Check out my new course Learn you some Lambda best practice for great good! and learn the best practices for performance, cost, security, resilience, observability and scalability.
If you’re reading this post, you probably know about F#’s Units of Measure already, it’s very useful when working with real-world units and adds extra safety to code that needs to work with and convert from one unit to another.
Here’s a quick snippet that shows you how to define and use units-of-measure:
This code outputs the following, note the units associated with the float values:
As you can see, units of measure can also be compounded by multiplication or division!
If you have a function that requires a int<m>, you won’t be able to call the function with a normal int, hence providing you with extra protection to ensure the correctness of your application because the unit of a numeric value is now a formal contract between a function and its caller:
Having said that, there are cases where you want to be able to convert between an int and an int<m>. For instance, to provide better interoperability with other .Net languages, as units-of-measure only exists in F# there’s no way to create a numeric value with units-of-measure in C# (that I’m aware of anyway).
To convert from int<m> to int (or any other numeric type) is easy, just do a straight cast:
Going the other way is slightly more tricky, you can’t use int<m> to cast an int to an int<m>, but you can either multiply the value with 1<m> or use the Int32WithMeasure method on the LanguagePrimitives core module:
I specialise in rapidly transitioning teams to serverless and building production-ready services on AWS.
Are you struggling with serverless or need guidance on best practices? Do you want someone to review your architecture and help you avoid costly mistakes down the line? Whatever the case, I’m here to help.
Check out my new podcast Real-World Serverless where I talk with engineers who are building amazing things with serverless technologies and discuss the real-world use cases and challenges they face. If you’re interested in what people are actually doing with serverless and what it’s really like to be working with serverless day-to-day, then this is the podcast for you.
Check out my new course, Learn you some Lambda best practice for great good! In this course, you will learn best practices for working with AWS Lambda in terms of performance, cost, security, scalability, resilience and observability. We will also cover latest features from re:Invent 2019 such as Provisioned Concurrency and Lambda Destinations. Enrol now and start learning!
Check out my video course, Complete Guide to AWS Step Functions. In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. There is something for everyone from beginners to more advanced users looking for design patterns and best practices. Enrol now and start learning!
Are you working with Serverless and looking for expert training to level-up your skills? Or are you looking for a solid foundation to start from? Look no further, register for my Production-Ready Serverless workshop to learn how to build production-grade Serverless applications!
Here is a complete list of all my posts on serverless and AWS Lambda. In the meantime, here are a few of my most popular blog posts.
- Lambda optimization tip – enable HTTP keep-alive
- You are wrong about serverless and vendor lock-in
- You are thinking about serverless costs all wrong
- Just how expensive is the full AWS SDK?
- Many faced threats to Serverless security
- We can do better than percentile latencies
- Yubl’s road to Serverless
- AWS Lambda – should you have few monolithic functions or many single-purposed functions?
- AWS Lambda – compare coldstart time with different languages, memory and code sizes
- Guys, we’re doing pagination wrong
- Top 10 Serverless framework best practices