Tagged: haskell

Ghcid for multi package projects []

GHCID magic

When I tried Ghcidfor a reflex, it wouldn’t rebuild on file change. This is because reflex has a multi package project setup by default. Recently I found that it is possible to use Ghcid for multi package project builds. The trick is to create an executable that includes …

Reflex server side html rendering []

Reflex is a single page app framework written in Haskell compiled to JavaScript. A major concern with reflex is the slow loading times, this can be mediated however by doing server side rendering1. This blog post will discuss how to do that2.

Bob doing SSR

The main idea is that we …

Authentication in Reflex & Servant []

In the previous blog post we saw interaction with servant in reflex. Although that covers the basics, there are several more hurdles to overcome to get comfortable with Reflex. I think most of these are encountered by building a simple login system. So let’s build something like:

                       +------------------+
   +-----------+       |    .      -      |
   | +--------+|       | .    -  .. .     |
   | +--------+|       | . .-- - + m..-.  |
   | +--------+|    \  |   m …

Lens into wrapped newtypes []

Categorical representation of the <abbr>NT</abbr> iso

All newtypes are isomorphisms


— My mother

Control.Lens.Wrapped uses the isomorphism property to introduce a type class Wrapped. Let’s explore use cases, because after all, it doesn’t appear to do much at first glance. What’s the point of formalizing wrapping and unwrapping of types?

Instance boilerplate …

Fullstack Haskell: Reflex and Servant []

In the pragmatic haskell series, we saw how to setup a simple webserver with database. But at some point you still need a frontend. If it were 2005 you may have been able to get away with just blaze. But we are in 2018+, and JavaScript is a problem. In …

Pragmatic Haskell III: Beam Postgres DB []

No need to read a book to use Haskell! This post will get you going with a serious web application while only sticking to the concepts that are encountered. This is a Haskell safari with as end goal a working webapp with database.

  1. Pragmatic Haskell: Simple servant web server
  2. Pragmatic …

Pragmatic Haskell II: IO Webservant []

  1. Pragmatic Haskell: Simple servant web server
  2. Pragmatic Haskell II: IO Webservant
  3. Pragmatic Haskell III: Beam Postgres DB

Most Haskell language guides will leave IOuntillater. This guide is different, this guide is about using Haskell. Our focus is different: We build first, then learn trough delight.

Fancy intro image

The previous blog …

Pragmatic Haskell: Simple servant web server []

  1. Pragmatic Haskell: Simple servant web server
  2. Pragmatic Haskell II: IO Webservant
  3. Pragmatic Haskell III: Beam Postgres DB

There are many guides available for learning Haskell. Setting up a something simple like a web server isn’t so straight forward. Perhaps choosing one of the 14 libraries is a bit much …

Fun with stack: Haskell dependency management []

Haskel stack logo

Working at Daisee, Jappie uses a lot of Haskell programming. Although Haskell is obviously as amazing as the stereotype asserts, the tooling can be a bit challenging. In this blogpost we explore these challenges.

One’s understanding start with the fact that there is not one unified Haskell package manager …