When I started with F#, I had some problems to find good libraries for the stuff we need in our software. Sometimes the problem was to find a library at all, sometimes several libraries provide similar functionality. So here is a list of the libraries I like to use (what we use and why).
We have a solution containing C# and F# code. In this post, I’ll show you how the CompilationRepresentationAttribute helps to use F# code from C# by preventing naming conflicts on types and modules.
Prepare for a long post about how we persist data with F# using Dapper into (Azure) SQL Server. I will also show, how we can run our tests either with an in-memory database simulation or a real database. As always, if you spot something that can be improved, please let me know. We are still learning…
In the previous blog post “bye-bye fluent syntax”, I wrote about a way how to implement an equivalent to a fluent syntax in F#, without classes and interfaces, using discriminated unions.
Steve Gilham pointed me to a much simpler solution (many thanks again!). And it looks like this:
We had one kind of defects in our C# that was very annoying: hidden usage of equality and missing equality members on involved classes.
We invested a lot of time to get rid of these in our C# code. Luckily, in F#, this problem does not exist because of the compiler.
But, let’s start at the beginning…
The application we are developing – it’s TimeRocket, just in case you forgot 😉 – has quite a lot of code that looks something like this (pseudo-code): given is an identifierload the data represented by the identifier if it existsif the data could be loaded, validate if the desired action can be executedif it can then continuereport back success or what failed In C#, we often resort to exceptions because otherwise, we get a pyramid of doom. So it’s time for one of the...
After a month of programming F#, I realized that I changed my usage of my IDE (JetBrains Rider). Here is how and why:
In C#, our preferred way to define a builder is using a fluent syntax. Whether it is setting up the system under test in our specifications by defining how we want external calls to be faked, setting up complex test data or defining the steps to be executed in an operation with automatic compensation in case of an exception. In F#, this works, but feels weird, because a fluent syntax typically uses classes and/or extension methods and there are a lot of . involved. So we experimented with a...
I develop code with C# for 18 years and I’m a heavy ReSharper/Rider user. So I know a lot of shortcuts. Really a lot.Actually, my fingers know them. Whenever I get asked during pair programming how I did this, I almost certainly reply with: “ask my fingers, I don’t know.”
Programming in F#, I had to retrain my fingers to use some new shortcuts that I was not used to. And that’s why I share them here with you:
To start our experiment with F#, we first needed to learn to write code in F#. Read a little I knew about the site quite some time, but finally, I took the time to read some posts there until I thought I’m fit enough to code something real. Code a little Once upon a time, I wrote a report generator for xBehave.net in C#. The report generator generates a markdown report from the results of a test run of xBehave.net tests/specs. The code was old and lacked some features. So I started...