Skip to main content

Learning Scala online

As I mentioned on my last post I've been attending Functional Programming Principles in Scala course at Coursera. It's been three weeks now and I thought I should express my current feelings about the course.

Course arrangements


Arrangements on the course are just about what I expected. Series of video lectures per week, some quizzes in the videos and homework that's evaluated automatically in a matter of minutes. Homework assignments and videos are given on mondays and homework deadline is in about ten days from that.

On the first three weeks the lectures and homework has been about abstract presentations of entities and mathematical definitions.

Lectures


Lectures i.e. videos can be viewed online or downloaded and one can also download english subtitles for the videos and the slides shown on videos are also downloadable as pdf's. The subtitles could be helpful sometimes but the quality isn't that good, missing and wrong words, so I don't use them.

The lectures contains theory and basic examples of the weeks topics and mostly I've found them easy to follow.

Quizzes


The videos also contains quizzes in the middle or at the end of the lecture and the quizzes are also resolved in the videos. The quizzes objectives are usually explained so poorly that I don't even try to solve them myself.

Homework


The homework... these too are pretty poorly explained and the first thing to do before even trying solve them is to go to the courses forums and read through the assignment FAQ and some of the other posts where people like me don't quite understand what's the objective.

Once I've understood the objective some of the homework has been pretty straight forward but some of them go beyond my understanding and are way more complex than the lecture material presented.

The automatic evaluation process is nice except that sometimes the feedback doesn't help at all. 

Example: This week I got a feedback that filter (this is predefined method that I'm suppose to implement) is too slow and the execution was stopped at 40 seconds. Browsing through the forums I figured out that the problem isn't neccessarily on my filter but on my union (similar predefined method) and got some tips on how to improve my implementation of union. I managed to get my union faster and the evaluation error of my slow filter dissapeared. Too bad I had already lost 3/5 submissions trying to fix my filter.

Overall


So far I'm not liking this course. I hate that I'm working on some abstract entities and mathematical definitions. I'm a pragmatic person and I'm just hoping that the course gets more pragmatic or I'll lose my interest. I'm not loosing my interest on Scala just on this course. 

It seems to me that this course is about theory and abstract presentations of what ever more than it's about real life utilisation of functional programming and scala itself.

I'll try to keep myself motivated and hopefully in four or five weeks I can say that I did learn Scala during the course and I've forgotten the unpleasantry of the first three weeks.

Comments

Popular posts from this blog

Simple code: Immutability

Immutability is a special thing that in my mind deserves a short explanation and praise. If you're familiar with functional programming you surely recognice the concept of immutability because it's a key ingredient of the paradigm. In the world of object oriented programming it's not as used and as easy to use approach but there are ways to incorporate immutability to parts of the code and I strongly suggest you to do so. Quick intro to immutablity The basic idea of immutability is unchangeable data.  Lets take a example. We have a need to modify a object's property but because the object is immutable we can't just change value but instead we make a copy of the object and while making the copy we provide the new value for the copy. In code it looks something like this. val pencil = Product(name = "Pencil", category = "Office supply") val blackMarker = pencil.copy(name = "Black marker") The same idea can be applied in functions and metho

Simple code: Contracts

Code works around contracts and contracts should be carefully thought and crafted. What are contracts A High abstraction level of contracts for code are API's. They define a interface that is basically a contract that the producer and consumer of the API agree to use to communicate with each other. Two common forms of API's are libraries that are used in code and external API's  that are used via HTTP, RPC etc. When thinking in a bit deeper contracts consist firstly of functions, methods or external endpoints and secondly of data, more precisely on data models and data types within the models.   Defining contracts Contracts should always be defined with careful thought. I've come accross few times to someone saying that "this is for intenal use only so it doesn't need to defined and/or documented as thoughtfully as a public API would be" but I disagree with that. The same care should be be given to internal and external contracts because the contracts are

Simple code: Unit tests

Unit tests are the developers number one safety net. Let that sink in. This is the number one reason for writing unit tests. Unit tests are written by developers for developers to ensure that the code works as expected and handles happy and sad paths correctly. With enough unit test coverage the tests enable a safe environment for refactoring and rewriting code. Unit test scope Unit test should test a single thing, a method or function call and it should test only one use case within. In other words a unit test should test a function with a single input. This is a important guideline to understand. When a unit test tests a function with single input it makes the test isolated, repeatable and predictable. Example of good tests: @Test fun findsAddress() {   val address = findAddress("Stevens street 35", "Southport", "Australia")   assertThat(address).isNotNull() } @Test fun doesNotFindAddress() {   val address = findAddress("Stevens street 697", &q