Http Server in Chapel

Here’s the translation of the HTTP Server example from Go to Chapel, formatted in Markdown suitable for Hugo:

use IO;
use HTTP;

// A fundamental concept in HTTP servers is handlers. A handler is an object
// that responds to HTTP requests. In Chapel, we can define handlers as procedures.

// This handler responds with a simple "hello" message.
proc hello(request: Request, response: Response) {
  response.write("hello\n");
}

// This handler does something a little more sophisticated by reading all the
// HTTP request headers and echoing them into the response body.
proc headers(request: Request, response: Response) {
  for (name, value) in request.headers {
    response.write(name + ": " + value + "\n");
  }
}

// In the main procedure, we set up the server and define the routes.
proc main() {
  var server = new HTTP.Server();

  // We register our handlers on server routes.
  server.addHandler("/hello", hello);
  server.addHandler("/headers", headers);

  // Finally, we start the server on port 8090.
  server.listen(8090);
}

In Chapel, we can create a basic HTTP server using the HTTP module. This example demonstrates how to set up a simple server with two routes.

The hello procedure is a simple handler that responds with “hello” to any request to the “/hello” route.

The headers procedure is a more complex handler that echoes back all the headers from the incoming request.

In the main procedure, we create a new HTTP.Server object, add our handlers to specific routes, and then start the server listening on port 8090.

To run the server:

$ chpl http-server.chpl
$ ./http-server

The server will start and listen on port 8090. You can then access it using curl or a web browser:

$ curl localhost:8090/hello
hello

$ curl localhost:8090/headers
User-Agent: curl/7.68.0
Accept: */*

Note that Chapel’s HTTP module might have a different API than what’s shown here, as Chapel’s standard library is still evolving. This example assumes a hypothetical HTTP module with a similar interface to other languages’ HTTP libraries. You may need to adjust the code based on Chapel’s actual HTTP implementation.