.Println("No valid input")
}
}
}

6
eBook/exercises/chapter_12/cat_numbered.go
View File

@@ -1,11 +1,11 @@
package main
import (
"os"
"io"
"fmt"
"bufio"
"flag"
"fmt"
"io"
"os"
)
var numberFlag = flag.Bool("n", false, "number each line")

21
eBook/exercises/chapter_12/degob.go
View File

@@ -3,30 +3,30 @@ package main
import (
"bufio"
"fmt"
"encoding/gob"
"fmt"
"log"
"os"
)
type Address struct {
Type string
City string
Country string
Type string
City string
Country string
}
type VCard struct {
FirstName string
LastName string
Addresses []*Address
Remark string
FirstName string
LastName string
Addresses []*Address
Remark string
}
var content string
var content string
var vc VCard
func main() {
// using a decoder:
// using a decoder:
file, _ := os.Open("vcard.gob")
defer file.Close()
inReader := bufio.NewReader(file)
@@ -37,5 +37,6 @@ func main() {
}
fmt.Println(vc)
}
// Output:
// {Jan Kersschot [0x12642e60 0x12642e80] none}

17
eBook/exercises/chapter_12/hash_md5.go
View File

@@ -2,18 +2,19 @@
package main
import (
"fmt";
"crypto/md5"
"io"
"crypto/md5"
"fmt"
"io"
)
func main() {
hasher := md5.New()
b := []byte{}
io.WriteString(hasher, "test")
fmt.Printf("Result: %x\n", hasher.Sum(b))
fmt.Printf("Result: %d\n", hasher.Sum(b))
hasher := md5.New()
b := []byte{}
io.WriteString(hasher, "test")
fmt.Printf("Result: %x\n", hasher.Sum(b))
fmt.Printf("Result: %d\n", hasher.Sum(b))
}
/* Output:
Result: 098f6bcd4621d373cade4e832627b4f6
Result: [9 143 107 205 70 33 211 115 202 222 78 131 38 39 180 246]

13
eBook/exercises/chapter_12/read_csv.go
View File

@@ -4,17 +4,17 @@ package main
import (
"bufio"
"fmt"
"log"
"io"
"log"
"os"
"strconv"
"strings"
)
type Book struct {
title string
price float64
quantity int
title string
price float64
quantity int
}
func main() {
@@ -40,12 +40,12 @@ func main() {
book := new(Book)
book.title = strSl[0]
book.price, err = strconv.ParseFloat(strSl[1], 32)
if err!=nil {
if err != nil {
fmt.Printf("Error in file: %v", err)
}
//fmt.Printf("The quan was:-%s-", strSl[2])
book.quantity, err = strconv.Atoi(strSl[2])
if err!=nil {
if err != nil {
fmt.Printf("Error in file: %v", err)
}
if bks[0].title == "" {
@@ -59,6 +59,7 @@ func main() {
fmt.Println(bk)
}
}
/* Output:
We have read the following books from the file:
{"The ABC of Go" 25.5 1500}

4
eBook/exercises/chapter_12/remove_3till5char.go
View File

@@ -2,9 +2,9 @@
package main
import (
"bufio"
"fmt"
"io"
"bufio"
"os"
)
@@ -27,7 +27,7 @@ func main() {
//fmt.Printf("The output was: --%s--", outputString)
_, err := outputWriter.WriteString(outputString)
//fmt.Printf("Number of bytes written %d\n", n)
if (err != nil) {
if err != nil {
fmt.Println(err)
return
}

12
eBook/exercises/chapter_12/stack/stack_struct.go
View File

@@ -2,16 +2,17 @@
package stack
import "strconv"
const LIMIT = 10
type Stack struct {
ix int // first free position, so data[ix] == 0
data [LIMIT]int
ix int // first free position, so data[ix] == 0
data [LIMIT]int
}
func (st *Stack) Push(n int) {
if (st.ix + 1 > LIMIT) {
return // stack is full!
if st.ix+1 > LIMIT {
return // stack is full!
}
st.data[st.ix] = n
st.ix++
@@ -24,9 +25,8 @@ func (st *Stack) Pop() int {
func (st Stack) String() string {
str := ""
for ix:=0; ix<st.ix; ix++ {
for ix := 0; ix < st.ix; ix++ {
str += "[" + strconv.Itoa(ix) + ":" + strconv.Itoa(st.data[ix]) + "] "
}
return str
}

1
eBook/exercises/chapter_12/wiki_part1.go
View File

@@ -33,6 +33,7 @@ func main() {
new_page.load("Page.md")
fmt.Println(string(new_page.Body))
}
/* Output:
* # Page
* ## Section1

3
eBook/exercises/chapter_12/word_letter_count.go
View File

@@ -2,11 +2,12 @@
package main
import (
"fmt"
"bufio"
"fmt"
"os"
"strings"
)
var nrchars, nrwords, nrlines int
func main() {

1
eBook/exercises/chapter_13/panic_defer.go
View File

@@ -28,6 +28,7 @@ func g(i int) {
fmt.Println("Printing in g", i)
g(i + 1)
}
/* Output:
Calling g.
Printing in g 0

27
eBook/exercises/chapter_13/panic_defer_convint.go
View File

@@ -8,14 +8,14 @@ import (
func main() {
l := int64(15000)
if i, err := IntFromInt64(l); err!= nil {
if i, err := IntFromInt64(l); err != nil {
fmt.Printf("The conversion of %d to an int32 resulted in an error: %s", l, err.Error())
} else {
fmt.Printf("%d converted to an int32 is %d", l, i)
}
fmt.Println()
l = int64(math.MaxInt32 + 15000)
if i, err := IntFromInt64(l); err!= nil {
if i, err := IntFromInt64(l); err != nil {
fmt.Printf("The conversion of %d to an int32 resulted in an error: %s", l, err.Error())
} else {
fmt.Printf("%d converted to an int32 is %d", l, i)
@@ -23,21 +23,22 @@ func main() {
}
func ConvertInt64ToInt(l int64) int {
if math.MinInt32 <= l && l <= math.MaxInt32 {
return int(l)
}
panic(fmt.Sprintf("%d is out of the int32 range", l))
if math.MinInt32 <= l && l <= math.MaxInt32 {
return int(l)
}
panic(fmt.Sprintf("%d is out of the int32 range", l))
}
func IntFromInt64(l int64) (i int, err error) {
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("%v", e)
}
}()
i = ConvertInt64ToInt(l)
return i, nil
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("%v", e)
}
}()
i = ConvertInt64ToInt(l)
return i, nil
}
/* Output:
15000 converted to an int32 is 15000
The conversion of 2147498647 to an int32 resulted in an error: 2147498647 is out of the int32 range

27
eBook/exercises/chapter_13/recover_divbyzero.go
View File

@@ -6,27 +6,28 @@ import (
)
func badCall() {
a, b := 10, 0
n := a / b
fmt.Println(n)
a, b := 10, 0
n := a / b
fmt.Println(n)
}
func test() {
defer func() {
if e := recover(); e != nil {
fmt.Printf("Panicing %s\r\n", e);
}
defer func() {
if e := recover(); e != nil {
fmt.Printf("Panicing %s\r\n", e)
}
}()
badCall()
fmt.Printf("After bad call\r\n");
}()
badCall()
fmt.Printf("After bad call\r\n")
}
func main() {
fmt.Printf("Calling test\r\n");
test()
fmt.Printf("Test completed\r\n");
fmt.Printf("Calling test\r\n")
test()
fmt.Printf("Test completed\r\n")
}
/* Output:
Calling test
Panicing runtime error: integer divide by zero

30
eBook/exercises/chapter_13/string_reverse_test.go
View File

@@ -5,25 +5,25 @@ import "testing"
import "./strev"
type ReverseTest struct {
in, out string
in, out string
}
var ReverseTests = []ReverseTest {
ReverseTest{"ABCD", "DCBA"},
ReverseTest{"CVO-AZ", "ZA-OVC"},
ReverseTest{"Hello 世界", "界世 olleH"},
var ReverseTests = []ReverseTest{
{"ABCD", "DCBA"},
{"CVO-AZ", "ZA-OVC"},
{"Hello 世界", "界世 olleH"},
}
func TestReverse(t *testing.T) {
/*
in := "CVO-AZ"
out := Reverse(in)
exp := "ZA-OVC"
if out != exp {
t.Errorf("Reverse of %s expects %s, but got %s", in, exp, out)
}
*/
// testing with a battery of testdata:
/*
in := "CVO-AZ"
out := Reverse(in)
exp := "ZA-OVC"
if out != exp {
t.Errorf("Reverse of %s expects %s, but got %s", in, exp, out)
}
*/
// testing with a battery of testdata:
for _, r := range ReverseTests {
exp := strev.Reverse(r.in)
if r.out != exp {
@@ -34,7 +34,7 @@ func TestReverse(t *testing.T) {
func BenchmarkReverse(b *testing.B) {
s := "ABCD"
for i:=0; i < b.N; i++ {
for i := 0; i < b.N; i++ {
strev.Reverse(s)
}
}

1
eBook/exercises/chapter_14/channel_block3.go
View File

@@ -14,6 +14,7 @@ func main() {
c <- 10
fmt.Println("sent", 10)
}
/* Output:
sending 10
(15 s later):

1
eBook/exercises/chapter_14/channel_buffer.go
View File

@@ -14,6 +14,7 @@ func main() {
c <- 10
fmt.Println("sent", 10)
}
/* Output:
sending 10
sent 10 // prints immediately

1
eBook/exercises/chapter_14/concurrent_pi.go
View File

@@ -39,6 +39,7 @@ func CalculatePi(n int) float64 {
func term(ch chan float64, k float64) {
ch <- 4 * math.Pow(-1, k) / (2*k + 1)
}
/* Output:
3.14179261359579
The calculation took this amount of time: 0.028002

1
eBook/exercises/chapter_14/concurrent_pi2.go
View File

@@ -39,6 +39,7 @@ func term(ch chan float64, start, end int) {
}
ch <- result
}
/* Output:
3.1413926535917938
The calculation took this amount of time: 0.002000

3
eBook/exercises/chapter_14/general_lazy_evalution2.go
View File

@@ -18,7 +18,7 @@ func main() {
fib := BuildLazyUInt64Evaluator(fibFunc, []uint64{0, 1})
for i := 0; i < 10; i++ {
fmt.Printf("Fib nr %v: %v\n", i, fib())
fmt.Printf("Fib nr %v: %v\n", i, fib())
}
}
@@ -45,6 +45,7 @@ func BuildLazyUInt64Evaluator(evalFunc EvalFunc, initState Any) func() uint64 {
return ef().(uint64)
}
}
/* Output:
Fib nr 0: 0
Fib nr 1: 1

2
eBook/exercises/chapter_14/gofibonacci.go
View File

@@ -3,8 +3,8 @@ package main
import (
"fmt"
"time"
"os"
"time"
)
func main() {

1
eBook/exercises/chapter_14/gofibonacci2.go
View File

@@ -21,6 +21,7 @@ func main() {
fmt.Println(i)
}
}
/* Output:
1
1

1
eBook/exercises/chapter_14/gofibonacci_select.go
View File

@@ -27,6 +27,7 @@ func main() {
}()
fibonacci(c, quit)
}
/* Output:
1
1

4
eBook/exercises/chapter_14/goroutine_close.go
View File

@@ -6,7 +6,7 @@ import (
)
func tel(ch chan int) {
for i:=0; i < 15; i++ {
for i := 0; i < 15; i++ {
ch <- i
}
close(ch) // if this is ommitted: panic: all goroutines are asleep - deadlock!
@@ -19,7 +19,7 @@ func main() {
go tel(ch)
for ok {
if i, ok= <-ch; ok {
if i, ok = <-ch; ok {
fmt.Printf("ok is %t and the counter is at %d\n", ok, i)
}
}

