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You can find the examples at https://github.com/feyeleanor/intro_to_fp_in_go
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8. THE CONDITIONAL LOOP
package main
import "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
fmt.Printf("%v: %vn", i, s[i])
}
}
9. THE CONDITIONAL LOOP
package main
import "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
fmt.Printf("%v: %vn", i, s[i])
}
}
10. THE CONDITIONAL LOOP
package main
import "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
fmt.Printf("%v: %vn", i, s[i])
}
}
11. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
12. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
13. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
14. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
15. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
16. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
17. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
18. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
19. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
20. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
21. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
22. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
23. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
24. THE CONDITIONAL LOOP
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
for i := 0; i < len(s); i++ {
Printf("%v: %vn", i, s[i])
}
}
42. ENUMERATION BY FUNCTION
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s []int) {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
43. ENUMERATION BY FUNCTION
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s []int) {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
44. ENUMERATION BY FUNCTION
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s []int) {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
45. ENUMERATION BY FUNCTION
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s []int) {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
46. ENUMERATION BY FUNCTION
package main
import . "fmt"
func main() {
print_slice(0, 2, 4, 6, 8)
}
func print_slice(s ...int) {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
48. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
for i, v := range s.([]int) {
Printf("%v: %vn", i, v)
}
}
49. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
for i, v := range s.([]int) {
Printf("%v: %vn", i, v)
}
}
50. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
for i, v := range s.([]int) {
Printf("%v: %vn", i, v)
}
}
51. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
if s, ok := s.([]int); ok {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
52. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
if s, ok := s.([]int); ok {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
53. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
if s, ok := s.([]int); ok {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
54. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
if s, ok := s.([]int); ok {
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
55. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
switch s := s.(type) {
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
56. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
switch s := s.(type) {
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
57. ABSTRACTING TYPE
package main
import . "fmt"
func main() {
print_slice([]int{0, 2, 4, 6, 8})
}
func print_slice(s interface{}) {
switch s := s.(type) {
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
76. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
77. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
78. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int, 16)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
79. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
80. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
81. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
82. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for i := 0; i++; i < 5 {
c <- i * 2
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
83. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for _, v := range []int{0, 2, 4, 6, 8} {
c <- v
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
84. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for _, v := range []int{0, 2, 4, 6, 8} {
c <- v
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
85. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for _, v := range []int{0, 2, 4, 6, 8} {
c <- v
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
86. CONCURRENCY
package main
import . "fmt"
func main() {
c := make(chan int)
go func() {
for _, v := range []int{0, 2, 4, 6, 8} {
c <- v
}
close(c)
}()
print_channel(c)
}
func print_channel(c chan int) (i int) {
for v := range c {
Printf("%v: %vn", i, v)
i++
}
return
}
88. INFINITE SEQUENCES
package main
import . "fmt"
func main() {
c := make(chan int)
go sequence(c)
print_channel(c)
}
func sequence(c chan int) {
for i := 0; ; i++ {
c <- i * 2
}
}
func print_channel(c chan int) {
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, <- c)
}
return
}
89. INFINITE SEQUENCES
package main
import . "fmt"
func main() {
c := make(chan int)
go sequence(c)
print_channel(c)
}
func sequence(c chan int) {
for i := 0; ; i++ {
c <- i * 2
}
}
func print_channel(c chan int) {
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, <- c)
}
return
}
90. INFINITE SEQUENCES
package main
import . "fmt"
func main() {
c := make(chan int)
go sequence(c)
print_channel(c)
}
func sequence(c chan int) {
for i := 0; ; i++ {
c <- i * 2
}
}
func print_channel(c chan int) {
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, <- c)
}
return
}
91. INFINITE SEQUENCES
package main
import . "fmt"
func main() {
c := make(chan int)
go sequence(c)
print_channel(c)
}
func sequence(c chan int) {
for i := 0; ; i++ {
c <- i * 2
}
}
func print_channel(c chan int) {
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, <- c)
}
return
}
92. INFINITE SEQUENCES
package main
import . "fmt"
func main() {
c := make(chan int)
go sequence(c)
print_channel(c)
}
func sequence(c chan int) {
for i := 0; ; i++ {
c <- i * 2
}
}
func print_channel(c chan int) {
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, <- c)
}
return
}
94. WORKING WITH KINDS
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := s.(type) {
case func(int) int:
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, s(i))
}
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
95. WORKING WITH KINDS
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := s.(type) {
case func(int) int:
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, s(i))
}
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
96. WORKING WITH KINDS
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := s.(type) {
