Download as PDF, PPTX
![AN
INTRODUCTION
TO
FUNCTIONAL PROGRAMMING
IN
GO [Y COMBINATOR REMIX]
ELEANOR MCHUGH](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-1-2048.jpg)
![OO makes code understandable by
encapsulating moving parts.
FP makes code understandable by
minimizing moving parts.
Michael Feathers
@mfeathers
AN INTRODUCTION TO FUNCTIONAL PROGRAMMING IN GO [Y COMBINATOR REMIX]](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-3-2048.jpg)
 T {
return x + y
}
51.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-12-2048.jpg)
 T {
return x + y
}
51.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-13-2048.jpg)
 T {
return x + y
}
51.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-14-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-15-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-16-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-17-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-18-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-19-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-20-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-21-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-22-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-23-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-24-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-25-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-27-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-28-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-29-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-30-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-31-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-32-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-33-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-34-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-35-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-36-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-37-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-38-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-39-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-40-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-41-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-42-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-44-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-45-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-46-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-47-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-48-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-49-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-50-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-51-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-52-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-53-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-54-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-55-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-56-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-57-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-58-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-64-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-65-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-66-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-67-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-68-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-69-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-70-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-71-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-72-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-73-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-75-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-76-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-77-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-78-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-79-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-80-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-81-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
76.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-82-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-84-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-85-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-86-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-87-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-88-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-91-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-92-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-93-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-94-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-95-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-96-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-97-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-98-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-99-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-100-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-106-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-107-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-108-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-109-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-113-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-114-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-115-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-116-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-117-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-118-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-119-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-120-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-121-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-122-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-123-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-124-2048.jpg)
![THE Y COMBINATOR
type Function[T any] func(T) T
type Transformer[T any] func(Function[T]) Function[T]
type Recursive[T any] func(Recursive[T]) Function[T]
func (r Recursive[T]) Apply(f Transformer[T]) Function[T] {
return f(r(r))
}
func Y[T any](f Transformer[T]) Function[T] {
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
return r.Apply(f)(x)
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
os.Exit(factorial(5))
}
105.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-148-2048.jpg)
![THE Y COMBINATOR
type Function[T any] func(T) T
type Transformer[T any] func(Function[T]) Function[T]
type Recursive[T any] func(Recursive[T]) Function[T]
func (r Recursive[T]) Apply(f Transformer[T]) Function[T] {
return f(r(r))
}
func Y[T any](f Transformer[T]) Function[T] {
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
return r.Apply(f)(x)
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
os.Exit(factorial(5))
}
105.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-149-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-150-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-151-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-152-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-153-2048.jpg)
![AN
INTRODUCTION
TO
FUNCTIONAL PROGRAMMING
IN
GO [Y COMBINATOR REMIX]
ELEANOR MCHUGH](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-1-2048.jpg)
