go module / go packages

my note as below

• 使用go modules 後，source code 不再需要放到$GOPATH 的src 目錄底下

1. custom package 要單玀一個folder?! (like pkg1 do)
2. 要在 pkg1 folder 內執行 go build後，此 pkg1 才能被使用?!
3. A package is a collection of source files in the same directory that are compiled together
4. to be continue...

ref URL

• EVERYTHING You SHOULD know about Go Modules

• Packages in Go

• under the hood