FsToolkit.ErrorHandling.IcedTasks 5.0.0-beta003

This is a prerelease version of FsToolkit.ErrorHandling.IcedTasks.

dotnet add package FsToolkit.ErrorHandling.IcedTasks --version 5.0.0-beta003

NuGet\Install-Package FsToolkit.ErrorHandling.IcedTasks -Version 5.0.0-beta003

This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.

<PackageReference Include="FsToolkit.ErrorHandling.IcedTasks" Version="5.0.0-beta003" />

For projects that support PackageReference, copy this XML node into the project file to reference the package.

paket add FsToolkit.ErrorHandling.IcedTasks --version 5.0.0-beta003

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

#r "nuget: FsToolkit.ErrorHandling.IcedTasks, 5.0.0-beta003"

#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.

// Install FsToolkit.ErrorHandling.IcedTasks as a Cake Addin
#addin nuget:?package=FsToolkit.ErrorHandling.IcedTasks&version=5.0.0-beta003&prerelease

// Install FsToolkit.ErrorHandling.IcedTasks as a Cake Tool
#tool nuget:?package=FsToolkit.ErrorHandling.IcedTasks&version=5.0.0-beta003&prerelease

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

FsToolkit.ErrorHandling

FsToolkit.ErrorHandling is a utility library to work with the Result type in F#, and allows you to do clear, simple and powerful error handling.

The library provides utility functions like map, bind, apply, traverse, sequence as well as computation expressions and infix operators to work with Result<'a, 'b>, Result<'a option, 'b>, Async<Result<'a, 'b>>, Async<Result<'a option, 'b>>, and Result<'a, 'b list>.

It was inspired by Chessie and Cvdm.ErrorHandling (the latter has now been merged into FsToolkit.ErrorHandling).

FsToolkit.ErrorHandling targets .NET Standard 2.0, .NET Standard2.1 and supports Fable.

Documentation

The documentation is available here.

Further material

The main resource as to learning this style of programming Railway Oriented Programming
However Result isn't a panacea, see what pitfalls and where you shouldn't use Result. In defense of Exceptions: Throw (away) your Result

Builds

GitHub Actions

NuGet

Package name	Release	Prelease
FsToolkit.ErrorHandling
FsToolkit.ErrorHandling.TaskResult
FsToolkit.ErrorHandling.JobResult
FsToolkit.ErrorHandling.AsyncSeq
FsToolkit.ErrorHandling.IcedTasks

Developing locally

Devcontainer

This repository has a devcontainer setup for VSCode. For more infomation see:

VSCode

Local Setup

.NET Core SDK
- v6.x
- v7.x
- v8.x

Optional

To test fable builds locally you will need:

Node
- v18.0.0 or Higher
- Not required but recommend that you use NVM to easily manage multiple versions of Node
Python
- v3.10.0 or higher
- Required for Fable-Python

Compiling

> build.cmd <optional buildtarget> // on windows
$ ./build.sh  <optional buildtarget>// on unix

Without specifying a build target, the default target is DotnetPack, which will run tests for all projects on dotnet and then pack the projects into nuget packages. For additional notable targets see below.

Build Targets

Clean - Will clean all projects bin and obj folders
DotnetTest - Will run tests for dotnet projects
NpmTest - Will run tests for fable-javascript projects
PythonTest - Will run tests for fable-python projects
RunTests - Will run tests for dotnet, fable-javascript and fable-python projects
FormatCode - Will run fantomas to format the codebase

This is not an exhausting list. Additional targets can be found in the ./build/build.fs file.

A motivating example

This example of composing a login flow shows one example of how this library can aid in clear, simple, and powerful error handling, using just a computation expression and a few helper functions. (The library has many more helper functions and computation expressions as well as infix operators; see the documentation for details.)

// Given the following functions:
//   tryGetUser: string -> Async<User option>
//   isPwdValid: string -> User -> bool
//   authorize: User -> Async<Result<unit, AuthError>>
//   createAuthToken: User -> Result<AuthToken, TokenError>

type LoginError = InvalidUser | InvalidPwd | Unauthorized of AuthError | TokenErr of TokenError

let login (username: string) (password: string) : Async<Result<AuthToken, LoginError>> =
  asyncResult {
    // requireSome unwraps a Some value or gives the specified error if None
    let! user = username |> tryGetUser |> AsyncResult.requireSome InvalidUser

    // requireTrue gives the specified error if false
    do! user |> isPwdValid password |> Result.requireTrue InvalidPwd

    // Error value is wrapped/transformed (Unauthorized has signature AuthError -> LoginError)
    do! user |> authorize |> AsyncResult.mapError Unauthorized

    // Same as above, but synchronous, so we use the built-in mapError
    return! user |> createAuthToken |> Result.mapError TokenErr
  }

Sponsor(s)

Product	Compatible and additional computed target framework versions.
.NET	net5.0 was computed. net5.0-windows was computed. net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 was computed. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 was computed. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. net9.0 was computed. net9.0-android was computed. net9.0-browser was computed. net9.0-ios was computed. net9.0-maccatalyst was computed. net9.0-macos was computed. net9.0-tvos was computed. net9.0-windows was computed.
.NET Core	netcoreapp2.0 was computed. netcoreapp2.1 was computed. netcoreapp2.2 was computed. netcoreapp3.0 was computed. netcoreapp3.1 was computed.
.NET Standard	netstandard2.0 is compatible. netstandard2.1 is compatible.
.NET Framework	net461 was computed. net462 was computed. net463 was computed. net47 was computed. net471 was computed. net472 was computed. net48 was computed. net481 was computed.
MonoAndroid	monoandroid was computed.
MonoMac	monomac was computed.
MonoTouch	monotouch was computed.
Tizen	tizen40 was computed. tizen60 was computed.
Xamarin.iOS	xamarinios was computed.
Xamarin.Mac	xamarinmac was computed.
Xamarin.TVOS	xamarintvos was computed.
Xamarin.WatchOS	xamarinwatchos was computed.

