README

Prelude is a static partial class, this type is loaded with functions for constructing the key data types, as well as many of the things you'd expect in a functional programming language's prelude. Note, the Prelude type extends into many other parts of the source-tree. It's the same type, but spread all over the code-base. And so, you may see Prelude in other areas of the documentation: it's the same type.

Because it's so fundamental, you'll want to add this to the top of every code file:

using static LanguageExt.Prelude;

So what's in here? Well, apart from the modules listed below, there's the data-type constructors, for example:

Option<int> mx = Some(100);

Seq<int> mx = Seq(1, 2, 3);

As well as the camelCase versions of the fluent-methods attached to each type:

var items = Seq(1, 2, 3);

// Fluent version
var sum = items.Fold(0, (s, x) => s + x);

// Prelude static function
var sum = fold(items, 0, (s, x) => s + x);

There is mostly a 1-to-1 mapping between the fluent methods and the Prelude static functions ... mostly.