如何在我的本地环境中运行 Effective GO 源代码？

Question

I am beginning learn GO, I try to run the Effective GO ( https://go.dev/doc/effective_go#multiple-returns ) example source code in my local environment(GO 1.18+VS code). For example

func nextInt(b []byte, i int) (int, int) {
    for ; i < len(b) && !isDigit(b[i]); i++ {
    }
    x := 0
    for ; i < len(b) && isDigit(b[i]); i++ {
        x = x*10 + int(b[i]) - '0'
    }
    return x, i
}

for i := 0; i < len(b); {
        x, i = nextInt(b, i)
        fmt.Println(x)
    } 

Another example:

    if fd < 0 {
        return nil
    }
    f := new(File)
    f.fd = fd
    f.name = name
    f.dirinfo = nil
    f.nepipe = 0
    return f
}

Very appreciate give some Tips! Thanks in advance!

Answer 1

You need to create a package main and a main function inside of it

Here is an example of a main.go file

package main

import "fmt"

func isDigit(b byte) bool {
  // function implementation here...
}

func nextInt(b []byte, i int) (int, int) {
    for ; i < len(b) && !isDigit(b[i]); i++ {
    }
    x := 0
    for ; i < len(b) && isDigit(b[i]); i++ {
        x = x*10 + int(b[i]) - '0'
    }
    return x, i
}


func main() {
    b := []byte{102, 97, 108, 99, 111, 110}
    for i := 0; i < len(b); {
        x, i = nextInt(b, i)
        fmt.Println(x)
    } 
}

To execute run: go run main.go