![OO makes code understandable by
encapsulating moving parts.
FP makes code understandable by
minimizing moving parts.
Michael Feathers
@mfeathers
AN INTRODUCTION TO FUNCTIONAL PROGRAMMING IN GO [Y COMBINATOR REMIX]](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-3-2048.jpg)
 T {
return x + y
}
51.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-12-2048.jpg)
 T {
return x + y
}
51.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-13-2048.jpg)
 T {
return x + y
}
51.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-14-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-15-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-16-2048.jpg)
![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))
}
type Scalar interface {
int | int8 | int16 | int32 | int64 |
uint | uint8 | uint16 | uint32 | uint64 |
float32 | float64
}
func add[T Scalar](x, y T) T {
return x + y
}
52.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-17-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-18-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-19-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-20-2048.jpg)
![A PURE FUNCTION
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[T Scalar](x, y T) T {
return x + y
}
53.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-21-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-22-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-23-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-24-2048.jpg)
![A PURE FUNCTION
func main() {
var sum int
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
sum = add(sum, x)
}
os.Exit(sum)
}
func add[T Scalar](x, y T) T {
return x + y
}
54.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-25-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-27-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-28-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-29-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-30-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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
}
55.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-31-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-32-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-33-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-34-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-35-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
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)
}
56.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-36-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-37-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-38-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-39-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-40-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-41-2048.jpg)
![FUNCTIONS WITH SIDE-EFFECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a(0))
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
59.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-42-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-44-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-45-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for _, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a(x)
}
os.Exit(a.Int())
}
type Accumulator[T Scalar] func(T) T
func MakeAccumulator[T Scalar]() Accumulator[T] {
var y T
return func(x T) T {
y += x
return y
}
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
61.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-46-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-47-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-48-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-49-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-50-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-51-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) {
var y T
a = func(x T) T {
y += x
return y
}
for _, v := range s {
a.Add(v)
}
return
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Accumulator[T]:
a(x(0))
}
return a
}
63.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-52-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-53-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-54-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-55-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-56-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-57-2048.jpg)
![FUNCTIONS AS OBJECTS
func main() {
a := MakeAccumulator[int]()
for i, v := range os.Args[1:] {
x, _ := strconv.Atoi(v)
a = a.Add(x).Add(MakeAccumulator(i))
}
os.Exit(a.Int())
}
type Integer interface {
Int() int
}
func (a Accumulator[T]) Int() int {
return int(a(0))
}
func (a Accumulator[T]) Add(x any) Accumulator[T] {
switch x := x.(type) {
case T:
a(x)
case Integer:
a(T(x.Int()))
}
return a
}
64.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-58-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-64-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-65-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-66-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-67-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-68-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-69-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
type Integer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
func Factorial[T Integer](n T) (r T) {
r = 1
switch {
case n < 0:
panic(n)
case n > 0:
for ; n > 0; n-- {
r *= n
}
}
return
}
72.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-70-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-71-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-72-2048.jpg)
![ITERATING FACTORIALS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
x, _ := strconv.Atoi(os.Args[1])
fmt.Printf("%v!: %vn", x, Factorial(x))
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
73.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-73-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-75-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-76-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-77-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
for _, v := range os.Args[1:] {
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
74.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-78-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-79-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-80-2048.jpg)
![PAINFUL EXCEPTIONS
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[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
75.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-81-2048.jpg)
![PAINFUL EXCEPTIONS
func main() {
for _, v := range os.Args[1:] {
func() {
defer func() {
if x := recover(); x != nil {
fmt.Println("no factorial")
}
}()
if x, e := strconv.Atoi(v); e == nil {
fmt.Printf("%v!: %vn", x, Factorial(x))
} else {
panic(v)
}
}()
}
}
func Factorial[T Integer](n T) (r T) {
if n < 0 {
panic(n)
}
for r = 1; n > 0; n-- {
r *= n
}
return
}
76.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-82-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-84-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-85-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-86-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-87-2048.jpg)
![HIGHER ORDER FUNCTIONS
func main() {
var errors int
computeFactorial := ForValidValues(
func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