11
eBook/exercises/chapter_14/goroutine_select.go
View File

@@ -7,7 +7,7 @@ import (
)
func tel(ch chan int, quit chan bool) {
for i:=0; i < 15; i++ {
for i := 0; i < 15; i++ {
ch <- i
}
quit <- true
@@ -21,11 +21,10 @@ func main() {
go tel(ch, quit)
for ok {
select {
case i:= <-ch:
fmt.Printf("The counter is at %d\n", i)
case <-quit:
os.Exit(0)
case i := <-ch:
fmt.Printf("The counter is at %d\n", i)
case <-quit:
os.Exit(0)
}
}
}

2
eBook/exercises/chapter_14/gosum.go
View File

@@ -12,5 +12,5 @@ func sum(x, y int, c chan int) {
func main() {
c := make(chan int)
go sum(12, 13, c)
fmt.Println(<-c) // 25
fmt.Println(<-c) // 25
}

3
eBook/exercises/chapter_14/multiplex_server3.go
View File

@@ -26,7 +26,7 @@ func server(op binOp, service chan *Request, quit chan bool) {
case req := <-service:
go run(op, req)
case <-quit:
return // stop infinite loop
return // stop infinite loop
}
}
}
@@ -52,6 +52,7 @@ func main() {
quit <- true
fmt.Print("done")
}
/* output:
3+4=7 150+250=400
done

1
eBook/exercises/chapter_14/polar_to_cartesian.go
View File

@@ -92,6 +92,7 @@ func floatsForStrings(numbers []string) ([]float64, error) {
}
return floats, nil
}
/* Output:
Enter a radius and an angle (in degrees), e.g., 12.5 90, or Ctrl+Z, Enter to qui
t.

1
eBook/exercises/chapter_14/producer_consumer.go
View File

@@ -28,6 +28,7 @@ func main() {
<-done
}
/* Output:
0
10

1
eBook/exercises/chapter_14/producer_consumer2.go
View File

@@ -26,4 +26,5 @@ func main() {
go consume()
<-done
}
// Output: 0 1 2 3 4 5 6 7 8 9

8
eBook/exercises/chapter_15/client1.go
View File

@@ -1,10 +1,10 @@
package main
import (
"fmt"
"os"
"net"
"bufio"
"fmt"
"net"
"os"
"strings"
)
@@ -41,6 +41,6 @@ func main() {
func checkError(error error) {
if error != nil {
panic("Error: " + error.Error()) // terminate program
panic("Error: " + error.Error()) // terminate program
}
}

5
eBook/exercises/chapter_15/hello_server.go
View File

@@ -8,12 +8,13 @@ import (
type Hello struct{}
func (h Hello) ServeHTTP(w http.ResponseWriter, r *http.Request) {
func (h Hello) ServeHTTP(w http.ResponseWriter, r *http.Request) {
fmt.Fprint(w, "Hello!")
}
func main() {
var h Hello
http.ListenAndServe("localhost:4000",h)
http.ListenAndServe("localhost:4000", h)
}
// Output in browser-window with url http://localhost:4000: Hello!

4
eBook/exercises/chapter_15/http_fetch2.go
View File

@@ -4,9 +4,9 @@ package main
import (
"bufio"
"fmt"
"net/http"
"io/ioutil"
"log"
"net/http"
"os"
"strings"
)
@@ -15,7 +15,7 @@ func main() {
fmt.Print("Give the url from which to read: ")
iread := bufio.NewReader(os.Stdin)
url, _ := iread.ReadString('\n')
url = strings.Trim(url," \n\r") // trimming space,etc.
url = strings.Trim(url, " \n\r") // trimming space,etc.
// fmt.Println("***", url,"***") // debugging
res, err := http.Get(url)
CheckError(err)