case func(int) int:
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, s(i))
}
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
97. WORKING WITH KINDS
package main
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := s.(type) {
case func(int) int:
for i := 0; i < 5; i++ {
Printf("%v: %vn", i, s(i))
}
case []int:
for i, v := range s {
Printf("%v: %vn", i, v)
}
}
}
98. WORKING WITH KINDS
package main
import "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := reflect.ValueOf(s); s.Kind() {
case reflect.Func:
for i := 0; i < 5; i++ {
p := []reflect.Value{ reflect.ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case reflect.Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
99. WORKING WITH KINDS
package main
import "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := reflect.ValueOf(s); s.Kind() {
case reflect.Func:
for i := 0; i < 5; i++ {
p := []reflect.Value{ reflect.ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case reflect.Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
100. WORKING WITH KINDS
package main
import "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := reflect.ValueOf(s); s.Kind() {
case reflect.Func:
for i := 0; i < 5; i++ {
p := []reflect.Value{ reflect.ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case reflect.Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
101. WORKING WITH KINDS
package main
import "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := reflect.ValueOf(s); s.Kind() {
case reflect.Func:
for i := 0; i < 5; i++ {
p := []reflect.Value{ reflect.ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case reflect.Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
102. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := ValueOf(s); s.Kind() {
case Func:
for i := 0; i < 5; i++ {
p := []Value{ ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
103. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := ValueOf(s); s.Kind() {
case Func:
for i := 0; i < 5; i++ {
p := []Value{ ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
104. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := ValueOf(s); s.Kind() {
case Func:
for i := 0; i < 5; i++ {
p := []Value{ ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case Slice:
for i := 0; i < s.Len(); i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
105. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
defer func() {
recover()
}
switch s := ValueOf(s); s.Kind() {
case Func:
for i := 0; ; i++ {
p := []Value{ ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
}
case Slice:
for i := 0; ; i++ {
Printf("%v: %vn", i, s.Index(i).Interface())
}
}
}
106. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := ValueOf(s); s.Kind() {
case Func:
for_each(func(i int) {
p := []Value{ ValueOf(i) }
Printf("%v: %vn", i, s.Call(p)[0].Interface())
})
case Slice:
for_each(func(i int) {
Printf("%v: %vn", i, s.Index(i).Interface())
})
}
}
func for_each(f func(int)) (i int) {
defer func() {
recover()
}
for ; ; i++ {
f(i)
}
}
107. WORKING WITH KINDS
package main
import . "reflect"
import . "fmt"
func main() {
s := []int{0, 2, 4, 6, 8}
print_values(s)
print_values(func(i int) int {
return s[i]
})
}
func print_values(s interface{}) {
switch s := ValueOf(s); s.Kind() {
case Func:
p := make([]Value, 1)
for_each(func(i int) {
p[0] = ValueOf(i)
Printf("%v: %vn", i, s.Call(p)[0].Interface())
})
case Slice:
for_each(func(i int) {
Printf("%v: %vn", i, s.Index(i).Interface())
})
}
}
func for_each(f func(int)) (i int) {
defer func() {
recover()
}
for ; ; i++ {
f(i)
}
}
116. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
var s Iterable = IterableSlice{ 0, 2, 4, 6, 8 }
i := 0
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
}
type Iterable interface {
Each(func(interface{}))
}
type IterableSlice []int
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
117. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
var s Iterable = IterableSlice{ 0, 2, 4, 6, 8 }
i := 0
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
}
type Iterable interface {
Each(func(interface{}))
}
type IterableSlice []int
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
118. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
var s Iterable = IterableSlice{ 0, 2, 4, 6, 8 }
i := 0
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
}
type Iterable interface {
Each(func(interface{}))
}
type IterableSlice []int
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
119. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
print_values(IterableLimit(5))
print_values(IterableSlice{ 0, 2, 4, 6, 8 })
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableLimit int
type IterableSlice []int
func (i IterableLimit) Each(f func(interface{})) {
for v := IterableLimit(0); v < i; v++ {
f(v)
}
}
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
120. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
print_values(IterableLimit(5))
print_values(IterableSlice{ 0, 2, 4, 6, 8 })
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableLimit int
type IterableSlice []int
func (i IterableLimit) Each(f func(interface{})) {
for v := IterableLimit(0); v < i; v++ {
f(v)
}
}
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
121. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
print_values(IterableLimit(5))
print_values(IterableSlice{ 0, 2, 4, 6, 8 })
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableLimit int
type IterableSlice []int
func (i IterableLimit) Each(f func(interface{})) {
for v := IterableLimit(0); v < i; v++ {
f(v)
}
}
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
122. INTERFACES = POLYMORPHISM
package main
import . "fmt"
func main() {
print_values(IterableLimit(5))
print_values(IterableSlice{ 0, 2, 4, 6, 8 })
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableLimit int
type IterableSlice []int
func (i IterableLimit) Each(f func(interface{})) {
for v := IterableLimit(0); v < i; v++ {
f(v)
}
}
func (i IterableSlice) Each(f func(interface{})) {
for _, v := range i {
f(v)
}
}
124. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
125. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
126. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
127. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
128. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := &IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
129. IMMUTABILITY IS A CHOICE
package main
import . "fmt"
func main() {
s := &IterableRange{ 0, 2, 5 }
print_values(s)
print_values(s)
}
func print_values(s Iterable) (i int) {
s.Each(func(v interface{}) {
Printf("%v: %vn", i, v)
i++
})
return i
}
type Iterable interface {
Each(func(interface{}))
}
type IterableRange struct {
start int
step int
limit int
}
func (r *IterableRange) Each(f func(interface{})) {
for; r.limit > 0; r.limit-- {
f(r.start)
r.start += r.step
}
}
130. OO makes code understandable by
encapsulating moving parts.
