seance/fp-patterns

Functional programming patterns tutorial in Scala, integrated with a Specs2 test suite

Functional Programming Patterns Tutorial

A tutorial and simple learning platform for studying basic functional patterns.

Getting started

Prerequisites

You'll need Java and Git.

Running

• Make sure that the ports 8000, 8001, 2552 and 2553 are available.

• Run ./meditate <spec> (use meditate.bat on Windows) from the command line at the root of the repo. Here <spec> is the class name of a specification, for example Options. Currently there are specs for Options, Eithers, Lists, Leo and Futures.

• Open your browser to localhost:8000, and select the tutorial matching the specification for your meditate command.

• In the specification (found in specs/src/test/scala), replace the placeholder symbols (__) with code that completes the example. As you complete examples, the web page will give you feedback in real time, and reveal more content for reading.

• When you complete a tutorial (like Options), terminate the meditate process running in the console simply by pressing enter (on Windows, close both opened command prompt windows). To start with the next tutorial, run the corresponding meditate command.

Note that compile errors in the specification will not be relayed to the web page. Keep an eye on the console window where you run the specs. If there are compile errors, use the compiler's error messages to help you fix them as usual.

fp-patterns's Issues

Should xs1 in lists -> reducing include 3?

https://github.com/seance/fp-patterns/blob/master/specs/src/test/scala/lists.scala#L34 uses List.range and therefore doesn't include 3. Is this an intentional gotcha?

Either and anInstanceOf checks

This should be correct, around line 37, right?

"Use the 'right' method to get a Right projection" ! {
    e1.right must be (anInstanceOf[Either.RightProjection[String, Int]])
}

However, I get

'RightProjection(Right(5))' is not the same as 'org.specs2.matcher.AnyBaseMatchers$$anon$9@7ce69957'