},
func() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
errors++
}
})
for _, v := range os.Args[1:] {
computeFactorial(v)
}
os.Exit(errors)
}
func ForValidValues[T Integer](f func(T), e func()) func(string) {
return func(v string) {
defer e()
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
79.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-88-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-91-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-92-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-93-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-94-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-95-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-96-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-97-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-98-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-99-2048.jpg)
![CURRYING AND COMBINATORS
func main() {
printErrors := IfPanics(PrintErrorMessage)
for _, v := range os.Args[1:] {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
}
}
func ValidInteger[T Integer](v string, f func(i T)) func() {
return func() {
if x, e := strconv.Atoi(v); e == nil {
f(T(x))
} else {
panic(v)
}
}
}
func IfPanics(e func()) func(func()) {
return func(f func()) {
defer e()
f()
}
}
func PrintErrorMessage() {
if x := recover(); x != nil {
fmt.Printf("no defined value for %vn", x)
}
}
82.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-100-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-106-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-107-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-108-2048.jpg)
![RECURSION
var limit int
func init() {
if x, e := strconv.Atoi(os.Args[1]); e == nil {
limit = x
}
}
func main() {
limit--
if limit > 0 {
main()
}
}
85.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-109-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-113-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-114-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-115-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-116-2048.jpg)
![RECURSION
func main() {
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, Factorial(i))
}))
})
}
func Each[T any](s []T, f func(T)) {
if len(s) > 0 {
f(s[0])
Each(s[1:], f)
}
}
func Factorial[T Integer](n T) (r T) {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * Factorial(n-1)
}
return
}
91.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-117-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-118-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-119-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-120-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-121-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-122-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-123-2048.jpg)
![RECURSION
func main() {
f := MakeFactorial[int]()
printErrors := IfPanics(PrintErrorMessage)
Each(os.Args[1:], func(v string) {
printErrors(
ValidInteger(v, func(i int) {
fmt.Printf("%v!: %vn", i, f(i))
}))
})
}
func MakeFactorial[T Integer]() (f func(T) T) {
c := make(Cache[T])
return func(n T) (r T) {
if r = c[n]; r == 0 {
switch {
case n < 0:
panic(n)
case n == 0:
r = 1
default:
r = n * f(n-1)
}
c[n] = r
c.Dump()
}
return
}
}
type Cache[T Integer] map[T]T
func (c Cache[T]) Dump() {
for k, v := range c {
fmt.Printf("c[%v] = %vn", k, v)
}
}
95.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-124-2048.jpg)
![THE Y COMBINATOR
type Function[T any] func(T) T
type Transformer[T any] func(Function[T]) Function[T]
type Recursive[T any] func(Recursive[T]) Function[T]
func (r Recursive[T]) Apply(f Transformer[T]) Function[T] {
return f(r(r))
}
func Y[T any](f Transformer[T]) Function[T] {
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
return r.Apply(f)(x)
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
os.Exit(factorial(5))
}
105.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-148-2048.jpg)
![THE Y COMBINATOR
type Function[T any] func(T) T
type Transformer[T any] func(Function[T]) Function[T]
type Recursive[T any] func(Recursive[T]) Function[T]
func (r Recursive[T]) Apply(f Transformer[T]) Function[T] {
return f(r(r))
}
func Y[T any](f Transformer[T]) Function[T] {
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
return r.Apply(f)(x)
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
os.Exit(factorial(5))
}
105.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-149-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-150-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-151-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-152-2048.jpg)
 Function[T] {
memo := make(map[T]T)
g := func(r Recursive[T]) Function[T] {
return func(x T) T {
if _, ok := memo[x]; !ok {
memo[x] = r.Apply(f)(x)
fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x])
}
return memo[x]
}
}
return g(g)
}
func main() {
factorial := Y(func(g Function[int]) Function[int] {
return func(n int) int {
switch {
case n < 0:
panic(n)
case n < 2:
return 1
}
return n * g(n-1)
}
})
fmt.Printf("%v! = %vn", 7, factorial(7))
fmt.Printf("%v! = %vn", 8, factorial(8))
fmt.Printf("%v! = %vn", 5, factorial(5))
}
106.GO](https://crownmelresort.com/image.slidesharecdn.com/2024anintroductiontofunctionalprogrammingwithgoycombinatorremix-241007114312-7e90a89d/75/2024-An-Introduction-to-Functional-Programming-with-Go-Y-Combinator-Remix-pdf-153-2048.jpg)
Uploaded byEleanor McHugh
[2024] An Introduction to Functional Programming with Go [Y Combinator Remix].pdf
The document provides an introduction to functional programming in Go, contrasting it with object-oriented programming. It covers pure functions and functions with side effects, demonstrating various implementations through practical examples. The content emphasizes the efficiency and understandability brought by functional programming practices using Go.
More Related Content
Similar to [2024] An Introduction to Functional Programming with Go [Y Combinator Remix].pdf
![A Gopher's Guide to *NIX Plumbing [workshop remixes!]](https://cdn.slidesharecdn.com/ss_thumbnails/2025agophersguidetonixplumbingworkshop-251009084052-82af3656-thumbnail.jpg?width=640&height=640&fit=bounds)
![[2023] Putting the R! in R&D.pdf](https://cdn.slidesharecdn.com/ss_thumbnails/2023puttingtherinrd-231122234738-294b2909-thumbnail.jpg?width=640&height=640&fit=bounds)
![The Browser Environment - A Systems Programmer's Perspective [sinatra edition]](https://cdn.slidesharecdn.com/ss_thumbnails/2022thebrowserenvironment-asystemsprogrammersperspectivesinatraedition-220314193951-thumbnail.jpg?width=640&height=640&fit=bounds)
![An introduction to functional programming with Go [redux]](https://cdn.slidesharecdn.com/ss_thumbnails/anintroductiontofunctionalprogrammingwithgoredux-191022131211-thumbnail.jpg?width=640&height=640&fit=bounds)
[2024] An Introduction to Functional Programming with Go [Y Combinator Remix].pdf
- 1. AN INTRODUCTION TO FUNCTIONAL PROGRAMMING IN GO [YCOMBINATOR REMIX] ELEANOR MCHUGH
- 2. ELEANOR MCHUGH @feyeleanor MISAPPLIED PHYSICIST EMBEDDEDSYSTEMS VIRTUAL MACHINES P2P NETWORKING DIGITAL IDENTITY SECURE COMMS JAVASCRIPT RUBY GO
- 3. OO makes codeunderstandable by encapsulating moving parts. FP makes code understandable by minimizing moving parts. Michael Feathers @mfeathers AN INTRODUCTION TO FUNCTIONAL PROGRAMMING IN GO [Y COMBINATOR REMIX]
- 4.
- 5.
- 6.
