After reading this question, I've realized that I can do a lot to improve the quality of my question, so I've edited this question quite a bit.
I've been teaching myself F# in my spare time off and on for the last 6 months. I've finally started getting comfortable enough with the language to feel that a lot of my code could be much better. The problem is, I don't know what changes to make.
Here's what I'm interested in:
- I'm using higher order functions to return functions for interacting with a specific message queue. Is this a good design. Would another F# developer feel comfortable with this?
- Does this fit the idiomatic style of F#?
- If you know RabbitMQ, are there any bugs which I may be creating here.
Here's the context of the little block of code:
I'm doing a lot of experiments with messaging systems and I've been using RabbitMQ as a messaging framework. There's a .Net library for RabbitMQ but it's written in and for C#. I can use it in F# but it feels clunky. I wanted a small wrapper around the RabbitMQ library which which convert it into a more functional interface. Also, this will hopefully make it very easy to use RabbitMQ in an F# program.
My wrapper handles the following for RabbitMQ:
- Connect to a RabbitMQ server
- Create a function which will let you read one message from a queue
- Create a function which will write a message to a queue
For both 2 and 3, if the queue doesn't exist, the queue will be created (that's the
module Client = let connectToRabbitMqServerAt address = let factory = new ConnectionFactory(HostName = address) factory.CreateConnection() let openChannelOn (connection:IConnection) = connection.CreateModel() let private declareQueue (channel:IModel) queueName = channel.QueueDeclare( queueName, false, false, false, null ) let private publishToQueue (channel:IModel) queueName (message:string) = let body = Encoding.UTF8.GetBytes(message) channel.BasicPublish("", queueName, null, body) let createQueueReader channel queue = declareQueue channel queue |> ignore fun () -> let ea = channel.BasicGet(queue, true) if ea <> null then let body = ea.Body let message = Encoding.UTF8.GetString(body) Some message else None let createQueueWriter channel queue = declareQueue channel queue |> ignore publishToQueue channel queue
An example use case would be:
// open a connection to a RabbitMQ broker let connection = connectToRabbitMqServerAt "localhost" let myChannel = openChannelOn connection // Connect to a queue for writing let writeToHelloQueue = createQueueWriter myChannel "hello" // write the message "Hello, World" to the queue "hello" "Hello, World" |> writeToHelloQueue