Compatible target framework(s)

Included target framework(s) (in package)

Learn more about Target Frameworks and .NET Standard.

.NETStandard 2.0
- FSharp.Core (>= 6.0.1)
- FsToolkit.ErrorHandling (>= 5.0.0-beta003)
- IcedTasks (>= 0.11.4)
- Microsoft.Bcl.AsyncInterfaces (>= 6.0.0)
.NETStandard 2.1
- FSharp.Core (>= 6.0.1)
- FsToolkit.ErrorHandling (>= 5.0.0-beta003)
- IcedTasks (>= 0.11.4)
net6.0
- FSharp.Core (>= 6.0.1)
- FsToolkit.ErrorHandling (>= 5.0.0-beta003)
- IcedTasks (>= 0.11.4)

NuGet packages (1)

Showing the top 1 NuGet packages that depend on FsToolkit.ErrorHandling.IcedTasks:

Package	Downloads
NBomber Modern and flexible load testing framework for Pull and Push scenarios, designed to test any system regardless a protocol (HTTP/WebSockets/AMQP etc) or a semantic model (Pull/Push).	2.6M

GitHub repositories

This package is not used by any popular GitHub repositories.

Version	Downloads	Last updated
5.0.0-beta003	70	1/6/2025
5.0.0-beta002	81	12/21/2024
5.0.0-beta001	85	12/7/2024
4.18.0	13,139	10/23/2024
4.18.0-beta001	81	10/23/2024
4.17.0	220	9/23/2024
4.17.0-beta002	81	9/23/2024
4.17.0-beta001	81	9/23/2024
4.16.0	774	7/15/2024
4.15.3	111	7/14/2024
4.15.3-beta001	94	7/14/2024
4.15.2	585	5/2/2024
4.15.2-beta001	71	5/2/2024
4.15.1	190	1/15/2024
4.15.0	135	1/10/2024
4.14.0	159	1/2/2024
4.13.0	172	12/10/2023
4.13.0-beta002	116	12/10/2023
4.13.0-beta001	119	12/10/2023
4.12.0	163	11/27/2023
4.11.1	158	11/23/2023
4.11.0	138	11/11/2023
4.10.0	153	10/16/2023
4.9.0	195	7/10/2023
4.8.0	156	7/7/2023
4.7.0	153	6/21/2023
4.7.0-beta001	125	6/21/2023
4.6.0	188	4/20/2023
4.6.0-beta001	136	4/20/2023
4.5.0	228	3/27/2023
4.5.0-beta002	149	3/19/2023
4.5.0-beta001	137	3/6/2023
4.4.0	251	2/21/2023
4.3.0	310	1/20/2023
4.2.1	365	12/19/2022
4.2.0	358	12/17/2022
4.1.0	312	12/13/2022
4.1.0-beta001	153	12/13/2022
4.0.0	351	11/19/2022
4.0.0-beta001	170	11/19/2022
3.3.1	337	11/19/2022
3.3.1-beta004	154	11/19/2022
3.3.1-beta003	152	11/18/2022
3.3.1-beta002	155	11/18/2022
3.3.1-beta001	150	11/18/2022
3.3.0-beta001	174	11/9/2022
3.2.0	374	10/31/2022
3.2.0-beta001	160	10/31/2022
3.1.0	436	10/19/2022
3.0.1	385	10/18/2022
3.0.0	416	10/14/2022
3.0.0-beta008	167	10/14/2022
3.0.0-beta007	184	4/15/2022
3.0.0-beta006	167	4/5/2022
3.0.0-beta005	174	4/5/2022
3.0.0-beta004	166	4/5/2022

- BREAKING: [Remove Ply and update to FSharp 6](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/248) Credits @TheAngryByrd
- BREAKING: [Remove MergeSources (and!) from some implementations like Result](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/261) Credits @TheAngryByrd
- BREAKING: [Merge TaskResult into Core library](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/285) Credits @TheAngryByrd
- This means FsToolkit.ErrorHandling.TaskResult is no longer a separate package and will not be updated. It is now part of the core library.
- BREAKING: [Rename retn to singleton](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/287) Credits @1eyewonder
- [Use Microsoft.Bcl.AsyncInterfaces in netstandard2.0 (Allows IAsyncDisposable and IAsyncEnumerable)](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/250) Credits @TheAngryByrd
- [Build against Net8](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/251) Credits @TheAngryByrd
- [Fix Overload Resolution to Align to Computation Expression used](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/252) Credits @TheAngryByrd
- [refactor!: Seq.sequenceResultM returns Array instead of seq](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/255) Credits @bartelink
- [feat(Seq): sequenceResultA](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/255) Credits @bartelink
- [Updated uses of Seq.append](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/290) Credits @1eyewonder
- [Add Option.traverseAsync and Option.sequenceAsync](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/298#event-15827853276) Credits @tw0po1nt
- [Add Require and Check helper methods](https://github.com/demystifyfp/FsToolkit.ErrorHandling/pull/295) Credits @PI-Gorbo