FP makes code understandable by
minimizing moving parts.
Michael Feathers
@mfeathers
LEANPUB://GONOTEBOOK
133. A PURE FUNCTION
package main
import "os"
func main() {
os.Exit(add(3, 4))
}
func add(x, y int) int {
return x + y
}
134. A PURE FUNCTION
package main
import "os"
func main() {
os.Exit(add(3, 4))
}
func add(x, y int) int {
return x + y
}
135. A PURE FUNCTION
package main
import "os"
func main() {
os.Exit(add(3, 4))
}
func add(x int, y int) int {
return x + y
}
136. A PURE FUNCTION
package main
import "os"
func main() {
os.Exit(add(3, 4))
}
func add(x int, y int) int {
return x + y
}
137. A PURE FUNCTION
package main
import "os"
func main() {
os.Exit(add(3, 4))
}
func add(x int, y int) int {
return x + y
}
138. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
x, _ := strconv.Atoi(os.Args[1])
y, _ := strconv.Atoi(os.Args[2])
os.Exit(add(x, y))
}
func add(x, y int) int {
return x + y
}
139. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
x, _ := strconv.Atoi(os.Args[1])
y, _ := strconv.Atoi(os.Args[2])
os.Exit(add(x, y))
}
func add(x, y int) int {
return x + y
}
140. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
x, _ := strconv.Atoi(os.Args[1])
y, _ := strconv.Atoi(os.Args[2])
os.Exit(add(x, y))
}
func add(x, y int) int {
return x + y
}
141. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
os.Exit(add(arg(0), arg(1)))
}
func arg(n int) (r int) {
r, _ = strconv.Atoi(os.Args[n + 1])
return
}
func add(x, y int) int {
return x + y
}
142. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add(x, y int) int {
return x + y
}
143. A PURE FUNCTION
package main
import "os"
import "strconv"
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add(x, y int) int {
return x + y
}
145. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
accumulate(x)
}
os.Exit(y)
}
var y int
func accumulate(x int) {
y += x
}
146. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
accumulate(x)
}
os.Exit(y)
}
var y int
func accumulate(x int) {
y += x
}
147. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
accumulate(x)
}
os.Exit(y)
}
var y int
func accumulate(x int) {
y += x
}
148. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
accumulate(x)
}
os.Exit(y)
}
var y int
func accumulate(x int) {
y += x
}
149. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(x)
}
os.Exit(int(a))
}
var a Accumulator
type Accumulator int
func (a *Accumulator) Add(y int) {
*a += Accumulator(y)
}
150. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(x)
}
os.Exit(int(a))
}
var a Accumulator
type Accumulator int
func (a *Accumulator) Add(y int) {
*a += Accumulator(y)
}
151. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(x)
}
os.Exit(int(a))
}
var a Accumulator
type Accumulator int
func (a *Accumulator) Add(y int) {
*a += Accumulator(y)
}
152. BEING IMPURE
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(x)
}
os.Exit(int(a))
}
var a Accumulator
type Accumulator int
func (a Accumulator) Add(y int) {
a += Accumulator(y)
}
154. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
155. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
156. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
157. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
158. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
159. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
var a = MakeAccumulator()
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
160. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
161. FUNCTIONS WITH MEMORY
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
func MakeAccumulator() func(int) int {
var y int
return func(x int) int {
y += x
return y
}
}
163. FUNCTIONS AS OBJECTS
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
func (a Accumulator) Int() int {
return a(0)
}
164. FUNCTIONS AS OBJECTS
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
func (a Accumulator) Int() int {
return a(0)
}
165. FUNCTIONS AS OBJECTS
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(x)
}
os.Exit(a.Int())
}
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
func (a Accumulator) Int() int {
return a(0)
}
func (a Accumulator) Add(x
interface{}) {
switch x := x.(type) {
case int:
a(x)
case Accumulator:
a(x.Value())
}
}
166. FUNCTIONS AS OBJECTS
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(MakeAccumulator()(x))
}
os.Exit(a.Int())
}
type Accumulator func(int) int
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
func (a Accumulator) Int() int {
return a(0)
}
func (a Accumulator) Add(x
interface{}) {
switch x := x.(type) {
case int:
a(x)
case Accumulator:
a(x.Value())
}
}
167. FUNCTIONS AS OBJECTS
package main
import "os"
import "strconv"
func main() {
a := MakeAccumulator()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a.Add(MakeAccumulator()(x))
}
os.Exit(a.Int())
}
type Accumulator func(int) int
type Integer interface {
Int() int
}
func MakeAccumulator() Accumulator {
var y int
return func(x int) int {
y += x
return y
}
}
func (a Accumulator) Int() int {
return a(0)
}
func (a Accumulator) Add(x interface{}) {
switch x := x.(type) {
case int:
a(x)
case Integer:
a(x.Int())
}
}
172. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
173. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
174. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
175. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
176. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
177. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = 1
for ; n > 0; n-- {
r *= n
}
}
return
}
178. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) int {
r := 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return r
}
179. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
180. ITERATING FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
Printf("%v!: %vn", x, Factorial(x))
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
182. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e != nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
183. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e != nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
184. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
185. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
186. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
187. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
188. MULTIPLE FACTORIALS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
190. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
191. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
192. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
193. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
194. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
SafeExecute(func(i int) {
Printf("%v!: %vn", i, Factorial(i))
})(v)
}
}
func SafeExecute(f func(int)) func(string) {
return func(v string) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
195. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
SafeExecute(func(i int) {
Printf("%v!: %vn", i, Factorial(i))
})(v)
}
}
func SafeExecute(f func(int)) func(string) {
return func(v string) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
196. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
SafeExecute(func(i int) {
Printf("%v!: %vn", i, Factorial(i))
})(v)
}
}
func SafeExecute(f func(int)) func(string) {
return func(v string) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
197. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
for _, v := range os.Args[1:] {
SafeExecute(func(i int) {
Printf("%v!: %vn", i, Factorial(i))
})(v)
}
}
func SafeExecute(f func(int)) func(string) {
return func(v string) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
198. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
f := func(i int) {
Printf("%v!: %vn", i, Factorial(i))
}
for _, v := range os.Args[1:] {
if !SafeExecute(f)(v) {
errors++
}
}
os.Exit(errors)
}
func SafeExecute(f func(int)) func(string) bool {
return func(v string) (r bool) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
s}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
r = true
} else {
panic(v)
}
return
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
199. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
f := func(i int) {
Printf("%v!: %vn", i, Factorial(i))
}
for _, v := range os.Args[1:] {
if !SafeExecute(f)(v) {
errors++
}
}
os.Exit(errors)
}
func SafeExecute(f func(int)) func(string) bool {
return func(v string) (r bool) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
r = true
} else {
panic(v)
}
return
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
200. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
f := func(i int) {
Printf("%v!: %vn", i, Factorial(i))
}
for _, v := range os.Args[1:] {
if !SafeExecute(f)(v) {
errors++
}
}
os.Exit(errors)
}
func SafeExecute(f func(int)) func(string) bool {
return func(v string) (r bool) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
r = true
} else {
panic(v)
}
return
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
201. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
f := func(i int) {
Printf("%v!: %vn", i, Factorial(i))
}
for _, v := range os.Args[1:] {
if !SafeExecute(f)(v) {
errors++
}
}
os.Exit(errors)
}
func SafeExecute(f func(int)) func(string) bool {
return func(v string) (r bool) {
defer func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
}
}()
if x, e := strconv.Atoi(v); e == nil {
f(x)
r = true
} else {
panic(v)
}
return
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
202. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
for _, v := range os.Args[1:] {
SafeExecute(
func(i int) {
Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
errors++
}
},
)(v)
}
os.Exit(errors)
}
func SafeExecute(f func(int), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
203. HIGHER ORDER FUNCTIONS
package main
import . "fmt"
import "os"
import "strconv"
func main() {
var errors int
for _, v := range os.Args[1:] {
SafeExecute(
func(i int) {
Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
Printf("no defined value for %vn", x)
errors++
}
},
)(v)
}
os.Exit(errors)
}
func SafeExecute(f func(int), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(x)
} else {
panic(v)
}
}
}
func Factorial(n int) (r int) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}