- 7. A PURE FUNCTION packagemain import "os" func main() { os.Exit(add(3, 4)) } func add(x, y int) int { return x + y } 50.GO
- 8. A PURE FUNCTION packagemain import "os" func main() { os.Exit(add(3, 4)) } func add(x, y int) int { return x + y } 50.GO
- 9. A PURE FUNCTION packagemain import "os" func main() { os.Exit(add(3, 4)) } func add(x int, y int) int { return x + y } 50.GO
- 10. A PURE FUNCTION packagemain import "os" func main() { os.Exit(add(3, 4)) } func add(x int, y int) int { return x + y } 50.GO
- 11. A PURE FUNCTION packagemain import "os" func main() { os.Exit(add(3, 4)) } func add(x int, y int) int { return x + y } 50.GO
- 12. A PURE FUNCTION funcmain() { os.Exit(add(3, 4)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 51.GO
- 13. A PURE FUNCTION funcmain() { os.Exit(add(3, 4)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 51.GO
- 14. A PURE FUNCTION funcmain() { os.Exit(add(3, 4)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 51.GO
- 15. A PURE FUNCTION packagemain import "os" import "strconv" func main() { x, _ := strconv.Atoi(os.Args[1]) y, _ := strconv.Atoi(os.Args[2]) os.Exit(add(x, y)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 52.GO
- 16. A PURE FUNCTION packagemain import "os" import "strconv" func main() { x, _ := strconv.Atoi(os.Args[1]) y, _ := strconv.Atoi(os.Args[2]) os.Exit(add(x, y)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 52.GO
- 17. A PURE FUNCTION packagemain import "os" import "strconv" func main() { x, _ := strconv.Atoi(os.Args[1]) y, _ := strconv.Atoi(os.Args[2]) os.Exit(add(x, y)) } type Scalar interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | float32 | float64 } func add[T Scalar](x, y T) T { return x + y } 52.GO
- 18. A PURE FUNCTION funcmain() { os.Exit(add(arg(0), arg(1))) } func arg(n int) (r int) { r, _ = strconv.Atoi(os.Args[n + 1]) return } func add[T Scalar](x, y T) T { return x + y } 53.GO
- 19. A PURE FUNCTION funcmain() { os.Exit(add(arg(0), arg(1))) } func arg(n int) (r int) { r, _ = strconv.Atoi(os.Args[n + 1]) return } func add[T Scalar](x, y T) T { return x + y } 53.GO
- 20. A PURE FUNCTION funcmain() { os.Exit(add(arg(0), arg(1))) } func arg(n int) (r int) { r, _ = strconv.Atoi(os.Args[n + 1]) return } func add[T Scalar](x, y T) T { return x + y } 53.GO
- 21. A PURE FUNCTION funcmain() { os.Exit(add(arg(0), arg(1))) } func arg(n int) (r int) { r, _ = strconv.Atoi(os.Args[n + 1]) return } func add[T Scalar](x, y T) T { return x + y } 53.GO
- 22. A PURE FUNCTION funcmain() { var sum int for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) sum = add(sum, x) } os.Exit(sum) } func add[T Scalar](x, y T) T { return x + y } 54.GO
- 23. A PURE FUNCTION funcmain() { var sum int for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) sum = add(sum, x) } os.Exit(sum) } func add[T Scalar](x, y T) T { return x + y } 54.GO
- 24. A PURE FUNCTION funcmain() { var sum int for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) sum = add(sum, x) } os.Exit(sum) } func add[T Scalar](x, y T) T { return x + y } 54.GO
- 25. A PURE FUNCTION funcmain() { var sum int for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) sum = add(sum, x) } os.Exit(sum) } func add[T Scalar](x, y T) T { return x + y } 54.GO
- 26.
- 27. FUNCTIONS WITH SIDE-EFFECTS funcmain() { for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) accumulate(x) } os.Exit(y) } var y int func accumulate(x int) { y += x } 55.GO
- 28. FUNCTIONS WITH SIDE-EFFECTS funcmain() { for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) accumulate(x) } os.Exit(y) } var y int func accumulate(x int) { y += x } 55.GO
- 29. FUNCTIONS WITH SIDE-EFFECTS funcmain() { for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) accumulate(x) } os.Exit(y) } var y int func accumulate(x int) { y += x } 55.GO
- 30. FUNCTIONS WITH SIDE-EFFECTS funcmain() { for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) accumulate(x) } os.Exit(y) } var y int func accumulate(x int) { y += x } 55.GO
- 31. FUNCTIONS WITH SIDE-EFFECTS funcmain() { for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) accumulate(x) } os.Exit(y) } var y int func accumulate(x int) { y += x } 55.GO
- 32. FUNCTIONS WITH SIDE-EFFECTS funcmain() { 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) } 56.GO
- 33. FUNCTIONS WITH SIDE-EFFECTS funcmain() { 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) } 56.GO
- 34. FUNCTIONS WITH SIDE-EFFECTS funcmain() { 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) } 56.GO
- 35. FUNCTIONS WITH SIDE-EFFECTS funcmain() { 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) } 56.GO
- 36. FUNCTIONS WITH SIDE-EFFECTS funcmain() { 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) } 56.GO
- 37. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 38. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 39. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 40. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 41. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 42. FUNCTIONS WITH SIDE-EFFECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a(0)) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } 59.GO
- 43.
