Скачать или смотреть fp-ts Tutorial | Chapter 2: Option

In Chapter 2 of this fp-ts tutorial (functional programming in TypeScript), we will introduce the Option data type, which is used to represent optional values, like the result of a computation that might fail.

Option is one of the most used data types in fp-ts programs, which is why it's important for you to understand it well and to learn how to work with it.

After defining what an Option is and seeing an example, we will learn about O.match (also known as O.fold), which allows us to do pattern matching on an Option.

We will also see how we can extract the value out of an Option by using O.getOrElse.

Finally, we will see how we can convert nullable values to Options by using O.fromNullable.

00:00 Option definition
01:23 Inverse example
02:43 Pattern matching with O.match
03:05 UI message example
04:02 Safe inverse example
04:42 Extract value with O.getOrElse
05:21 O.getOrElseW and O.matchW
06:29 Option from nullable