Explore creating robust HTTP services in Scala's functional programming paradigm. Gain insights into pure vs. impure implementations, their pros and cons, and effective tool usage.

scala-platform.tar.gz

Scala-Pure

Scala-Impure

Scala-Tapir

Scala-Impure-Test

Scala-Pure-Test

Scala-Tapir-Test

Test

Scala - Run Code Widget 

Scala-Pure-copy

Scala is one of the most popular general-purpose languages that supports both object-oriented and functional programming. In this course, you will learn how to create back-end HTTP services using Scala's functional programming paradigm.

You will also learn how to develop, test, and document the service using both pure and impure ways. You will be exposed to the differences between pure and impure implementation, their respective pros and cons, and how pure implementation can be more robust in terms of performance, understandability, testability, and type safeness. 

By the end of the course, you will have a clear idea of how functional programming works in Scala and how you can use the available tools more effectively.

Pure Functional HTTP APIs in Scala

## Using types to describe an API

Describing your API using types is not bleeding edge academic research stuff like you might have guessed. There are several libraries existing for it!

Some of these are [*endpoints*](https://endpoints4s.github.io/), [*rho*](https://github.com/http4s/rho) included in http4s, and [*tapir*](https://github.com/softwaremill/tapir). We will be using *tapir* in our implementation.

### Why did we pick the tapir library?
- We wanted to use something that allows us to generate a http4s server. This already narrowed down the options a bit. 
- It should be able to generate API documentation, which nowadays means Swagger/OpenAPI support.
- It should support not only http4s but more options as well. 

_Tapir_ meets all our requirements.
The library is still pretty young and may be subject to breaking changes, so please keep this in mind when reading through the following part.

# Using types to describe an API

Describing your API using types is not bleeding edge academic research stuff like you might have guessed. There are several libraries existing for it!

Some of these are [*endpoints*](https://endpoints4s.github.io/), [*rho*](https://github.com/http4s/rho) included in http4s, and [*tapir*](https://github.com/softwaremill/tapir). We will be using *tapir* in our implementation.

## Why did we pick the tapir library?
- We wanted to use something that allows us to generate a http4s server. This already narrowed down the options a bit. 
- It should be able to generate API documentation, which nowadays means Swagger/OpenAPI support.
- It should support not only http4s but more options as well. 

_Tapir_ meets all our requirements.
The library is still pretty young and may be subject to breaking changes, so please keep this in mind when reading through the following part.

Get started with Tapir and implement some schemas.

Introduction

Impure Implementation

Pure Implementation

Testing Impure Services

Testing Pure Services

Benchmarks

Documentation

Epilogue

A Pure Implementation Using Tapir

Using types to describe an API

Why did we pick the tapir library?