# Chainable operations in a Continuation flow

The use of chained operations in C# is nothing new, we uses this feature in several different libraries.

Any method that returns an instance of itself is a fluent method, then, is capable of creates continuous process. Once again we can see this type of implementation in the [`System.Linq`](https://msdn.microsoft.com/pt-br/library/system.linq%28v=vs.100%29.aspx) namespace. With this namespace you can perform a filtering and a transformation through the methods `Where` and `Select` in a chainable operation, see an example:

```csharp
IEnumerable<int> values = Enumerable.Range(0,10)
values.Where(value => value % 2 == 0)
      .Select(value => value * value);
```

As the previous example shows, it is possible to make several consecutive calls on a single command line. This is what we call a continuous or fluent process.

The **Tango** implements this feature in several types and modules, like `Option`, `Either` and even `IEnumerable`.

In addition, there's a special object called `Continuation`. This object is used mainly to this type of fluent process, but dealing with a success and a fail outputs.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://gabriel-schade-cardoso.gitbook.io/tango/fundamentals/using-chainable-operations-in-a-continuation-flow.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.