How to Load External Dependencies Using Kotlin Interactive Shell (KIS)

 

How to Load External Dependencies Using Kotlin Interactive Shell (KIS)

Kotlin Interactive Shell (KIS) provides a powerful and flexible way to interact with Kotlin code in an interactive environment. While it’s an excellent tool for testing snippets and prototyping code, working with external dependencies can enhance its capabilities. Here’s a guide on how to load external dependencies in KIS to streamline your development workflow.

1. Understanding Kotlin Interactive Shell (KIS)

Kotlin Interactive Shell (KIS) is a REPL (Read-Eval-Print Loop) that allows developers to execute Kotlin code snippets interactively. It’s ideal for experimenting with Kotlin syntax, testing small code fragments, and exploring Kotlin libraries.

2. Adding External Dependencies

To load external dependencies in KIS, you’ll need to leverage Kotlin’s support for dependency management. The process involves configuring KIS to recognize and include libraries from repositories. Here's how you can do it:

a. Using Kotlin Script (.kts) Files

KIS supports Kotlin script files (.kts). You can include dependencies in these files by specifying them in the script’s classpath. Follow these steps:

1. Create a .kts File: Create a Kotlin script file where you will specify your dependencies. For example, dependencies.kts.

2. Add Dependencies: Use the @file:DependsOn annotation to add external dependencies. For instance:

   kotlin
   @file:DependsOn("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
   @file:DependsOn("com.google.guava:guava:31.1-jre")
   
   import kotlinx.coroutines.*
   import com.google.common.base.Charsets
   

3. Run the Script: Load your script in the Kotlin Interactive Shell:

   bash
   kotlinc -script dependencies.kts
   

   The dependencies specified will be available in your interactive session.

b. Using Kotlin CLI Options

If you are using the Kotlin CLI, you can specify the classpath directly when launching the shell:

1. Download the Required Libraries: Ensure you have the required .jar files for your dependencies. You can download them manually or use a build tool like Gradle to manage them.

2. Launch Kotlin REPL with Classpath: Use the -cp (classpath) option to include the libraries:

   bash
   kotlinc -cp /path/to/your/dependency.jar
   

   For multiple dependencies, separate them with a colon : on Unix-based systems or a semicolon ; on Windows.

   bash
   kotlinc -cp /path/to/dependency1.jar:/path/to/dependency2.jar
   

3. Practical Examples

Let’s see a practical example of using external dependencies in KIS.

Example 1: Using Guava Library

1. Create a Script File: Create guava_example.kts.

   kotlin
   @file:DependsOn("com.google.guava:guava:31.1-jre")
   
   import com.google.common.base.Joiner
   
   val result = Joiner.on(", ").join("apple", "banana", "cherry")
   println(result)
   

2. Run the Script:

   bash
   kotlinc -script guava_example.kts
   

   Output:

   apple, banana, cherry
   

Example 2: Using Kotlin Coroutines

1. Create a Script File: Create coroutines_example.kts.

   kotlin
   @file:DependsOn("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
   
   import kotlinx.coroutines.*
   
   runBlocking {
       launch {
           delay(1000L)
           println("World!")
       }
       println("Hello,")
   }
   

2. Run the Script:

   bash
   kotlinc -script coroutines_example.kts
   

   Output:

   Hello,
   World!
   

4. Managing Dependencies with Gradle or Maven

If you are working with more complex projects or multiple dependencies, consider using a build tool like Gradle or Maven to manage dependencies and generate classpath configurations. You can then use these configurations to launch the Kotlin REPL or run scripts.

5. Conclusion

Loading external dependencies in Kotlin Interactive Shell (KIS) enhances its functionality and makes it a more powerful tool for experimenting with Kotlin code. By leveraging Kotlin scripts or specifying classpaths directly, you can seamlessly integrate external libraries and streamline your development process.

With these methods, you can take full advantage of Kotlin’s rich ecosystem and libraries while working interactively.