Other examples:

Package

Golang Version: 1.20
- In Go, one package == one directory. That is, all .go files for a package should be contained in the same directory, and a directory should contain the .go files for one package only. You shouldn’t ever have .go files with different package names in the same directory.
- For all non-main packages, the directory name that the code lives in should be the same as the package name. When choosing a name you should pick something that is short, descriptive, lower case and ideally one word.
- The Go blog has a helpful post with additional guidance and some examples of good and bad names:
  - https://go.dev/blog/package-names

Go package sample

 |-package-main.go
 |-greeting
 | |-hello.go
 | |-hi.go
 |-version
 | |-get-version.go
 |-random
 | |-a.go

mkdir -p greeting version random

cat << "EOF" > package-main.go
paste the code here
EOF

cat << "EOF" > greeting/hello.go
paste the code here
EOF

cat << "EOF" > greeting/hi.go
paste the code here
EOF

cat << "EOF" > version/get-version.go
paste the code here
EOF

cat << "EOF" > random/a.go
paste the code here
EOF

// package-main.go
package main

/*
Golang Version: 1.20

The Go blog has a helpful post with additional guidance and
some examples of good and bad names: -
https://go.dev/blog/package-names -

In Go, one package == one directory. That is, all `.go`
files for a package should be contained in the same
directory, and a directory should contain the `.go` files
for one package only. You shouldn't ever have `.go` files
with different package names in the same directory.

For all non-main packages, the directory name that the code
lives in should be the same as the package name. When
choosing a name you should pick something that is short,
descriptive, lower case and ideally one word.
*/

import (
  foo "foo"
  greeting "package-example/greeting"
  _ "package-example/version"
)

func main() {
  foo.RandomA()
  greeting.Hi()
  greeting.Hello()
}

/*
OUTPUT

version/get-version.go ==> getVersion()
1.0.0
aaaaa
Hi!
Hello!
*/

// greeting/hello.go
package greeting

import "fmt"

func Hello() {
  fmt.Println("Hello!")
}

// greeting/hi.go
package greeting

import "fmt"

func Hi() {
  fmt.Println("Hi!")
}

// version/get-version.go
package version

import "fmt"

func init() {
  fmt.Println(getVersion())
}
func getVersion() string {
  fmt.Println("version/get-version.go ==> getVersion()")
  return "1.0.0"
}

// random/a.go
package random

import "fmt"

func RandomA() {
  fmt.Println("aaaaa")
}

# golang version: 1.20

go mod init package-example
go mod tidy

# create a sub package inside the current package
(cd random && \
go mod init package-random && \
go mod tidy)

# create an alias for the sub package above
# use the relative package path above
go mod edit -replace foo=./random
go get foo
go mod tidy