6
eBook/exercises/chapter_15/server1.go
View File

@@ -2,8 +2,8 @@ package main
import (
"fmt"
"os"
"net"
"os"
"strings"
)
@@ -48,7 +48,7 @@ func doServerStuff(conn net.Conn) {
}
// extract clientname:
ix := strings.Index(input, "says")
clName := input[0:ix-1]
clName := input[0 : ix-1]
//fmt.Printf("The clientname is ---%s---\n", string(clName))
// set clientname active in mapUsers:
mapUsers[string(clName)] = 1
@@ -61,7 +61,7 @@ func doServerStuff(conn net.Conn) {
// a simple return continues in the function where we came from!
func checkError(error error) {
if error != nil {
panic("Error: " + error.Error()) // terminate program
panic("Error: " + error.Error()) // terminate program
}
}

80
eBook/exercises/chapter_15/statistics.go
View File

@@ -3,11 +3,11 @@ package main
import (
"fmt"
"log"
"net/http"
"sort"
"strings"
"strconv"
"log"
"strings"
)
type statistics struct {
@@ -16,7 +16,7 @@ type statistics struct {
median float64
}
const form = `<html><body><form action="/" method="POST">
const form = `<html><body><form action="/" method="POST">
<label for="numbers">Numbers (comma or space-separated):</label><br>
<input type="text" name="numbers" size="30"><br />
<input type="submit" value="Calculate">
@@ -29,50 +29,50 @@ var pageBottom = ""
func main() {
http.HandleFunc("/", homePage)
if err := http.ListenAndServe(":9001", nil); err != nil {
log.Fatal("failed to start server", err)
}
if err := http.ListenAndServe(":9001", nil); err != nil {
log.Fatal("failed to start server", err)
}
}
func homePage(writer http.ResponseWriter, request *http.Request) {
writer.Header().Set("Content-Type", "text/html")
err := request.ParseForm() // Must be called before writing response
fmt.Fprint(writer, pageTop, form)
err := request.ParseForm() // Must be called before writing response
fmt.Fprint(writer, pageTop, form)
if err != nil {
fmt.Fprintf(writer, error, err)
} else {
if numbers, message, ok := processRequest(request); ok {
stats := getStats(numbers)
fmt.Fprint(writer, formatStats(stats))
} else if message != "" {
fmt.Fprintf(writer, error, message)
}
}
fmt.Fprint(writer, pageBottom)
fmt.Fprintf(writer, error, err)
} else {
if numbers, message, ok := processRequest(request); ok {
stats := getStats(numbers)
fmt.Fprint(writer, formatStats(stats))
} else if message != "" {
fmt.Fprintf(writer, error, message)
}
}
fmt.Fprint(writer, pageBottom)
}
func processRequest(request *http.Request) ([]float64, string, bool) {
var numbers []float64
var text string
if slice, found := request.Form["numbers"]; found && len(slice) > 0 {
//处理如果网页中输入的是中文逗号
if strings.Contains(slice[0], "&#65292") {
text = strings.Replace(slice[0], "&#65292;", " ", -1)
} else {
text = strings.Replace(slice[0], ",", " ", -1)
var numbers []float64
var text string
if slice, found := request.Form["numbers"]; found && len(slice) > 0 {
//处理如果网页中输入的是中文逗号
if strings.Contains(slice[0], "&#65292") {
text = strings.Replace(slice[0], "&#65292;", " ", -1)
} else {
text = strings.Replace(slice[0], ",", " ", -1)
}
for _, field := range strings.Fields(text) {
if x, err := strconv.ParseFloat(field, 64); err != nil {
return numbers, "'" + field + "' is invalid", false
} else {
numbers = append(numbers, x)
}
}
}
for _, field := range strings.Fields(text) {
if x, err := strconv.ParseFloat(field, 64); err != nil {
return numbers, "'" + field + "' is invalid", false
} else {
numbers = append(numbers, x)
}
}
}
if len(numbers) == 0 {
return numbers, "", false // no data first time form is shown
}
return numbers, "", true
if len(numbers) == 0 {
return numbers, "", false // no data first time form is shown
}
return numbers, "", true
}
func getStats(numbers []float64) (stats statistics) {
@@ -91,7 +91,7 @@ func sum(numbers []float64) (total float64) {
}
func median(numbers []float64) float64 {
middle := len(numbers)/2
middle := len(numbers) / 2
result := numbers[middle]
if len(numbers)%2 == 0 {
result = (result + numbers[middle-1]) / 2
@@ -100,7 +100,7 @@ func median(numbers []float64) float64 {
}
func formatStats(stats statistics) string {
return fmt.Sprintf(`<table border="1">
return fmt.Sprintf(`<table border="1">
<tr><th colspan="2">Results</th></tr>
<tr><td>Numbers</td><td>%v</td></tr>
<tr><td>Count</td><td>%d</td></tr>

