Units of measure in F#

A very interesting feature of F# – besides many others – is that we can assign a unit of measure to a variable value. These units of measure are located in the Microsoft.FSharp.Data.UnitSystems.SI.UnitNames namespace. As the namespace suggests the units are taken from the international system of units.

They are surrounded with angled brackets in code. Here’s an example:

open Microsoft.FSharp.Data.UnitSystems.SI.UnitNames
let meterValue = 100

We can easily define our own units of measure that are not part of the namespace. The following example shows the “pound” type and how we can convert it to kilos:

namespace units

module Units =
open Microsoft.FSharp.Data.UnitSystems.SI.UnitNames

type pound =
static member toKilos = 0.453592

let asKilos pounds:float = pounds * pound.toKilos

let converted = Units.asKilos 1.

“converted” will be 0.453592 as expected.

View all F# related articles here.


About Andras Nemes
I'm a .NET/Java developer living and working in Stockholm, Sweden.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Elliot Balynn's Blog

A directory of wonderful thoughts

Software Engineering

Web development

Disparate Opinions

Various tidbits

chsakell's Blog


Once Upon a Camayoc

Bite-size insight on Cyber Security for the not too technical.

%d bloggers like this: