Go by Example: Embed Directive

Starting in Go version 1.16+, Go supports use of `//go:embed` which is a directive to embed files and folders into the application binary by the compiler.
Since Go does not have preprocessor or macros like C type of languages, `pragmas/directives` are implemented by the compiler as comments `//`. Using `//go:embed` tells the compiler to include arbitrary files/folders in binary.	package main
If you are not using any exported identifiers from `embed` package directly, you can add an underscore `_` before the package name, ask Go to import `embed` without directly using it, like this: `_ "embed"`. In this example, we remove the underscore as we need to use the `embed.FS` type from the package.	import ( "embed" )
Since one file is defined after the directive, the compiler will only include this single file, followed by variable `single_file_string` to access as `string` type.	//go:embed embed-directive.sh var single_file_string string
Here is a similar example but include single file as `[]byte`. Note that `//go:embed` can only be used in package level, define it in any function will result in error.	//go:embed embed-directive.sh var single_file_byte []byte
We can also embed multiple files or even folders with wildcard. Since Go resolves these files and folders during compile time, we have to use the files in current working directory as examples. In practice, you can embed files with `"//go:embed /path/to/folder"` or with another example `"//go:embed /path/to/folder/*"`. You can add multiple `//go:embed` before defining a variable.	//go:embed *.hash //go:embed embed-directive.sh var folder_FS embed.FS
	func main() {
Print out the content of `embed-directive.sh` as `string`.	println(single_file_string)
Print out the content of `embed-directive.sh` as `[]byte`.	println(string(single_file_byte))
Print out the content of `embed-directive.hash` by reading the file from `folder_FS` first, then print out the content.	hash_file := "embed-directive.hash" hash_content, _ := folder_FS.ReadFile(hash_file) println(string(hash_content))
	}

Use these commands to run the example

$ go run embed-directive.go

Next example: Generics.