3
eBook/exercises/chapter_15/template_validation_recover.go
View File

@@ -2,9 +2,9 @@
package main
import (
"text/template"
"fmt"
"log"
"text/template"
)
func main() {
@@ -22,6 +22,7 @@ func main() {
fmt.Println("The next one ought to fail.")
template.Must(tErr.Parse(" some static text {{ .Name }"))
}
/* Output:
The first one parsed OK.
The next one ought to fail.

33
eBook/exercises/chapter_15/twitter_status_json.go
View File

@@ -2,31 +2,32 @@
package main
import (
"net/http"
"fmt"
"encoding/json"
"io/ioutil"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
)
type Status struct {
Text string
Text string
}
type User struct {
Status Status
Status Status
}
func main() {
/* perform an HTTP request for the twitter status of user: Googland */
res, _:= http.Get("http://twitter.com/users/Googland.json")
/* initialize the structure of the JSON response */
user := User{Status{""}}
/* unmarshal the JSON into our structures */
temp, _ := ioutil.ReadAll(res.Body)
body := []byte(temp)
json.Unmarshal(body, &user)
fmt.Printf("status: %s", user.Status.Text)
func main() {
/* perform an HTTP request for the twitter status of user: Googland */
res, _ := http.Get("http://twitter.com/users/Googland.json")
/* initialize the structure of the JSON response */
user := User{Status{""}}
/* unmarshal the JSON into our structures */
temp, _ := ioutil.ReadAll(res.Body)
body := []byte(temp)
json.Unmarshal(body, &user)
fmt.Printf("status: %s", user.Status.Text)
}
/* Output:
status: Robot cars invade California, on orders from Google:
Google has been testing self-driving cars ... http://bit.ly/cbtpUN http://retwt.me/97p

20
eBook/exercises/chapter_15/webhello2.go
View File

@@ -2,23 +2,23 @@
package main
import (
"net/http"
"fmt"
"strings"
"fmt"
"net/http"
"strings"
)
func helloHandler(w http.ResponseWriter, r *http.Request) {
remPartOfURL := r.URL.Path[len("/hello/"):] //get everything after the /hello/ part of the URL
fmt.Fprintf(w, "Hello %s!", remPartOfURL)
remPartOfURL := r.URL.Path[len("/hello/"):] //get everything after the /hello/ part of the URL
fmt.Fprintf(w, "Hello %s!", remPartOfURL)
}
func shouthelloHandler(w http.ResponseWriter, r *http.Request) {
remPartOfURL := r.URL.Path[len("/shouthello/"):] //get everything after the /shouthello/ part of the URL
fmt.Fprintf(w, "Hello %s!", strings.ToUpper(remPartOfURL))
remPartOfURL := r.URL.Path[len("/shouthello/"):] //get everything after the /shouthello/ part of the URL
fmt.Fprintf(w, "Hello %s!", strings.ToUpper(remPartOfURL))
}
func main() {
http.HandleFunc("/hello/", helloHandler)
http.HandleFunc("/shouthello/", shouthelloHandler)
http.ListenAndServe("localhost:9999", nil)
http.HandleFunc("/hello/", helloHandler)
http.HandleFunc("/shouthello/", shouthelloHandler)
http.ListenAndServe("localhost:9999", nil)
}