This is a forked version of the Result and Result<Ok> types from Functional Extensions for
C# which swap in a list of Validation Errors for the single
string error message found in the original, where each Validation Error consists of an optional list of field names and
error message, similar to the System.ComponentModel.DataAnnotations set of functionality. And indeed, you can use Data
Annotations and validate via the EnsureDataAnnotations() extension method.
The Result structs and extensions are a great foundation, but the single string Error inside Result and
Result<Ok> were too limiting, while Result<Ok, Err> extensions were incomplete.
Adding all the extra functionality to Result<Ok, Err> just proved too cumbersome and was just to unwieldy in the end,
so I instead chose to swap out the internals of Result Result<Ok> with an Error value I have found useful in the
past, and which allows an easy way to plug in the System.ComponentModel.DataAnnotations style of declarative
validation annotations. Initially I had intended to use a different naming convention than the original Result, but
this project grew enough that it is a separate fork, and as such contains mirrors of the Maybe types from the
original as well.
The ValidationError and Result classes are immutable, but the classes can be joined and chained together in a few
different ways, as in using Combine() or Join().
- Propagate
continueOnCapturedContextto new async methods (oops) - More tests
- Documentation and examples
- Publish on nuget.org
Contributors to the Original Functional Extensions for C#
A big thanks to the Functional Extensions for C# project contributors!