Embed Directive in Scala

Here’s the translation of the Go code to Scala, with explanations in Markdown format suitable for Hugo:

Scala doesn’t have a direct equivalent to Go’s //go:embed directive. However, we can demonstrate a similar concept using Scala’s resource management capabilities. We’ll use the scala.io.Source and scala.io.Codec classes to read files, and we’ll package our resources with the application.

import scala.io.Source
import scala.io.Codec

object EmbedExample {
  // In Scala, we don't embed files at compile time like Go's //go:embed.
  // Instead, we can read files from the resources folder at runtime.
  val fileString: String = {
    val source = Source.fromResource("folder/single_file.txt")(Codec.UTF8)
    try source.mkString finally source.close()
  }

  val fileByte: Array[Byte] = {
    val source = Source.fromResource("folder/single_file.txt")(Codec.UTF8)
    try source.map(_.toByte).toArray finally source.close()
  }

  // For multiple files, we can create a method to read them
  def readResource(path: String): String = {
    val source = Source.fromResource(path)(Codec.UTF8)
    try source.mkString finally source.close()
  }

  def main(args: Array[String]): Unit = {
    // Print out the contents of 'single_file.txt'
    println(fileString)
    println(new String(fileByte))

    // Retrieve some files from the resources folder
    val content1 = readResource("folder/file1.hash")
    println(content1)

    val content2 = readResource("folder/file2.hash")
    println(content2)
  }
}

In this Scala example:

1. We use scala.io.Source to read files from resources. This is similar to embedding files, as these resources are packaged with the application.

2. fileString and fileByte are defined as vals (immutable variables) that read the content of “single_file.txt” when the object is initialized.

3. We define a readResource method to read multiple files, which is analogous to using embed.FS in Go.

4. In the main method, we print the contents of the files, similar to the Go example.

To run this example:

1. Create a resources folder in your project’s src/main directory.
2. Inside the resources folder, create a folder subdirectory.
3. Add the following files:
   • folder/single_file.txt with content “hello scala”
   • folder/file1.hash with content “123”
   • folder/file2.hash with content “456”

Compile and run the Scala program:

$ scalac EmbedExample.scala
$ scala EmbedExample
hello scala
hello scala
123
456

This Scala example demonstrates a similar concept to Go’s embed directive, but using Scala’s resource management capabilities. The files are read at runtime rather than embedded at compile time, but they are still packaged with the application, achieving a similar result.