- 44. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a.Int()) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } func (a Accumulator[T]) Int() int { return int(a(0)) } 61.GO
- 45. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a.Int()) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } func (a Accumulator[T]) Int() int { return int(a(0)) } 61.GO
- 46. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for _, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a(x) } os.Exit(a.Int()) } type Accumulator[T Scalar] func(T) T func MakeAccumulator[T Scalar]() Accumulator[T] { var y T return func(x T) T { y += x return y } } func (a Accumulator[T]) Int() int { return int(a(0)) } 61.GO
- 47. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 48. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 49. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 50. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 51. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 52. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } func MakeAccumulator[T Scalar](s ...T) (a Accumulator[T]) { var y T a = func(x T) T { y += x return y } for _, v := range s { a.Add(v) } return } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Accumulator[T]: a(x(0)) } return a } 63.GO
- 53. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 54. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 55. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 56. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 57. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 58. FUNCTIONS AS OBJECTS funcmain() { a := MakeAccumulator[int]() for i, v := range os.Args[1:] { x, _ := strconv.Atoi(v) a = a.Add(x).Add(MakeAccumulator(i)) } os.Exit(a.Int()) } type Integer interface { Int() int } func (a Accumulator[T]) Int() int { return int(a(0)) } func (a Accumulator[T]) Add(x any) Accumulator[T] { switch x := x.(type) { case T: a(x) case Integer: a(T(x.Int())) } return a } 64.GO
- 59.
- 60.
- 61.
- 62. 0! = 1 1!= 1 2! = 2 3! = 6 4! = 24 5! = 120 6! = 720 7! = 5040 8! = 40320 9! = 362880 COMPUTING FACTORIALS
- 63.
- 64. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 65. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 66. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 67. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 68. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 69. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 70. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } type Integer interface { int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 } func Factorial[T Integer](n T) (r T) { r = 1 switch { case n < 0: panic(n) case n > 0: for ; n > 0; n-- { r *= n } } return } 72.GO
- 71. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 73.GO
- 72. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 73.GO
- 73. ITERATING FACTORIALS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() x, _ := strconv.Atoi(os.Args[1]) fmt.Printf("%v!: %vn", x, Factorial(x)) } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 73.GO
- 74.
- 75. PAINFUL EXCEPTIONS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() for _, v := range os.Args[1:] { if x, e := strconv.Atoi(v); e == nil { fmt.Printf("%v!: %vn", x, Factorial(x)) } else { panic(v) } } } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 74.GO
- 76. PAINFUL EXCEPTIONS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() for _, v := range os.Args[1:] { if x, e := strconv.Atoi(v); e == nil { fmt.Printf("%v!: %vn", x, Factorial(x)) } else { panic(v) } } } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 74.GO
- 77. PAINFUL EXCEPTIONS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() for _, v := range os.Args[1:] { if x, e := strconv.Atoi(v); e == nil { fmt.Printf("%v!: %vn", x, Factorial(x)) } else { panic(v) } } } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 74.GO
- 78. PAINFUL EXCEPTIONS func main(){ defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() for _, v := range os.Args[1:] { if x, e := strconv.Atoi(v); e == nil { fmt.Printf("%v!: %vn", x, Factorial(x)) } else { panic(v) } } } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 74.GO
- 79. PAINFUL EXCEPTIONS 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[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 75.GO
- 80. PAINFUL EXCEPTIONS 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[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 75.GO
- 81. PAINFUL EXCEPTIONS 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[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 75.GO
- 82. PAINFUL EXCEPTIONS func main(){ for _, v := range os.Args[1:] { func() { defer func() { if x := recover(); x != nil { fmt.Println("no factorial") } }() if x, e := strconv.Atoi(v); e == nil { fmt.Printf("%v!: %vn", x, Factorial(x)) } else { panic(v) } }() } } func Factorial[T Integer](n T) (r T) { if n < 0 { panic(n) } for r = 1; n > 0; n-- { r *= n } return } 76.GO
- 83.
