Golang 架构中的要点解析，你知道都有哪些吗？

package main

import (
    "fmt"
)

func fibonacci(n int, c chan int) {
    x, y := 0, 1
    for i := 0; i < n; i++ {
        c <- x
        x, y = y, x+y
    }
    close(c)
}

func main() {
    c := make(chan int)
    
    go fibonacci(10, c)
    
    for num := range c {
        fmt.Println(num)
    }
}

package main

import "fmt"

type Shape interface {
    area() float64
}

type Rectangle struct {
    width, height float64
}

func (r Rectangle) area() float64 {
    return r.width * r.height
}

type Circle struct {
    radius float64
}

func (c Circle) area() float64 {
    return 3.14 * c.radius * c.radius
}

func main() {
    r := Rectangle{width: 5, height: 3}
    c := Circle{radius: 2}
    
    shapes := []Shape{r, c}
    
    for _, shape := range shapes {
        fmt.Println(shape.area())
    }
}

package main

import (
    "errors"
    "fmt"
)

func divide(a, b float64) (float64, error) {
    if b == 0 {
        return 0, errors.New("division by zero")
    }
    return a / b, nil
}

func main() {
    result, err := divide(6, 0)
    if err != nil {
        fmt.Println("Error:", err)
    } else {
        fmt.Println("Result:", result)
    }
}