added missing Append extensions

README.md

@@ -4,6 +4,108 @@ This library uses features of C# to achieve railway-oriented programming.
 
 The desire is to make somewhat user-friendly experience while using result-object pattern.
 
-## Contents
+## Features
 
-_Coming soon..._
+- Immutable ```Error``` class
+- ```Result``` object
+- A bunch of extensions to use result-object pattern with
+- ```Try``` extensions to wrap function calls with result-object
+- ```Ensure``` extensions to utilize result-object in validation scenarios
+
+## Getting Started
+
+### Install from local Gitea package repository
+
+```sh
+# Setup NuGet registry from the command line
+dotnet nuget add source --name gitea_jstdev https://gitea.jstdev.ru/api/packages/just/nuget/index.json
+# then install the package using NuGet
+dotnet add package --source gitea_jstdev Just.Railway
+```
+
+## Examples
+
+### Error
+
+```csharp
+using Just.Railway;
+Error expectedError = Error.New(type: "Some Error", message: "Some error detail");
+Error exceptionalError = Error.New(new Exception("Some Exception"));
+Error manyErrors = Error.Many(expectedError, exceptionalError);
+// the same result while using .Append(..) or +
+manyErrors = expectedError.Append(exceptionalError);
+manyErrors = expectedError + exceptionalError;
+```
+
+> **Note**
+> You can easily serialize/deserialize Error to and from JSON
+
+### Result
+
+#### As return value:
+
+```csharp
+Result Foo()
+{
+    // ...
+    if (SomeCondition())
+        return Result.Failure(Error.New("Some Error"));
+        // or just: return Error.New("Some Error");
+    // ...
+    return Result.Success();
+}
+
+Result<T> Bar()
+{
+    T value;
+    // ...
+    if (SomeCondition())
+        return Error.New("Some Error");
+    // ...
+    return value;
+}
+```
+
+#### Consume Result object
+
+```csharp
+Result<int> result = GetResult();
+
+var value = result
+    .Append("new")
+    .Map((i, s) => $"{s} result {i}")
+    .Match(
+        onSuccess: x => x,
+        onFailure: err => err.ToString()
+    );
+// value: "new result 1"
+
+Result<int> GetResult() => Result.Success(1);
+```
+
+### Try
+
+```csharp
+Result result = Try.Run(SomeAction);
+// you can pass up to 5 arguments like this
+result = Try.Run(SomeActionWithArguments, 1, 2.0, "3");
+
+// you also can call functions
+Result<int> resultWithValue = Try.Run(SomeFunction);
+
+void SomeAction() {}
+void SomeActionWithArguments(int a1, double a2, string? a3) {}
+int SomeFunction() => 1;
+```
+
+### Ensure
+
+```csharp
+var value = GetValue();
+Result<int> result = Ensure.That(value)
+    .NotNull()
+    .Satisfies(i => i < 100)
+    .Result();
+
+int? GetValue() => 1;
+```