In F# you can write an extension method like this:
Whilst this will work perfectly fine in your F# code, the extension method will not be visible to any C# code using the FileInfo type because F# and C# compiles extension methods differently.
To make C#-compatible extension methods in F#, here’s what you need to do instead:
That’s it, just follow these 3 simple steps and you’re done:
- wrap the extension methods inside a class decorated with the [<Extension>] attribute
- write the extension methods as static members where the first argument is of the type which should be extended (like how you would write an extension method in C#)
- mark the extension methods with the [<Extension>] attribute
Hi, I’m Yan. I’m an AWS Serverless Hero and the author of Production-Ready Serverless.
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 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. Including basic concepts, HTTP and event triggers, activities, callbacks, nested workflows, design patterns and best practices.
Further reading
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 thinking about serverless costs all wrong
- Many faced threats to Serverless security
- We can do better than percentile latencies
- I’m afraid you’re thinking about AWS Lambda cold starts all wrong
- 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