- 84. HIGHER ORDER FUNCTIONS funcmain() { var errors int computeFactorial := ForValidValues( func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) }, func() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) errors++ } }) for _, v := range os.Args[1:] { computeFactorial(v) } os.Exit(errors) } func ForValidValues[T Integer](f func(T), e func()) func(string) { return func(v string) { defer e() if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } 79.GO
- 85. HIGHER ORDER FUNCTIONS funcmain() { var errors int computeFactorial := ForValidValues( func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) }, func() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) errors++ } }) for _, v := range os.Args[1:] { computeFactorial(v) } os.Exit(errors) } func ForValidValues[T Integer](f func(T), e func()) func(string) { return func(v string) { defer e() if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } 79.GO
- 86. HIGHER ORDER FUNCTIONS funcmain() { var errors int computeFactorial := ForValidValues( func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) }, func() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) errors++ } }) for _, v := range os.Args[1:] { computeFactorial(v) } os.Exit(errors) } func ForValidValues[T Integer](f func(T), e func()) func(string) { return func(v string) { defer e() if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } 79.GO
- 87. HIGHER ORDER FUNCTIONS funcmain() { var errors int computeFactorial := ForValidValues( func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) }, func() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) errors++ } }) for _, v := range os.Args[1:] { computeFactorial(v) } os.Exit(errors) } func ForValidValues[T Integer](f func(T), e func()) func(string) { return func(v string) { defer e() if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } 79.GO
- 88. HIGHER ORDER FUNCTIONS funcmain() { var errors int computeFactorial := ForValidValues( func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) }, func() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) errors++ } }) for _, v := range os.Args[1:] { computeFactorial(v) } os.Exit(errors) } func ForValidValues[T Integer](f func(T), e func()) func(string) { return func(v string) { defer e() if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } 79.GO
- 89.
- 90.
- 91. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 92. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 93. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 94. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 95. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 96. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 97. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 98. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 99. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 100. CURRYING AND COMBINATORS funcmain() { printErrors := IfPanics(PrintErrorMessage) for _, v := range os.Args[1:] { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) } } func ValidInteger[T Integer](v string, f func(i T)) func() { return func() { if x, e := strconv.Atoi(v); e == nil { f(T(x)) } else { panic(v) } } } func IfPanics(e func()) func(func()) { return func(f func()) { defer e() f() } } func PrintErrorMessage() { if x := recover(); x != nil { fmt.Printf("no defined value for %vn", x) } } 82.GO
- 101.
- 102. RECURSION package main func main(){ main() } 83.GO
- 103. RECURSION package main func main(){ main() } 83.GO
- 104. RECURSION package main func main(){ main() } 83.GO
- 105. RECURSION package main func main(){ defer func() { recover() } main() } 84.GO
- 106. RECURSION var limit int funcinit() { if x, e := strconv.Atoi(os.Args[1]); e == nil { limit = x } } func main() { limit-- if limit > 0 { main() } } 85.GO
- 107. RECURSION var limit int funcinit() { if x, e := strconv.Atoi(os.Args[1]); e == nil { limit = x } } func main() { limit-- if limit > 0 { main() } } 85.GO
- 108. RECURSION var limit int funcinit() { if x, e := strconv.Atoi(os.Args[1]); e == nil { limit = x } } func main() { limit-- if limit > 0 { main() } } 85.GO
- 109. RECURSION var limit int funcinit() { if x, e := strconv.Atoi(os.Args[1]); e == nil { limit = x } } func main() { limit-- if limit > 0 { main() } } 85.GO
- 110.
- 111.
- 112.
- 113. RECURSION func main() { printErrors:= IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) }) } func Each[T any](s []T, f func(T)) { if len(s) > 0 { f(s[0]) Each(s[1:], f) } } func Factorial[T Integer](n T) (r T) { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * Factorial(n-1) } return } 91.GO
- 114. RECURSION func main() { printErrors:= IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) }) } func Each[T any](s []T, f func(T)) { if len(s) > 0 { f(s[0]) Each(s[1:], f) } } func Factorial[T Integer](n T) (r T) { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * Factorial(n-1) } return } 91.GO
- 115. RECURSION func main() { printErrors:= IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) }) } func Each[T any](s []T, f func(T)) { if len(s) > 0 { f(s[0]) Each(s[1:], f) } } func Factorial[T Integer](n T) (r T) { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * Factorial(n-1) } return } 91.GO
- 116. RECURSION func main() { printErrors:= IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) }) } func Each[T any](s []T, f func(T)) { if len(s) > 0 { f(s[0]) Each(s[1:], f) } } func Factorial[T Integer](n T) (r T) { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * Factorial(n-1) } return } 91.GO
- 117. RECURSION func main() { printErrors:= IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, Factorial(i)) })) }) } func Each[T any](s []T, f func(T)) { if len(s) > 0 { f(s[0]) Each(s[1:], f) } } func Factorial[T Integer](n T) (r T) { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * Factorial(n-1) } return } 91.GO
- 118. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 119. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 120. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 121. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 122. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 123. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 124. RECURSION func main() { f:= MakeFactorial[int]() printErrors := IfPanics(PrintErrorMessage) Each(os.Args[1:], func(v string) { printErrors( ValidInteger(v, func(i int) { fmt.Printf("%v!: %vn", i, f(i)) })) }) } func MakeFactorial[T Integer]() (f func(T) T) { c := make(Cache[T]) return func(n T) (r T) { if r = c[n]; r == 0 { switch { case n < 0: panic(n) case n == 0: r = 1 default: r = n * f(n-1) } c[n] = r c.Dump() } return } } type Cache[T Integer] map[T]T func (c Cache[T]) Dump() { for k, v := range c { fmt.Printf("c[%v] = %vn", k, v) } } 95.GO
- 125.
- 126. THE Y COMBINATOR sogiven f(x) = x2 - 3x + 4 f(2) = 2 is a fi xed point meaning that calculating f for a value returns that value unchanged
- 127. THE Y COMBINATOR Yg = (λf.(λx.f (x x)) (λx.f (x x))) g = (λx.g (x x)) (λx.g (x x)) = g ((λx.g (x x)) (λx.g (x x))) = g (Y g) in untyped lambda calculus every function has a fi xed point (this is not the general case in mathematics) this Y combinator creates recursive functions from anonymous functions (func values in Go)
- 128. THE Y COMBINATOR //Y = ->f.(->x.f(x x))(->x.f(x x)) func Y(g func(any) any) func(any) any { return func(f any) func(any) any { return f.(func(any) any)(f).(func(any) any) }(func(f any) any { return g(func(x any) any { return f.(func(any) any)(f).(func(any) any)(x) }) }) } func main() { factorial := Y(func(g any) any { return func(n any) (r any) { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g.(func(any) any)(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 101.GO
- 129. THE Y COMBINATOR //Y = ->f.(->x.f(x x))(->x.f(x x)) func Y(g func(any) any) func(any) any { return func(f any) func(any) any { return f.(func(any) any)(f).(func(any) any) }(func(f any) any { return g(func(x any) any { return f.(func(any) any)(f).(func(any) any)(x) }) }) } func main() { factorial := Y(func(g any) any { return func(n any) (r any) { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g.(func(any) any)(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 101.GO
- 130. THE Y COMBINATOR //Y = ->f.(->x.f(x x))(->x.f(x x)) func Y(g func(any) any) func(any) any { return func(f any) func(any) any { return f.(func(any) any)(f).(func(any) any) }(func(f any) any { return g(func(x any) any { return f.(func(any) any)(f).(func(any) any)(x) }) }) } func main() { factorial := Y(func(g any) any { return func(n any) (r any) { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g.(func(any) any)(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 101.GO
- 131. THE Y COMBINATOR //Y = ->f.(->x.f(x x))(->x.f(x x)) func Y(g func(any) any) func(any) any { return func(f any) func(any) any { return f.(func(any) any)(f).(func(any) any) }(func(f any) any { return g(func(x any) any { return f.(func(any) any)(f).(func(any) any)(x) }) }) } func main() { factorial := Y(func(g any) any { return func(n any) (r any) { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g.(func(any) any)(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 101.GO
- 132. THE Y COMBINATOR //Y = ->f.(->x.f(x x))(->x.f(x x)) func Y(g func(any) any) func(any) any { return func(f any) func(any) any { return f.(func(any) any)(f).(func(any) any) }(func(f any) any { return g(func(x any) any { return f.(func(any) any)(f).(func(any) any)(x) }) }) } func main() { factorial := Y(func(g any) any { return func(n any) (r any) { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g.(func(any) any)(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 101.GO
- 133. THE Y COMBINATOR typeFunction func(any) any func Recurse(f any) Function { return f.(func(any) any)(f).(func(any) any) } func Y(g Function) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f)(x) }) }) } 102.GO
- 134. THE Y COMBINATOR typeFunction func(any) any func Recurse(f any) Function { return f.(func(any) any)(f).(func(any) any) } func Y(g Function) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f)(x) }) }) } 102.GO
- 135. THE Y COMBINATOR typeFunction func(any) any func Recurse(f any) Function { return f.(func(any) any)(f).(func(any) any) } func Y(g Function) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f)(x) }) }) } 102.GO
- 136. THE Y COMBINATOR Yg = (λf.(λx.f (x x)) (λx.f (x x))) g = (λx.g (x x)) (λx.g (x x)) = g ((λx.g (x x)) (λx.g (x x))) = g (Y g) in untyped lambda calculus every function has a fi xed point (this is not the general case in mathematics)
- 137. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function func Recurse(f Function) Function { return f(f).(Function) } func Y(g Transformer) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f.(Function))(x) }) }) } func main() { factorial := Y(func(g Function) Function { return func(n any) any { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 103.GO
- 138. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function func Recurse(f Function) Function { return f(f).(Function) } func Y(g Transformer) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f.(Function))(x) }) }) } func main() { factorial := Y(func(g Function) Function { return func(n any) any { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 103.GO
- 139. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function func Recurse(f Function) Function { return f(f).(Function) } func Y(g Transformer) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f.(Function))(x) }) }) } func main() { factorial := Y(func(g Function) Function { return func(n any) any { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 103.GO
- 140. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function func Recurse(f Function) Function { return f(f).(Function) } func Y(g Transformer) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f.(Function))(x) }) }) } func main() { factorial := Y(func(g Function) Function { return func(n any) any { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 103.GO
- 141. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function func Recurse(f Function) Function { return f(f).(Function) } func Y(g Transformer) Function { return Recurse( func(f any) any { return g(func(x any) any { return Recurse(f.(Function))(x) }) }) } func main() { factorial := Y(func(g Function) Function { return func(n any) any { if n, ok := n.(int); ok { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1).(int) } panic(n) } }) os.Exit(factorial(5).(int)) } 103.GO
- 142. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 143. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 144. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 145. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 146. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 147. THE Y COMBINATOR typeFunction func(any) any type Transformer func(Function) Function type Recursive func(Recursive) Function func (r Recursive) Apply(f Transformer) Function { return f(r(r)) } func Y(f Transformer) Function { g := func(r Recursive) Function { return func(x any) any { return r.Apply(f)(x) } } return g(g) } 104.GO
- 148. THE Y COMBINATOR typeFunction[T any] func(T) T type Transformer[T any] func(Function[T]) Function[T] type Recursive[T any] func(Recursive[T]) Function[T] func (r Recursive[T]) Apply(f Transformer[T]) Function[T] { return f(r(r)) } func Y[T any](f Transformer[T]) Function[T] { g := func(r Recursive[T]) Function[T] { return func(x T) T { return r.Apply(f)(x) } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) os.Exit(factorial(5)) } 105.GO
- 149. THE Y COMBINATOR typeFunction[T any] func(T) T type Transformer[T any] func(Function[T]) Function[T] type Recursive[T any] func(Recursive[T]) Function[T] func (r Recursive[T]) Apply(f Transformer[T]) Function[T] { return f(r(r)) } func Y[T any](f Transformer[T]) Function[T] { g := func(r Recursive[T]) Function[T] { return func(x T) T { return r.Apply(f)(x) } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) os.Exit(factorial(5)) } 105.GO
- 150. THE Y COMBINATOR funcY[T comparable](f Transformer[T]) Function[T] { memo := make(map[T]T) g := func(r Recursive[T]) Function[T] { return func(x T) T { if _, ok := memo[x]; !ok { memo[x] = r.Apply(f)(x) fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x]) } return memo[x] } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) fmt.Printf("%v! = %vn", 7, factorial(7)) fmt.Printf("%v! = %vn", 8, factorial(8)) fmt.Printf("%v! = %vn", 5, factorial(5)) } 106.GO
- 151. THE Y COMBINATOR funcY[T comparable](f Transformer[T]) Function[T] { memo := make(map[T]T) g := func(r Recursive[T]) Function[T] { return func(x T) T { if _, ok := memo[x]; !ok { memo[x] = r.Apply(f)(x) fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x]) } return memo[x] } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) fmt.Printf("%v! = %vn", 7, factorial(7)) fmt.Printf("%v! = %vn", 8, factorial(8)) fmt.Printf("%v! = %vn", 5, factorial(5)) } 106.GO
- 152. THE Y COMBINATOR funcY[T comparable](f Transformer[T]) Function[T] { memo := make(map[T]T) g := func(r Recursive[T]) Function[T] { return func(x T) T { if _, ok := memo[x]; !ok { memo[x] = r.Apply(f)(x) fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x]) } return memo[x] } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) fmt.Printf("%v! = %vn", 7, factorial(7)) fmt.Printf("%v! = %vn", 8, factorial(8)) fmt.Printf("%v! = %vn", 5, factorial(5)) } 106.GO
- 153. THE Y COMBINATOR funcY[T comparable](f Transformer[T]) Function[T] { memo := make(map[T]T) g := func(r Recursive[T]) Function[T] { return func(x T) T { if _, ok := memo[x]; !ok { memo[x] = r.Apply(f)(x) fmt.Printf("Y: setting memo[%v] = %vn", x, memo[x]) } return memo[x] } } return g(g) } func main() { factorial := Y(func(g Function[int]) Function[int] { return func(n int) int { switch { case n < 0: panic(n) case n < 2: return 1 } return n * g(n-1) } }) fmt.Printf("%v! = %vn", 7, factorial(7)) fmt.Printf("%v! = %vn", 8, factorial(8)) fmt.Printf("%v! = %vn", 5, factorial(5)) } 106.GO
- 154.
- 156.