Railway

Portable library for using railway oriented programming in C#. Heavily inspired by http://fsharpforfunandprofit.com/posts/recipe-part2/, see the site for information about the theory and how railway oriented programming works.

Documentation

Result

The basis of everyhting. Results are created like this:

// Success result
Result<string, int>.CreateSuccess("Success")

// Failed result
Result<int, string>.CreateFailure("Failure")

Composing

Composing functions (all functions must return Result<TSucces, TFailure>) is done like this:

Validate1().Compose(Validate2)

// or using Func
Validate1().Compose(success => Result<string, string>.CreateSuccess("Success"))

Composing with "dead-ends", meaning functions returning void, is done the same way, except an Action is used instead of a Func:

Validate1().Compose(success => { })

Double mapping

Double mapping, means running a function depending on the result. The functions must return object of the same type as the original input.

Validate1().DoubleMap(success => success, failure => failure)

Switch

Switches are adapters for functions not accepting any input.

Switch.Create(() => "Success")

A basic switch always returns object as failure type.

A switch can also handle exceptions thrown by the function:

Switch.CreateWithException(() => { throw new Exception(); return "Success"; })

The returning result will be a failed result containing the thrown exception.