Add some improvements

Signed-off-by: peterzhu1992 <peterzhu1992@gmail.com>

examples.txt

@@ -20,7 +20,6 @@ Structs
 Methods
 Interfaces
 Struct Embedding
-Embed Directive
 Generics
 Errors
 Goroutines
@@ -66,6 +65,7 @@ Line Filters
 File Paths
 Directories
 Temporary Files and Directories
+Embed Directive
 Testing and Benchmarking
 Command-Line Arguments
 Command-Line Flags

examples/embed-directive/embed-directive.go

@@ -1,51 +1,45 @@
-// 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.
+// `//go:embed` is a compiler directive that allows programs to include arbitrary
+// files/folders in the binary. Read more about go directive
+// [here](https://dave.cheney.net/2018/01/08/gos-hidden-pragmas).
 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.
+// If no exported identifiers is directly used from `embed` package,
+// you can add an underscore `_` before the package name. In this example, we simply
+// import it as we need to use the `embed.FS` type from the package.
 import (
+	//_ "embed"
 	"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
+//go:embed example_folder/single_file.txt
 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
+//go:embed example_folder/single_file.txt
 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
+//go:embed example_folder/single_file.txt
+//go:embed example_folder/*.hash
 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 `example_single_file.txt` as `string`.
+	print(single_file_string)
 
-	// Print out the content of `embed-directive.sh` as `[]byte`.
-	println(string(single_file_byte))
+	// Now handle `[]byte`.`
+	print(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))
+	// Retrieve the file(s) matching `*.hash` pattern by reading from `folder_FS` first,
+	// then print out.
+	hash_file1 := "example_folder/multi_file1.hash"
+	hash_file2 := "example_folder/multi_file2.hash"
+	hash_content1, _ := folder_FS.ReadFile(hash_file1)
+	hash_content2, _ := folder_FS.ReadFile(hash_file2)
+	print(string(hash_content1))
+	print(string(hash_content2))
 
 }

examples/embed-directive/embed-directive.hash

@@ -1,2 +1,2 @@
-10914400b16498094a1a876856181673c3fcdfe0
-gk3Zh5Sx8rV
+33356517e565ff2d1f9d7f935012a326e8f5b3ea
+yTsQsPe9jth

examples/embed-directive/embed-directive.sh

@@ -1,4 +1,15 @@
 # Use these commands to run the example
+# Note: due to limitation on go playground
+# This example can only be run on your local machine
+
+$ mkdir -p example_folder
+$ echo "hello go" > example_folder/single_file.txt
+$ echo "123" > example_folder/multi_file1.hash
+$ echo "456" > example_folder/multi_file2.hash
+
 $ go run embed-directive.go
-
+hello go
+hello go
+123
+456
 

examples/embed-directive/example_folder/multi_file1.hash

@@ -0,0 +1 @@
+123

examples/embed-directive/example_folder/multi_file2.hash

@@ -0,0 +1 @@
+456

examples/embed-directive/example_folder/single_file.txt

@@ -0,0 +1 @@
+hello go