Hello World
This is a simple example of how to create a "Hello World" application using Hayride. We make the assumption that you have already installed the Hayride CLI and TinyGo. If you haven't done so, please refer to the installation guide for instructions.
If you are not familiar with the Hayride platform or the various WebAssembly tools, we recommend checking out the Hayride Overview to get a better understanding of the platform and its capabilities.
Prerequisites
See Tools for additional information on these tools.
Step 1: Create a new directory
Create a new directory for your project and navigate into it:
mkdir hello-world
cd hello-world
Step 2: Create a WIT file
First, create the necessary WIT files. In the root level of the project, create a directory called wit and create a file called world.wit inside it:
mkdir wit
touch wit/world.wit
In the wit/world.wit file, define the interface for your Morph. This interface will include a function to return a greeting message:
package hayride-examples:hello-world@0.0.1;
world hello-world {
include hayride:wasip2/imports@0.0.51;
include hayride:wasip2/exports@0.0.51;
}
Since we simply be returning a string, we don't need to include any additional imports or exports. The wasip2 imports and exports are sufficient for this example.
Our morph will be a Command component that returns a string. Which means, we will be exported the cli:run function from wasip2.
The the above example, we are using the hayride:wasip2/imports and hayride:wasip2/exports modules to provide the necessary WASI functionality. These are shorthand references to the WASI imports and exports that are required for the Morph to function correctly.
To include these files we will use wit-dep to pull in the necessary dependencies. The wit-dep tool is a dependency manager for WIT files.
WIT Dependencies
In the wit directory, create a deps.toml file to manage the dependencies for your WIT files.
This file will specify the dependencies required for your Morph:
wasip2 = "https://github.com/hayride-dev/coven/releases/download/v0.0.51/hayride_wasip2_v0.0.51.tar.gz"
Using wit-dep, we can pull in the dependencies for our WIT files.
From the root directory of your project, run the following command:
wit-dep update
This will download the dependencies specified in the deps.toml file and place them in the wit/deps directory.
Step 3: Create the Morph
Next, create a file called main.go in the root directory of your project. This file will contain the implementation of your Morph:
go mod init hello-world
touch main.go
In the main.go file, implement the Morph:
package main
import "fmt"
func main() {
fmt.Println("Hello, World!")
fmt.Println("This is a simple example to demonstrate the usage of the Hayride Platform.")
}
This is a simple Go program that prints "Hello, World!" and a message to the console.
Under the hood, we are using TinyGo's support for wasip2 in order to use the standard library functions of the fmt package.
Step 4: Build the Morph
We can build the Morph using TinyGo. Run the following command in the root directory of your project:
tinygo build -target wasip2 --wit-package ./wit/ --wit-world hello-world -o hello-world.wasm
This command will compile the Morph to a WebAssembly binary called hello-world.wasm. The --wit-package flag specifies the directory containing the WIT files, and the --wit-world flag specifies the name of the WIT world to use.
Step 5: Register the Morph
To register the Morph with the Hayride platform, we can use the hayride CLI. First, initialize the Hayride environment:
hayride register --bin hello-world.wasm --package hayride-examples:hello-world@0.0.1
Step 6: Cast the Morph
To execute the Morph, we can use the hayride CLI to cast the Morph. Run the following command:
hayride cast --package hayride-examples:hello-world@0.0.1 -it
This command will execute the Morph and print the output to the console. The -it flag indicates that we want to run the Morph in interactive mode.
You should see the following output:
Hello, World!
This is a simple example to demonstrate the usage of the Hayride Platform.
This indicates that the Morph has been successfully executed and the greeting message has been printed to the console.
What's Next?
Now that you have created a simple "Hello World" Morph using Hayride, you can explore more advanced features and capabilities of the platform. Here are some suggestions for what to do next: