Tag : monad

In my last post, I was writing about the use of coproduct of free monads to do content-type dispatching in a web monad. It was working but it was not the right approach. I changed everything and introduced a lattice of lists at the type level to track hierarchical dependencies between formats and do content-type dispatching thanks to type information. I also added a few other features to my Web Monad.

This is the third part of my serie about Haskell and category theory. In the previous post, I described a bit the Hask category and some categorical constructs. The goal of this text is to understand the meaning of a recursive type like List. For that, we will have to understand what is a free algebra and have a quick look at the relationship with monads (for applications look at the blog of sigfpe). But first, I would like to highlight a problem with the category Hask.

From time to time, I continue my experiments with Haskell and web development and try to build my own framework. I will never release anything because I am just exploring a few ideas. Recently, I experimented with a common problem : when a client is getting an URL, it is communicating the formats it wants with some preference values. The server should return the best format according to what is requested by the client and what is supported by the server.

This post is not about functional programming but about plain old imperative languages (C, Java, Python ... replace the dots with your favorite imperative language). I will try to show that you are forced to invent monads if you want to define the meaning of imperative languages ! I have not yet seen this approach to monads in the blogs and tutorials available on the web so I thought it could be a good idea to say a few words about it.

I am doing some additional experiments with Haskell and web development. In this post, I am looking at the problem of composability for web pages. I have tested different methods for building a web page and what I don't like is the lack of composability. When I look at most web pages, I see several components with their own state and control flow. But, when I build a web page from those components, the composability on the server side (for the request handlers) is less obvious. So, I have attempted to build a composable solution based upon the idea of a web object. A web object is something with a state, that can be displayed on a web page and can react to some actions. Web objects must be reusable.